关键词: 苹果; 乳酸发酵; 乳酸饮料; 抗氧化

Abstract: In this study, a clarified beverage was developed based on lactic acid fermentation of apple juice and raw milk. The production process was optimized by one-factor-at-a-time and orthogonal array desigh methods. The optimal fermentation conditiions were a blend of Lactobacillus delbruechii subsp. bugaricus, S. thermophilus and Lactobacillus acidophilus at a ratio of 2:1:2 inoculated at an inoculum size of 6%, 38 ℃ of fermentation temperature, 11 mL/100 mL of milk concentration, and 11 d of fermentation time, yielding a lactic acid concentration of 13.85 g/L. The optimal clarification conditions were 2 h treatment with chitosan added at 0.3 g/L at 40 ℃, resulting in a transparency of 96.167%. The optimal beverage formula was composed of 0.5 g of lactic acid, 6 g of sucrose, 60 mg of sodium chloride and 0.05 g of honey per 100 mL. The trolox equivalent total antioxidant capacity of the fermentation broth was 42.68 mg/mL, and the DPPH radical scavenging rate was as high as 52.186% at a dose of 100 μL.

Key words: apple；lactic acid fermentation；lactic acid beverage；antioxidant activity