Bioactivity of wine prepared from ripened and over-ripened kiwifruit

In order to evaluate the fruit maturity value of 'Hayward' kiwifruit (Actinidia deliciosa) as material for wine production, ripened and over-ripened fruit samples were analyzed. In addition, the effect of pectinase enzyme treatment on physicochemical characteristics of the wine during the fermentation process was also examined. The results showed that wine production from ripening kiwifruit took almost twice as long as from over-ripened fruit. The yield of wine production was increased from 63.35% to 66.19% by using riper kiwifruits and adding pectinase before amelioration. The soluble solid content (13.5%) in the wine produced from over-ripened fruits increased in comparison with the wine produced from ripened samples (10.3%). In both groups there was a decrease to 5° Brix at the end of fermentation. Difference of fruit maturity did not have a significant effect on acidy, pH, nor color of wine. The highest scores of total acceptance estimated during fermentation were for wine made from over-ripened fruits. Total phenolics content and antioxidant activities were similar in both wine groups while the mineral content, especially potassium, in wine made from over-ripened kiwifruit was higher than wine produced from ripened fruits. In conclusion, the quality characteristics of kiwifruit wine made from over-ripened fruit treated with pectinase showed higher values of wine in many aspects such as sensory value, alcohol and total phenolics content, antioxidant activity, minerals and production yield.