Nutritional and Sensory Quality Evaluation of Low-Temperature Yogurt Sold in the Market Based on Principal Component Analysis and Cluster Analysis

In order to explore the quality differences of various brands of low-temperature yogurt sold in the market, the nutritional components and physical characteristics of 11 kinds of stirred lowtemperature commercial yogurt were analyzed by principal component analysis (PCA), including protein content, total sugar content, fat content, sodium content, calcium content, probiotic content, solid content, pH value, L*, a*, b*, viscosity and whey precipitation rate. In addition, combined with the method of sensory evaluation, the quality evaluation model is initially constructed. The results show that the cumulative variance contribution rate of the four principal components extracted by principal component analysis method reaches 90.74%. Based on the comprehensive evaluation function of principal component analysis method, the calculated results are significantly positively correlated with the sensory evaluation results (r = 0.909, P <0.001), which reflects the high reliability and effectiveness of the evaluation model. By cluster analysis, 11 kinds of yogurt can be divided into four groups. The first group is characterized by high protein and mellow taste, the second group is characterized by balanced nutrition and popular taste, the third group is characterized by no additive and original flavor, and the fourth group is characterized by moderate quality in all aspects. The research results provide a theoretical basis for the quality evaluation of stirred low-temperature yogurt and the research and development of fermented dairy products.