Abstract:

Mulberry juice containing a certain amount of alcohol was directly inoculated with activated acetic acid bacterial culture for the production of mulberry vinegar by acetic acid fermentation. Based on a series of one-factor-at-a-time experiments, orthogonal array designs were applied to optimize some key technological conditions for the acetic acid fermentation of mulberry juice. Alcohol concentration of 6%, shake flask agitation speed of 130 r/min, innoculum size of 15% were found optimum. Chitosan solution of 1% was selected as an optimum clarifier out of 3 single ones and its optimum amount was 1.6 mL/100 mL. As a result, a clear, transparent, light rose colored and both vinegar-flavored and mulberry-flavored fruit vinegar product was obtained.

Key words: mulberry vinegar, one-step fermentation, technological conditions, clarifier