Abstract: Biological preservatives of lactic acid bacteria (LAB) have been gradually applied to food preservation because of their excellent properties such as naturality, antibacterial activity, safety and reliability. The screening of Lactobacillus plantarum with superior fermentation ability and antifungal activity is important for the production and preservation of fermented milk. In this research 33 strains of L. plantarum with potential antifungal properties were used as starters to ferment skim milk. Variations in mold and yeast counts and post-acidification during storage at room temperature under open conditions and mixed-culture fermentation properties were assessed to select L. plantarum with superior preservation properties. The results indicated that 9 selected strains of L. plantarum from initial screening had obvious antifungal activity. The variation of acidity of milk fermented by L. plantarum IMAU80091 and IMAU80106 was significantly lower than that of milk fermented by other strains and commercial preservative bacteria (P < 0.05). Moreover, milk fermented with mixed cultures (1:1) of L. plantarum IMAU80091 and IMAU80106 showed great inhibitory activity against yeasts than did commercial preservative bacteria significantly (P < 0.05). After storage for 21 d, the titratable acidity was (138.24 ± 1.19) °T, which was significantly lower (P < 0.05) than that of milk fermented by commercial preservative bacteria (146.41 ± 1.18) °T. In summary, mixed cultures of L. plantarum IMAU80091 and IMAU80106 possess superior antifungal properties as a promising biopreservative and could prevent fungal contamination effectively.

Key words: Lactobacillus plantarum; preservative; screening; yoghurt

摘要： 以33株具有潜在抑制真菌活性的植物乳杆菌为研究对象,分别与基础发酵剂复配制备酸乳,通过测定发酵酸乳在敞口室温条件下贮藏期间霉菌、酵母菌的菌数变化及酸乳的酸度,筛选具有良好保鲜效果的植物乳杆菌.结果表明:初筛所得9株植物乳杆菌(IMAU80152、10156、80091、50045、10155、80106、10216、10996、10239)可明显抑制真菌生长,复筛出IMAU80091和IMAU80106在酸乳中酸度变化程度显著低于其他菌株及商业保鲜菌(P＜0.05),当上述2株菌以1∶1复配发酵时抑制酵母菌效果显著优于商业保鲜菌(P＜0.05).复配发酵的酸乳样品贮藏21d后,滴定酸度为(138.24±1.19)°T,显著低于商业保鲜菌组(146.41±1.18)°T(P＜0.05).IMAU80091和IMAU80106复配组合可有效抑制货架期内酸乳真菌污染,具有作为生物保鲜菌的优良特性.

关键词: 植物乳杆菌；生物保鲜剂；筛选；酸乳