牡蛎肽酸奶工艺及体外抗氧化活性研究

以牡蛎肽添加量、菌种接种量、白砂糖、发酵时间为单因素指标,感官评分为考核指标,采用响应曲面设计优化牡蛎肽酸奶配方,并对产品的微生物指标、理化指标、抗氧化活性进行分析。结果表明,牡蛎肽酸奶最优配方为:菌种3.47%,发酵时间8 h,白砂糖7.69%,牡蛎添加量0.37 g/100 mL,在此工艺下感官评分最高为83.90分,该产品呈乳白色,色泽均匀,有光泽,香味协调,有发酵乳固有香味,组织细腻均匀无气泡,有酸牛奶固有滋味,酸甜可口。牡蛎肽酸奶乳酸菌总数为1.7×10^7cfu/mL,pH值为4.02,滴定酸度为113°T,持水力为70%,符合国家标准。牡蛎肽酸奶总还原力为0.257,DPPH自由基清除率为25.90%,抗氧化能力显著优于对照组。牡蛎肽酸奶制备工艺条件能较好满足感官和生产所需,为牡蛎的高值化利用提供了重要的参考依据。

Process and Anti-oxidative Activity in Vitro of the Oyster Peptide Yoghurt

The oyster peptide yoghurt formulation was optimized by response surface methodology with oyster peptide addition,bacterial inoculation,sugar and fermentation time as the single factor indexes and sensory score as the evaluation index.The microbial index,physical and chemical index and antioxidant activity of the product were analyzed.The results showed that the optimum formula of oyster peptide yoghurt was as follows:bacteria inoculation 3.47%,fermentation time 8 h,sugar 7.69%,oyster peptide addition 0.37 g/100 mL.Under this process,the sensory score of oyster peptide yoghurt was 83.90.The product was milky white,uniform in color,luster,harmonious in flavor,with inherent fragrance of fermented milk,fine and uniform in structure,without bubbles,with inherent taste of yoghurt,and sweet and sour.The total number of lactic acid bacteria in oyster peptide yoghurt was 1.7×10^7 cfu/mL,the pH was 4.02,the titration acidity was 113°T,the water-holding capacity was 70%,the total reducing power was 0.257,and the DPPH free radical scavenging rate was 25.90%.The anti-oxidation ability of the oyster peptide yoghurt was significantly better than the control group.The processing conditions of oyster peptide yoghurt can better meet the sensory and production needs,which provides an important reference for the high value utilization of oysters.