Physicochemical properties and antioxidant activity of banana vinegar produced using one-stage and two-stage fermentation

Abstract

Fruit and vegetable waste has been widely utilized as a low-cost natural source for vinegar production. In this study, the pulp of banana (Musa acuminata ‘Gros Michel’) cv. ‘Hom Thong’ was utilized to produce vinegar using one-stage (acetous) and two-stage (alcoholic and acetous) fermentation and the obtained vinegars were assessed for their physicochemical properties, antioxidant activities and polyphenolic contents. It was found that the one-stage fermentation yielded greater levels of acetic acid (5.83% volume per volume; v/v) than two-stage fermentation (5.13% v/v). The 2,2-diphenyl-1-picrylhydrazyl hydrate and ferric reducing/antioxidant power assays, respectively, indicated that the antioxidant activity of the one-stage fermented vinegars (80.27% and 1274 μM Fe(II)/L) was greater than that of the two-stage fermented vinegars (73.20%, 1001 μM Fe(II)/L). In a similar manner, the polyphenolic content of the one-stage fermented vinegars (92.67 μg/mL) was higher than that of the two-stage fermented vinegars (68.01 μg/mL). The color parameters (L*, a*, b*) only showed significant differences in a* for the color change of the vinegars aged during days 0–100 for the one- and two-stage fermented vinegars. Moreover, it was observed that the one-stage fermented vinegars had higher levels of acetic acid, antioxidant activity and polyphenolics contents than the two-stage fermented vinegars. The results suggested that the use of banana pulp to produce vinegar via one-stage fermentation is a good choice to retain the bioactive compounds.