Abstract:
Fruits are dense sources of nutrients with many functional properties. Acetification of fruit juices generates different types of fruit vinegar with a variety of flavors and uses. In this study, Alcoholic juices fermented by employing Saccharomyces cerevisiae were subjected to acetification by pre-cultured Acetobacter pasteurianus PP21 at both 30 °C and 36 °C temperatures and they were tested for their Brix value, titratable acidity, alcohol content, antioxidant activity, phenolic content and flavonoid contents. Compared to the acetic acid production at 36 °C, both mango and jackfruit juices showed their peak acetic acid production of 4.5 ± 0.015% (w/v) and 4.2 ± 0.04% (w/v) respectively, at 30 °C. The final Brix value of mango and jackfruit juices subjected to acetification at 30 °C and 36 °C was found to be constant at 3.6, 5.7, and 3.1, 5.7 °Bx respectively. Furthermore, the final alcohol level of all the vinegar samples was found to be less than 0.5% (v/v). Moreover, the antioxidant activity, phenolic content and flavonoid contents of both mango and jackfruit juices after acetification were significantly higher (p<0.05) at 36 °C compared to vinegar produced at 30 °C. As per the results, both mango and jackfruit juices can be successfully used as a potential source of functional constituents in vinegar production at both 30 °C and 36 °C.
