黄精-枸杞复合酸奶工艺条件优化及其品质分析

以鲜牛奶、黄精（Polygonatum sibiricum）、枸杞（Lycium barbarum）为原料，研制黄精-枸杞复合酸奶。通过单因素试验和响应面法对黄精-枸杞酸奶的工艺条件进行优化，并在储藏期间对其活菌数、酸度及持水性进行测定。结果表明，黄精-枸杞复合酸奶的最佳工艺条件为：黄精、枸杞浸提液添加量20%（黄精、枸杞浸提液体积比2.0∶1.0），蔗糖添加量7.4%，接种量0.2%，发酵时间8.3 h。在此优化条件下，黄精-枸杞复合酸奶感官评分为89.33分、活菌数为1.18×107 CFU/mL、酸度为82.3 °T、持水性为70.12%，风味口感甚佳，黄精枸杞香气浓郁，符合国标GB 19302—2010《发酵乳》要求。

Optimization of technology conditions and quality analysis of Polygonatum sibiricum- Lycium barbarum compound yoghurt

The Polygonatum sibiricum-Lycium barbarum compound yoghurt was prepared with fresh milk, P. sibiricum and L. barbarum as raw materials, the technological conditions of the yoghurt were optimized by single factor tests and response surface methodology, and the number of viable bacteria, acidity and water holding capacity were determined during storage. The results showed that the optimal technology of the P. sibiricum- L. barbarum compound yoghurt was P. sibiricum and L. barbarum extract addition 20% (P. sibiricum extract and L. barbarum extract volume ratio 2.0:1.0), sugar addition 7.4%, inoculum 0.2%, and fermentation time 8.3 h. Under the optimal conditions, the sensory score of the yoghurt was 89.33, the number of viable bacteria was 1.18×107 CFU/ml, the acidity was 82.3 °T, and the water holding capacity was 70.12%. The yogurt with rich P. sibiricum and L. barbarum aroma had the optimal flavor and taste, which met the requirements of the national standard GB 19302—2010 "Fermented milk".