西沙诺尼果汁抑菌特性与抑菌物质研究

Studies on the Antimicrobial Properties and Substances in Xisha Noni Juice

以西沙诺尼果汁为研究对象,检测其对5种常见食源性致病菌和3种乳酸菌的抑制活性,研究温度、p H和蛋白酶K等因素对果汁抑菌活性的影响。考察了不同溶剂对抑菌成分的萃取活性,并对果汁中的有机酸组成和抑菌性能进行检测。结果表明,诺尼果汁对肠炎沙门氏菌、大肠埃希氏菌O157、福氏志贺氏菌、金黄色葡萄球菌、铜绿假单胞菌5株常见食源性致病菌具有明显的抑制作用,而对动物双歧杆菌、植物乳杆菌和德氏乳杆菌3种常见肠道益生菌未表现出抑制活性。抑菌物质在酸性条件下作用较强,热稳定性良好,对蛋白酶K不敏感,经乙醇萃取后的果汁溶解及沉淀部分均具有抑菌活性。西沙诺尼果汁总酸含量为7.26 g/L,采用离子色谱法检测,其有机酸主要组成为苹果酸(7 114.5 mg/L)、3-甲基戊酸(6 113.30 mg/L)、乙酸(2 036.00 mg/L)和己酸(1 969.3mg/L)。抑菌试验表明有机酸是诺尼果汁的主要抑菌物质。

The inhibition of five foodborne pathogens and three lactobacillus of Xisha Noni juice were investigated in this study, and the effect of temperature, p H and proteinase K on the antimicrobial activity was also tested. The resulted showed that Xisha Noni juice could inhibit the Salmonella enterica, Escherichia coli O157, Shigella flexneri, Staphylococcus aureus, Pseudomonas aeruginos, and had no antibacterial activity to the Bifidobacterium animalis, Lactobacillus plantarum and Lactobacillus delbrueckii. Antibacterial substances was stronger when the p H value was less than 4.0. It had good thermal stability and not sensitive to proteinase K. Different organic solvents were used to extract the active ingredient in Noni juice, we found that the dissolved in ethanol and precipitated portion had the antibacterial activity. Total acid content of Xisha Noni juice was 7.26 g/L. Detected by ion chromatography, the main organic acid was malic acid, 3-methyl-pentanoic acid, hexanoic acid and acetic acid, and the contents were 7 114.5, 6 113.30, 2 036.00,1 969.3 mg/L. Inhibition experiments showed that organic acid in Noni juice was the main inhibitory substances.