肉桂醛及其复配单离香料对食品有害微生物的抑制作用研究

通过抑菌圈法测试肉桂醛、百里香酚、香芹酚、丁香酚、茴香脑和柠檬醛对几种常见有害微生物的抑菌敏感性。同时采用直接接触法测定最小抑菌浓度和最小杀菌浓度,研究这六种单离香料及复合单离香料对常见的食品腐败菌及致病菌的抗菌能力,并与常见防腐剂进行对比。研究结果表明：相对于细菌而言,肉桂醛对真菌抑菌能力更强,尤其对黄曲霉的抑菌效果最好;不同供试菌对不同单离香料的敏感度不同,其中大肠杆菌对所选单离香料的敏感度最低;百里香酚的综合抗菌能力最好,肉桂醛和香芹酚次之;但在试验浓度范围内,仅肉桂醛能将枯草芽孢杆菌杀死;复配精油对所有的供试菌（除了金黄色葡萄球菌）杀菌效果都有明显的提高,不同配比的复配精油对不同菌种的抗菌效果有所不同,肉桂醛-百里香酚复配精油对7种供试菌表现出了相加作用或者无关;复配精油的抗菌效果远强于苯甲酸钠和山梨酸钾这两种食品防腐剂。     

植物精油的熏蒸抗菌活性及其机理研究

本文采用平板熏蒸法测定六种植物精油在气相状态下对四种常见细菌的最低抑菌浓度(Minimum Inhibitory Concentration,MIC)和最小杀菌浓度(Minimum Bactericidal Concentration,MBC),对效果好的精油进行复配研究并将其应用于小米椒保鲜,通过透射电镜和电导率来阐述肉桂精油熏蒸对大肠杆菌的抗菌机制。结果表明,六种精油中抑菌效果显著的是香茅精油、肉桂精油和罗勒精油,在精油浓度为0.125μL/mL时可以抑制所有的供试菌,而杀菌效果较好的是香茅精油和肉桂精油,除铜绿假单胞菌外,在精油浓度为0.125μL/mL时可杀死其余供试菌。将香茅精油、肉桂精油和罗勒精油进行复配,当三者比例为4:1:8时联合熏蒸抗菌效果最好,复配精油对大肠杆菌和沙门氏菌表现出协同增效作用,而对金黄色葡萄球菌则表现为拮抗作用。GC-MS结果表明,香茅精油的熏蒸抗菌能力主要来自香茅醛、香叶醇和香茅醇;肉桂精油主要来自于肉桂醛;罗勒精油则主要来自于草蒿脑、芳樟醇。当复合精油空间浓度为0.125μL/mL时,对小米椒具有较好的防腐保鲜效果。透镜结果显示经肉桂精油熏蒸后的大...     

肉桂醛和百里香酚对生料工艺酒精发酵的影响

肉桂醛和百里香酚具有较强的抑菌活性,常用于食品的保鲜和防腐,也可作为饲料添加剂。文中对肉桂醛和百里香酚对生料工艺酒精发酵的影响进行了研究。表明肉桂醛和百里香酚在酒精发酵中有一定的抑菌效果;以大米为原料时,10μg/L的肉桂醛和50μg/L的百里香酚使酒精产量分别提高了1.7%和0.7%;以玉米为原料时,50μg/L的肉桂醛提高酒精产量2.0%,25μg/L百里香酚提高1.43%;但如果继续提高肉桂醛和百里香酚的浓度,会抑制酵母的生长,导致酒精产量降低。     

Nisin Z复配剂对常见食源性致病菌的协同抑菌作用

利用乳酸乳球菌K6产生的nisin Z与几种常见添加剂(EDTA二钠、双乙酸钠、柠檬酸钠、山梨酸钾)和高效的抗生素(多粘菌素B)联合作用,探讨nisin Z复配剂对食源性致病菌的抑菌效应。通过96孔板测定nisin Z与9种抑菌物质的最小抑制浓度,进而确定nisin Z和几种抑菌物质对食源性致病菌的最低使用量。使用棋盘法测定nisin Z复配剂联合抑菌浓度并计算部分抑制浓度(FIC),根据时间-杀菌试验确定nisin Z复配剂在不同时间对食源性致病菌的协同抑菌效果。结果显示,nisin Z复配剂对革兰氏阳性菌(蜡样芽孢杆菌、金黄色葡萄球菌和单增李斯特菌)在12 h内未有明显的协同抑菌效果;nisin Z(1.25 BU/mL)与EDTA二钠(0.25 mg/mL)联用对沙门氏菌的抑制作用要高于两者单独抑制沙门氏菌的效果,说明二者联用具有协同效应;1.25 BU/mL的nisin Z与0.1μg/mL的多粘菌素B联用在3 h内对大肠杆菌有协同抑菌效应。     

肉桂提取物在冷却肉保鲜中的应用研究

本文采用常压回流方法提取肉桂醛,通过对不同菌种及冷却肉的抑菌实验,研究肉桂醛的防腐保鲜效果。结果表明:肉桂提取物对不同菌种均有抑制作用,效果好于山梨酸钾,对各种菌的抑制强弱顺序为:啤酒酵母>黑曲霉>金黄色葡萄球菌>大肠杆菌;提取物与山梨酸钾复配防腐效果增强,说明两者具有较好的协同增效作用,其抑菌强度分别是提取物和山梨酸钾的1.3和2.1倍,防腐强弱顺序为:复配物>肉桂提取物>山梨酸钾;提取物对冷却肉具有明显的保鲜作用,能使保鲜期延长5天左右。     

肉桂提取物在卤肉保鲜中的应用研究

本文采用常压回流方法提取肉桂醛,通过对不同菌种及卤肉的抑菌实验,研究肉桂醛的防腐保鲜效果。结果表明：肉桂提取物对不同菌种均有抑制作用,效果好于山梨酸钾,对各种菌的抑制强弱顺序为：啤酒酵母〉黑曲霉〉金黄色葡萄球菌〉大肠杆菌;提取物与山梨酸钾复配防腐效果增强,说明两者具有较好的协同增效作用,其抑菌强度分别是提取物和山梨酸钾的1．4和2倍,防腐强弱顺序为：复配物〉肉桂提取物〉山梨酸钾,能使卤肉保鲜期延长一周左右。     

七种单离食用香料对食品腐败菌抑菌活性的研究

通过测定抑菌圈直径和最低抑菌浓度,研究百里香酚、水杨醛、肉桂醛、丁香酚、茴香脑、柠檬醛和香兰素七种单离食用香料对引起食品腐败的供试菌种的抑菌活性.结果表明:七种香料均对细菌、霉菌和酵母具有一定的抑制能力,且表现出对霉菌抑菌较强的特点;其综合抑菌能力强弱顺序为:百里香酚＞水杨醛＞肉桂醛＞丁香酚＞茴香脑＞柠檬醛、香兰素.实验进一步选取百里香酚、丁香酚、肉桂醛、水杨醛四种香料进行优化重组,重组配比为5:5:5:1时,0.05μL/mL重组香料就可以完全抑制所有供试菌的生长.     

抗菌肽brevilaterin与食品防腐剂联用对食源性致病菌的抑制

侧孢短芽孢杆菌抗菌肽brevilaterin对细菌具有广谱抑菌活力,但是对革兰氏阴性菌的最小抑菌浓度显著高于革兰氏阳性菌,只有增大用量才能发挥广谱抑菌活性。该研究以食源性致病菌金黄色葡萄球菌、单核细胞增生李斯特菌、大肠杆菌、鼠伤寒沙门氏菌为指示菌,首先测定了食品中常用抑菌剂的最小抑菌浓度,然后分别考察了抗菌肽brevilaterin与各添加剂的联合抑菌效应,筛选了与brevilaterin具有协同作用的添加剂,进一步通过复配形成brevilaterin广谱高效抑菌配方。结果显示,天然防腐剂的抑菌效果优于化学防腐剂,且天然防腐剂对革兰氏阳性菌的抑菌效果普遍优于革兰氏阴性菌; brevilaterin分别与ε-聚赖氨酸、nisin联用对革兰氏阳性致病菌具有协同抑菌效应,与EDTA-Na_2、柠檬酸、Na_3PO_4联用对革兰氏阴性菌具有协同抑菌效应;选取brevilaterin、nisin和柠檬酸进行复配,时间杀菌曲线结果表明该组合能够发挥协同广谱抑菌效应,brevilaterin添加量降低为原用量的1/8。说明协同抑菌物质复配可有效降低brevilaterin使用剂量,且对食源性致病菌具有广谱抑菌活性。     

植物精油及消毒剂对常见鱼病病原菌的抑菌研究

研究植物精油和消毒剂对常见鱼病病原菌的抑制效果,通过抑菌圈法确定复配1号精油、复配2号精油、山鸡椒精油、芹菜精油、香茅精油、强氯精和纳必净对水体微生物的抑菌活性,同时通过直接接触法检测其对5种常见鱼病病原菌的最小抑菌浓度和最小杀菌浓度。结果显示:复配1号精油的抑菌和杀菌效果最好,无论是对霉菌还是细菌都表现出强抑菌活性;芹菜精油对不同的微生物表现出不同的抑制效果,对细菌特别是单胞类细菌表现出强抑菌活性,但对霉菌表现出低抑菌活性;在消毒剂中,纳必净的抑菌活性效果最好,但在其推荐的最大使用量时,仅仅与效果普通的精油的抑菌活性相同。     

肉桂精油复配香芹酚和百里香酚对食用畜禽有害微生物熏蒸的抗菌活性

通过测定抑菌圈直径确定肉桂精油及单离香料香芹酚和百里酚对食用畜禽有害微生物的敏感性,同时采用气相熏蒸法测定最低抑菌浓度（Minimum Inhibitory Concentration,MIC）和最低杀菌浓度（Minimum Bacterial Concentration,MBC）。结果表明：肉桂精油及香芹酚和百里酚对食用畜禽有害微生物都具有一定的抑杀能力。肉桂精油对黑曲霉的抗菌效果优于百里香酚和香芹酚,肉桂精油对黑曲霉的MIC和MBC为62.5 μL/L,而百里香酚和香芹酚的MIC和MBC均为125 μL/L;将肉桂精油与香芹酚进行复配,复配精油对白色葡萄球菌和黑曲霉均表现出相加作用（FICI≤1）,而对白色念珠菌则表现为无关作用。通过GC-MS分析,肉桂精油的主要挥发性化学成分中相对含量较高的为肉桂醛（78.19%）、2-甲氧基肉桂醛（8.70%）。采用电子鼻分析溶剂稀释后对复配精油抑菌活性的影响,抑菌能力大小为：丙二醇稀释≈无水乙醇稀释＞未稀释＞甘油稀释＞食用油稀释。实验表明：香芹酚与肉桂精油复配可以提高肉桂精油的抗菌活性,溶剂挥发性的差异会对复配精油的抑菌活性造成不同影响,稀释复配精油时溶剂的较优选择为丙二醇。     

50种植物源化合物对阪崎克罗诺肠杆菌的抑菌活性评价

阪崎克罗诺肠杆菌（Cronobacter sakazkaii）是一种食源性条件致病菌,它能够引起菌血症、坏死性小肠 结肠炎和新生儿脑膜炎等多种疾病。本研究选取50 种植物源化合物,检测其在含C. sakazkaii培养基中抑菌圈直径 及最小抑菌浓度（minimum inhibitory concentration,MIC）,旨在评价植物源化合物对C. sakazakii的抑菌作用并筛 查优选高效抑菌剂。结果表明：使C. sakazakii ATCC 29544培养基产生可见抑菌圈的植物源化合物有40 种,其中 7 种（香芹酚、百里醌、百里酚、肉桂醛、柠檬醛、原儿茶醛和原儿茶酸）的抑菌圈平均直径不小于13 mm;在本 研究选取的50 种植物源化合物中,百里酚和香芹酚对C. sakazakii有着最强的抑制作用,对9 株C. sakazkaii的MIC均 为0.1～0.2 mg/mL;百里醌、肉桂醛、柠檬醛和原儿茶醛对C. sakazkaii有良好的抑菌效果,对C. sakazkaii的MIC为 0.30～1.25 mg/mL;阿魏酸、绿原酸、丁香酸、硫辛酸、原儿茶酸、表儿茶素、咖啡酸、丹皮酚和菊苣酸的MIC为 2.50～5.00 mg/mL。以上结果表明,部分植物源化合物对C. sakazakii有良好的抑菌作用,有潜力作为天然抑菌剂应 用于食品加工、流通、贮藏过程中,从而发挥其控制C. sakazakii的作用。     

Evaluation of Combined Antibacterial Effects of Eugenol, Cinnamaldehyde, Thymol, and Carvacrol against E. coli with an Improved Method

ABSTRACT:  In this study, the antibacterial activities of eugenol, cinnamaldehyde, thymol, carvacrol, and their combinations against  E. coli  were investigated separately. First, broth macro-dilution assay was adopted to determine the minimal inhibitory concentration (MIC) of the 4 components. Second, the combination testing was performed using chequerboard method. Finally, the combined effects were evaluated with an improved method, which was based on the indices of fractional inhibitory concentration (FIC) and Effect of the Combination (EC) jointly. The results indicated that MICs of the 4 components were 1600, 400, 400, and 400 mg/L, respectively; treatments with cinnamaldehyde/eugenol, thymol/eugenol, carvacrol/eugenol, and thymol/carvacrol revealed synergistic effects according to the 2 indices. By means of combination, MICs of eugenol, cinnamaldehyde, thymol, and carvacrol decreased to 400, 100, 100, and 100 mg/L, respectively. Consequently, the negative impacts of unpleasant smell of these 4 components could be minimized, making it possible to add them to foods as preservatives. In addition, this improved evaluation method provided a more accurate and comprehensive way to evaluate combined effects.     

基于传统培养和高通量测序分析德州扒鸡优势腐败菌及相关抑菌剂价效评定

为分离鉴定充氮包装德州扒鸡低温贮藏条件下的优势腐败菌,并选择出抑菌效果好的天然抑菌剂,将高通量测序与传统培养技术相结合,对充氮包装德州扒鸡贮藏过程中优势腐败菌进行鉴定,同时有针对性的选择四种天然抑菌剂,通过测定OD₆₀₀、最小抑菌浓度（MIC）,研究其对德州扒鸡腐败菌的抑制效果。结果表明,德州扒鸡优势腐败菌主要为广布肉杆菌（Carnobacterium divergens）、水域微小杆菌（Exiguobacterium undae）、血嗜冷杆菌（Psychrobacter sanguinis）、变形斑沙雷氏菌（Serratia proteamaculans）、隆德假单胞菌（Pseudomonas lundensis）、溶酪大球菌（Macrococcus caseolyticus）、绿色气球菌（Aerococcus viridans）。乳酸链球菌素（Nisin）和ε-聚赖氨酸（ε-poly-L-lysine,ε-PL）对各受试菌的抑菌能力最强,MIC约为3.91~16000 μg/mL。本研究为后续Nisin和ε-PL复配在德州扒鸡防腐保鲜上的应用并延长其货架期提供了理论依据。     

红豆皮多酚提取物对两种致病菌的抑菌活性及作用机理

多酚类化合物具有一定的抑菌活性，为探究红豆皮多酚对两种致病菌的抑菌机理，本实验采用高效液相色谱法确定红豆皮多酚的组成。通过最小抑菌浓度（minimum inhibitory concentration，MIC）和抑菌生长曲线分析红豆皮多酚提取物对李斯特菌ATCC19119和沙门氏菌ATCC14028的抑菌效果，并从菌体细胞蛋白和核酸含量、细胞膜电位、细胞内ATP含量、细胞外碱性磷酸酶活力和菌体细胞形态变化的角度来揭示其抑菌机理。结果表明，红豆皮多酚组成成分中含有13 种酚类化合物，红豆皮多酚提取物对李斯特菌ATCC19119和沙门氏菌ATCC14028的MIC分别为625 μg/mL和2 500 μg/mL，红豆皮多酚提取物的添加对菌体细胞蛋白和核酸含量、细胞膜电位、细胞内ATP含量、细胞外碱性磷酸酶含量和菌体细胞形态变化等有明显影响。综上，本研究结果可为粮食源天然抑菌产品的开发和粮食加工副产物的综合利用提供理论参考。     

青钱柳多糖抑菌活性及及作用机理

为研究青钱柳多糖的抑菌活性和作用机制，用不同质量浓度的青钱柳多糖处理细菌，通过最小抑菌浓度（minimum inhibitory concentration, MIC）、抑菌生长曲线分析青钱柳多糖对细菌的抑菌效果，并从抑制效果最佳的受试菌菌体电导率、细胞蛋白和核酸含量、还原糖的释放、呼吸链脱氢酶活性、脂质过氧化程度、细胞内ATP含量、细胞外碱性磷酸酶活力的角度来揭示其抑菌机理。结果表明，青钱柳多糖对金黄色葡萄球菌（Staphylococcus aureus）、大肠杆菌（Escherichia coil）、单增李斯特氏菌（Listeria monocytogenes）和鼠伤寒沙门氏菌（Salmonella typhimurium）有明显的抑制作用，MIC分别为2、4、6、6 mg/mL，对枯草芽孢杆菌（Bacillus subtilis）的抑菌性不明显；对指示菌的电导率、蛋白质和核酸渗漏、还原糖释放、呼吸链脱氢酶活性、细菌脂质过氧化程度、菌体胞内ATP和胞外碱性磷酸酶（AKP）含量均有影响。以上现象表明，青钱柳多糖的抑菌性主要是破坏菌体细胞壁和细胞膜完整性，改变其通透性，使得胞内大小分子物质外泄，抑制了细胞的呼吸代谢和引起氧化损失，进而影响细胞的生长代谢或造成细胞死亡，达到抑菌效果。     

Essential oils: their antibacterial properties and potential applications in foods--a review

In vitro studies have demonstrated antibacterial activity of essential oils (EOs) against Listeria monocytogenes, Salmonella typhimurium, Escherichia coli O157:H7, Shigella dysenteria, Bacillus cereus and Staphylococcus aureus at levels between 0.2 and 10 microl ml(-1). Gram-negative organisms are slightly less susceptible than gram-positive bacteria. A number of EO components has been identified as effective antibacterials, e.g. carvacrol, thymol, eugenol, perillaldehyde, cinnamaldehyde and cinnamic acid, having minimum inhibitory concentrations (MICs) of 0.05-5 microl ml(-1) in vitro. A higher concentration is needed to achieve the same effect in foods. Studies with fresh meat, meat products, fish, milk, dairy products, vegetables, fruit and cooked rice have shown that the concentration needed to achieve a significant antibacterial effect is around 0.5-20 microl g(-1) in foods and about 0.1-10 microl ml(-1) in solutions for washing fruit and vegetables. EOs comprise a large number of components and it is likely that their mode of action involves several targets in the bacterial cell. The hydrophobicity of EOs enables them to partition in the lipids of the cell membrane and mitochondria, rendering them permeable and leading to leakage of cell contents. Physical conditions that improve the action of EOs are low pH, low temperature and low oxygen levels. Synergism has been observed between carvacrol and its precursor p-cymene and between cinnamaldehyde and eugenol. Synergy between EO components and mild preservation methods has also been observed. Some EO components are legally registered flavourings in the EU and the USA. Undesirable organoleptic effects can be limited by careful selection of EOs according to the type of food.     

Enhancement of antilisterial activity of essential oil constituents by nisin and diglycerol fatty acid ester

Plant-derived essential oil components in combination with nisin and diglycerol fatty acid esters were investigated for their antibacterial activity against Listeria monocytogenes. Carvacrol and thymol were found to have the strongest antilisterial properties, followed by eugenol, cinnamaldehyde and isoeugenol. The antilisterial activity of the other essential oils (limonene, pinene, ally lisothiocyanate and linalool) was found to be low, even at the highest concentration used (0.1%). Among the diglycerol esters of fatty acids with different carbon chain lengths, diglycerol monolaurate was the most active against L. monocytogenes. A combined antilisterial effect was observed between nisin and the essential oils (carvacrol, thymol and eugenol); moreover, the addition of diglycerol monolaurate as a third preservative factor led to further combined antilisterial activities between the essential oil constituents (carvacrol, thymol and eugenol) and nisin even at lower, sub-lethal concentrations. These results indicate that nisin and diglycerol monolaurate can be used to enhance the antilisterial activity of essential oils, allowing for a reduction in the dosage used in food preservation and thereby resulting in the reduction of undesirable flavors.     

Inhibition of Arcobacter butzleri, Arcobacter cryaerophilus, and Arcobacter skirrowii by plant oil aromatics

The inhibitory effect of some plant oil aromatics against three strains of Arcobacter butzleri, two strains of Arcobacter cryaerophilus, and one strain of Arcobacter skirrowii was evaluated. When MICs were determined using the broth macrodilution method, cinnamaldehyde was most inhibitory followed by thymol, carvacrol, caffeic acid, tannic acid, and eugenol (P < 0.001). Sublethal concentrations of the three most potent plant oil aromatics also were examined. Overall, cinnamaldehyde was the most bacteriostatic against all arcobacters tested except A. butzleri when these strains were exposed to the MIC25 of this aromatic aldehyde. The bacteriostatic activities of thymol and carvacrol were concentration and species dependent.     

百里酚和香芹酚对阪崎克罗诺肠杆菌的抑制作用

为探究百里酚和香芹酚对阪崎克罗诺肠杆菌的抑制作用及机理。测定百里酚、香芹酚对阪崎克罗诺肠杆菌最小抑菌浓度(MIC),研究两种物质对阪崎克罗诺肠杆菌生长曲线、膜电位、胞内pH、胞内ATP、细胞膜完整性的影响,利用场发射扫描电镜观测细胞形态的变化。结果表明:百里酚和香芹酚对阪崎克罗诺肠杆菌具有良好的抑制作用,两者对9株阪崎克罗诺肠杆菌的最小抑菌浓度均在0.1~0.2 mg/mL之间。百里酚和香芹酚均可使阪崎克罗诺肠杆菌细胞膜出现超极化,浓度为4MIC的百里酚和香芹酚分别使菌株的胞内pH由5.45降低至4.96和4.97,胞内ATP浓度由0.584降低为0.048和0.027 μmol/L,细胞膜完整性分别下降85.0%和88.1%。场发射扫描电镜结果显示,百里酚和香芹酚均能够导致菌体出现干瘪皱缩,细胞膜出现孔洞甚至裂解。结果显示,百里酚和香芹酚对阪崎克罗诺肠杆菌均具有良好的抑制效果,其作用机理可能与细胞膜的通透性及细胞形态有关。百里酚和香芹酚虽然互为同分异构体,但二者对阪崎克罗诺肠杆菌的抑制作用并未表现出明显的规律性差异。