Modelling of in vitro starch digestion kinetics and α-amylase inhibition of novel soup mix as a functional food

Abstract

Solanum nigrum (SN) is an underutilised food crop, rich in polyphenols, antioxidants and other functional bioactive components. In this study, the formulated functional soup mix of SN leaves evaluated the α-amylase inhibition activity and also studied the amylase inhibition during in vitro-digestion process of the soup and in simulated assimilation. The soup mix was also studied and compared with standard cornstarch for in vitro starch digestion kinetics for 3 h at 15 min intervals and the respective hydrolysis index and predictive glycemic index were also determined to identify whether the soup was diabetic-friendly for consumption. It was found that the α-amylase inhibition rate of SN leaf (100 mg/mL) was 84.46% and the soup mix (100 mg/mL) was 97.95% and their respective IC50 were, 21.65 and 7.68 mg/mL respectively. On in vitro digestion, it was found that the amylase inhibition increased in the supernatant of later stages of digestion and residual digestate had very less levels at the end of the intestinal phase. On the in vitro starch digestion kinetics, it was observed that the soup mix was having around 39.72% starch hydrolysis rate, 52.29 hydrolysis index and 53.27 glycemic index, making it a low glycemic food with a low glycemic response, thus diabetic-friendly.