黑枸杞风味酸奶发酵条件优化及低聚果糖和水苏糖对其品质的影响

该研究以黑枸杞、牛奶为主要原料制备黑枸杞风味酸奶，以感官评分和乳酸菌总数为考察指标，采用单因素试验和响应面法对黑枸杞风味酸奶的发酵工艺条件进行优化，并考察低聚果糖和水苏糖对黑枸杞风味酸奶品质的影响。结果表明，黑枸杞风味酸奶的最佳发酵工艺条件为白砂糖添加量8.9%，黑枸杞汁添加量4.1%，羧甲基纤维素钠添加量0.3%，接种量2.2%。在此优化条件下，黑枸杞风味酸奶的感官评分为89.48分，乳酸菌总数为1.3×10⁹ CFU/mL。当低聚果糖和水苏糖添加量分别为1.8%和0.8%时，黑枸杞风味酸奶乳酸菌总数分别提高7.08倍和5.6倍，酸度分别降低23.4%和20.2%，蛋白质含量分别升高65.2%和61.3%,1,1-二苯基-2-三硝基苯肼(DPPH)自由基清除率分别提高22.7%和26.5%，表明低聚果糖和水苏糖可使黑枸杞风味酸奶抗氧化性增强。

Optimization for fermentation conditions of black wolfberry flavored yoghurt and the effects of fructooligosaccharide and stachyose on its quality

In this study, black wolfberry flavored yogurt was prepared with black wolfberry and milk as the main raw materials. Using sensory score and total counts of lactic acid bacteria as investigation indicators, the fermentation process conditions of black wolfberry flavored yogurt were optimized by single factor experiments and response surface methodology, and the effects of fructooligosaccharide and stachyose on the quality of the yogurt were investigated. The results showed that the optimum fermentation conditions for black wolfberry flavored yogurt were as follows: sugar addition 8.9%, black wolfberry juice addition 4.1%, sodium carboxymethyl cellulose addition 0.3%, and inoculum 2.2%. Under the optimized conditions, the sensory score of the yogurt was 89.48, and the total counts of lactic acid bacteria were 1.3×109 CFU/ml. When the fructooligosaccharide and stachyose addition were 1.8% and 0.8%, respectively, the total counts of lactic acid bacteria of the yogurt increased by 7.08 times and 5.6 times, the acidity decreased by 23.4% and 20.2%, the protein content increased by 65.2% and 61.3%, and the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging rate increased by 22.7% and 26.5%, respectively, indicating that fructooligosaccharide and stachyose could enhance the antioxidant capacity of black wolfberry flavored yogurt.