Morphology, Rheology and Functional Properties of Starch from Cassava, Sweet Potato and Cocoyam

Abstract

Aims: To produce starch from cassava variety varieties (30572, 419, and umu 37), sweet potato root (x-igbariam), cocoyam (edeuhie and NXS003). To study and compare their functional, pasting and micro-structural properties. Study Design: Multifactor randomized complete block design (RCBD) was used for this study.  Each experiment was repeated in duplicate. Data obtained were subjected to analysis of variance (ANOVA) at the significant level of 5% (p≤.05) using SPSS 20. Place and Duration of Study: Department of food science and technology, Michael Okpara University of Agriculture, Umudike, between May 2016 and October 2016. Methodology: A Total of 6 (six) starch samples were produced from cassava variety varieties (30572, 419, and umu 37), sweet potato root (x-igbariam), cocoyam (edeuhie and NXS003). The starch samples were analyzed for functional, pasting and micro-structural properties. Results: The starch from different tuber crops analysed showed different functional, pasting and micro-structural properties. At p≤.05 significant level, Pasting temperature was highest in cocoyam starch sample (ede) while cassava starch sample 419 was the lowest. Peak, trough and breakdown result was highest in sweet potato starch while peak was lowest in Cocoyam starch sample. Solubility was highest in cocoyam (Ede) and lowest in cassava sample 419. The microscopic picture of starches showed spherical shape for all granules with cocoyam starch having smooth, fine and regular circle shape. Cassava starch sample 30572 was highest in granular size while 419 recorded lowest granular size. Conclusion: Starch from different plants and varieties significantly differ in their functional, pasting and micro-structural properties. Different starch products require different physiological properties and when starch source is rightfully selected; different starch source shows optimum functionalities in specific product.