摘要:本文研究了迷迭香精油、肉桂精油、牛至精油和百里香精油对食物中常见腐败菌大肠杆菌和金黄色葡萄球菌的抑菌活性,并选取抑菌性最好的精油作为抑菌剂来研究其对大肠杆菌和金黄色葡萄球菌抗性的影响。金黄色葡萄球菌在1/2MIC和1/4MIC的肉桂精油中暴露24小时后,对肉桂精油的直接保护和各种应力(高温45oC,乳酸pH4.5,氯化钠1g/10mL)下的间接保护进行了研究。主要实验结果如下(1)迷迭香精油、肉桂精油、牛至精油和百里香精油对大肠杆菌和金黄色葡萄球菌都有抑菌效果,但是其中肉桂精油的抑菌效果最为明显,其大肠杆菌的MIC为250μl/L为金黄色葡萄球菌的MIC为500μl/L。(2)所有肉桂精油的实验浓度(MIC, 1/2MIC和1/4 MIC)下,都抑制了金黄色葡萄球菌的生长。(3)金黄色葡萄球菌在亚致死浓度的肉桂精油中,直接保护和交叉保护对金黄色葡萄球菌抗性的影响没有明显变化。由以上实验结论可以得出在食品中可以使用肉桂精油来代替防腐保鲜剂,短时间内并不需要担心腐败菌会产生抗性问题,在食品中使用的可行性有了进一步的确定。38745
毕业论文关键词: 肉桂精油;金黄色葡萄球菌;直接保护;交叉保护;抗性
Spices plant essential oil of food spoilage organisms stress research
Abstract: In this study, the antimicrobial effects of rosemary oil, cinnamon oil, organo oil and thyme essential oils on common spoilage bacteria in food ,as E. coli and S. aureus, are evaluated. And cinnamon oil, which showed the best antimicrobial activity, was selected as a natural preservative bacteriostatic agent to study the effects on E.coil and S. aureus resistance. The induction of direct protection against cinnamon of cross protection against various stresses (high temperature 45 oC; lactic acid, pH 4.5; NaCl 1g/10mL) after exposure to sublethal amounts of cinnamon was also evaluated. The main results are as follows:(1) essential oil, cinnanmon oil., organo oil and thyme essential oils all decreased the cell viability of E.coil and S. aureus, cinnamon oil whose MIC against E.coil is 250μl/L and MIC against S. aureus is 500μl/L is the best of them.(2) cinnanmon oil decreased the cell viability of S. aureus in LB broth over 120min of exposure at all assayed concenteations (MIC,1/2MIC,1/4MIC).(3) Sublethal concentrations of cinnamon oil did not induce the direct protection and cross-protection in S. aureus in cinnamon oil.
Key words: Cinnanmon oil; S. aureus; direct protection; cross-protection; resistance
目录
1引言 1
1.1 植物提取物研究现状 1
1.1.1香辛料精油及其成分的概述 1
1.1.2香辛料精油的特点 1
1.1.3 香辛料植物精油对食品腐败微生物的抑制作用 2
1.1.3.1 对细菌的抑菌活性 2
1.1.3.2 对真菌的抑菌活性 2
1.1.4香辛料精油抑菌机理 3
1.2 植物精油的生物安全性 3
1.3本课题的研究目的和意义 4
2实验材料和方法 5
2.1 实验材料 5
2.1.1植物精油, 5
2.1.2菌种和培养基 5
2.1.3试剂 6
2.1.4主要仪器 6
2.2 实验方法 6
2.2.1精油的最低抑菌浓度(MIC)的测定 6
2.2.2精油的动态杀菌曲线 7
2.2.3直接保护效应 7
2.2.4 间接保护效应 7
2.3数据统计与分析 8
3结果与讨论 8
3.1香辛料植物精油的筛选 8
3.1.1精油对大肠杆菌的MIC的测定 8 香辛料植物精油对食品腐败菌的胁迫研究:http://www.751com.cn/shiping/lunwen_37798.html