Optimization of Submerged Batch Fermented Coconut Water Vinegar Production Process

H. K. Vidulani Shanika, M.A. Jagath Wansapala

Abstract: Vinegar is a condiment made from various sugary and starchy materials by alcoholic and subsequent acetic fermentation. The present study was aimed to improve the efficiency of coconut water vinegar production process by reducing the fermentation time, along with identifying the product conformity to SLS 1681999-Specification for Coconut Vinegar. Optimum conditions for ethanol fermentation was investigated by Taguchis factorial design with L8 orthogonal array. The optimum inoculum type, pH, Total soluble solids, and concentration of nutrient respectively was brewers yeast, 4.97 (natural pH of coconut water), 16o brix and 1 % w/w yeast nutrient for the highest yield of ethanol (8.280.029 % m/V). This optimum treatment combination was proceeding for next levels of acetic acid fermentation 20 % w/w 11 ratio of coconut water mother (solid scum) and liquid culture (unpasteurized coconut water vinegar) was most efficient in producing acetic acid (within 10 days 4.020.21 % m/V total acidity as acetic acid) in submerged batch fermented condition compare to other two inoculums (20 % w/w liquid culture and 20 % w/w coconut water vinegar mother). Descriptive sensory evaluation of products shows that there is a significant (at 95 % CI) acceptance in terms of aroma, taste, astringency and overall acceptability to the coconut water vinegar made with 20 % w/w 11 ratio of coconut water mother (solid scum) and liquid culture (unpasteurized coconut water vinegar) compare to other two.

Keywords: coconut water vinegar, ethanol and acetic acid fermentation, Taguchis factorial design, sensory evaluation