OPTIMIZATION OF THE TWO-STAGE FERMENTATION PROCESS FOR Antidesma bunius (L.) Spreng. FRUIT TOWARD THE DEVELOPMENT OF PHENOLIC-RICH BEVERAGE

Abstract

Fermentation is a well-established food processing technique that has been used to improve the shelf life, organoleptic and nutritional properties of food products such as fruits and berries. In this study, the two-stage fermentation of the ‘bignay’ fruit [Antidesma bunius (L.) Spreng.], involving alcoholic and acetic acid fermentation, has been optimized through the aid of response surface methodology to produce a phenolic-rich fermented ‘bignay’ fruit functional beverage. The factors used for the process optimization of the two-stage fermentation of bignay were the duration of the acetic acid fermentation and the amount of fruit puree, while the response variables used were the total phenolic (TPC) and total flavonoid content (TFC). The resulting optimization process suggested a quadratic model design for both total phenolic and total flavonoid content. Furthermore, verification of the model, resulted in optimized conditions of 3.5 days of acetic acid fermentation using 75% fruit must. This optimized process was able to yield a maximum of 251.90 ± 0.30 GAE mg g⁻¹ (TPC) and 249.01± 0.41 QE mg g⁻¹ (TFC). The fermented ‘bignay’ juice using the optimized fermentation process had a significant increase in its TPC and TFC when compared to its unfermented counterpart. The optimization process of the two-stage fermentation can be applied for the development of phenolic-rich bignay beverages.