Potential of three probiotic lactobacilli in transforming star fruit juice into functional beverages.

The star fruit is popularly cultivated and consumed in Southeast Asia due to its high antioxidant capacity and various nutrients. In this study, three commercial probiotic strains (Lactobacillus helveticus L10, Lactobacillus paracasei L26, and Lactobacillus rhamnosus HN001) were evaluated in star fruit juice fermentation and all strains grew well with the final cell counts of around 108 CFU/ml. The star fruit juice fermented by L. rhamnosus produced the highest amount of lactic acid, resulting in a significant lower pH (4.41) than that of L. helveticus (4.76) and L. paracasei (4.71). Most of aldehydes and esters endogenous in star fruit juice decreased to low or undetectable levels, while ketones, alcohols, and fatty acids were produced at varying levels that could impart different aroma notes to the beverages. Therefore, the selection of appropriate probiotics can be an alternative way to develop new functional beverages from star fruit juice with specific aroma notes.