Bioprocess optimization for production of apple tea wine: influence of different variables on the quality attributes

Apple tea wine having phytochemical potential of tea and apple, is an option to improve quality characteristics of wine. However, quality of wine is greatly dependent on different initial variables which need to be optimized before preparation of any wine with desirable quality characteristics. Therefore, present study was conducted to investigate the effects of different initial variables, i.e., tea concentration (3–5 g tea per 100 ml of the apple juice), sugar concentration (18–22°B), DAHP concentration (0.1–0.3%), KMS concentration (50–150 ppm) and inocula size (2.5–7.5%) on quality attributes of apple tea wine. Results indicated that for all the variables under study exerted a significant effect on the alcoholicity and sensory quality characteristics of apple tea wine and the same has been observed during the cluster analysis of the data. The optimum wine qualities; rate of fermentation (0.78°B/24 h), ethanol (7.83%), volatile acidity (0.025%), fusel alcohol (84.62 mg/l) and overall acceptability (8.27) with 0.81 desirability were obtained using 4 g tea, 20°B initial sugar concentration, 0.2% DAHP, 100 ppm KMS and 5% inoculum size. Verification experiments were conducted to compare predicted and actual values, which were found to nearly concur, confirming that models were capable of reasonably and accurately predicting the dependent variables. The developed conditions will help in improving the quality of apple tea wine and no doubt will open a new door for fruit wine industry with a new product.