滨海白首乌酸乳的制备及其抗氧化能力

Preparation and Antioxidant Capacity of Cynanchum auriculatum Root-Fermented Yogurt

该文以滨海白首乌粉和全脂乳粉为主要原料,通过单因素试验研究白首乌粉添加量、发酵剂接种量、蔗糖添加量及发酵温度对滨海白首乌酸乳的品质和总抗氧化能力的影响,并利用正交试验对其制备条件进行优化,同时研究其贮藏特性。结果表明,全脂乳粉中添加2.0%的滨海白首乌粉和5.0%的蔗糖,接种0.015 U/kg Y450A发酵剂,40.0℃发酵5 h,制备的滨海白首乌酸乳总抗氧化能力为0.1292 mmol/L,显著高于未发酵和不含滨海白首乌粉的酸乳(P<0.05),且酸甜适中,风味和口感良好。异丙醇、2,3-丁二酮、正己醇、2-庚酮、仲丁基亚硝酸酯及三乙二醇单乙醚为其主要的风味物质。4℃贮藏9 d后,滨海白首乌酸乳的总抗氧化能力为0.1035 mmol/L,乳酸菌活菌数为1.57×10^(8)CFU/mL,并保持了良好的感官品质。

The dried roots of Cynanchum auriculatum Royle ex Wight,containing a variety of active components including polysaccharides and total glycosides,have antioxidant and immunomodulatory activities.The C.auriculatum root powder and whole milk powder were used to prepare a yogurt product.The effects of the root powder addition,starter inoculation amount,and fermentation temperature on the quality and total antioxidant capacity(T-AOC)of the product were studied by single factor tests,and the preparation conditions were optimized by orthogonal design.Furthermore,the storage characteristics of the product were studied.The results showed that the yogurt product prepared by fermentation of whole milk powder with 2.0%C.auriculatum root powder,5.0%sucrose,and 0.015 U/kg Y450A starter at 40.0℃for 5 h had the T-AOC of 0.1292 mmol/L,which was higher than that of unfermented product and the product without the addition of C.auriculatum root powder(P<0.05).Moreover,the product had moderate acidity and sweetness,a good flavor and taste,with isopropanol,2,3-butanedione,n-hexanol,2-heptanone,sec-butyl nitrite,and triethylene glycol monoethyl ether as the main flavor substances.After 9 d of storage at 4℃,the T-AOC and viable count of lactic acid bacteria were 0.1035 mmol/L and 1.57×10^(8)CFU/mL,respectively,and the good sensory quality was maintained.The fermentation with C.auriculatum root powder endowed the yogurt with strong antioxidant capacity and a good flavor and taste.