Study on Peony Pure Dew Nutritional Yogurt and Quality Analysis

Taking the addition amount of peony dew, the inoculation amount of starter and the addition amount of granulated sugar as single factor indexes, and the acidity, pH, water holding capacity, texture characteristics and sensory score of peony dew yogurt as evaluation indexes. The fermentation formula of peony dew yogurt was optimized by response surface analysis, and the microbial index, physical and chemical index and antioxidant activity of the product were analyzed. The results showed that the optimum fermentation formula of Peony flower yogurt was peony flower dew 4.0%, starter inoculum 0.2%, granulated sugar 7%. Under the optimized process conditions, the sensory score of peony yogurt was 96, which was close to the predicted value (96.242 points). The hardness, elasticity, viscosity, cohesion and viscosity of peony dew yoghurt were 3.892 N, 0.9985 mm, 3.275 N, 0.851 and 1.43 mJ, respectively, and the indexes were better than those of peony dew yoghurt. The water holding capacity of peony dew yoghurt was 81.5%, pH was 4.23, protein content was 3.01 g/100 g, fat content was 2.88 g/100 g, acidity was 78.85°T, and the number of lactic acid bacteria was 1.5×10⁸ CFU/mL, Escherichia coli was not detected, and the test results met the national food safety standards. The scavenging rates of DPPH and hydroxyl radical of peony dew yoghurt (When the mass concentration was 25 mg/mL) were 63.2% and 59.5%, respectively. The antioxidant capacity was significantly better than that of original yoghurt. Peony juice yogurt has better quality and strong antioxidant activity.