Effects of fermentation period and soybean flour supplementation on the glycemic indices and starch digestibility of biofortified provitamin A cassava meal

Abstract

Background/Aim: Across the globe, the prevalence of diabetes mellitus is rapidly increasing even in populations with significant undernutrition. In this study, the effect of fermentation period and soybean flour supplementation on the glycemic indices and starch digestibility of biofortified provitamin A cassava meal was investigated.
Method: Biofortified provitamin A cassava (TMS 011368) was processed into cassava meal under different fermentation periods (24 and 72 hrs) and supplemented with soybean flour at 0-80% to produce different composite meals. The composite meals were evaluated for its predicted glycemic index (pGI) and in-vitro starch digestibility.
Results: Soybean supplementation significantly (p<0.05) decreased the hydrolysis index and pGI of the samples from 68.15-47.28% and 73.20-44.56% for composite meals fermented for 24 and 72 hrs, respectively. pGI, digestible starch, and resistant starch contents was significantly (p<0.05) higher in composite meals fermented for 72 hrs than for 24 hrs fermentation. Increase in soybean supplementation significantly (p<0.05) decreased the resistant starch, and digestible starch contents of the samples.
Conclusion: Composite meals supplemented with 40-80% soybean flour and fermented for 24 hrs had reduced rate of invitro starch hydrolysis and glycemic indices, which may therefore be better suited in dietary prevention and management of diabetes milletus.