Influence of Chemical Modification on Some Properties of Starches from Tiger Nut (Cyperus esculentus) and Cocoyam (Xanthosoma sagittifolium) as a Potential Biomaterial
Abstract: Starch is known to be the principal carbohydrate constituent of many plant materials and this necessitate a detailed investigation to understand better its biochemical and functional characteristics because they are used by the food, paper, chemical, pharmaceutical, textile and other industries. In this study, starches were extracted from cocoyam and tiger nut using standard methods and were modified by oxidation, acetylation and pre-gelatinization and evaluated for chemical, functional, pasting properties and colour. The result shows that pre-gelatinization significantly (p<0.05) increases the solubility, viscosity and paste clarity of tigernut and cocoyam starches by 12.5 and 10.33%, 1065 and 2188.33 CP, 16.31% T and 23.33%T, respectively. Modification significantly (p<0.05) increases the water holding capacity of tigernut by 2.00% (acetylation), dual modification (1.77%), oxidized starch (1.55%). The water holding capacity of both the dual and modified tiger nut starches had no significant difference (p<0.05). Pre-gelatinization improves the swelling and solubility properties of cocoyam starch which was required in baking industry and also improved the viscosity which is useful in adhesive industries where high viscosity is required. Dual modified tigernut and cocoyam had high OAC of 0.75 and 1.07%, respectively, which was of great importance as fat acts as flavor retainer and increases the mouth feel of food. In this report, it shows that pregelatinized starch possessed the highest L* value (108.34) and the lowest chrome C* value (12.44), therefore it is desirable to meet consumer’s preference. From these results concluded that the undesirable properties in native cocoyam and tigernut starches could be overcome through the use dual-modification and pregelatinization.
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O.P. Olatidoye, D.A. Adenoye and B.J. Idemudia 2019. Influence of Chemical Modification on Some Properties of Starches from Tiger Nut (Cyperus esculentus) and Cocoyam (Xanthosoma sagittifolium) as a Potential Biomaterial. International Research Journal of Biological Sciences, 1: 13-24