Technological and functional properties of exopolysaccharides produced by Weissella confusa strains isolated from kunu-zaki - A cereal-based Nigerian fermented beverage

Abstract

Exopolysaccharides (EPS) are gaining attention as natural additives in foods, pharmaceuticals, and cosmetics. However, limited research exists on EPS from lactic acid bacteria in traditional Nigerian fermented beverages like kunu-zaki. This study characterized the technological and functional properties of EPS produced by Weissella confusa YKDIA1 and YKDIA4 isolated from kunu-zaki. Antioxidant activities were assessed using ABTS⁺, FRAP, total antioxidant capacity (TAC), and DPPH assays, while hypoglycemic potential was evaluated through α-amylase and α-glucosidase inhibition. The results revealed significant antioxidant activities for YKDIA1-EPS and YKDIA4-EPS, including ABTS⁺ (1.61 ± 0.16 mg/ml), FRAP (10.74 ± 0.36 mg AAE/g), TAC (44.19 ± 0.54 mg AAE/g), and DPPH (0.77 ± 0.04 mg/ml). YKDIA4-EPS showed superior inhibitory effects on α-amylase (0.97 ± 0.02 mg/ml) and α-glucosidase (1.25 ± 0.04 mg/ml). Both EPS exhibit antioxidative and antidiabetic activities, suggesting their potential for nutraceutical formulation. Additionally, they possess valuable physical and bioactive properties suitable for various applications. EPS from W. confusa YKDIA1 and YKDIA4 could replace synthetic antioxidants like butylated hydroxytoluene and butylated hydroxyanisole in food, cosmetic, and therapeutic products, providing a safer, natural alternative.