茶叶抗菌肽粗提物的抑菌活性及其对冷却肉保鲜的影响

为了制备茶叶抗菌肽粗提物并将其应用在冷却肉保鲜上,以龙井茶叶为材料提取茶叶抗菌肽粗提物,采用平板抑菌法检测茶叶抗菌肽粗提物的抑菌活性,通过细胞膜渗透率、磷离子泄漏、DNA结合和透射电子显微镜等指标分析茶叶抗菌肽粗提物对细菌的作用机制,通过微生物菌落数量和pH值两个指标评价茶叶抗菌肽粗提物对冷却肉的防腐保鲜效果。结果表明:提取的茶叶抗菌肽粗提物主要包括分子量小于18.4 ku的多肽,其对金黄色葡萄球菌和大肠埃希菌均具有抑菌活性,可造成细菌细胞膜渗透率增强,引起细菌细胞外磷离子浓度增加,造成细菌细胞膜不完整、出现破损,但不与细菌基因组DNA结合。茶叶抗菌肽粗提物可以显著抑制冷却肉中微生物的生长,延缓pH值上升,延长保鲜时间,对冷却肉具有防腐保鲜作用,具有较高的开发利用价值。

Antibacterial activity of tea antimicrobial peptide extraction and its effect on preservation of chilled meat

To prepare antimicrobial peptide (AMP) extraction from tea and apply it in chilled meat preservation, tea AMP extraction (TAE) was extracted from Longjing tea. Antibacterial activity of TAE was determined by radial diffusion assay. The mechanism of action of TAE against bacteria was analyzed by membrane permeability, phosphorus ions leakage, DNA binding and transmission electron microscopy. The effect of TAE on preservation of chilled meat was also evaluated based on microbial colonies and pH value. The results showed that TAE mainly contained peptides with a molecular weight of less than 18.4 ku, it showed antibacterial activity against Staphylococcus aureus and Escherichia coli, and it could disrupt bacterial cell membrane and enhance cell membrane permeability, resulting in phosphorus ions leakage. However it did not bind to bacterial genomic DNA. TAE could significantly inhibit the growth of bacteria in chilled meat and delay the increasing of pH value, which could prolong the preservation time and had high development and utilization value in food preservation.