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

摘要： 通过单因素及正交试验,对清汁苹果乳酸饮料工艺进行优化研究。结果表明：苹果乳酸饮料发酵工艺条件：保加利亚乳杆菌、嗜热链球菌、嗜酸乳杆菌菌液按体积比2：1：2复配,温度38℃、复合菌剂接种量6%、牛奶添加量11mL/100mL、发酵时间11d,此时乳酸产量达13.85g/L;澄清条件：壳聚糖添加量0.3g/L、温度40℃、时间2h,该条件下透光率达96.167%。饮料配方为：100mL饮料中,乳酸含量0.5g、蔗糖添加量6g、氯化钠添加量60mg、蜂蜜添加量0.05g。苹果乳酸发酵醪的总抗氧化能力为42.68mg/mL,100μL时对DPPH自由基清除率达52.186%。

关键词: 苹果; 乳酸发酵; 乳酸饮料; 抗氧化