Abstract: The aim of this study was to prepare a new antioxidant peptide-containing dairy beverage by the fermentation of Lactobacillus paracasei. The fermentation conditions and medium ingredients were optimized based on final viable cell count, acidity, peptide concentration, peptide yield, and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity. A shaking speed of 180 r/min, a fermentation time of 24 h, an inoculum size of 5％, a skim milk powder concentration of 12％ and a glucose concentration of 6％ were found to be the optimal conditions to obtain the highest peptide concentration of 0.98 mg/mL, highest final viable cell number of 8.5 × 108 CFU/mL and highest DPPH radical scavenging activity of 62.38％.

Key words: Lactobacillus paracasei; fermentation; Lactobacillus-fermented beverage; peptide content; antioxidant activity

摘要： 将副干酪乳杆菌用于牛乳发酵,制备含抗氧化肽的新型乳酸菌功能性饮料。通过测定发酵终产品的活菌数、酸度、多肽含量、多肽转化率和1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基清除率,探讨最优的发酵培养方式和培养基配方。结果表明:确定出的最佳培养方式为摇床培养,摇床转速180 r/min、发酵时间24 h、脱脂乳粉添加量12 g、葡萄糖添加量6 g、接种量5％,在此条件下,产品的多肽产量最高达0.98 mg/mL,活菌数最高达8.5×108 CFU/mL,DPPH自由基清除率最高可达62.38％。

关键词: 副干酪乳杆菌; 发酵; 乳酸菌饮料; 多肽含量; 抗氧化活性