Statistical and Biochemical Optimization of Acetic Fermentation for Vinegar Production

Abstract

This study aims to optimize the acetic fermentation process for vinegar production using three strains of acetic bacteria including KS1, KS2, KS3 by combining two approaches, statistical and biochemical. The results obtained with the BBD experiences led to the determination of the optimal values of the key fermentation parameters for each of the isolates. Maximum acidity was obtained at fermentation temperature, initial ethanol and acetic acid concentrations respectively of 37.5˚C, 20% (v/v), 2% (w/v) for KS1; 45˚C, 20% (v/v), 1 (w/v) for KS2 and 45˚C, 5% (v/v), 1 (w/v) for KS3. The addition of CaCl 2 in optimal quantities has improved the acetic fermentation process, giving acetic acid bacteria better resistance to stress conditions, resulting in a considerable increase in biomass and acetic acid yield, with a maximum degree of 15.45 for KS2 and 15.30 for KS1. However, unlike previous isolates, the addition of CaCl 2 to the concentrations tested in this study have antagonistic effects on acetic acid production involving KS3, the degree of acetic acid therefore decreasing with increasing concentration of CaCl 2 . The combination of the two optimizations, statistical and biochemical resulted in a considerable increase in the yield of acetic acid produced: with an increase of 525.77% for KS1; 504.90% for KS2 and 310.27% for KS3.