Biotechnology can help find ways to utilize surplus dates as raw materials for the production of value-added products such as medical and industrial ethanol, bakery yeast, single-cell protein as a fodder yeast, citric acid, date flavored probiotic fermented dairy products, etc. Date juice is one of the richest foodstuffs in neutral compounds such as monosaccharides, disaccharide, mineral salts and vitamins. These substances are considered essential elements for the growth of microorganisms, especially yeasts. Another product that could be produced from date is bakery yeast. Claims are made that there are no technological constraints in using date extract for bakery yeast production. Dates are a good potential substrate for single-cell protein (SCP) production due to their sugar content. SCP can be used in animal feed without problems including for cattle, fish, poultry and rabbits. Dates present a good vehicle to transport probiotics both for their micro-architecture and for the presence of nutrients. Dates contain some micronutrients such as vitamins and minerals which might enhance the growth of microbial flora in probiotic dairy products. Addition of date syrup to probiotic yogurt enhanced the bifidobacterial count of the product. There is an increasing concern about the loss of economic value resulting from the large surplus of dates. This indicates the urgent need for biotechnology to expand and diversify the manufacture of date products.
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IntroductionDates can be utilized as a substrate for fermentation processes to manufacture different products such as alcohol, bakery yeast, organic acids, antibiotics and others. Date palm fruits are found to contain carbohydrates (44-88%), fats (0.2-0.4%), protein (2.3-5.6%), fiber (6.4-11.5%), minerals and vitamins (Al-Shahib and Marshall 2003). Carbohydrates in dates are mostly in the form of fructose and glucose, which are easily absorbed by the human body (Al-Farsi et al. 2005). Interestingly, dates contain higher concentrations of protein as compared to other major cultivated fruits such as apples, oranges, bananas and grapes (containing 0.3%, 0.7%, 1.0% and 1.0% protein, respectively) (Al-Showiman 1998). Twentythree different amino acids are found in date protein, many of which are not contained in the most popular fruits. Several studies in the literature concluded that the aqueous extracts of dates have potent antioxidant and antimutagenic activity (Mansouri et al. 2005;Mohamed and Al-Okabi 2004). Dates are reported to have the second highest antioxidant activity among fruits commonly consumed in China (Guo et al. 2003). Al-Farsi et al. (2005) found that dates are a high source of antioxidants, anthocyanins, carotenoids and phenols. Antioxidants have received increased attention by nutritionists and medical researchers for their potential effects in the prevention of chronic and degenerative diseases such as cancer, cardiovascular diseases and to slow aging (Kaur and Kapoor 2001;Young and Woodside 2001). The most effective antioxidants in this r...