乳酸杆菌抑制致病菌及生物保鲜发酵剂特性评价

以15 株乳酸杆菌为研究对象，动物双歧杆菌乳亚种BB-12作为对照，研究它们对肠道致病菌的抑菌特性。结果表明：9 株菌对5 株指示菌均有较好抑制作用，2 株菌对金黄色葡萄球菌、肠炎沙门氏菌、大肠杆菌和蜡样芽孢杆菌均有抑制作用；以抑菌效果、凝乳状态、产酸性能为指标，筛选出4 株菌，与嗜热链球菌ST-21组合制备生物保鲜发酵剂；通过测定各发酵剂产酸性能、各组发酵乳产酸性能、质构（硬度、稠度、黏聚性）和感官评价表明，发酵剂配方3产酸快、后酸化能力及奶油香气突出，适用于生产风味发酵乳；发酵剂配方7发酵乳的

Antagonistic Effect of Lactobacillus Strains against Bacterial Pathogens and Performance Evaluation of Bio-preservative Starter Cultures

A total of 15 food-grade Lactobacillus strains were evaluated for their antagonism against gastrointestinal pathogens using Bifidobacterium animalis subsp.lactis BB-12 as a control.The results showed that nine of the strains possessed excellent antibacterial properties against five indicator bacteria tested,and two of the remaining six strains were antagonistic against four of the indicator bacteria,Staphylococcus aureus,Salmonella,E.coli and Bacillus cereus.According to their antagonistic effect,acid producing ability and milk curding ability,four strains were selected and each of them was combined with Streptococcus thermophilus ST-21 for use as bio-preservative starter cultures.Streptococcus thermophilus ST-21+strain Z-38 at a ratio of 2:1 could produce acid rapidly,have potent post-acidification capacity and produce a strong milky aroma,being suitable for the production of flavored yogurt.Streptococcus thermophilus ST-21+strain Z-40 at a ratio of 2:1 resulted in the best texture of yogurt,being suitable for the production of fermented dairy drink.Yogurt fermented by Streptococcus thermophilus ST-21+strain Z-12 at a ratio of 1:1 showed the lowest consistency and cohesiveness.