Effect of Enhanced Fermentation on the Antioxidant, Proximate and Shelf Life Properties of Kunu

Abstract

The significance of antioxidants to human health cannot be overemphasized, owing to the brilliant advances in understanding the mechanisms of their reaction with free radicals to reduce the likelihood of disease manifestation. The effect of enhanced fermentation with species of Lactobacillus (L. reuteri, L. plantarum and L. acidophilus) on the antioxidant potentials, shelf life and nutrient composition of Kunu, a widely accepted and enjoyed local beverage in Nigeria made from millet, was investigated in this study. Proximate analysis (using the AOAC assay methods), spoilage bacterial density (aerobic colony forming unit assay) and the antioxidant potential (H 2 O 2 scavenging assay) of Kunu produced through enhanced fermentation with Lactobacillus species were determined. At the 5 th day of storage, the microbial abundance of Kunu made through natural and enhanced fermentation were 570 × 10 5 and 410 × 10 5 CFU/mL respectively. Proximate compositions (fat, total solid, acidity and crude protein) were higher in Kunu fermented with Lactobacillus species, with crude protein having the highest recorded difference (0.77%) when compared to samples produced through natural fermentation. Kunu samples (made from millet) appeared to generally possess better antioxidant activities when compared to ascorbic acid standard. At 10% stock dilution, linear regression plot revealed H 2 O 2 inhibition by ascorbic acid, Kunu with natural and enhanced fermentation as 58, 73 and 80% respectively. It is therefore suggestive (from the results) that the improvement of nutrient qualities, shelf life properties and antioxidant potentials of Kunu could be achieved through enhanced fermentation of processed millet with species of Lactobacillus.