School of Life Sciences, Zhengzhou University, Zhengzhou, Henan, 450001, China.
The Quartermaster Research Institute of Engineering and Technology, Academy of Military Sciences PLA China, Beijing 100010, China.
J Dairy Sci. 2020 Apr;103(4):3038-3044. doi: 10.3168/jds.2019-17396. Epub 2020 Feb 7.
Nisin, a natural peptide produced by Lactococcus lactis cultivation in milk whey, is widely used as a preservative in industrial production. However, nisin can be degraded by endogenous enzymes in foods. In this study, we investigated the antibacterial activity of nisin-soybean protein and nisin-egg white protein and compared them with that of free nisin in cantaloupe juice, which was used as a model of endogenous protease environment. Results showed that endogenous proteases in the model resulted in a loss of nisin activity, but combining nisin with protein (soybean or egg white) resulted in greater protection of its antimicrobial activity by inhibiting endogenous proteases. The microbial addition experiment (Staphylococcus aureus and Micrococcus luteus) and preservation experiment in the food model showed that the antibacterial activity of nisin combined with either of the 2 proteins was higher than that of nisin alone in an endogenous protease environment. In summary, soybean protein and egg white protein improved the protease tolerance of nisin, expanding the application scope of nisin in food.
乳链菌肽是一种由牛奶乳清中培养的乳球菌产生的天然肽，被广泛用作工业生产中的防腐剂。然而，乳链菌肽可以被食品中的内源性酶降解。在这项研究中，我们研究了乳链菌肽-大豆蛋白和乳链菌肽-蛋清蛋白的抗菌活性，并将其与作为内源性蛋白酶环境模型的哈密瓜汁中的游离乳链菌肽进行了比较。结果表明，模型中的内源性蛋白酶导致乳链菌肽活性丧失，但将乳链菌肽与蛋白质（大豆或蛋清）结合使用可以通过抑制内源性蛋白酶来更好地保护其抗菌活性。在食品模型中的微生物添加实验（金黄色葡萄球菌和藤黄微球菌）和保存实验表明，在内源性蛋白酶环境中，乳链菌肽与这两种蛋白质中的任何一种结合的抗菌活性都高于单独的乳链菌肽。总之，大豆蛋白和蛋清蛋白提高了乳链菌肽对蛋白酶的耐受性，扩大了乳链菌肽在食品中的应用范围。
