English tool kit

The Flour Millers Tool Kit on Fortification Table of Contents Section 1: Introduction to Flour Fortification Section 2: Procuring Materials & Setting up the Mill Section 3: On the Production Line Section 4: Assuring Quality Control Section 5: Keys to Effective Marketing of Fortified Flour Section 6: Cost Issues

Section 1: Introduction to Flour Fortification  Reasons for Flour Fortification  Overview of the Fortification Process  Vitamins & Minerals Used in Flour Fortification  Impact of Flour Fortification on Public Health  Benefits to Mills from Fortifying Flour  Understanding Fortification Regulations  Ensuring Consumer Satisfaction of Fortified  Products Section Summary

Seven Reasons to Fortify Flour (Slide 1 of 2) 1. Fortifying commonly eaten foods, like wheat flour, is an effective and economical way to ensure that national populations are provided with essential vitamins and minerals.

2. These vitamins and minerals help prevent nutritional deficiencies such as iron deficiency anemia, and some health problems and birth defects.

3. Flour an ideal medium for fortification, because it is a staple food. More people can be reached by fortifying the flour at the mill than by fortifying only flour products.

4. Fortification can significantly improve the health of a national population

Seven Reasons to Fortify Flour (Slide 2 of 2)

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Fortifying flour can be beneficial for the national economy. Healthy citizens lead to increased productivity.

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The World Bank estimates that vitamin and mineral deficiencies as a whole depress GDP by as much as 5%. Fortification of key staple foods with specific vitamins and will help eliminate these deficiencies for as little as 0.15% of GDP- the approximate fortification cost.

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Flour millers can play a major part in solving these nutritional problems by adding key vitamins and minerals. These nutrients produce a better product, they can do so at low or no cost, and they help wholesalers bring better products to their customers.

Overview of Flour Fortification (Slide 1 of 4)

Fortification is the process of adding vitamins and minerals to flour during the milling process, resulting in a higher quality, more nutritious product.

Vitamins and minerals are typically added to flour during the milling process via small amounts of a powdered premix.

More information about premixes is found later in this toolkit.

Overview of Flour Fortification (Slide 2 of 4)

Prior to milling, whole grain wheat contains significant levels of calories, protein, carbohydrates and dietary fiber in addition to many vitamins and minerals.

Most of the vitamins and minerals are in the bran and the germ of the wheat.

When flour is milled, the bran and the germ are removed and discarded, leaving mostly pure, white endosperm. This means that many of the vitamins and minerals are removed leaving, a product that is less nutritious than whole grain wheat.

Overview of Flour Fortification (Slide 3 of 4)

The table shows the degree to which nutrients are reduced during milling. 100 grams/day of whole wheat flour supplies 22% of the United States Recommended Daily Allowance for iron.

Refined flour has less than one fourth of this amount (less than 6% of the RDA

Overview of Flour Fortification (Slide 4 of 4) Fortification can restore to milled flour the natural levels of vitamins and minerals found in the wheat kernel or whole wheat flour. This process is commonly referred to as enrichment or restoration. It is one type of fortification.

Fortification can also add vitamins and minerals in amounts higher than those naturally present in the whole wheat kernel. This type of fortification is very common and is used where the populations consuming flour and flour products are deficient in one or more of the vitamins and minerals added.

Another type of fortification used to help prevent deficiencies adds additional vitamins and minerals that are not naturally present in wheat. Examples include vitamin A, calcium and vitamin B12.

Vitamins & Minerals Used in Flour Fortification Common minerals and vitamins added to flour  Iron  Zinc  Folic Acid  Other B vitamins (Thiamin, Riboflavin and Niacin)  In some countries Vitamin A, Calcium and B12 are added.

How to decide on premix ingredients:  Generally, these decisions are made with the help of nutrition and research organizations that are involved in nutrition standards and problems of the population.  Decisions about which vitamins and minerals will be added to wheat flour depend on a number of factors -- existing government regulations -- dietary needs and deficiencies in the population -- the cost of different premix combinations -- results of research aimed at determining vitamin and mineral deficiencies More information to help guide decision making on which vitamins and minerals should be added to flour are found later in this tool kit.

Impact of Flour Fortification on Public Health Fortification is a success

(Slide 1 of 3)

Some countries, including the United States and Canada have successfully fortified flour with vitamins and minerals since the early 1940s. As a result, several vitamin deficiencies have been virtually eliminated in these countries.

The chart below shows reduced deaths from pellagra (niacin deficiency) in the United States since flour fortification began there.

Impact of Flour Fortification on Public Health (Slide 2 of 3)

Impact of fortified flour has been measured 

The fortification process has a been tested again and again around the world, as successful fortification programs have been implemented in many countries.

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In the United States, folic acid fortification is estimated to have an annual economic benefit of between $312 million and $425 million. The net reduction in direct costs are estimated to be between $88 million and $145 million per year.

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In a Canadian study of 38,000 women aged 18 to 42 years, there was a significant improvement in folate status after fortification with folic acid began. Folic acid, the form of folate used in fortification, helps reduce the incidence of neural tube birth defects.

Impact of Flour Fortification on Public Health (Slide 3 of 3) Through iron fortification of wheat and corn flours, Venezuela has lowered its rates of iron deficiency and anemia.

Benefits to Mills from Fortifying Flour Flour fortification is an opportunity for mills to:  improve product quality by restoring vitamins and minerals to original wheat levels and improving its nutritional state  raise the company’s profile by helping create an image as innovative and on the cutting edge of milling technology  expand market share and consumer brand loyalty through improved products  contribute to the health and productivity of the national population and receive recognition as a good corporate citizen

Understanding Fortification Regulations (Slide 1 of 4) Explore national status and requirements  Mills owners and management start by learning the status of existing regulations related to fortification.  Mills owners and management can consult with the government authorities on what is required and what is permitted regarding fortification.

General information on flour fortification regulations:  By July 2009, 57 countries had set flour fortification standards or customary fortification practices.  Regulations differ widely by country.  Some governments require mandatory fortification with certain vitamins and minerals. Others allow fortification based on decisions by the milling companies.  A government may also decide to prohibit adding certain vitamins and minerals to flour.

Understanding Fortification Regulations (Slide 2 of 4) Fortification Status – March 2010

The map indicates countries that have fortification regulations.

Some have been fortifying for years; others are working toward implementation.

Understanding Fortification Regulations (Slide 3 of 4) For millers in countries without fortification regulation:

Setting Standards National flour fortification standards are most often generated by technical groups.

They often include:  government health specialists  standards specialists  nutritionists,  millers and often bakers and major flour product manufacturers.  International donors may support work by such groups.

 In a country without current standards or regulations on flour fortification, a mill wanting to fortify flour needs to determine whether flour fortification is allowed.  A special permit will need to obtained, or the regulations will need to be changed, in the very few countries that specifically prohibit adding anything to flour.  Millers also need to learn about any general fortification regulations which apply to all foods. Such general regulations for all industries fortifying food products should also be observed by a mill fortifying wheat flour.

Understanding Fortification Regulations (Slide 4 of 4) Regional fortification guidelines Some regions where countries have similar basic food consumption practices have established regional fortification guidelines as a basis for country specific regulations. Such regulations facilitate inter-country active trade of wheat flour. Where the same premix is used nationally or in a region, procurement for mills may be easier and often at lower cost.

Basic Recommendations for Flour Fortification

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Always include iron, folic acid and zinc in any wheat flour or maize meal fortification program.

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Addition of riboflavin is recommended.

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Addition of thiamin in rice consuming countries and niacin in maize consuming countries is recommended.

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Addition of other vitamins and minerals is optional.

Ensuring Consumer Satisfaction (slide 1 of 4)

 In general, any good quality fortified wheat or wheat product should not change consumer acceptability of the fortified food. Ideally, fortification should be invisible to the consumer.  If possible, there should be no detectable difference in the appearance, or sensory properties of the fortified product, and the price should only be marginally higher.

Characteristics to be controlled to help ensure consumers acceptance and satisfaction:  Color and Appearance

 Flavor and Aroma  Shelf Life  Taste and Mouth feel  Sensory Testing

Ensuring Consumer Satisfaction (slide 2 of 4) Color and Appearance  The visual appearance of fortified flour and of foods products made from fortified flour make a strong impression on the customer. Any change from unfortified flour should be minimal.  At the current fortification levels used in wheat, there is no adverse impact. Although premix is generally a light yellow color, the very small amounts added cause little change in color of flour.  Elemental iron powders may cause a slight darkening of flour.  High levels of riboflavin and folic acid can cause a slight yellowing.  Experience has shown that these changes are accepted when consumers learn that the slight difference is caused by a vitamin or mineral once all flour is similarly treated

Premix

Fortified flour

Ensuring Consumer Satisfaction (slide 3 of 4) Flavor and Aroma  Like color and appearance, the flavor and aroma of fortified flour should not be different from unfortified flour and products.

Shelf Life  Generally, the addition of vitamins and minerals to wheat flour should not reduce the normal or expected shelf life of the flour.  Any reduction in shelf life can result in lost products and reduced consumer acceptance of the food. Rancid products have a slightly soapy mouth feel and a distinctive unpleasant odor.

Texture and Mouth feel  Product texture and mouth feel should be the same.

The premix ingredients decided upon should take expected shelf life into account.

Ensuring Consumer Satisfaction (slide 4 of 4)

Sensory properties preserved Extensive testing and experience prove that fortification can be done without adversely affecting the sensory properties in final products.

These include:  Flour  Bread  Cakes  Instant Noodles  Pasta

Unique products should be tested Flour-based foods products unique to different regions of the world should be tested prior to starting a general fortification program to insure that products are acceptable to consumers.

(China has successfully fortified flour for steam bread and home made noodles after initial testing.)

Section 1 – Summary Compelling reasons to begin fortifying flour:  Fortifying flour can help improve the health of a national population by providing essential vitamins and minerals lacking in daily diets.  Flour fortification can be beneficial for the miller:  Helps to improve product quality  May increase market share and brand loyalty  Careful consideration of consumer’s expectations can be used so that consumers accept fortified flour and it becomes part of their daily diet.  The many successful fortification programs implemented around the world offer models on which to base new programs

Summary of Fortification Strategies The general fortification strategies used in each country should be based on the public health and economic situation. Usually a team of experts will determine which strategy is best.

Examples of strategies commonly used: 1. Restoration/Enrichment – The level of each nutrient in the unprocessed food must be known if the criteria is based wholly or partially on restoring lost nutrients, which was the original criteria for cereal enrichment in the United States and Canada.

2. Balancing dietary requirements – It is desirable to balance the levels of nutrients contained in the fortified product and the dietary requirements. Folic acid is an exception to this because higher levels are often added to prevent more neural tube birth defects.

3. Making up for dietary deficiencies – This strategy makes up all or part of the difference between the dietary requirement for a nutrient and its average consumption by the general or target population. This calculation depends on which dietary requirement values are used. It can also be difficult to find good data on nutrient intakes for some target populations.

Summary of Millers’ Role in Standards 

The process of establishing standards and associated regulations is complex and time consuming. It should always involve representatives from the medical community, the milling and baking industry and the government (usually through the ministry of health and government standards organizations). Others involved may include consumer groups, educational/research institutions, interested NGOs and international and bilateral specialists.

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An alliance of these groups needs to assess what is needed and what is feasible.

To assure acceptance of the fortified products and compliance with regulations, major stakeholder groups must agree to the final regulations.

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Cost is always a major factor in decisions about standards. Cost often restricts the types and levels of vitamins and minerals to include. High costs make it very difficult to require vitamin A and calcium. Costs also makes it more practical to add a premix of other minerals and vitamins that are needed by the population, because their addition to the premix involves very low additional costs.

End of Section One Continue Return to Table of Contents Go to first slide of this Section

Section 2A

Procuring Materials and Setting Up the Mill WHEAT

Issues to Consider Choosing a Micronutrient Premix Choosing an Addition Method

Issues to Consider Choose high quality wheat: 

Nothing added during vitamin and mineral fortification will improve the mixing and baking performance of poor quality wheat.

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If low quality wheat is fortified, consumers will likely blame the poor quality of the fortified flour on the added vitamins and minerals. This bad first impression may lead them to reject all fortified flour.

Issues to Consider Phytic acid that is naturally in grains inhibits the absorption of iron, zinc and other minerals by the human body. 

Whole grain wheat contains nearly 1% phytic acid. Milling removes phytic acid in flour by 60% to 90% depending on the extraction rate. These lower levels improve the absorption of minerals.

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As a general rule, the lower the level of ash in the flour, the lower the phytic acid content.

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When yeast is combined with flour in bread making, it further lowers the level of phytic acid.

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Vitamins and minerals are absorbed best from white refined wheat flour with an ash content of below 0.80%. Higher extraction rates of flour can and should be fortified if consumers prefer higher extraction flours.

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To counteract the effect of phytic acid and maximize the benefits of fortification, flours of different extraction rates need to be fortified with different forms and amounts of premix fortificants.

Phytic Acid’s Effect on Mineral Absorption (slide 1 of 4) Whole cereal grains contain phytic acid, which forms insoluble compounds with minerals, particularly calcium, iron and zinc. These compounds are difficult to absorb in the body.

OPO3H2 H

H2O3PO H2O3PO

Much of the phytic acid is located in the outer layer of the wheat between the endosperm and the bran. Much of the phytic acid is removed in the milling process, so highly refined white flour contains lower levels of phytic acid compared to high extraction whole wheat flours.

H

H OPO H 3 2

H2O3PO H H H

OPO3H2

Phytic Acid’s Effect on Mineral Absorption (slide 2 of 4)

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Yeast and flour provide the enzyme phytase which destroys most of the phytic acid during dough fermentation in the bread making process. More than 70% of the phytic acid can be hydrolyzed; the longer the fermentation and the lower the pH, the more phytic acid is removed.

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Phytic acid therefore is of most concern when high extraction flour is used to make unleavened bread, or in non-fermented flour products like noodles. This, however, is a common use of wheat in many countries of the world.

Phytic Acid’s Effect on Mineral Absorption (slide 3 of 4)

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If the molar ratio of phytic acid to iron is less than 6 for normal populations, iron will be absorbed. This is the case for yeast leavened bread made from white flour.

If greater than 6 for normal populations, iron will not be well absorbed. This may be the case for noodles made from white (low extraction) flour.

An ideal ratio of less than 1 ensures absorption by any population. This will not be possible for non-fermented flour products like chapattis, noodles and steamed bread.

You can lower the ratio by  Increasing iron (through fortification) but you can only add so much iron.  Lowering phytic acid (through milling, fermentation or adding the enzyme phytase).

Phytic Acid’s Effect on Mineral Absorption (slide 4 of 4)

Two compounds prevent phytic acid from inhibiting iron absorption:  ascorbic acid (vitamin C)  sodium EDTA

Unfortunately, ascorbic acid is destroyed in most baking processes. It is also expensive to add.

Sodium EDTA, however, is not destroyed.

The Addition of Ascorbic Acid Adding ascorbic acid to enhance iron absorption from fortified food is a widely-used practice for processed foods, but not for wheat flour due to stability issues.

The main difficulties with adding ascorbic acid as a food fortificant are that substantial amounts can be lost during storage and preparation, and compared to other nutrients, it is relatively expensive.

When ascorbic acid is used to enhance iron absorption, it should be added in a 6:1 ascorbic acid:iron weight ratio. A higher ascorbic acid:iron ratio of 12:1 can be recommended for foods with high levels of phytic acid. In most studies, the 6:1 ratio increased iron absorption 2 to 3 fold in adults and children.

Many millers add ascorbic acid as a bread improving agent.

Unfortunately, it must be oxidized in the dough to the dehydroscorbic acid form for it to function in that manner, but that form does not provide iron absorption enhancement activity.

NOTE:

The Addition of Sodium EDTA Sodium EDTA is stable during processing and storage. It works by chelating iron at the low pH levels of the stomach to prevent it from binding to phythic acid. It enhances the absorption of both food iron and soluble iron fortificants, but not the relatively insoluble iron compounds such as ferrous fumarate, ferric pyrophosphate or elemental (reduced) iron.

A Na2EDTA:iron weight ratio of 3.3:1 to 6.6:1 is recommended for foods fortified with soluble iron compounds such as ferrous sulfate to increase the absorption 2 to 3 fold.

Issues to Consider The World Health Organization recommends the following types and amounts of iron in premix based on different extraction rates for low extraction flour (ash content < 0.8%):  Use small particle size dried ferrous sulfate or small particle size ferrous fumarate.  In populations consuming more than 300 g/day of wheat flour products, add 20 ppm iron from dried ferrous sulfate or fumarate.  In populations consuming 150-300 g/day of wheat flour products, add 30 ppm iron from ferrous sulfate or ferrous fumarate.  In populations consuming less than 149 g/day of wheat flour products, add 60 ppm iron from ferrous sulfate or ferrous fumarate.

If cost or other factors (such as storing fortified flour longer than three months) make it impossible to fortify flour with either ferrous sulfate or fumarate at the levels above, use electrolytic iron or other iron fortificants with a relative biologic value of at least 50% of dried ferrous sulfate. The level of these iron sources added to flour should be 2 times that of ferrous sulfate.

Sodium iron EDTA (NaFeEDTA) at levels up to 40 ppm is recommended for low extraction flours where there is no fermentation process in food preparation (i.e. in the preparation of unleavened breads such as chapatti or noodles).

Issues to Consider The World Health Organization only recommends sodium iron EDTA for high extraction flour (ash content > 0.8%). The recommended rate is:  In populations consuming more than 300 g/day of wheat flour products, add 15 ppm NaFeEDTA.  In populations consuming 150-300 g/day of wheat flour products, add 20 ppm NaFeEDTA.  In populations consuming less than 149 g/day of wheat flour products, add 40 ppm NaFeEDTA. NaFeEDTA should also be used in populations where the overall diet is of low iron bioavailability. In these environments, the addition of up to 30ppm of iron from NaFeEDTA is recommended as long as there are no adverse effects on the flour’s sensory properties.

Back to section 2A table of contents

Choosing a Micronutrient Premix  Premix Components  Advantages of Using a Commercial Premix  Determination of the Premix Formula  Procuring Premix  Choosing a Reliable Premix Supplier  Shelf Life of the Bulk Premix  Considerations When Using Other Flour Additives  Addition Rates and Overages  Recommendations

Premix Components The most common flour fortification practice is to add multiple vitamins and minerals using a single ingredient- called a premix.

Premixes are produced by large commercial manufacturers and can be purchased in specific blends that meet the production needs of the mill and the dietary needs of the country.

A premix is made up of two major elements:  Fortificants (powdered vitamins and minerals)  Excipients (carriers, fillers and free-flow agents)

Premix Components 

Small amounts of concentrated vitamins and minerals individually are hard to add to flour because they are excessively light or dense, tend to clump, and are difficult to feed in the small amounts required. A larger amount of diluted premix is easier to feed and to obtain uniform distribution in the fortified flour.

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An excipient such as starch or maltodextrin is often blended into the premix by the manufacturer to dilute the concentration of the vitamins and minerals. Excipients may be referred to as carriers or fillers by premix manufacturers. After an excipient is added, the bulk density of the premix is lowered, bringing it closer to the bulk density of the flour. This makes for easier feeding and blending.

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In addition to excipients, a free-flow agent, such as tricalcium phosphate or precipitated silica (silicon dioxide) may be added to keep the premix from clumping and bridging in the hopper.

Advantages of Using a Commercial Premix Generally, it is NOT recommended for millers to order concentrations of vitamins or minerals individually and add them one at a time or blend them at the mill. The one exception is calcium, which is normally added separately due to the large amount required.

Few mills are sufficiently equipped to undertake the complex task of blending their own high quality premix, which requires difficult ingredient procurement and extensive quality control testing.

The major advantages to using a commercial premix are: 1.â&#x20AC;Ż Easier Feeding: Some of the vitamins and minerals are very dense, (reduced iron) while others are very light (riboflavin). The proper use of excipients by commercial premix manufacturers mixes them into a single ingredient that is much easier to feed and will cause fewer problems on the flour millâ&#x20AC;&#x2122;s production line.

Advantages of Using a Commercial Premix 2. Easier Quality Control Testing: A properly manufactured premix has verified levels of different vitamins and minerals that will allow testing of a single micronutrient to serve as an indicator for the amounts of the others. Most often, iron is used as the indicator nutrient (but others could be used as well). If a mill blended its own premix, it would need to prove that the blend met required specifications. Very few mills have the lab facilities or staff needed to carry out such quality control procedures. It is much easier and less expensive for the premix manufacturers to carry out this task. See Section 4 for more information quality control testing.

3.â&#x20AC;Ż Feed Rate Adjustments/Weighing: A single premix requires only one feed rate adjustment for continuous flow systems or one weighing for batch systems. This reduces labor requirements and lessens the chance of error. See Section 3 for more information on feed rates.

Determination of a Correct Premix Formula As noted in Section 1, determining which vitamins and minerals will be added and in what amounts for fortified flour in a country is a complex process that may require the expertise of health specialists, nutritionists, millers, bakers and food manufacturers, international donors and the national government.

In most countries, the government has the final say about the fortification standards. However, the premixâ&#x20AC;&#x2122;s specific composition is not normally regulated. Usually, it is determined by the experience of the premix manufacturer and the needs of the miller to ensure that the flour produced meets a regulated minimum standard set by the government.

Premix manufacturers have extensive experience calculating premix formulas and can work with each mill to provide the proper premix for that mill.

Determination of a Correct Premix Formula The following factors are considered by the premix manufacturers when determining a premix formula: 1)â&#x20AC;Ż Nutrient concentration of the different forms of fortificants: Some vitamins and minerals are available in multiple forms, and the concentration of vitamins and minerals varies among these different forms. This variation must be accounted for in determining how much of each nutrient to add.

2)â&#x20AC;Ż Premix addition rate and bulk density: The bulk density of the premix will affect the addition rate and vice versa.

Both of these factors need to be considered together.

3) Overages: Commercial premixes may have extra amounts of fortificants to control for losses in nutrients throughout the fortification process.

Pre-blends: Preparation of Diluted Premix

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Ideally, the feeder should be set to operate between 20 and 80% of full capacity. In some cases mills may find that the flow of flour to be fortified is so slow as to require operation less than 20%, even when using all the adjustments available in screw size and gears available. In that case the mill may want to consider making a dilution of the premix.

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A diluted premix, called a pre-blend, may also be needed if the premix is not feeding uniformly or properly for some reason.

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To make a pre-blend, use a batch mixer to mix flour or semolina (granulated flour) with the premix. An example would be 1 part premix and 4 parts semolina. The resultant pre-blend would then be used at 5 times the addition rate of the original premix (or 1000 grams/MT if the premix was specified at 200 g/MT).

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Pre-blends have a limited shelf life of only a couple weeks, so the amount produced or delivered to a mill should not exceed a two week supply.

Addition Rates and Overages The addition rate of the premix is needed to determine the final formulation of the premix. Ideally, the addition rate is set to be in whole units, and typically added at a rate between 50 and 300 grams per metric ton of flour.

Rates lower than this may be too difficult to control accurately.

Small mills may require a more diluted premix that can be added at rates higher than 300 g/MT. In that case the mill may mix the premix with flour to create a pre-blend that is more dilute and that can be added at higher addition rates.

Addition Rates and Overages Some added vitamins and minerals may be lost during milling due to exposure to heat, oxygen and light. Some very light or small particle size materials with large surface area may be physically removed with the dust during pneumatic suction. Larger particles may be removed during sieving. Such milling losses need to be factored in when calculating how much of each nutrient to include in the premix to meet a minimum standard in the final product.

Manufacturing Overage 

Premix manufacturers usually include individual premix fortificants at levels approximately 2% to 5% higher than listed on the lable to ensure that the premix meets the label claims.

Mill Overage 

Millers usually add extra amounts of the premix or individual nutrients to the flour to ensure that the final fortified flour meets the label claims. This is done to account for variation in the natural level of vitamins and minerals in the flour and it makes up for any processing or storage losses.

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As an example, to fortify wheat flour, that naturally contains 12 ppm iron to the U.S. standard of 44 ppm, 35 ppm iron is typically added, (This is the target level minus the natural level plus 10.)

How to Procure Premix Normally, mills purchase premix from one supplier who provides all the premix for a set amount of time.

The Mill Purchasing Department should keep the following information about the supplier on file:  The name and address of the supplier’s company or organization.  The name and phone number of the principal contact to whom the order should be directed.  The name or type of the premix to order  The standard amount of the premix that is ordered  The price history of the premix  The method and time of delivery

Mill staff should meet with the suppliers’ agent at least once per year to review premix performance with respect to timeliness of delivery, quality, and price.

Sufficient stocks of premixes should always be maintained. Therefore, premixes should be purchased well in advance of their running out. A reordering point in inventory levels should be specified in the mills quality assurance plan to trigger the purchase order, but production schedules should also be regularly consulted.

How to Procure Premix Some

countries have companies which manufacture premix, but in other cases, it needs to be imported.

Smaller mills may find it more convenient and less costly to obtain premix through a centralized, cooperative purchasing group, either through a local millers association, a private enterprise or a government run operation. It may be possible for these groups to obtain competitive bids from approved suppliers for a specified premix through an internet bidding system being set up by GAIN known as the Premix Facility. GAIN is the Global Alliance for Improved Nutrition.

The reliability of premix suppliers remains an issue of concern that many organizations are working to address. Organizations such as the Micronutrient Initiative of Canada ( http://www.micronutrient.org) maintain lists of premix manufacturers.

Some countries, such as South Africa, have gone as far as to create approved lists of premix-suppliers that must be used. See http://www.grainmilling.org.za/ - click Vitamin Suppliers.

Please note that no specific supplier is specifically endorsed by this toolkit, and all potential suppliers should be thoroughly investigated prior to purchasing premix.

Premix Receiving Procedures (slide 1 of 5) To ensure that the received premix is correct and of good quality, the mill purchasing or receiving department should be responsible for inspecting premix upon delivery. A premix receiving procedure including the steps listed below should be implemented to ensure thoroughness: 1. Check the boxes for any damage and record if there is some. Mild damage to the cardboard box is acceptable, but severe water damage and tears in the inner bag are not.

2. Record date received and who is recording this data.

3. Record type or name of product and number of boxes or total weight and check against what was ordered.

4. Record the lot numbers.

5. Check for a certificate of analysis (CoA) and put it in the fortification file. This may be on one of the boxes or sent separately (fax or email).

Record all of this information on a “Premix Receiving Report”

Premix Receiving Procedures (slide 2 of 5)

Check the contents of one box of each lot received to see if the appearance is normal. The premix should be free flowing with no lumps, white spots or specs, and no off-odor. Run a gloved hand through the premix to check this. The operator will do the same thing when he uses it, but by then it may be too late to register a complaint if something is wrong.

Premix Suppliers Should Provide: (slide 3 of 5) A label should be firmly affixed to every box.

The label should show: a) The name of the product b) The intended use of the product c) The manufacturer with contact information d) Handling precautions, if any e) The date of manufacturer or “use by” date. (This is sometimes imbedded in the lot number) f) The lot number g) The recommended application rate h) The net weight i) A list of ingredients.

Premix Suppliers Should Provide: (slide 4 of 5) A Certificate of Analyses (CoA) on each lot of premix for all nutrients in the premix The CoA (sometimes referred to as a “Certificate of Quality”) is the official documentation of premix quality. This certificate should be provided for each lot of premix in the shipment. The CoAs for all premix batches received should be kept on file and made available for any inspections that may be required.

The CoA should indicate:  Chemical assay of the premix batch for each nutrient contained (except for vitamin B12 if present, whose level can be verified by audit rather than actual assay). It may indicate the minimum and maximum assay standards for that premix as reference.  Batch or lot number  Date of manufacture or expiration date or “use by” date if not imbedded in the lot number

Premix Suppliers Should Provide: (slide 5 of 5) A Product Information Sheet or Fact Sheet This document should be kept on file at the mill and made available to all operating and quality control personnel.

Information provided in this document should include: • The name of the premix • The name and contact information of the manufacturer • The intended use of the premix • The ingredient composition of the premix – usually in descending order • The food grade status of the ingredients used, (i.e. Food Chemicals Codex (FCC) grade) • The recommended addition rate of the premix to flour and the levels of micronutrients added at that rate • The minimum assay standards for the premix, and maximum assay standards if any exist • Storage and handling instructions • Allowable storage periods or shelf life of premix

Shelf Life of the Bulk Premix Vitamins in the fortificant premix have a limited shelf life. Over time their biological effectiveness is reduced. Most premixes not containing vitamin A or C will last up to three years if stored properly. Minerals are particularly stable and the vitamin shelf life usually determines the shelf life of the premix overall. Premix manufacturers should always provide shelf life information for their specific premixes. Millers should not expect premix manufacturers or distributors to accept return of premix that has exceeded its shelf life period.

Vitamin A is the only fortificant normally added to flour that is very perishable. Premixes containing vitamin A may have a shelf life of as little as 6 months.

These shelf-life specifications were taken from information provided from premix manufacturers, but shelf life may be further reduced if premix is stored incorrectly at the mill.

Mill Storage of Premix 

Premix boxes should be kept somewhere in the mill that is handy but not exposed to sunlight, not excessively hot (i.e. next to a boiler) and safe from getting wet or hit by lift trucks. The boxes can be piled on top of each other, but it should be so arranged that a first-in, first out system of use could be easily accomplished.



One or two working boxes of premix can be kept near the feeders, as shown in the picture.



Note additional information on safe handling of premix later in this tool kit.

Back to section 2A table of contents

Considerations When Using Other Flour Additives Some flour mills add small amounts of bleaching agents and improvers to flour, such as enzymes and oxidants. Azodicarbonamide, benzoyl peroxide, potassium bromate and ascorbic acid are commonly added oxidants.

Even though it might be tempting to add improvers and fortificants with the same feeder, this is NOT recommended, for the following reasons:

1. Improver addition rates need to be adjusted frequently to ensure that different flours all meet commercial specifications.

• Combining improvers and fortificants makes changing the addition rate of the improvers more difficult.

2. There are also safety reasons for avoiding combining improvers and fortificants.

• Some fortificants can react with improvers. For example, concentrated forms of potassium bromate and benzoyl peroxide (“flour bleach”) should NEVER be combined with fortificants because there is a danger of combustion.

• The shelf life of vitamins might be altered if combined with improvers.

Considerations When Using Other Flour Additives It is helpful to segregate boxes of premix and improvers. This could be done with color coding or clear labeling.

The container storing the premix as well as the feeder being used to add a particular premix or improver should be well identified to prevent accidental replacement with any other flour additive or premix.

When multiple feeders are installed in a row, it is referred to as a feeder bank.

These photos show various sizes of feeder banks.

(Photos courtesy of Research Products Company)

End of Section 2A Continue Return to Table of Contents Go to first slide of this Section

Section 2B

Choosing an Addition Method 

Mill Requirements for Proper Fortification



Methods Used to Add Premix to the Flour



Information on Premix Feeders



Considerations Regarding the Size of the Mill



Types of Delivery Mechanisms



Ensuring Adequate Mixing



Equipment Suppliers



Lessons Learned from Other Millers



Information on Specific Nutrients Added

Mill Requirements for Proper Fortification

1.â&#x20AC;Ż A premix feeder to measure out the correct dose of premix and its placement at a point in the production line where it delivers the premix into the production line to mix with flour.

Sometimes a small shoot or tube is fabricated and installed to carry the premix from the feeder to flour line. This should be at a steep angle to insure it drops down cleanly without stoppage.

Mill Requirements for Proper Fortification 2.â&#x20AC;Ż Mechanisms to assure that the premix is uniformly mixed into the flour after the point of addition and before packout. This can involve mixing during the normal transport of flour from the conveyor to packout, or insertion of special mixing equipment.

addition of premix at flour collection conveyor

Packout

Methods Used to Add Premix to the Flour Once the premix formula is determined, the best method to add the premix to the flour needs to be selected.

There are two main delivery systems: - Batch - Continuous There are different requirements for each method.

Methods Used to Add Premix to the Flour Batch Systems: The premix is measured out and is put into a batch of flour and blended with a mixing device. Fortifying within a batch system can be slower and more labor intensive than other methods, but it can be very accurate when a precise scale is used and can be made automated.

(Photo courtesy of Buhler Company)

Batch Systems In-line batch mixers 



Some mills have batch mixers as part of their normal milling process (such as that shown in the picture to the right). This is to blend flours or add vital wheat gluten.

A fortification premix can be added to these mixers, either manually or automatically using standard microfeeders.

Separate mixers 

It is possible to use a separate mixer to fortify flour, but it is very inconvenient to do so and only small batches of flour can be processed, so it is not recommended except for very small mills where continuous fortification is not feasible.

Methods Used to Add Premix to the Flour Continuous Systems: Most larger and newer mills operate within a continuous system. The premix is continuously metered or fed into the flour flow using a precision micro feeder, also referred to as a dosifier. The dosage rate is controlled and depends on the rate of flour production of flour flow.

The continuous system incorporates a collection conveyor (shown on right) where premix can be continuously and easily added. The majority of the information presented here refers to such milling systems.

Feeders Information on Premix Feeders 

To prevent premix from bridging in the hopper, a large conditioning screw, flexible pulsating plates on the bottom of the hopper, or a vibration device may be installed in the hopper.



A low-level detector may be installed on the bottom of the hopper to indicate when the premix is close to running out.



The outlet spout of the feeder should be covered but afford easy access to inspection and check weighting.

Feeders 

Feeders should be set up with an electrical interlock system that prevents the flow of premix when flour flow is stopped.



The on/off switch, speed controller, and low- level indicator light can be located near the feeder or at a remote location.



Some installations may need a voltage regulator to ensure proper performance of the feeder and controller.

Feeder Controller

Electrical Interlock System 

An interlock causes the feeder to stop if the flour collection conveyor stops. This will prevent the inadvertent over-treatment of the flour, if there is a mechanical breakdown in the mill.



It is highly recommended that an electrical interlock system be installed between the feeder motor and the motor driving the flour collection conveyor.



In pneumatic delivery systems, an interlock should be made between the feeder and the blower to insure that the feeder cannot be turned on without the blower operating. This will prevent buildup of the premix in the pneumatic lines followed by over-treatment of flour once the blower is turned on.



An alternative approach is to have an automatic shut off switch on the feeder that is hooked up to a flour flow indicator or a pressure indicator in a pneumatic system.

Electrical Interlock System Interlocking (slaving) premix addition to flour flow:



The most accurate method of flour fortification is to continuously interlock the addition rate of the feeder with the measured flow rate of the flour.



This requires equipment for measuring the flow rate of the flour and computerized mill control allowing the interlock.

Feeders Premix Feeder Mechanisms Three main types of premix feeders are available to fortify flour. They differ in terms of the mechanism used to deliver a constant rate of premix powder. There are also differences in cost. See Section 6 for more information about the cost of feeders.

Type one Screw Feeder

Type two Revolving Disk

Type three: Drum / Roller

Mechanical Principles of Feeders Gravimetric Addition: One general principle by which feeders control the amount of premix added to flour is gravimetric addition.

Gravimetric addition involves measuring the weight of material to be added on a continuous basis. Weigh belt feeders are used in continuous systems that can give direct weighings of the material being dispensed, but they usually require a greater volume of material than used in most fortification operations.  All three types of feeders can be made into “loss in weight” feeders by mounting them on load cells that send out an electronic signal proportional to the total weight. The rate at which this weight drops with time indicates the true addition rate.  This system is somewhat more complex and expensive than is required in most cereal milling operations, but it allows greater accuracy of addition and continuous traceability on the amount of premix used.

Mechanical Principles of Feeders Volumetric Addition: A second general principle by which feeders control the amount of premix added to flour is volumetric addition (most commonly used via screw feeders): Volumetric addition is similar to using a cup or spoon to measure out ingredients. This is based on the principle that the volume of the material being added has a set weight when handled in a uniform manner. The minimum error of measurement for volumetric addition is Âą 2%.

Screw Feeders Volumetric screw feeders that dispense a set volume of a premix at a constant rate are the most commonly used machines to fortify flour at the mill. They are powered by a variable speed direct current motor with a controller that is used for fine adjustment of the feed rate of the powder.

The size of the feed screw determines the feed rate capacity. Large capacity feeders may also use a gearbox to increase and adjust the feed rate capacity.

Screw Feeders Advantages of screw feeders:  Better able to sustain a constant addition rate for a longer time  Wider range of delivery rates  Fewer mechanical parts  Fewer repairs because they breaks down less often  Less expensive to build  Can be more sanitary  Easier to maintain than the other types of feeders  Widely available because screw feeders are now the most common type of microfeeders and are produced by a larger number of manufacturers.

Photo courtesy of Buhler Company

Revolving Disk Feeder This is an older type of volumetric feeder that uses a revolving disk equipped with a slide mechanism to control the rate of powder discharge. The disk revolves at a constant speed powered by either an AC or DC motor. The hopper size is usually smaller than in other types of feeders, and must therefore be refilled more frequently. This can be a disadvantage for larger flour mills. This type of feeder also has more mechanical components than the screw feeder.

Drum or Roll Type Feeders Drum or roll-type feeders have been used for decades and many thousands are still in use. They can be set up as volumetric, gravimetric or loss of weight feeders. They operate by allowing the premix powder to pass between two closely set revolving cylinders.

Drum or Roll Type Feeders 

Either a DC or AC motor can power the drum and a gearbox. A pulley system controls the rotation speed. Pulleys and wheels of differing diameters make gross adjustments in the feed rate. An adjustable gate is used to make fine adjustments.



Drum or roll-type feeders require more parts to operate and higher maintenance.

Shear pins in the drive mechanism break if large objects (bolts, plastic) get stuck between the rolls, and the feeder will stop working until a new pin is installed.



In some newer drum feeder models, a variable speed DC drive motor is used to allow the addition rate to be adjusted electronically rather than mechanically.

Variable speed AC drive motors are also available.

Sizing Feeders to the Capacity of the Mill 

Mills generally need one feeder per flour or meal line to be fortified. Larger milling units with multiple products may require additional feeders including spares.



Feeders used for flour fortification need to deliver only relatively small amounts of material. The size and number of feeders needed will depend on the hourly throughput of flour in the mill or load-out system. Hopper size on the feeder is also an important consideration, since you do not want to fill it constantly, nor do you want to let it go for many days without filling.

Photos courtesy of Research Products Company

Feeder Sizing 



Powder premix feeders are available in different sizes.  A small feeder may discharge premix at levels as low as 25 g per hour (0.4 g/min)  The largest can discharge up to 32 kg per hour. This would only be needed with calcium fortification.

Volumetric feeder and hopper capacity are normally given in Liters/min and Liters. This can be converted to weight units by knowing the bulk density of the premix (in g/cc).

Mill Capacity (MT/day)

Flour flow rate* (kg/min)

Premix** Add rate (g/min)

5

2.5

0.4

20

10

1.5

50

25

3.8

100

50

7.5

200

100

15

400

200

30

* At 72% extraction rate ** At 150 g/MT

Delivery Mechanisms

There are two main ways to deliver the premix to the flour:  pneumatic  gravity feed

Pneumatic System In a pneumatic system, the premix drops into a venturi tube, that injects the premix into an air stream. The material is blown by positive pressure or sucked by a vacuum through a pipe into the flour collection conveyor.

If this can not be set up, some downstream location in the flour flow can be used to add premix provided it will be well mixed with the flour.

venturi tube

Pneumatic System Advantages of the pneumatic method  The feeder can be located at several places in the mill, allowing it to be added to existing mills.

Things to Consider:  Pneumatically conveyed flour does not provide much mixing with the premix. Premix should be blown in before flour reaches a mixing (collection) conveyor or sieve rather than directly into a flour holding bin.  Pneumatic addition requires some investment on additional equipment such as blowers, valves and piping.  The pipes used to convey the material should have a minimum number of sharp bends and twists to prevent the possibility of blocking pipes and clumping by the flour fortificant.  The venturi tube should be checked occasionally to see if there is any build up of the premix, and cleaned when necessary.

Venturi Tubes A venturi tube is a simple piece of equipment that connects the premix feeder and the pneumatic delivery pipes. Venturi tubes are used to deliver the premix into the flour stream in an entirely closed pneumatic system.

Venturi tube arrangement at discharge from feeder

Gravity Feed System With this system, the feeder is placed above a flour conveyor. The premix is dropped directly into the flour as it flows through the conveyor. Most often the feeder is placed above or near the flour collection conveyor that blends the various flour streams.

Gravity Feed System Advantages of the Gravity Feed System:  Requires less equipment than pneumatic conveying.  The feeder can sit directly on top of a flour collection conveyor, on a platform.  It can be installed on floor directly above the collection conveyor with the discharge spout feeding into a mostly vertically tube dropping down onto the conveyor.

Gravity Feed System Considerations when using gravity feed systems: 

New mills can be designed or adapted to allow easy installation of gravity feeder locations. Older mills may be configured in ways that makes installation of this type of system difficult.



If the system is installed above the collection conveyor, it may require building a platform or purchasing additional equipment.

Examples of Gravity Field Setup

Mixing screw flour conveyor

Flour collection conveyors for three different lines of flour.

Section 2C

Ensuring Adequate Mixing (slide 1 of 3)

Location of feeder on flour collection conveyor 

At the front half of collection conveyor above the blades of the mixing screw



At least 3 meters of conveyor length is normally needed to ensure adequate blending

Poor Too little mixing

Good

Flour flow

Poor Too little flour

Ensuring Adequate Mixing (slide 2 of 3)

Another option for feeder location: If it would be difficult to install the feeder at the beginning of a conveyor, the feeder can be connected to the flour discharge spout of a plansifter:  The sifter flour spout must have a significant amount of flour entering into the flour collection conveyor on the floor below.  The sifter flour spout must enter the flour stream at least three meters from the discharge end of the collection conveyor to ensure adequate blending.  The three meter distance can be shortened in mills where the flour is:  pneumatically blown from the collection conveyor to either a packing bin or flour storage bin  the flour collection conveyor discharges into another conveyor and the total length of the mixing distance after the premix is added is at least three meters

Ensuring Adequate Mixing (slide 3 of 3)

In the case of erratic flour flow: Install mixing conveyor: 

One solution for small, older mills without a point of a known, constant flow of flour is to install a mixing conveyor running from a flour holding bin to the packout bin. The feeder would drop or blow the premix into the start of the special conveyor.

Slave feeder output to flour flow: 

If the flow of flour is erratic through a conveyor but its flow rate is measurable by some devise that gives a proportional milliamp signal, that signal can be used to control the output of the feeder.

Equipment Suppliers Many companies sell fortification equipment. Mills should ensure that directions for installing and maintaining equipment are available in the national language, or make arrangements to have them translated. 

When considering equipment, look for these specifications: o Screw type feed mechanism. o Automatic shut off capability. o All surfaces in contact with the premix of sanitary of stainless steel or noncorrosive material. o Manually adjustable delivery control, calibrated from 0 to 100% of feeder capacity that can be mounted separate from feeder. o 220 volt ± 10% 50/60 Hz single phase power. o Agitation mechanism to prevent bridging or tunneling of premix in hopper. o Capable of delivering from 0.04 to 8 L/hr with ± 5% accuracy over full range through the use of different size screws, gears or belts supplied with feeder. o Hopper capacity of 8 liter minimum. o Device to allow operator to easily check if hopper is empty or near empty.

Equipment Suppliers 

Vendor must provide two references of maize or flour mills where this feeder has been in operation for at least one year.



Vendor must agree to provide: o Spare parts of gears, belts, screws, fuses or other parts that the manufacturer is aware of possible replacement in the first three years of operation. o

A technician to help install X number of feeders in X number of mills and to conduct workshops for miller groups on the installation, calibration and maintenance of the feeder.

o

Operating instruction book that explains in words and with diagrams the installation, calibration and maintenance of the feeder.

o

A price list of spare parts.

Lessons Learned from Other Millers When ordering mill fortification equipment avoid these problems: 

Motors with incorrect voltage or numbers of phases supplied (110v vs. 220v, single phase vs. 3-phase, etc)



Required or expected components that are optional and not ordered or substantially increased the cost of equipment.



No spare parts ordered and no mechanism for quickly obtaining spare parts (brass gears, belts, etc)



Feeder designed for use with a specific premix, which did not work well with other premixes due to different flow and packing properties.



Feeder placement may need to be located some distance from the flour line so that a tube/shoot needed to be fabricated to carry the premix to the conveyor (via gravity).



When donor ordered equipment there is seldom detailed expertise. Milling specialists MUST liaise closely and carefully review order details.



Equipment manuals may come in a different language than that of mill specialists (correct language version of manual must be specified).

Nutrient Specific Information

Iron Zinc Folic Acid

Each of these vitamins and minerals that can be added to flour has itâ&#x20AC;&#x2122;s own issues surrounding which forms of the nutrient can be added, how much to add, etcâ&#x20AC;Ś For more information on the specific nutrients and their fortificant forms, choose from the list to the left.

B vitamins

For information on health concerns regarding the overconsumption of any of these nutrients, please see Section 4: Assuring Quality Control.

Vitamin A

For information on what these nutrients do for the body, please see Section 1: Introduction to Flour Fortification.

Calcium

Iron How well people absorb iron from fortificants depends on both the fortificantâ&#x20AC;&#x2122;s solubility and the amount of iron inhibitors in the diet. Inhibitors include phytates and phenolic compounds found in tea, coffee and other foods. Reducing the effect of inhibitors by adding ascorbic acid, using sodium EDTA or removing phytates can increase the total amount of iron absorbed from iron fortified foods.

Unfortunately, these methods do not work well in wheat based foods.

The goal of fortification should be to use the iron compound that has the greatest relative bioavailability compared to ferrous sulfate, yet does not cause unacceptable properties in the flour. Cost is also an important consideration.

Types of iron compounds used in fortification  Elemental iron powders (Reduced (Fe0) Iron)  Electrolytic iron  Hydrogen reduced iron  Atomized iron (all water insoluble)  Ferrous (Fe2+) Sulfate (moderately water soluble)  Ferric (Fe3+) Phosphates (water insoluble)  Sodium Ferric (Fe3+) EDTA (water soluble)  Ferrous (Fe2+) Fumarate (nearly water insoluble)

Insoluble Iron Compounds that are Soluble in Stomach Acids These compounds (Ferrous Fumarate) are reasonably well absorbed because they are soluble in the stomach of healthy adults and adolescents.

There is some concern regarding absorption levels in infants who may secrete less acid, but absorption is expected to be similar to water soluble compounds in most people.

Water insoluble compounds cause fewer sensory problems in foods and should be the fortificant of choice if the water soluble forms cause unacceptable changes. Ferrous fumarate is the most commonly used iron compound in this group.

Insoluble Iron Compounds that are Insoluble in Stomach Acids These compounds (elemental or reduced iron powders) have a relative bioavailability of approximately 20 to 75 percent of ferrous sulfate iron. They are widely used in the food industry, however, because they have a lesser effect on the sensory properties of the foods. These compounds are relatively inexpensive, but should be used as a last resort in areas where the diets are high in iron absorption inhibitors. If used, they should be added at higher levels than that of ferrous sulfate.

Elemental iron powders are used widely to fortify cereals, but the bioavailability of the several different types is very dependent on the size, shape and surface area of the iron particles, as well as the composition of the foods to which they are added.

Only electrolytic iron has been proven to be sufficiently bioavailable for humans, but recent data indicate that carbonyl iron and some H-reduced iron may have a comparable bioavailability to electrolytic iron.

Water Soluble Compounds Ferrous sulfate is the most frequently used water soluble iron fortificant because it is inexpensive. The water soluble iron compounds have the highest relative bioavailability because they are very soluble in the gastric juices. They should be the iron fortificant of choice whenever possible.

However, these compounds are most likely to have adverse effects on the color and flavor of foods during prolonged storage accelerating rancidity. The free iron can also oxidize some vitamins in the food if they are supplied in the same premix.

The water soluble forms of iron can be useful for fortifying cereal flours that have a relatively fast turnover. But, because ferrous sulfate can cause rancidity dependent on the climate and the fat content of the flour, its suitability as a fortificant should be considered before use.

Sodium Iron EDTA (NaFeEDTA) Iron is two to three times better absorbed from NaFeEDTA than from ferrous sulfate or ferrous fumarate in foods high in phytic acid.

FeNaEDTA does not accelerate rancidity in stored cereals. However, it may cause color changes in some foods as it is not very soluble in water. It is more expensive than other types of iron, but less is needed per metric ton of flour because it is better absorbed. The iron spot test is not compatible with sodium iron EDTA, but other testing methods are available.

Relative Bioavailability of Iron Sources Relative Biological Value (RBV) is the comparison in bioavailability (ability of the body to utilize the added iron) of different iron sources to that of ferrous sulfate, which is 100% by definition. The absolute absorption of ferrous sulfate can vary from 5% to 30% depending on the iron status of the individual and the composition of the diet.

SUSTAIN studies

Types of iron compounds used in cereal fortification

Elemental Iron powder (reduced) iron

Ferrous Fumarate

Ferrous Sulfate NaFeEDTA

Ferric phosphate

Fortification and Iron Deficiency 



The World Health Organization says iron deficiency is the most common and widespread nutritional disorder in the world. Fortifying flour with iron helps reduce iron deficiency.

Anemia is measured by serum hemoglobin levels. There are multiple causes of anemia, but iron deficiency is the primary one.

Anemia Iron Deficiency Anemia

Iron Deficiency 

Iron deficiency is measured by indices of body iron stores such as ferritin. It can cause a number of health problems besides anemia.



Iron Deficiency Anemia (IDA) is indicated by the presence of both low hemoglobin and low iron stores.

Studies on Iron Bioavailability Efficacy studies involve a select population that was given a known, controlled diet to see if their nutritional status improves.

Effect of different iron sources on iron status â&#x20AC;&#x201C; 36 week human efficacy trial

SUSTAIN studies

Studies on Iron Bioavailability 135

0 month 2 months 4 months 6 months

Mean Hb Levels (g/L)

130 125 120

Iron supply sufficient Iron deficiency

115 110 105 100 Control

FeNaEDTA 20 ppm

FeSO4 30 ppm

Elemental Iron 60 ppm

Modif. from Chen Chunming et al. (2005)

Effect of Iron Fortification of White Flour on Hb Levels (China)

Studies on Iron Bioavailability Effect of 24 ppm Fe as NaFeETDA Flour Fortification on Serum Iron Levels in Weichang, China *

*

*

*

Significant difference from control

Studies on Iron Bioavailability Effect of 24 ppm Fe as NaFeETDA Flour Fortification on Hemoglobin Levels in Weichang, China

*

*

*

*

Significant difference from control

Back to nutrient table of contents

B Vitamins  Thiamin (B1)  Riboflavin (B2)  Niacin (B3)  Pyridoxine (B6)  Cobalamin (B12)  Folic Acid (B9)

Thiamin (vitamin B1) Thiamin Compounds Used 

For flour fortification, thiamin mononitrate is the preferred fortificant compound as it is less soluble in water than thiamin hydrochloride.

Both compounds are white or almost white in color and thus do not affect the color of the flour product.



Both thiamin compounds are susceptible to losses from exposure to light and heat and alkaline conditions (pH over 7).

Riboflavin (vitamin B2) Riboflavin Compound Used 

The only vitamin B2 source used in cereal fortification is riboflavin. It is soluble in water. The compound is yellow in color.



Riboflavin preparations differ in their physical properties and crystalline structure, which influences its color, solubility and particle size. Only products designated by the manufacturer for flour fortification should be considered for use.



Riboflavin compounds are highly unstable when exposed to light.

Niacin (vitamin B3) Niacin Compounds Used 

Two niacin compounds are commonly used in fortification: nicotinic acid (normally just called niacin) and nicotinamide.

Nicotinamide is soluble in water, while nicotinic acid is relatively insoluble in water but soluble in alkaline environments. Niacin does not cause color changes to the flour as it is white in color.



Nicotinic acid is a vasodilator and can cause a flushing reaction (reddening) in the skin on exposure.



Both niacin compounds are very stable in heat and light.

Pyrodoxine (vitamin B6) Pyrodoxine Compounds Used 

Pyrodoxine hydrocloride is the pyrodoxine fortificant of choice for flour fortification. It is water soluble. The compound is white in color and thus does not affect the color of the flour produced.



The pyrodoxine compound is stable to heat, but sensitive to UV light.

Cobalamin (vitamin B12) Cobalamin Compounds Used 



Cyanocobalamin is the cobalamin fortificant used in flour fortification. Diluted forms are usually used because only extremely small amounts of the vitamin are needed. Cyanocobalamin is dark red in color but does not adversely affect the color of the flour because of the minute amounts added.

Cyanocobalamin is relatively stable in heat, but unstable in alkali and strong acidic environments.

Analytical Testing 

It is very difficult and expensive to test for the small amounts of vitamin B12 used in fortification. A microbiological test method is normally employed.

Cobalamin Bioavailability 

The formulation of cobalamin in fortified foods is absorbed two times more readily than natural cobalamin occurring in foods.

Folic Acid (vitamin B9) Folic Acid Compound Used 

Pteroyl monoglutamic acid is the form of folic acid used in fortification.

It is light yellow in color, but this does not affect the sensory aspects of the food because of the small amounts added. The compound is relatively stable with some loss from exposure to light and food preparation.



Pteroyl monoglutamic acid is only slightly soluble in water, but is easily soluble in the low pH of the stomach.

Folic Acid Bioavailability 

Folic acid provided in fortified foods is more readily absorbed than natural food folate. On average 1.7 times more is absorbed.

Back to nutrient table of contents

Vitamin A Vitamin A Compounds Used 

Several forms of vitamin A are used in fortification: retinyl acetate, retinyl palmitate and beta-carotene. Beta-carotene has an orange color that makes it unsuitable for flour fortification.



The retinyl esters are available in a protected, spray-dried form for use in flour fortification, sometimes referred to as SD-250 or SD-250S, since they contain 250 IU/mg. These forms do not affect the sensory properties of the flour.



Different commercial products can vary in their stability, both in the concentrated product and in a premix. Significant losses can occur on storage if the encapsulation and antioxidant protection system is poor. A standard stability test at 45° C on the raw material should show losses no greater than 20% after 21 days.

Back to nutrient table of contents

Calcium Calcium Compounds Used 

The most common calcium fortificants used in flour fortification are calcium sulfate and calcium carbonate. Both compounds are white in color and have a bland taste resulting in no significant changes to the flour product.

Levels added 

The level of calcium added ranges from 1.1 to 2.1 grams/kilogram.



Because these levels are far higher than the premix addition, calcium is always added separately.

Ca level 1.1 g/kg

2.1 g/kg

Ca Sulfate

4.8

9.1

Ca Carbonate

2.8

5.3

Level of the calcium salts needed (in grams per kilogram flour) To be added at the two most common levels of calcium fortification.

Back to nutrient table of contents

Zinc Zinc Compounds Used 

Zinc oxide is the most commonly used zinc source for the fortification of cereals. It is also the least expensive and the source that causes the least problems with flavor and other organoleptic properties.

Zinc Level 

The level of zinc added depends on the average wheat consumption and the flour extraction rate as well as phytic acid intake from other dietary sources.

Zinc Bioavailability 

Zinc absorption depends primarily on the amount of zinc consumed and the amount of phytic acid present in the food. According to the International Zinc Nutrition Consultative Groups (IZiNCG), when consuming just enough zinc to meet physiological needs, about 27 to 35 percent is absorbed from diets with a relatively low amount of phytic acid, while 19 to 26 percent is absorbed from diets with relatively higher amounts.

Back to nutrient table of contents

End of Section 2 Continue Return Table of Contents Go to first slide of this Section

Section 3

On the Production Line Installation & Calibration of Premix Dosing Machinery Premix: Handling, Storage & Management Equipment: Maintenance & Troubleshooting

Installation & Calibration of Premix Dosing Machinery

 Location of Premix Feeders  Feeder Set-up  Feeder Calibration  Fortification Operation Guidelines

Location of Premix Feeders  Place feeders in a dry location and away from sunlight.

Vitamin A, riboflavin and folic acid are sensitive to light and atmospheric oxygen.  Ideally, place feeders in an area of the mill easily accessible to the operators. Controller should be handy to the miller’s office or flour testing station.  There should be room adjacent to the feeders for a supply of the premix ready to add (a box or two depending on use rates).  Feeders should be located near the beginning of the conveyor to assure good mixing with the flour after it is added.

Feeders Details with Premix Box

Feeder Details

Location of feeder on flour collection conveyor  

At the front half of collection conveyor above the blades of the mixing screw At least 3 meters of conveyor length is normally needed to ensure adequate blending.

Feeder located on platform or floor above

Poor Too little mixing

Flour discharge

Good

Poor Too little flour

Premix Feeder Set-up 

In general, one feeder is needed for each production line of flour to be fortified.



Locate feeders to allow adequate mixing with flour after point where premix is added.



Speed controller and low level indicator light should be in readily visible, convenient and easily accessible location.



Feeder hopper should be convenient for filling.



Install voltage stabilizers whenever electrical voltage fluctuates more than ± 20%.



Install electrical interlock systems directly to either the flour collection conveyor motor or the mill control panel.



Check low premix level indicator lights to assure hopper is operating correctly.

Two lines, two feeders

Conveyor Direction

Feeder Controller

Feeder Details (Mongolia example) Screw Premix Feeder

Conveyor direction

Feeder Calibration Check the flour production rate (kg/hr) for each production line, even if the rate has been established. his can be done with the following procedure:  While the mill is running, count number of bags packed per 60 minutes or use on-line flour scale (if one is installed).  Calculate the flour production rate using the following formula. This is the actual production rate per minute and not rated capacity.

(weight of bags in kg) x (number of bags per 60 minutes 60

= kg flour per minute.

Feeder Calibration Premix Feed Rate Determination: Next, determine the premix feed (discharge) rate at different speed settings on your feeder.

1. Fill hopper half full with premix to be added.

2. Set feeder to maximum discharge.

3. Run feeder for two minutes.

4. Weigh the premix that has been discharged.

5. Calculate maximum discharge per minute.

6. Optional: Repeat at different speeds or percent settings.

7. Graph paper or a spreadsheet program can be used to make a chart that shows the premix discharge rate per minute at different speed settings from 0 to 100% of maximum discharge. This should be displayed near the feeder.

Feeder Calibration Individualized Premix Feed Rate Determination to Fortify at Set Levels: Finally, you need to take both the flour production rate measure and the premix feed rate measure you calculated previously and use them to determine the feed rate of premix in grams per minute required to fortify the flour at the recommended level.

Determine the recommended addition rate of premix (from supplier specifications on the package) 1.â&#x20AC;Ż Calculate the required premix feed rate per minute using these formulas: 2.â&#x20AC;Ż Adjust the control/dial on the feeder to deliver the calculated weight of premix per minute. You should now be ready to begin fortification. premix weight in grams per ton

1000

= grams per kg flour

(premix weight per kg) X (production rate per minute in kg) = premix weight required per minute

Feeder Calibration Chart Prepare and post near feeder

Fortification Operation Guidelines 1. Be sure feeders are calibrated and actual production rate of mill has been measured.

2. Ensure feeder hopper contains premix.

3. Start mill up and let run for at least 15 minutes to reach normal production rate.

4. Start feeder at required setting as determined by the feeder calibration process.

5. Conduct check weighing at start of mill production run and every TWO hours to verify correct addition rate. Adjust if addition rate is greater than 10% above or below target. Recheck addition rate using check weigh procedure. Try to maintain check weight within 5% of target. Check weights should be run at the start of every shift or every 8 hours of operation.

Fortification Operation Guidelines 5. Each premix feeder should be checked routinely during production run to ensure there is sufficient premix in the hopper and that feeder is operating properly.

6. Note: To add an extra quality control measure, mills may require premix feeder hoppers to be filled on a regular basis and the weight of the material left in the premix carton recorded. If the amount used between weightings is compared with the flour production during the same period, a measure of addition is obtained.

7. The most important check on the production line is to ensure that the feeder does not run out of premix. Many feeders have a low level indicator that can be checked.

8. At the end of a production run, the premix feeder should be turned off before shutting down the mill.

9. Production records need to record the following:  The lot number of the premix used  Check weights  

Feeder adjustments if made Times of check weighing

Check-Weighing Procedure

Premix: Handling, Storage & Management

 Safe Premix Handling  Maintaining Premix Shelf Life  Premix Delivery and Receiving Procedures  Management of the Premix Supply

Safe Storage and Handling of Premix Premixes are concentrated sources of vitamins and minerals, and small doses over a prolonged period can be harmful.

Some workers may have a mild allergic skin reaction to some premix ingredients.

The following worker precautions should be used when handling premix: 1.â&#x20AC;Ż The premix boxes should have a Warning Label and handling precautions that should be followed.

2.â&#x20AC;Ż Premix is never for direct use in foods: IT IS TOO CONCENTRATED FOR DIRECT CONSUMPTION. Mill workers MUST BE INFORMED and understand this safety precaution. Materials safety data sheet (MSDS) or a product information sheet with handling instructions should be distributed or made known to all workers who will contact the premix.

Safe Storage and Handling of Premix (continued)

3.

When filling the feeder hopper, the operator should wear a long sleeve shirt, gloves and dusk mask. He may also wear safety goggles, a hair net, safety helmet or other protective devices depending on the policies of the mill. (Since the filling of the hopper may take less than a minute, the operator may see this as unnecessary.)

4.

Workers handling premix should wear long sleeve shirts and gloves when handling the product. Some people have an allergic skin reactions to flour fortificants such niacin. A common reaction is skin reddening caused by the vasodilatation effect of niacin. This effect is not dangerous and is transitory, but it can be annoying.

5.

After filling hoppers, workers should wash their hands and skin areas that were exposed to premix.

6.

Premix boxes should be stored in a convenient location but not exposed to sunlight, not excessively hot (i.e. next to a boiler) and safe from getting wet or hit by lift trucks. The boxes can be piled on top of each other, but they should be arranged so that a first in, first out system of use can be easily accomplished.

Safe Storage and Handling of Premix (continued) 7.â&#x20AC;Ż

Normally, one box at a time is brought adjacent to the feeder for filling. The box and the inner bag are opened. A scoop can be placed inside the opened bag for convenient use. Keep paper, plastic, and other contaminates out of the bag as they may get in the feeder cause its malfunction. Ideally, the inner plastic premix bag should be a colored material so any pieces would be noticeable to the operator.

8.â&#x20AC;Ż

Once the hopper has been filled, the operator should put the scoop back in the bag or at some other designated location. The inner bag should be twirled close and the cardboard flaps folded over. This operating box should be left in a location that is convenient for future use but not exposed to conditions that could damage it.

9.â&#x20AC;Ż

Any spill of premix should be cleaned up immediately by putting meal on the spill prior to sweeping.

Maintaining Premix Shelf Life 1.

Ideal storage Conditions: Store in well-ventilated rooms at low or mild temperatures (preferably not higher than 25°C), and avoid humid conditions. Where humidity cannot be controlled, vapor barrier packaging should be used.

2.

Purchase in Small Quantities: The amount of commercial premix needed should be estimated and obtained in quantities small enough so that it does not need to be stored for long periods of time.

3.

Stock Rotation: Upon receipt of the shipment, the production lot number(s) should be recorded and retained. A first-in, first-out (FIFO) system of stock rotation should be used.

4.

Use of Open Containers: Once a premix bag has been opened, it should be kept closed when not in use and protected from heat and light.

Premix Receiving Procedures 1) Assess condition of the packaging

3) Record Lot # and type of premix

2) Ensure that you receive what you ordered

4) Remove certificate of analysis and keep on file

Management of the Premix Supply Responsibilities for mill staff for each aspect of premix supply needs to be clearly assigned at the mill. The major assignments include the following:  Stock control and ordering (ordering times need to take into account usage rates and the time it takes to process, ship and receive a shipment)  Mill handling to include storage, movement to the production line and addition to the feeder(s).  Premix quality control on arrival at the mill and periodically in storage and on the production lines. This function is different from quality control of the fortified flour.

Equipment: Maintenance & Troubleshooting

 Routine Inspection & Maintenance  Problems with Magnets  Troubleshooting

Routine Inspection & Maintenance 

Typically, inspection and maintenance of premix feeders and control equipment is minimal, but will vary depending on feeder type.



Manufacturers should provide specific inspection and maintenance information with the machines (check on delivery).



Instructions may need to be translated into national language if not done by manufacturer.



Manufacturers can be consulted to learn what parts may wear out and how they can be obtained.



A stock of high turnover spare parts should ordered and kept on hand.

Problems with Magnets (Slide 1 of 2)

Magnets on the production line may cause minor problems by attracting the elemental (reduced) iron forms used in some premixes.  Iron salts (ferrous sulfate, ferrous fumarate and iron EDTA) used in some premixes WILL NOT be attracted to magnets intended to remove tramp iron.

Elemental iron powders in premixes may be attracted to magnets, BUT:  Only rare earth magnets are strong enough to actually pull elemental iron powders out of flour as it passes by the magnet. This magnet quickly becomes saturated with the iron powder and a state of equilibrium is reached causing no additional iron to be removed.  Extensive experience shows that magnets will generally remove tramp iron but little to no iron powder because the tramp iron is thousands of times larger and much more strongly attracted.  If a problem is suspected, it can be checked by inspecting the surface of magnets to see if they hold large amounts of iron powder.

Problems with Magnets (Slide 2 of 2)

If magnets have a manual cleaning system, as do most of the new tube magnets, check the amount of iron powder that is removed on cleaning.

ď&#x201A;§â&#x20AC;Ż

If there does seem to be a problem, there may be are alternative solutions as noted on the next page.

Fixes for Problems with Magnets Actions to correct magnets causing problems with iron separation: 

Install magnets in a location so that the flour stream acts as a continuous cleaning mechanism as it passes over the magnet.



If the iron powder bridges between the magnet tubes, use a magnet system with a larger distance separating the tubes.



Place magnets prior to the addition of the premix and rely on sieves to remove tramp iron after that point.



Use a non-magnetic iron source, such as iron salts.

Troubleshooting 

The best way to prevent and easily fix production problems is to be prepared and know what to expect.



The links below are for troubleshooting information and action steps regarding the following problems:  Trouble with Premix and Feeders  Electrical Power Supply Variations  Segregation and Loss of Vitamins and Minerals

Trouble with Premix and Feeders 

Frequent, visual inspections of the premix feeder are important, especially after it is newly installed.



Compaction and stickiness of the premix may cause it to ball-up, bridge or tunnel in the feeder. A loose material will feed slower in weight per unit time than the compacted material. Thus, compacted premix can cause problems because it results in feed rate variability.

ACTIONS:

1.

2.

3.

Have premix supplier change the levels of excipients and free-flow agents Install mechanical agitation in premix feeder hoppers. (See next page.)

Empty feeders that will be unused for any length of time.

Mechanical Agitation ď&#x201A;§â&#x20AC;Ż

Installing a mechanical agitator in the hopper will help prevent the premix from bridging, clumping and compacting. Some models of feeders may automatically come with an agitator device already installed.

Trouble with Premix and Feeders 

If there are problems with the flour flow or the premix flow, the level of premix added to the flour will be incorrect.

ACTIONS:

1.

2.

3.

Make frequent inspections of the feeder Install low-level alarm or indicator light on hopper Install electrical interlock system between the mill and feeder controls. (See next page.)

Electrical Interlock System (slide 1 of 2) 

An interlock causes the feeder to stop if the flour collection conveyor stops. This will prevent the inadvertent over-treatment of the flour if there is a mechanical breakdown in the mill.



It is highly recommended that an electrical interlock system be installed between the feeder motor and the motor driving the flour collection conveyor.



In pneumatic delivery systems, an interlock should be made between the feeder and the blower to insure that the feeder cannot be turned on without the blower operating. This will prevent buildup of the premix in the pneumatic lines followed by over-treatment of flour once the blower is turned on.



An alternative approach is to hook up an automatic shut off switch on the feeder to a flour flow indicator or a pressure indicator in a pneumatic system.

Electrical Interlock System (slide 2 of 2)

Interlocking (slaving) premix addition to flour flow:



The most accurate method of flour fortification is to continuously interlock the addition rate of the feeder with the measured flow rate of the flour.



This requires equipment for measuring the flow rate of the flour and computerized mill control allowing the interlock.

Electrical Power Supply Variations 

Electrical voltage power fluctuations may occur in your mill, due to national grid supply problems and generator variability.



This can cause a problem because feeders and controllers must operate in a consistent, uniform manner to ensure adequate fortification.



Variations in voltage can alter the flour production rate and the premix feed rate, which will cause the flour to be fortified incorrectly.

ACTIONS: 1. Use voltage regulators when you are working with single voltage feeder motors.

2. Use three-phase motors. Three-phase motors are more reliable and generally run cooler and last longer than single phase motors. But they also require three-phase electricity and are a higher initial investment.

Segregation and Loss of Vitamins and Minerals Some of the added vitamins and minerals may be destroyed, segregated or removed in other parts of the production line, such as pneumatic suction or sieving. This may be discovered upon quantitative testing. Vitamin A and riboflavin are particularly vulnerable.

ACTIONS:  Confirm that you are using a premix that is appropriate for your flour.  Check the dust collector. Excess riboflavin will give the dust a yellow color.

Quantitative testing will identify other vitamins and minerals that may be present. If this is the case, alter or remove the pneumatic suction after the point of addition, or fortify the flour at a later stage of the milling process.  Make sure that the flour is not exposed to high heat (>40° C) or light during after the premix has been added.  Do not run the flour through purifiers or under heavy suction after you have added the premix. Purifiers need to be installed earlier in the production line.

Back to table of contents Back to section front

Section 4

Quality Control 

The importance of quality control system



Safety Concerns



Overview of Quality Control Methods



Record Keeping



Feed Rate Monitoring



Iron Spot Test



Quantitative Testing Using an Indicator Nutrient



Outside Quantitative Testing



Quality Control Schedule



External Monitoring by the Authorities

Importance of a Quality Control System 

 

Flour millers play the largest role in assuring success of national efforts to bring fortified flour to populations and gain customer satisfaction with fortified flour A uniformly high quality fortified product is needed to gain customer satisfaction and meet government standards.

Good quality requires a well-developed and comprehensive quality assurance and control program in the mills and across all levels of a national fortification program. Plans to strengthen the overall national level, good quality and good development requires a comprehensive quality assurance and control procedures.

Monitoring of fortified flour There are three aspects of fortification monitoring 1.â&#x20AC;Ż

Internal monitoring (quality assurance and control) by the mills, with possible help from a central milling association

2.â&#x20AC;Ż

External monitoring (food control and enforcement) by the government.

3.â&#x20AC;Ż

Coverage and effectiveness monitoring by the government of a designated organization

Qualitative Flour Testing 

 

Qualitative tests are simple, rapid tests that can be done at the mill to determine if a flour sample has been fortified or not, and, with some test procedures, obtain an estimate of whether it is under or over fortified.

The primary test used for this purpose is the Iron Spot Test (but other tests are needed for Sodium Iron EDTA In some cases, the iron spot test can not be used because of the type and level of iron added. In that case, possible alternative qualitative tests are: o Riboflavin black light test – riboflavin will fluoresce under ultraviolet light. This should be done in a dark room or box using a wet Pekar slick of the flour compared to unfortified and a standard fortified flour. o Vitamin A color test – This is a somewhat involved test that must be done in a laboratory. It is based on comparing the intensity of a blue color that forms with vitamin A with a standard solution of copper sulfate.

These two alternative tests are poor replacements for the iron spot test. One suggestion is to always have some elemental iron included in the premix to act as a marker, recognizing that this would increase the total iron content if measured quantitatively.

Semi-qualitative Flour Testing The iron spot test and vitamin A color test when properly done with known fortified flour samples afford a rough estimate on the level of fortification in an unknown sample. The following descriptive scale is one way the results can be reported.     

No fortification detected Low level Normal level High level Very high level

Safety Concerns Fifty years of experience has proven that flour fortification is very safe and has minimal risks that are easily controlled by established quality assurance an control procedures.

Two main safety concerns: 1.â&#x20AC;Ż Setting safe and appropriate standards: The national fortification standards of vitamins and minerals in foods need to be set high enough to insure nutritional benefits are provided, but low enough to guarantee that consumers do not chronically consume too much of any nutrient.

2.â&#x20AC;Ż Preventing the accidental over-fortification of flour: Avoiding levels of minerals and vitamins that are excessively high is accomplished through a set of standard practices using equipment and procedures to monitoring the use of pre-mix and the nutrient levels in the fortified flour. oâ&#x20AC;Ż Mill production staff can easily recognize if a higher than expected rate of premix is being added through normal quality control testing. Additionally, the highly over-fortified flour would show an off-color, from the iron and riboflavin making it unacceptable to most consumers.

Overview of Quality Control Method The standard procedures that test fortification during production need to assure reliable results and be able to be performed quickly to allow immediate corrective action if a problem is found. 

As with other quality control procedures, both the process of fortification and the results need to be monitored and recorded.



The four basic quality control methods for flour fortification that should be used in every mill are relatively fast and simple to perform on a regular basis.



1.

Record keeping of premix usage and fortified flour production

2.

Monitoring of the premix feed rate and flour flow rate

3.

Qualitative testing (iron spot test)

4.

Regularly sending samples for quantitative testing

Except in cases of an extreme problem, adjustments should be based on trends over time and not on the results on any one test.

Iron Spot Test This is the most common test used by mills for quality control to assure

that a correct amount of premix is being added to flour and a uniform product is being achieved. 

A modified procedure that gives excellent results on flour fortified with elemental iron powders uses a solution of 1 part 1 N HCI and 6 parts methanol or denatured ethanol in the place of the 2 N HCI called for in the standard procedure. This solution is very stable and can be kept for months. This procedure gives dark spots on a white background and avoids the need for a stronger acid solution.



The iron spot test cannot be used to test for sodium iron EDTA, however. If NaFeEDTA is used, ask the company which supplies the compound about testing methods.

Iron Spot Test How often performed: Every 4 hours and at the start and end of each production run.

1

What is tested: Flour samples taken at the end of the production line (most often prior to bagging but samples from bags in warehouses can also be tested Description of the method:

2

This method, approved by the AACC, is applicable for qualitative determinations of iron in enriched flour Ferric iron added to flour reacts with a thiocyanate (KSCN) reagent to form a red-colored complex A higher number of red spots and deeper red color appear with fortified flour compared with untreated flour.

Iron Spot Test 3 Advantages of the Spot Test  Simple, fast and easy technique requiring no sample pre-treatment.  Inexpensive; requiring only two reagents, KSCN (or NaSCN) and HCI  Personnel with minimum training can carry out this assay.

Limitations  Not quantitative, i.e., it does not determine the amount of iron present in the sample.  Method shows only ferric iron. If iron is added in the ferrous form, the sample needs to be oxidized with hydrogen peroxide to convert the ferrous to ferric iron before analysis.  This works poorly with NaFeEDTA

4

5

Iron Spot Test

6

RED SPOTS

7

Iron Spot Test 

Food grade NaSCN is available in case there is concern about the safety of this reagent. However care should be taken with its use, as with any concentrate chemical.



The spot test works best with elemental iron powders, and very poorly with NaFeEDTA. Some NaFeEDTA products produce no spots, giving only a reddish background color.



Mill chemists use many different ways to prepare the flour for testing. o The simplest is to make an impression with a 50cc beaker into a small pile of flour sitting directly on the work bench. Add the reagents with a plastic, disposable dropper and sweep the flour pile into a waste basket when finished. o Other flour preparation methods take more time but give better semiquantitative results. One is to make a wet Pekar slick test with both unknown and known samples, and let the reagents run down the wet slicks. o Some premix companies can provide additional advice on the use of the iron spot test and ways to optimize its effectiveness.

Iron Spot Test Appropriate Response to Results from Spot Tests 

  



Single spot test results conducted during the daily production run (taken every 2, 4 or 8 hours depending on need) showing more or less spots than target level is not a reason to make adjustments to the feeder system for micronutrients.

Some variability in the amount of iron will always be found through the spot tests as well as through qualitative tests.

Adjustment is called for if a systematic trend (i.e. consistently low or consistently high or trending low or high) over time is noticed.

Adjusting a premix addition system based on one or two spot test results when no adjustment is warranted is likely to widen system variability and complicate future measurements.

When what appears to be too low or too high a level of iron is observed in the iron spot test count based on several measurements over time, action is needed.  

Check the premix feeder and flour transport and mixing machinery and adjust if necessary Take an additional sample for testing

Record Keeping 

Premix Records: Check, record and maintain information on the delivery and usage of the premix.



Flour Production Records: Collect and maintain information on how much fortified flour was produced.



Premix Usage Reconciliation: Reconcile and record actual usage of premix versus target needs. The amount of premix used should be compared against the flour production records and recorded. This provides a simple way of determining if the correct amount of premix is being used.



Quality Control Testing Records: Results of quality control tests performed in the mill and also those done outside must be carefully recorded and kept on file.

These document the history and producer’s supervision of the fortification process.

Feed Rate Monitoring The toolkit previously described how to calibrate the feed rate of a premix feeder and how to select the correct feed rate based on the flour production rate.

It is important to continue to conduct check weighing tests regularly to ensure that the feederâ&#x20AC;&#x2122;s feed rate remains steady.

Reminder note: Check Weighing: the weight of the premix discharged over a specific time (1 or 2 minutes) is measured and compared to the target weight for the premix.

Quantitative Testing Using Indicator Nutrient 



  

Quantitative testing for fortified flour is most often done by laboratories with more sophisticated equipment and greater experience and throughput than what is available at a mill.

Typically one of the premix ingredients will be tested as an “indicator” of the others. This method is a valid method for premix that has been properly designed, manufactured and mixed to achieve a constant ratio of the different nutrients.

Because the ratio is constant, measuring one of the micronutrients in flour can verify the delivery doses of the others.

This assumes there has been no destruction or separation of the indicator nutrient after the premix was added.

Iron is often used as an indicator nutrient, but vitamin A has also been used when it is added.

Outside Quantitative Testing 

Quantitative testing of vitamins and minerals in fortified flour requires sophisticated equipment and careful adherence to protocols because the levels of the vitamins and minerals are so small compared to the volume of the flour.



Quantitative tests for the mills should be done on documented composite samples taken on the production line or warehouse and sent by the mill.



Questions on the accuracy of the results should be referred to a certified, reference laboratory using officially approved testing procedures.

It is highly recommended that any lab running quantitative tests:  Use a fortified food standard with certified levels of micronutrients to correct for any bias in results  Regularly run a fortified flour standard to assess the lab’s analytical error for each assay.

Outside Quantitative Testing Collecting a Composite Sample of Fortified Flour Composite samples are created by blending small samples of fortified flour taken at spaced time intervals across a production shift. 

The composite sample made of 5 to 10 spot samples should be representative of a production lot, such as an 8 hour run.



The samples making up the composite sample should be of the same size taken evenly over the production period in order to represent the total production throughout the period.



The purpose of the composite sample is to estimate the average value of the nutrients in a production run. Use of composite samples keeps the cost of fortification analysis down by limiting the number of tests needed to establish an estimate of the mean value.



Responding to single or even several observations of high or low nutrient values is an inappropriate use of quantitative testing. Its main purpose is to establish trends over time and is a valuable tool when used in that manner.

Outside Quantitative Testing Uniformity or Mill Capability Testing



When a mill starts fortifying, it may wish to determine its capacity of producing a uniformly fortified flour.



This is normally done by quantitatively testing an indicator nutrient (typically iron) in spot flour samples (not composite samples) over a production run. Suggest taking 7+ samples over an 8 hour run.



Calculate the coefficient of variation (CV) = standard deviation as the average percentage of the mean.



If the analytical error or the lab for that assay is known and less than 5%, a CV, less than 20% is indicative of an acceptable variability. If the CV is higher than 20% the mill should investigate possible reasons for the variation, such as variation in the flour low rate or erratic premix addition.

Outside Quantitative Testing Use of quantitative test results 

Mills should not adjust the addition rates based on the results of a single analysis.



Long term trends can influence whether to adjust the premix addition rate up or down or request a different premix formulation from the supplier.



Any decision or change should be based on the “trends” in multiple cases of quantitative testing over time. This is best seen by plotting a standard control chart.

Outside Quantitative Testing Flour Testing Laboratories

Types of testing done at laboratories involved with fortified flour Runs quantitative tests.

Runs or manages biological testing.

Audits mills.

Can run quantitative tests of all added micronutrients and Checks results and Procedures of other labs.

Runs quantitative tests on indicator nutrient and other tests

CoA on premix, quantitative tests of all added micronutrients

Mills QC Activities:

1. Fortificant inventory control 2. Feeder checks 3. Iron spot tests (if applicable) 4. Flour sampling

External Qualitative Test Flour Testing Laboratory 

The Central Lab can be part of a milling association, a large milling company, or an independent lab/organization designate, providing routine testing service for mills, particularly smaller mills that do not have testing capabilities. This would include quantitative tests of the indicator nutrient not normally run by the mills themselves.



The Government Lab and Food Control Agency is associated with the enforcement and regulatory function of the central government. It may do quantitative testing of flour samples collected at mills, homes and markets during mill audits. Its analytical capacity is more advanced, and may also be involved with coverage and effectiveness studies.



The Reference Lab is typically an outside, certified lab with the ability to run quantitative tests on all added nutrients. It may be located in another country. It would be used to resolve disputes on fortification levels and to determine whether the other labs are providing accurate results.



Premix suppliers have their own labs for assaying micronutrient content on their premixes. They may also provide flour testing services to their premix customers, usually at no cost.

Quality control schedule Suggested activities for mill level quality control of fortified flour: 1.

2.

3.

4.

Check premix feeder controller hourly (that low level indicator is not lit and speed detector shows it is running) Run feeder check weights at least every 8 hour shift.

Run iron spot tests at least every 8 hour shift.

Conduct inventory control of premix usage and fortified flour production at least quarterly.

The responsibility, frequency, protocol and reporting for the above activities should be spelled out in the mill QA manual and communicated to all involved mill personnel. All reporting must be to someone with the authority and the ability to act on the information.

Dynamic Monitoring Problems and actions: Adjusting quality control test frequency 

If spot tests show that levels of the nutrient tested are lower than the factory minimum or higher than the maximum tolerable level, (see next page), then sampling frequency should be increased and corrective actions should be taken.



If on 2 out of 5 consecutive sampling times the product fails to meet the technical requirements, the intensity of sampling should be changed to a more demanding intensity, and corrective actions should be implemented.



If the next 2 out of 5 consecutive sampling periods results in failure to meet requirements, the production should be stopped until the source of error is found and the necessary corrective measures are introduced.



Once production is started again, sampling should be more frequent.



A less frequent schedule can be adopted, if in 3 consecutive sampling periods for each category, the quality control results are correct.

Upper Levels

External Monitoring by the Authorities Roles of external authorities in flour fortification:  



Checking the performance and records of the producers’ quality assurance procedures (technical or off-site auditing) Confirming that technical specifications are fulfilled in the product at factories, packaging sites and points of entry into the country (inspection or on-site auditing) Inspecting and verifying legal compliance (should be based on the analytical assessment of the nutrient content by means of a quantitative assay.)  All samples should contain the fortificant, and at least 80% of samples in factories, importation sites, and warehouses should present the legal minimum.  Less then 20% of them should have a nutrient content above but always near the maximum tolerable level, if one has been established.

External Monitoring by the Authorities Government Auditing There are two types of audits: 

One is technical or off-site audits where a government official or designate reviews information supplied by mills, or milling association if it has been designated to collect data, to determine whether flour is fortified correctly. This may be done quarterly.



The other type of audit is inspection or on-site audit where authorized environmental health officers visit the mill to determine if the mill is properly fortifying flour and to validate that data being supplied in the offsite audits.

Some government food control agencies will adjust the frequency of on-site audits depending on how well the mill has performed in the past, and how many complaints or violations have been reported for the mill.

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Section Five

Keys to Effective Marketing 

Types of Flour Fortification Programs



Marketing Strategies



Consumer Concerns



Marketing Samples



Government Support

Types of Flour Fortification To know how to best market fortified flour, first consider the type of program being used. The World Health Organization has described three basic types: 1. Targeted fortification is for specific population groups. Examples include food aid, complementary foods for infants and young children, food developed for school feeding programs and foods designed for the sick and elderly.

2. Mass fortification describes the widespread addition of one or more nutrients to foods commonly consumed by the general pubic, such as cereal flours, sugar and vegetable oil, to correct known deficiency problems in the general population.

3. Market-driven fortification describes food manufacturers which voluntarily fortify some of their processed food products to enhance the nutritional quality and public image of those products.

Voluntary versus Mandatory 

Targeted and mass fortification may be mandatory or voluntary.



Mass fortification is generally mandatory, in which case it becomes a true public health program benefiting the majority of the population.



Market-driven fortification (also referred to as open-market, industry-driven or private label fortification) is always voluntary. It will provide a health benefit to segments of the population but can not be considered a public health program.



Some countries, like the United States, do not mandate flour fortification nationally, but make it so difficult to sell non-fortified flour that it becomes universally practiced by the milling industry, thereby making it a true public health program.

Marketing Strategies Marketing strategies differ according to type of fortification.

For example: 

In a targeted situation, the company markets to a specific group, say school or hospital feeding, within the requirements set by government, school system, or organization that is purchasing and distributing the product. There is little need for promotion since the fortification of the flour would be specified by the customer. The cost of fortification would be factored into the selling price and would not be a constraint.



With mandatory or universal mass fortification, companies fortify to national standards. They are not likely to heavily promote their product since other bakeries offer the same or similar product. They might promote that they have better quality and control over fortification. Cost would be an important concern.



In a market-driven situation, companies add whatever types and levels of nutrients they think would sell , following national regulations that might exist.

They promote the product, especially at the start, to get consumer interest.

They live with higher costs, within reason, since they expect higher market share, sales and profits.

Marketing Strategies



The mix of marketing strategies and tools will differ depending on perceptions of costs and benefits. Where the perceived costs are high and benefits low, government regulation may be needed to ensure all flour products are fortified.



Where perceived costs are low and benefits high, consumer information and education may be sufficient to add value.



When the perception of costs and benefits are mixed, marketing tools such as advertising and promotion may also be needed to build consumer perceptions of added value.

Fortified Flour is a Better Product 

Fortified flour is superior nutritionally to flour that has not had vitamins and mineral added.



Fortified flour is "natural" – the vitamins and mineral added are already in wheat, but many are removed in industrial milling.



Fortified flour will not be different from non-fortified in terms of color, texture, taste or shelf life. In other words, it is invisible. The consumer will not know that the flour or baked products made from the flour is fortified, unless they are told.



Fortified flour improves nutrition and reduces vitamin and mineral deficiencies.

Recognize and Research Consumer Concerns 

As flour is a traditional food staple, consumers may be concerned about any changes.



Flour may be seen as a special, pure and/or natural product. Added substances, even replacing those lost in milling, may raise concern about product quality.



Some consumers may resist even a slightly higher price.



When prices are controlled by government or a competitive environment, millers may be concerned about any higher production costs.



Wholesale fortified flour purchasers and re-processors are usually very sensitive about product quality and price.



Learn from and use research to identify specific concerns and find those characteristics of fortified flour that are most appealing to consumers.

See Morocco logo study on separate file on this CD for example of consumer research

Logo Examples Three country logos are shown below. South Africa did consumer pretesting of different options for fortified foods logo that would eventually appear on all fortified products. Consumers chose the logo at bottom right with three children representing the ethnic diversity of South Africans with the rising sun in the background.

Packaging Examples

Advertisements

Develop Government Support 

Governments can provide various fiscal incentives that offset or reduce mill costs for fortifying flour including reduced or no VAT, tariff or duty on premix, wheat or other inputs.



Examples of international donor supported government strategies to support production and marketing fortified flour.

Check services projects that promote fortified flour and have international donor support.

Micronutrient Initiative, Flour Fortification Initiative, A2Z Project, Iron Deficiency Project Advisory Service, GAIN

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Section Six

Cost Issues 

Basic Pricing Information



Premix and Ingredient Costs



Equipment costs



Lab Expenses



Miscellaneous Expenses

Basic Pricing Information The costs of fortifying flour are often less significant to mill profits than annual and semiannual changes wheat costs other mill input costs.

A very small price increase will pay the slightly higher costs of fortified flour and should also provide added profit for bakers, pasta makers and others.

For millers:  US$1.00 - $2.00 metric ton (roughly 0.5 to 1% the cost of wheat flour) For bakers and re-processors:  US $0.05 - $0.10 per 50 kilogram of flour For consumers:  < US $0.01 per 5 kilogram bag of four  < US $0.003 per 1.5 kilogram loaf of bread,  < US$0.0001 for 250 grams pasta.

Premix and Ingredient Costs 

The major recurring cost of flour fortification is in the vitamin/mineral premix added to the flour on the production line.



Different vitamins and minerals have different costs, as do different forms of some vitamins and minerals, so premix cost varies based on the ingredients.



The premix costs also covers fillers, production and packaging, and marketing



Larger quantities ordered, and often a commitment to purchase premix from a single supplier for a longer period, reduces the costs of the premix.



In some cases, governments eliminate various taxes on premix or on flour and flour products that are fortified. This also lowers the cost of fortifying flour.

* Disclaimer: All cost information represented in this section is general and should be used with caution. Actual costs may vary by as much as 30% and is dependent on manufacturer, location, amount ordered, etc.

Estimated Premix Costs Estimated Costs (USD) for select nutrients per one metric ton of flour: Premix

$ per MT of flour

Iron + folic acid

$0.85 - $1.10

Iron as NaFeEDTA + folic acid

$2.50 - $3.00

Iron, folic acid, other B vitamins

$1.60 - $2.00

Iron, folic acid, other B vitamins, vitamin A

$2.85 - $8.00

These prices indicate the estimated cost of premix and should NOT be used as official market prices. These prices do not reflect shipping, import duties and value added tax.

Millers must always request price quotations for premix from more than two suppliers to ensure that they are getting competitive prices.

Equipment Costs 







Two basic options for adding premix during production are through feeders that and through use of large blenders.

In general the cost of feeders varies with the capacity of the production line and optional equipment.

Costs shown do not include shipping, import duties or value added tax.

Installation costs are generally about 5% of feeder costs.

Equipment

Cost Range (USD)

Option One: Feeders Volumetric Feeder

$1,000 - $8,000

Gravimetric Feeder

$5,000 - $20,000

Loss-of-weight Feeder

$10,000 - $21,000

Powder Feeder

$1,000 - $25,000

Electronic Scales

$100 - $2000

Option Two: Blenders Horizontal Ribbon Blender

$9,000 - $130,000

Horizontal Paddle Blender

$9,000 - $130,000

Rotary Batch Blender

$35,000 - $170,000

Vertical Batch Mixer

$15,000 - $200,000

Lab Expenses 

Extensive quantitative testing at mills is seldom needed for reasonable quality control. Laboratories which need to purchase equipment might incur substantial costs such as:  Ashing / Fume Hood - $3,400 - $16,625  Muffle Furnace - $1,150 - $3,200  Spectrophotometer - $8,510 - $15,750



Most mills use well established qualitative testing methods, (iron spot test costs ranges from US $2.00- 5.00 per test ). Mills periodically send samples to outside facilities for more precise measurement. (US$10 - $100) per test)  Some premix companies provide quantitative testing services of fortified flour at low cost or free of charge.  Some government flour fortification projects include central reference laboratories that do precise quantitative testing of the micronutrient levels in flour, fortified flour and fortified flour products, including analysis of samples sent periodically from mills.

* Disclaimer: All cost information represented in this section is general and should be used with caution. Actual costs may vary by as much as 30% and is dependent on manufacturer, location, amount ordered, etc.

Miscellaneous Expenses Most mills that begin fortifying flour can expect some additional initial expenses beyond equipment and installation:  production line training  quality control  premix ordering and handling,  new package labels  marketing costs for the new product to wholesalers and major flour product producers (bakers, pasta makers, etc).

Most mills will also have recurrent costs associated with ongoing production of the improved product:  costs of premix  added production line costs related to premix addition  added costs of additional quality control tests Additional recurrent costs should be offset by small increase in product price and increased sales based on improvement to product.

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