Enhancing the phenolic profile and antioxidant potency of finger millet gruels through lactic acid fermentation and incorporation

Abstract

This study evaluated the effects of souring (fermenting using Lactobacillus plantarum and back-slopped inoculum and lactic acid acidification) and cooking of finger millet on phenolic content, radical scavenging properties, and inhibition of oxidative DNA damage in finger millet. Fermentation with Lactobacillus plantarum and back-slopped inoculum, and lactic acid acidification significantly increased the total phenolic content and radical scavenging properties of finger millet extracts, whereas cooking resulted in the reduction of these bioactive properties. Liquid chromatography–mass spectrometry (LC–MS) analysis confirmed the presence of phenolic acids, flavonoids, and proanthocyanidins in finger millet extracts. Both total phenolic acids and total flavonoids were elevated by fermentation (back-slopped inoculum and Lactobacillus plantarum inoculated) and lactic acid acidification but diminished by cooking. Notably, extracts from both unsoured and soured finger millet flour and gruel demonstrated protective properties against DNA damage. These findings suggest that souring enhances the phenolic content and antioxidant properties of finger millet, underscoring the potential of soured finger millet gruels for health promotion.