Probiotic Gac fruit beverage fermented with Lactobacillus paracasei: Physiochemical properties, phytochemicals, antioxidant activities, functional properties, and volatile flavor compounds

This study aimed to develop a probiotic beverage from Gac juice (GJ) at 5–10 g/100 g fermented with L. paracasei CASEI 431 at 37° for 24 h. Probiotic viability, physicochemical properties, phytochemicals, antioxidant activity, volatile flavor compounds, and sensory acceptability of fermented GJ were investigated. A decrease in pH value and sugar content with an increase in organic acids (lactic and acetic acid) and probiotic viability were detected after GJ fermentation. Interestingly, the β-carotene content, DPPH radical scavenging activity, ferric reducing antioxidant power, and lipid peroxidation inhibition capacity of fermented GJ were all higher than those of non-fermented GJ. Furthermore, fermented GJ at 10 g/100 g showed a remarkable ability to disrupt cholesterol micellization formation and increase bile acid binding activity. The fermentation of GJ introduced various volatile compounds without affecting sensory acceptability. The findings suggest that GJ might be a promising ingredient for developing a non-dairy probiotic beverage with increased bioactive phytochemicals and functional properties.