Effects of Lactobacillus plantarum Isolated in Our Laboratory on the Quality and Functional Properties of Goat Milk Yogurt

In order to improve the flavor and quality of goat milk yogurt and enhance its functional value, Lactobacillus plantarum JS5 and JS19, isolated from Jiangshui, a traditional Chinese fermented vegetable food, were used for goat milk fermentation. The physicochemical properties, textural characteristics, and functional properties of goat milk yogurt were evaluated. The results showed that mixed-culture fermentations with each isolate and a commercial starter culture improved the water-holding capacity and apparent viscosity of goat milk yogurt, reduced its hardness and gumminess and promoted the release of acetaldehyde and diacetyl. The rate of cholesterol degradation (up to 36.62%) in goat milk yogurt containing Lactobacillus plantarum JS5 was significantly higher than that in the control group (P < 0.05). Goat milk yogurt containing Lactobacillus plantarum JS19 showed stronger antioxidant capacity in vitro, which could scavenge 70.58% of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and had a ferric ion reducing antioxidant power (FRAP) value of 32.03 μmol ferrous sulfate equivalent/L on the first day of storage. Therefore, both strains are suitable for goat milk fermentation.