核桃油酸奶开发及其品质分析

Development of Walnut Oil Yogurt and Its Quality Analysis

以核桃油、牛奶为主要原料,经过乳化、发酵开发一款新型复合酸奶。通过单因素试验确定核桃油酸奶的最佳配方:以牛奶的质量计,核桃油5%、蔗糖酯0.2%、月桂酸0.05%、聚甘油脂肪酸酯0.05%。将核桃油酸奶与原味酸奶的副干酪乳酸杆菌菌落数进行对比,确定核桃油对益生菌增殖有促进作用。通过气相色谱质谱联用仪(GCMS)分析核桃油酸奶与原味酸奶的香气成分,确定核桃油酸奶比原味酸奶多出8种风味物质,其中壬醛、庚醛等物质赋予核桃油酸奶独特的风味。通过在30℃下贮存酸奶,结果发现随着时间的延长,酸奶品质发生明显的劣变,黏度、p H降低,酸度升高,核桃油的添加可减缓酸奶品质劣变速度。

Walnut oil and milk were used as the main materials to develop a new type of compound yogurt through emulsification and fermentation.The best formula of walnut oil yogurt was determined by single factor experiment which was 5% walnut oil,0.2% sucrose ester,0.05% lauric acid 0.05% and 0.05% polyglycerol fatty acid ester based on milk quality.Comparing the number of Lactobacillus paracasei colonies between walnut oil yogurt and plain yogurt,it was determined that walnut oil had a promoting effect on probiotics proliferation.The aroma components of walnut oil yogurt and plain yogurt were analyzed by gas chromatography-mass spectrometry(GC-MS),and it was determined that walnut oil yogurt had 8 more flavor substances than plain yogurt.Among them,nonanal,heptaldehyde and other substances gave walnut oil yogurt unique flavor.By storing yogurt at 30 ℃,it was found that the quality of yogurt deteriorated significantly over time,the viscosity and p H decreased,and the acidity increased.The addition of walnut oil could slow down the deterioration of yogurt quality.