5799_SCA_Jacopo_Mistrello

BCFN Young Earth Solutions YES! The date industry: new frontiers for its sustainable development Abstract: The expansion of the date industry has brought social and economic benefits in the poor and underdeveloped realities of the producing countries; however, the uncontrolled generation of waste still poses a threat to the environment. Thus, the recycling of date seeds, the major waste material of the date processing industry, is to be considered a potential solution to promote its sustainable growth if specific applications of such material are identified. This report proposes two suitable opportunities to make efficient use of date seeds through the development of dietary fibre concentrates and antioxidant extracts. These products can offer cheaper alternatives for the growing market of functional food ingredients, and have therefore unlimited potentials and functionalities. Though, their future development and commercialization depends on the collaboration between research institutions and industries from both date producing countries and the European Union. The success of this joint effort can deliver benefits for all the actors involved, particularly in terms of enhanced profitability for date processors and creation of new job opportunities in underdeveloped areas.

Author

Jacopo Mistrello

Jacopo Mistrello (MSc Food Science)

London Metropolitan University (UK)

The date industry: new frontiers for its sustainable development 1. Introduction

The fruits of Phoenix dactylifera L., commonly known as dates, are largely produced in the hot arid regions of South West Asia and North Africa such as Egypt, Iran, Saudi Arabia, India and Pakistan (FAO, 2011). In these countries dates play essential roles in both the society and economy of local communities, serving as a staple food and often being their only source of remuneration (Baliga et al., 2011). The last decade has witnessed a steady increase in the worldwide date production passing from about 6.50 in 2000 to 7.90 million metric tons in 2009 (FAO, 2011), which in turn has promoted the industrialization of date fruits. Packed pitted dates, syrups, pastes, and juices are currently available on the international market; moreover, they can be used as substrates for fermentation processes to manufacture organic acids, bakery yeasts and ethanol (Aleid, 2011).

The expansion of date production and processing has surely brought social and economic benefits in the poor and underdeveloped realities of the producing countries.

A key element of the upgrading process is the formation of rural collection centers where farmers can be assisted by agricultural extension agents to implement agricultural practices, production yields and crop quality (Aleid, 2011). On the other hand, this growth has also led to generation and disposal of greater amounts of food waste, posing a significant threat to the environment. Therefore, further enhancements should be accompanied by the application of appropriate waste management systems aiming for example to the efficient recovery and recycling of food processing residues.

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1.1 Date seeds

Date seeds account for up to 15% of the total fruit weight and represent a major waste material of the date industry. According to recent estimates, up to 800,000 tonnes/year of seeds could enter the waste stream (Al-Farsi and Lee, 2008), having an impact on both the economy of the processors (which have to dispose them at their own expense), and the environment. Though, they offer an unexploited source of nutrients and bioactive compounds for food and non-food applications. For example, the high amounts of dietary fibre (DF) which accounts for more than 70% of the whole seed could be used in the fibre-fortification of bread and other bakery products (Bouaziz et al., 2010). Moreover, their high amounts of phenolic compounds and associated antioxidant capacity render date seeds an appealing and inexpensive raw material for production of novel, active ingredients and dietary supplements (Al-Farsi and Lee, 2008).

Nevertheless, up to now date seeds have been poorly utilized for industrial purposes, and only little attention has been dedicated to the development of methods of extraction of targeted compounds for specific applications in the food industry.

2. Further studies to support the date industry

In order to support the sustainable growth of the date processing industry, further studies are needed aiming to identify opportunities for recycling its residues and reuse them in specific industrial applications. In view of the nutritional characteristics reported in section 1.1, date seeds can be used as raw material for production of novel: 

Dietary fibre ingredients;



Antioxidant extracts.

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The procedure for obtaining DF concentrates from other food processing residues is well-established in the literature, and encompasses some basic steps such as milling, washing, removal of excess solvent, drying, and conservation (Larrauri, 1999). Tough, such method is not specific for date seeds and more in-deep investigations are necessary to assess the most efficient processing conditions. For example, blanching (water or steam) and freeze-drying were used instead of the washing and oven-drying steps, respectively (Borchani et al., 2011; Tanongkankit et al., 2010), but their efficiency in fibre recovery from date seeds has never been investigated. Thus, a new process could be developed according to the scheme reported in Figure 1 (page 4). The resulting date seed DF concentrates could offer cheaper alternatives to commercially available fibre ingredients which are massively used as ingredient substituents in reduced-calories foods, and technological aids in highly processed food products (Rodriguez et al., 2006).

Relatively more difficult is the elaboration of standardized methods of extraction and purification of antioxidant extracts. This is due to several factors that can affect the antioxidant capacity of plant products including the variability of bioactive compounds, their different mechanisms of action and efficiency, polarity, and degradation kinetics.

Nonetheless, dietary antioxidants are generally soluble in polar solvents and commonly extracted in aqueous mixtures of ethanol, methanol or acetone (Al-Farsi and Lee, 2008). Although a simple solvent-extraction is more often used, emerging technologies including supercritical fluid, subcritical fluid, microwave-, and ultrasound-assisted extractions may be more efficient for such purpose (Galanakis, 2012). Date seed extracts presenting high antioxidant capacity have unlimited potentials in the modern industry. They could in fact be used as alternatively natural preservatives in food and cosmetic formulations, dietary supplements and nutraceuticals.

Those reported are just a few examples on how to potentially reuse date seeds as secondary raw material for production of food and non-food ingredients. However, their future development and commercialization depends on the setup of collaborations between research institutions and industries from both the producing countries and the 3|Page

European Union. The successful outcome of this joint effort can not only strengthen the scientific relationship between low-income and developed countries but also promote the recycling of other waste materials such as cereal brands, eventually leading to more eco-friendly processing.

Date seeds (processing residue)

Grinding

Blanching (hot water or steam)

Cooling to room temperature with cold water

Removal of excess solvent (by centrifugation or pressing)

Freeze-drying

Dietary fibre concentrates

Figure 1. DF concentrates from date seeds: a new procedure.

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4. Conclusions

As this report shows, date seeds offer a wide range of potentialities that should be taken into account in the modern industry. The large availability at relatively low cost is surely the main advantage of recycling this material; however such procedure could also: 

Implement the sustainable growth of the date processing industry by reducing the associated environmental pollution;



Enhance the profitability of date processors and create new job opportunities in low-income countries;



Create scientific collaboration and dialogue between developing and developed countries.

In addition, the commercialization of DF concentrates and antioxidant extracts from date seeds can offer new, functional, and cheap ingredients to the current food industry with unlimited potentials and functionalities.

Number of words: 992 (Figure 1 and reference list not included).

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References Aleid, S.M. (2011). Industrial Biotechnology: Date Palm Fruit Applications. In: Jain, S.M., Al-Khayri, J.M. and Johnson, D.V. Date Palm Biotechnology. London: Springer Science + Business Media, pp 675-709.

Al-Farsi, M.A. and Lee, C.Y. (2008). Optimization of phenolics and dietary fibre extraction from date seeds. Food Chemistry, 108, 977-985.

Baliga, M.S., Baliga, B.R.V., Kandathi, S.M., Bath, H.P. and Vayalil, P.K. (2011). A review of the chemistry and pharmacology of the date fruits (Pheonix dactylifera L.).

Food Research International, 44, 1812-1822.

Borchani, C., Besbes, S., Masmoudi, M., Blecker, C. and Paquot, M. (2011). Effect of drying methods on physico-chemical and antioxidant properties of date fibre concentrates. Food Chemistry, 125, 1194-1201.

Bouaziz, M.A., Amara, W.B., Attia, H., Blecker, C. and Besbes, S. (2010). Effect of the addition of defatted date seeds on wheat dough performance and bread quality. Journal of Texture Studies, 41, 511-531.

Food and Agriculture Organization of the United Nations (FAO) (2011). Statistical Database. Available at: http://faostat.fao.org/default.aspx. [Accessed: 7 May 2012].

Galanakis, C.M. (2012). Recovery of high added-value components from food wastes: conventional, emerging technologies and commercialized applications. Trends in Food Science and Technology. Article in press.

Larrauri, J.A. (1999). New approaches in the preparation of high dietary fibre powders from fruit by-products. Trends in Food Science and Technology, 10, 3-8.

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Rodriguez, R., Jimenez, A., Fernandez-Bolanos, J., Guillen, R. and Heredia, A. (2006).

Dietary fibre from vegetable products as source of functional ingredients. Trends in Food Science and Technology, 17, 3-15.

Tanongkankit, Y., Naphaporn, C. and Devahastin, S. (2010). Effect of processing on antioxidants and their activity in dietary fiber powder from cabbage outer leaves. Drying Technology, 28, 1063-1071.

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