Cassava starch is found to be well-adapted to various applications of starch. It has the edge over other starches in bakery because of its expansion property. Based on utilization, cassava starch (like any other starch) is classified into native, modified, hydrolysates and others (Sansavini and Verzoni, 1998). Utilization of cassava starch in food and non-food sectors is presented in Table 10.1.6.
Table 10.1.6 Food and non-food utilization of CS
Sector | Industry | Form of starch | Products
Food | Local consumption | Native | Tapioca
Food processing industries | Modified/hydrolysates | Bakery and pastry products, noodles, soups, sauces, ice creams, yoghurts, lactic drinks
―"― | ―"― | Modified | Fat substitutes for dietary products, processed meats, puddings
―"― | ―"― | hydrolysates | Color enhancer/taste enhancer, canned fruits, juices, soft drinks, marmalades, jams, alternative protein source, seasoning
Non-food sector | Paper and plywood | Modified | Cartons, papers of different quality, plywoods
―"― | Textile | Modified | Fillers, Stiffeners, leather goods
―"― | Pharmaceutical | Modified/hydrolysates | Fillers, excipients, Vitamins C and B12, antibiotics,
―"― | Chemical | Modified/hydrolysates | Glues, cements, paints, oil drilling materials, biodegradable plastics, polyesters, water treatment agents
―"― | ―"― | Hydrolysates | Soaps, detergents, bleaching agents, insecticides, explosives, cosmetics, industrial alcohols, ethanol, combustibles
―"― | Feed industry | Modified | Feed binder, protein substitutes, carbohydrate substitutes, supplements
―"― | Energy | Hydrolysates/native starch/cassava starch baggase | Biofuels
10.1.3.3 Potential Uses
Tapioca Flakes or Meal Cassava starch is being consumed in its native form at the household level in some West African countries as tapioca. Starch paste is consumed as the main meal or as an accompaniment in dishes. It is also consumed in a partially gelatinized form, also known as tapioca flakes, which is prepared by soaking in water and then cooked in water to form tapioca meal. Sugar and/or milk are added before consumption. It is consumed in many parts of West Africa and widely accepted as a convenience food (Adebowale et al., 2006). Oyewole and Obieze (1995) reported some preliminary works on the traditional processing of cassava to tapioca grits. Cassava variety and roasting methods had significant influence on the quality of the product (Adebowale et al, 2006) and the sorption isotherms of tapioca grits (Adebowale et al., 2007). Adebowale et al. (2007) reported that peak and hot paste viscosities were the principal pasting parameters for characterizing tapioca grits from different cassava varieties and roasting methods.
Sour CS Chemical and enzymatic modification of native CS through fermentation is an age-long practice in some African, Latin American and Asian countries (Srinivas, 2007). The products of such modification, which include sour starch (Latin America) (Defloor et al., 1995) and krupuk (Malaysia and Indonesia) (Howeler and Hershey, 2002), are known to possess specific property of expansion with important applications in bakery (Marcon et al., 2009). Sour CS, also known as polviho azedo in Brazil and almindon agrio in Colombia, is a gluten-free raw material use in production of cheese bread and sour CS roscas in Brazil (Marcon et al., 2009). The unusual expansion of sour starch during baking is mainly influenced by the interaction of drying and action of lactic acid (Mestres et al., 1996; Vatanasuchart et al., 2005).
Influence of drying on the degree of expansion was reported by several studies to be dependent on the method of drying; action of ultraviolet radiation in sunlight, which caused significant changes in granule structure of fermented cassava starch such as perforation of the granules; changes in the ratio amylose/amylopectin content; reduction in the polymerization of remaining amylose and amylopectin in the granules, were reported to be responsible for the most significant influence of sun-drying on cassava starch expansion (Demiate et al., 2000; Guyot and Mulon-Guyot, 2001; Mestres and Rouau, 1997). A protocol proposed by Marcon et al. (2009) showed that maximizing the expansion of sour starch dough would depend on such physico-chemical parameters as degree of polymerization, the number of carboxyl and hydroxyl groups, pH, and granule density among others. Other important factors reported to affect the expansion property of sour CS during baking includes cassava variety, genetic factors, prevailing climatic conditions during the growth and environmental conditions during fermentation (Rickard et al., 1991; Tian et al., 1991). The resulting organoleptic properties and reduction in acid were mainly driven by lactic acid (Atichokudomchai et al., 2004).
Significant improvement has been recorded in the production of sour starch through the adoption of appropriate technologies. Use of locally fabricated equipment for processing and centrifugal separators for starch extraction has contributed significantly to increased sour starch production in the producing countries. However, long fermentation periods of up to 70 days (Mestres et al., 1996), and heavy reliance on sun-drying, could be highly unpredictable and inconsistent quality standards have been identified as the major bottlenecks to large-scale commercialization of cassava sour starch production (Marder et al., 1996). It is essential to establish standard quality factors and develop effective market penetration strategies to increase utilization of the product and develop affordable technology for efficient waste management to make its production appealing on the large scale.
Controlled fermentation in a covered tank with enough water to ensure anaerobic conditions and inoculation with starter culture were recommended by Brabet et al. (1996) for reduced fermentation time. The study also recommended the use of artificial drying apparatus using UV radiation and effective starch moisture control to standardize the drying process and improve the quality of the product, which would not be at the disposition of unpredictable weather condition.
Krupuk Krupuk or keropok is another important product from Southeast Asia, which also requires expansion properties specific to cassava starch. It is a traditional cracker made from starch and protein source. Processing steps are ingredient mixing, kneading, cooking, cooling, slicing and drying (Taewee, 2011). Reports from several studies show that cassava starch remains the best for the production of krupuk due to its linear expansion capacity, which was reported by Taewee (2011) to be about 80 % of the original dough volume and final crispness of the cracker (Mohamed et al., 1989; Saeleaw and Schleining, 2010; Tongdag et al., 2008). Besides the aforementioned factors which affect sour starch, protein source and content also had a significant effect on the final quality of the product. Krupuk are usually named after the added protein source.
Fish and shrimps are the most popular sources of protein for krupuk production. However, fish is often used because the final product is cheaper and affordable and therefore enjoys higher patronage. Inclusion of fish in krupuk enhances the nutrition of the product; however, it has adverse effects on the expansion of the cracker. The higher the fish ratio in the dough formulation, the lower the expansion of the cracker (Cheow et al., 1999; Kyaw et al., 2001).