Flour Blend Optimization

Getting Flour Blend OPTIMIZATION RIGHT

Key factors to consider when producing breadmaking flour

Wheat prices have been on an upward trend in recent years largely due to the RussoUkrainian war which has disrupted exports from both Russia and Ukraine, two of the most important wheat exporters in the world accounting for more than a quarter of the world’s total wheat supply.

East Africa has been heavily impacted by the war as the region largely depends on wheat from these two countries. Argentina, another major supplier of wheat to the region, had a terrible 2021/22 season due to a prolonged wet season that impacted both the quality and quantity of wheat. Even Australia, another source country, was adversely impacted by a prolonged dry season, meaning it had less wheat for exports. With diminished supply, millers in the region have had to contend with highly-priced wheat that is of unreliable quality.

During the just concluded milling and bakery workshop by Ait Ingredients in Nairobi, Kenya, Joy Mwangi, a senior laboratory technician at AIT East Africa made an interesting observation. She noted that despite the changes in wheat grain prices worldwide, consumers have been experiencing increases of only 10-20% from millers and 5-10% from bakers. “These slight increases are not significant to the price increases in the wheat grain. This is a big concern because either the millers or the bakers are making losses and not maximizing their profitability,” Joy comments.

Millers however don’t have to sacrifice margins in a push to shield their clients from the high cost of wheat prices. Joy notes that optimizing the wheat blending process could be all the millers need to take back control of the final quality and cost of their products. This article explores the key decision-making criteria that millers must consider when optimizing their wheat blending processes to achieve the highest quality of flour for a particular purpose at the least cost possible.

INFORMED WHEAT SOURCING

Getting the flour blending right starts with sourcing. Before sourcing, the miller must first consider the intended use of the flour. Different wheat products such as bread, pastries, and cakes require flours of different specifications which are primarily influenced by the composition of the initial grain. Getting wheat grain that is optimally suited for the final wheat product helps enhance the efficiency of the milling process, saves on costs, and ensures customers get consistent high-quality flour for their desired purposes.

With the desired type of wheat in mind, Joy sourcing the desired quality of wheat can be quite challenging. “In the last few months, we have been experiencing deviations in the quality of the product we anticipate to receive. Sometimes, we order wheat of 13.5% protein and instead receive wheat of 12.5% protein,” Joy explains. To avoid such undesired eventualities, Joy advises millers to identify and only source their wheat from trusted and reliable traders. This ensures that you always receive wheat as per the specifications which they had informed you of prior to purchase.

For example, if they tell you that this wheat is coming at 13.5% protein content that is what you are receiving. If the foreign matter in the wheat is less than 5%, that is exactly what you will receive when the consignment arrives at your factory premises. Dealing with unreliable trader exposes you to receiving wheat whose quality is uncertain and might force you to incur extra costs in cleaning the wheat to remove excess foreign matter or in blending wheat to achieve the desired quality of wheat.

Lastly, when it comes to wheat sourcing, timing is of utmost importance. “If you source when the prices are low, you are able to be more competitive in the market but if you start sourcing when the prices have shot up it eats into your profitability,” Joy advises. Knowledge of the country of origin, planting season, harvesting time, and production outlook comes in handy when it comes to timing.

For instance, if the source country was forecast to have a bumper harvest and the harvest season is at its peak, millers can anticipate favorable prices and plan to buy early on before prices start to spike. Conversely, it the wheat outlook is grim, millers can anticipate higher wheat prices and plan to look for other alternative sources where prices are competitive.

GRISTING

Wheat is categorized as hard, semi-hard, or soft wheat depending on its protein content with hard wheats having the highest protein content levels of between 13.5 to 15% and soft wheat having the lowest protein content (8.5 to 10.5%. As wheat pricing is based on protein content, hard wheat, which is used in making bread, buns, and pasta products, is often expensively priced compared to soft wheat.

To keep raw material costs at a minimum, millers often blend soft and hard wheat. Blending, otherwise known as gristing, in the milling industry also allows millers to maintain consistency in the quality of their final flour despite receiving wheat of varying protein specifications. Additionally, blending allows millers to develop unique products that give them a competitive edge in the market.

To optimize the gristing process, Joy notes that knowing the quality of the wheat that comes to the factory is important as it helps inform the level of blending required to achieve the desired grain for milling. As mentioned before, during wheat sourcing, millers can get quality deviations in the wheat they receive, getting consignments with a low protein content that call for blending with wheat of higher quality.

The second factor that is critical in the blending process is the quality of the desired product. Different end products beg for different compositions of the raw materials, thereby informing the process of wheat blending at different levels. For example, flour that is needed for bread making will have a different constitution from flour needed for pastries and cakes.

Also when customer requirements demand that their flours have a certain percentage of protein, it is up to millers to work on solutions that ensure the customers get the desired quality while maintaining the profitability of the business as well.

Lastly, the need to minimize the cost of raw materials influences blending decisions. Gristing allows millers to minimize costs, maximizing the use of the cheaper soft wheat varieties and using minimal levels of the costly hard wheat while ensuring that there is no compromise to the quality of the resultant flour.

“You need to know your gristing costs. You ought to know the individual costs of every variety of wheat,” Joy Mwangi insists. For example, if soft wheat goes for 45ksh/kg and hard wheat goes for 65ksh/kg, blending involving the use of a small percentage of the hard wheat and more of the soft wheat cuts down the total gristing cost to maximize profitability. Owing to the higher prices of acquiring hard wheat, millers should aim at saving as much of their hard wheat supplies as they can, and utilize soft wheat maximally.

This optimization is especially important because of the price volatility of wheat, which primarily affects hard wheat varieties. According to Joy, “if you can go as far as utilizing 90% of soft wheat and 10% of hard wheat, that would be quite impressive and cost-saving.” Moreover, saving these hard wheat shields millers if they receive future consignments of lower-quality wheat.

FLOUR CORRECTION

Sometimes, even after the gristing process, millers may fail to achieve the desired quality of their wheat. This is because, apart from the protein, wheat is also comprised of other components including starch, non-starchy polysaccharides, lipids, inorganic components, and trace elements which all affect how flour behaves when subjected to a baking process. These components are mostly adjusted to the desired level through a process called flour correction.

With flour correction, millers can always have a standard flour released to market despite the quality of wheat they receive varying from one batch to another. Moreover, flour correction provides millers with a competitive edge when it comes to product differentiation. “With flour blending and wheat sourcing, every other miller is doing the same thing as you. What will define you differently are the flour correctors. We come to you, analyze the quality of your flour, and develop a customized product for your needs,” Joy advises.

During flour correction, an optimization tool, such as the one offered by AIT Ingredients is used to determine the levels of the various wheat components. The rapid test saves millers time that they would have spent conducting rheology tests and gives an accurate picture of the levels of each wheat component which they can then improve using flour correctors to their desired level.

With flour correction, even the protein content in the flour can be improved. This allows millers to use a greater amount of soft wheat in their operations. “We complement the quality of soft wheat with flour correctors,” Joy commented, explaining that with flour correction, it is possible to save 5-25% in the cost of acquiring raw materials.

ENZYMES AND THEIR ACTIONS

When it comes to flour correction, enzymes are preferred as they only alter the specific component of the grain desired by the miller. They are also generally regarded as safe as they get denatured at temperatures higher than 40℃ and therefore do not persist in the final consumer product.

When used in flour correction, enzymes correct the baking performance of flour. They also optimize the technological process parameters to attain the needed dough properties. They also ensure the quality of baked products and allow the production of specialty flours.

Enzymatic correctors at the milling level include amylases, proteases, lipases, hemicellulases, and oxidases. Amylases act on starch, breaking it into simple sugars on which the yeast acts during the fermentation process. This positively CO2 production fermentation leading to production of baked goods with the desired volume.

Amylases also contribute to the shelf-life of baked products. This is because the breakdown of starches allows for more water uptake which makes baked products to stay fresh longer. Moreover, these enzymes contribute to the brown color of baked products as a result of caramelization and Maillard reactions with amino acids during baking.

On the other hand, hemicellulases act on non-starchy polysaccharides, breaking down fiber into simple sugars. Therefore, similar to amylases, they impact the volume, improve machinability, and prevent dough stiffening. They also contribute to the fine texture of baked products.

Proteases break down the protein strands of the gluten skeleton, reducing dough resistance, shortening dough resting time and enhancing flavor and browning. Proteases are especially applicable in biscuit and cookie production because they promote extensibility, preventing biscuits from cracking and enhancing their flavor and color.

Similarly, lipases act on lipids in wheat flour and act as emulsifiers. They enhance Fermentation tolerance by promoting gas retention during fermentation. They also promote dough stability during processing and also have enhance crumb softness, thus increasing shelf life. They also bleach flour pigments, resulting in a brighter crumb that is firm as well.

Another important group of enzymes is the oxidases. These correctors strengthen the s-s bonds in the protein network of the dough, thus strengthening the gluten. These are important correctors when millers get soft wheat, with a low gluten index. The resultant effect is that they improve the tolerance of dough to fermentation, which also supports volume in baked products. They also enhance the crispiness of the crust in baked products.

Bakers also have a chance of improving their flour if millers failed in the gristing or flour correction stages. When it comes to flour improvement, non-enzymatic correctors such as ascorbic acid and active soy flour are used. Ascorbic acid improves dough tolerance to fermentation by strengthening the ss bonds in the protein network and improving machinability. This enhances the volume of baked products and improves crust crispiness.

Active soy flour, on the other hand, promotes dough stability and creates a brighter crumb in baked products. Additionally, using gluten boosters and replacers allows for gluten strengthening in soft wheat, helping millers reduce the cost of raw materials. These replacers promote gas retention and dough stabilization, impacting the volume of baked products. This way, millers can optimize their flour blends by easily utilizing a lot of soft wheat in breadmaking.

Another improver is cysteine, which also acts on the ss bonds in the protein network of wheat flour, weakening the strands to promote extensibility. This also reduces kneading time and makes it easier to handle dough during processing. Other improvers include lecithin and fatty acids (mono and diglycerides), and both are emulsifiers. They lead to fine crumb development, softness, and thus increased shelf life.

A parting shot for millers is that Flour correction is an intricate process that requires customization. There is no one size fits all solution for flour blend optimization as characteristics of wheat grains vary from one batch to another. Millers must therefore understand their wheat profile and determine the desired output profile before deciding on which flour correctors to use in their blend optimization. Talking to flour improvement experts before embarking on a flour blending exercise could be the difference between consistently satisfying customer demands and always responding to customer complaints about poor-quality flour.

TALKING TO FLOUR IMPROVEMENT EXPERTS BEFORE EMBARKING ON A FLOUR BLENDING EXERCISE COULD BE THE DIFFERENCE BETWEEN CONSISTENTLY SATISFYING CUSTOMER DEMANDS AND ALWAYS RESPONDING TO CUSTOMER COMPLAINTS.