自主筛选的植物乳杆菌对酸羊乳品质与功能特性的影响

为改善酸羊乳风味与品质，提高酸羊乳的功能价值，将自浆水中筛选的植物乳杆菌JS5和JS19用于羊乳发酵，研究其对酸羊乳理化性质、质构特性及功能特性的影响。结果表明：2 种植物乳杆菌与商业发酵剂复合发酵后，均能在贮藏期内有效提高酸羊乳持水性和表观黏度，降低其硬度与胶着性，促进乙醛和双乙酰的释放；添加植物乳杆菌JS5的酸羊乳胆固醇降解率显著高于对照组（P＜0.05），最高可达36.62%；添加植物乳杆菌JS19的酸羊乳体外抗氧化能力更强，贮藏1 d时1,1-二苯基-2-三硝基苯肼自由基清除率高达70.58%，铁离子还原/抗氧化能力达32.03 μmol/L。2 种菌株均为适用于羊乳发酵生产的优良菌株。

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.