Effect of natural hydrocolloids addition on the physicochemical, antioxidant, and digestive-enzyme-inhibitory properties of Sorghum bicolor flour

Abstract

Studies have shown that adding modified food hydrocolloids as gluten replacement in gluten-free products could be associated with an increase in cost of production and loss of some health-benefitting qualities. In this study, the effects of adding two natural hydrocolloid sources— Brachystegia eurycoma (BE) and Detarium microcarpum (DM)—and a modified hydrocolloid, sodium carboxymethyl cellulose (SCMC), on the physicochemical, antioxidant, and digestive- enzyme-inhibitory properties (including pancreatic lipase, α-amylase, and α-glucosidase) of Sorghum bicolor (SB) flour were evaluated. Each of BE, DM and SCMC was blended with SB at 2 and 4% proportions. The blends’ peak and final viscosities increased, while their starch content decreased significantly with an increasing BE and DM addition. Blends of SB with either BE or DM had higher polyphenolics (total phenol, tannins, and total flavonoids) levels, and stronger antioxidant and digestive-enzyme-inhibitory activities than the blend of SB with SCMC. Among the blends, SB+BE had the highest polyphenolics level and the most potent antioxidant and digestive-enzyme-inhibitory capacity. The blends’ pasting attributes were significantly correlated with the polyphenolic’s levels. The blends’ polyphenolics levels were also correlated with their antioxidant and digestive-enzyme- inhibitory capacities. Hence, blending SB with either BE or DM may be a low-cost approach for developing a gluten-free flour, while retaining its antioxidant and digestive-enzyme-inhibitory qualities.