Optimization of a Process for Preparation of Base Wine for Cider Vinegar Production

Abstract

Apple juice is used to prepare cider vinegar a traditional fermented product consumed world over. An attempt has been made to optimize the alcoholic fermentation of apple juice by Saccharomyces cerevisiae var. ellipsoideus UCD 595 for subsequent acetic acid fermentation to prepare cider vinegar, with respect to initial concentration of TSS, DAHP and sulfur dioxide content, using RSM. It was found that the fermentability of the different runs varied according to the initial sugar and DAHP concentration. The optimum base wine quality characteristics: TSS (4.03 °B), rate of fermentation (0.42 °Brix/24 h), ethanol (6.05%), titratable acidity (0.43%), volatile acidity (0.021%), phenolics (149.76 mg/100 g), pH (3.43), reducing sugars (107.88 mg/100 gm), total sugars (0.377%) and residual sulfur dioxide (28.77 ppm) with 0.837 desirability, were obtained using 14 °B initial TSS, 0.1% DAHP and 50 ppm sulfur dioxide. Verification experiments were conducted to compare predicted and actual values, which revealed near concurrence among them; confirming that models used were capable of reasonably and accurately predicting the dependent variables. Hence, these conditions are considered optimum for the alcoholic fermentation to produce a desirable level of alcohol in the shortest time for subsequent conversion into cider vinegar by acetic acid fermentation.