Sensory Qualities, Antioxidant Activities, and in vitro Inhibition of Enzymes Relevant to Type-2 Diabetes by Biscuits Produced from 5 Wheat-Bambara Groundnut Flour Blends

In this study, wheat flour was replaced and/or substituted with bambara groundnut flour. Four blends were prepared by mixing the wheat flour with bambara groundnut flours in the proportions of 100:0 (WWB), 75:25 (BGFB-25), 50:50 (BGFB-50), and 0:100 (BGFB-100). These blends were then fortified with powdered orange peels (3%), for the production of biscuits. The sensory evaluation of the biscuits revealed that there was no significant difference ( p > 0.05) between all the biscuits in aroma, color, and texture, while significant difference was observed in their taste and general acceptability; with WWB ranking the highest in taste and general acceptability. Aqueous extracts of biscuits were prepared. The result revealed that biscuit extracts exhibited good antioxidant [DPPH (1,1-diphenyl-2-picrylhyrazyl) and ABTS (2,2-azinobis-3-ethylbenzo-thiazoline-6-sulfonate) radical scavenging abilities and reducing property] and enzyme (α-amylase and α-glucosidase) inhibitory properties (in vitro). The inhibitory effects on α-amylase and α-glucosidase could be attributed to the phenolic contents and antioxidant properties of the biscuit extracts; moreover, BGFB-100 showed the highest antioxidant and enzyme inhibitory properties.