Vinegar production trial from cashew apple (Anacardium occidentale) using thermotolerant Acetobacter strains with high acetic acid yield in non-optimized small scale conditions

This study aims to evaluate whether or not selected acetic bacteria strains could optimally perform fermentation at high temperature with ordinary laboratory materials without adjusting growth temperature. Vinegar production was carried out by controlled successive alcoholic and acetous fermentation in batch mode. Progress of fermentation was monitored by using various biochemical tests. Cashew apple vinegars quality was determined by sensory analysis. The selected acetic acid bacteria strains produced maximum acid after the 2nd day of acetic fermentation. The produced vinegars had an acidity of 5.34±1.07-5.86±0.07 acetic acid g/100mL, productivity 0.74±0.15-0.81±0.01 g/Lh and pH 3.15±0.09- 3.19±0.07 respectively. The end of the fermentation was noticed by a decrease in acidity that occurred after the 3rd day. Sensory evaluation rated the vinegar acceptable in terms of astringency, pungency and acidity when compared to commercial samples. Thus, the use of thermotolerant bacteria to prepare commercial-grade vinegar from cashew apple, commodities without economic value, has potential to scale up to domestic use. . Keywords: thermotolerant, acetic acid bacteria, vinegar, sensory analysis, cashew apple