Departamento de Ciência de Alimentos, Laboratório de Bioquímica e Microbiologia Aplicada, ICTA, Universidade Federal do Rio Grande do Sul, 91501-970 Porto Alegre, RS, Brazil.
Food Microbiol. 2010 Feb;27(1):175-8. doi: 10.1016/j.fm.2009.09.013. Epub 2009 Oct 6.
Commercial nisin was encapsulated in nanovesicles (mean diameter 140 nm) prepared from partially purified soy lecithin. Nisin-loaded liposomes and unencapsulated (free) nisin were initially tested in BHI medium and skim milk inoculated with Listeria monocytogenes and incubated for 48 h at 30 degrees C. At such abuse temperature conditions, free nisin showed better inhibitory than the liposomal counterparts. Subsequently, the effect of encapsulated or free nisin was evaluated in combination with refrigeration (7 +/- 1 degrees C) in both whole (3.25% fat) and skim (0% fat) milk for up to 14 day. A decrease of 3-4 log cycles in L. monocytogenes counts was observed for free and encapsulated nisin at 0.5 mg/ml concentration. Liposome encapsulation of antimicrobial peptides may be important to overcome stability issues and interaction with food components. The utilization of nanovesicle-encapsulated nisin in combination with low temperatures appeared to be effective to control L. monocytogenes in milk, emphasizing the importance of hurdle technology to assure food safety.
商业乳链菌肽被包裹在纳米囊泡（平均直径 140nm）中，这些纳米囊泡由部分纯化的大豆卵磷脂制备而成。乳链菌肽负载的脂质体和未包裹（游离）的乳链菌肽最初在 BHI 培养基和接种了单核细胞增生李斯特菌的脱脂乳中进行测试，并在 30°C 下孵育 48 小时。在如此滥用的温度条件下，游离乳链菌肽的抑制效果优于脂质体。随后，在 3.25%脂肪全脂牛奶和 0%脂肪脱脂牛奶中，以 0.5mg/ml 的浓度，在冷藏（7 +/- 1°C）条件下，评估了游离和包裹乳链菌肽的效果，持续时间长达 14 天。游离和包裹乳链菌肽在 0.5mg/ml 浓度下，可使单核细胞增生李斯特菌数量减少 3-4 个对数周期。抗菌肽的脂质体包封可能对于克服稳定性问题和与食物成分的相互作用很重要。纳米囊泡包封的乳链菌肽与低温相结合的使用，似乎可以有效地控制牛奶中的单核细胞增生李斯特菌，这强调了障碍技术对于确保食品安全的重要性。
