Liquid fermentation technology and antioxidant activity of honeycomb vinegar

Honeycomb was used as raw material in the liquid fermentation of vinegar for the first time in this paper. The fermentation process was optimized and the optimum conditions was obtained:5.33% of initial sugar degree, 0.10% of yeast activated liquid, 5.0% of alcohol degree, 35℃ of acetate fermentation temperature. Under the conditions, compared to solid-state fermentation the honeycomb vinegar was lower in soluble solids, total sugar, aroma, taste, but was higher in color, posture, flavor typicality. These results could be attributed to the single materials and strain in liquid fermentation of honeycomb vinegar. Moreover, DPPH radical scavenging activity (33.29%) and total antioxidant capacity (2252.63mmol·g-1) of the honeycomb vinegar by liquid fermentation were significantly lower than that of solid-state fermentation (66.25%, 5092.63mmol·g-1) , due to the lower content of flavonoids and polyphenol (0.38%, 1.20%) compared to solid-state fermentation (0.71%, 2.33%) .