Heat-moisture treated, oxidized and acetylated taro starches are more soluble, while cross-linked taro starch are less soluble as compared to raw taro starch (Alam and Hasnain, 2009). All these modified starches have greater swelling capacity and solubility at pH 2.0 and 10.0. Optimization of chemical synthesis of hydroxypropyl starch from two native starch sources, corn and taro, exhibits final optimum conditions for taro starch as 30 % sodium sulfate, 40 % starch slurry and 5.6 % propylene oxide concentrations. The highest value of swelling power for hydroxypropyl taro starch is 62.33, which may further be increased depending upon the conditions (Chattopadhyay et al., 2015).
9.1.7.6 Applications
Taro starch is known to have high leaching and swelling abilities when cooked like non-conventional starches (sago and tapioca). This ability allows the application of both starches (sago and tapioca) in an expanded snack product made of starch-protein mixture. The range of food products employing taro starch in one form or another can almost be without limit. But the utility of taro starch is almost entirely based upon the natural or synthesized functional characteristics. Taro starch is considered to be easily digestible, hence it can be widely used in baby foods and the diets of people allergic to cereals and children sensitive to milk.
Taro starch can be used in tomato ketchup (Sit et al., 2014). The colour of the ketchup is not affected by incorporation of starch up to 2 % concentration and is rated better than the control sample and is comparable to the ketchup prepared using maize starch. Taro starch has the potential to be used in hot extruded snacks, chips, pretzels, fried foods and ready-to-eat cereals. Snacks from rice, corn and taro starch, at 141,150 and 159 °C, showed increasing expansion, decreasing density and decreasing breaking force (Bhattacharrya et al., 2006). The extrusion process parameter, such as the barrel temperature, greatly affects the texture, starch digestible characteristics and surface morphology of extrudates prepared from taro, rice and corn starch.
Because of its small granular size, taro starch has been considered a good filling agent for biodegradable polyethylene film (Lim et al., 1992) and as a fat substitute. Chemically-modified taro starch can be used as food additives in a broad range of applications such as thickening, bulking, stabilizing and gelling agents.
The small size of granules in taro starch makes it ideal in cosmetic formulations like face powder and in dusting preparations that use aerosol dispensing systems. Taro starch can also find potential applications in noodles, bakery foods, snack foods (Wan-jekeche and Keya, 1995), confectionery products (Suzuki, 1978), the textile industry (Radley, 1976) and alcohol and brewing industries (Wanjekeche and Keya, 1995).
9.1.7.7 Future Aspects
Taro’s digestibility, because of small starch grains and its hypoallergenic qualities, make it a unique product. Industries can draw nutritional advantage of taro flour and can use it as an alternative or supplement to cereal flours. The major products from taro can be flour, starch, achu, chips, cookies, noodles, etc. Lack of mechanization and awareness of the people regarding benefits provided by taro and various processing problems need to be resolved so as to promote this under-utilized tuber on the global platform. The standardized methods for different products need to be experimented on and exploited on a commercial scale. And, if required, modifications in the method can be explored. The uniform global standards for the different products from taro should also be focused.
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