汉麻叶提取物抑菌活性及抑菌稳定性研究

目的研究汉麻叶提取物的抑菌活性及抑菌稳定性。方法用乙醇对汉麻叶成分提取并依次用石油醚、乙酸乙酯、正丁醇分级萃取,以4种常见食源性致病菌:金黄色葡萄球菌、大肠杆菌、单核细胞李斯特菌、沙门氏菌为指示菌,用牛津杯法和微量2倍稀释法测定汉麻叶提取物的抑菌活性并分别对其热稳定性、酸碱稳定性、紫外线稳定性、金属离子稳定性、蔗糖稳定性进行考察。结果汉麻叶提取物对大肠杆菌和沙门氏菌无抑制作用,但对金黄色葡萄球菌和单核细胞李斯特菌具有良好的抑菌作用,活性成分主要分布于乙酸乙酯相,其对2种细菌的最小抑菌浓度(minimum inhibitory concentration,MIC)分别为7.81mg/mL和15.63mg/mL;汉麻叶乙酸乙酯相经紫外线照射、蔗糖添加和不同温度处理仍表现出良好的稳定性,酸性条件使其对金黄色葡萄球菌和李斯特菌的抑菌活性增强,Ca~(2+)使其抑菌活性提高,Fe~(3+)使其抑菌活性降低,Na~+能够增强其对单核细胞李斯特菌的抑菌活性,K+使其对金黄色葡萄球菌的抑制作用有所增加。结论汉麻叶提取物具有良好的抑菌活性和抑菌稳定性,具备作为一种天然防腐剂进行开发和利用的前景。

Antibacterial activity and stability of extract from hemp (Cannabis sativa L.) leaves

To evaluate the antibacterial activity and stability of hemp (Cannabis sativa L.) leaves extract, hemp leaves extract was obtained from hemp leaves after ethyl alcohol, petroleum ether, ethyl acetate and butyl alcohol extraction, respectively. Staphylococcus aureus, Escherichia coli, Listeria Monocytogenes and Salmonella were selected as the indicator strain and the antibacterial activity of hemp leaves extract against four kinds of food-borne pathogens was determined by oxford cup method and micro double-dilution method. Hemp leaves extract was treated with heat, acid, base, ultraviolet, metal iron and saccharose, and its antibacterial stability was studied as well. The results indicated that hemp leaves ethyl acetate phase extract had strong antibacterial activity against staphylococcus aureus and listeria monocytogenes with the minimal inhibitory concentration of 7.8 and 15.6 mg/mL, respectively. However, it had no antibacterial activity against Escherichia coli and Salmonella typhimurium. The antibacterial activity of the extract from hemp leaves was not affected by the change of ultraviolet light, saccharose concentration and temperature, so it had high ultraviolet light, thermal and saccharose stabilities. The antibacterial activity against staphylococcus aureus and listeria monocytogenes was enhanced with acid or Ca2+ condition and decreased with Fe3+ condition. Na+ increased the antibacterial activity against listeria monocytogenes, while k+ boosted its antibacterial activity against staphylococcus aureus. In conclusion hemp leaves extract had a broad prospect of development and utilization by using as a natural preservative.