Development of fermented beverage using corn silk and mulberry leaf extracts

Abstract

The qualitative changes of the fermented beverage prepared from corn silk (Zea mays L.) and mulberry leaf (Morus alba) extracts were investigated. The thickness of cellulose was 7.17-8.30 mm after 15 days of fermentation. Moreover, the pH significantly decreased to 3.68-3.93 (p<0.05) and the total acidity increased significantly to 3.41-3.77% (p<0.05), indicating Gluconacetobacter xylinus fermentation activity. The total flavonoid and phenol contents were 37.42-164.65 μg/mL and 138.67-620.17 μg/mL, respectively. The DPPH and ABTS radical scavenging and reducing powers were 23.87-69.39%, 59.92-75.68% and 27.27-82.33%, respectively. Corn silk showed antimicrobial activity for all test strains, especially Acinetobacter calcoaceticus, Bacillus coagulans and Escherichia coli. In addition, although antidiabetic activity of the fermented beverage (22.51-33.66%) was lower than that of acarbose control, the fermented beverage may prove to be a natural alternative. There was no observable synergy between the active ingredients in the beverage. Further, mulberry leaf had a significantly higher contribution to the total flavonoid and phenol contents, as well as the antioxidant, antidiabetic, and antimicrobial activities, compared to corn silk. The results of the study confirmed the functional characteristics of the novel fermented beverage. Further evaluation is needed for the analysis of sensory characteristics of the novel fermented beverage.