Physicochemical properties and storage stability of blueberry fermented by lactic acid bacteria
The physicochemical properties and storage stability of blueberries fermented by lactic acid bacteria were investigated. The viable cell count of lactic acid bacteria slowly increased to 5.96 log CFU/mL after 72 hr of fermentation. The pH decreased whereas titratable acidity increased after fermentation. The contents of total anthocyanin (31.52 mg/100 g) and cyanidin-3-glucoside (C3G) (5.41 mg/100 g) after 72 hr of fermentation were higher than those of non-fermented blueberries (16.10 mg/100 g and 2.21 mg/100 g, respectively). The L and a value decreased, and the b and △E value increased. The total polyphenol and flavonoid contents of fermented blueberries (2.21 g/100 g and 0.91 g/100 g, respectively) were higher than those of non-fermented blueberries (1.13 g/100 g and 0.49 g/100g, respectively). The DPPH radical scavenging activity and superoxide radical scavenging activity of the fermented blueberries were 30.74%, and 52.76%, respectively. The ferric reducing antioxidant power of the fermented blueberries (256.42 μM/g) was higher than that of non-fermented blueberries (191.52 μM/g). Anthocyanin and C3G content was stable in fermented blueberries after 42 days of storage. The results suggest that blueberries fermented by lactic acid bacteria have the potential to be functional materials in the food industry.