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。     

6种植物精油对果蔬灰霉菌和青霉菌的抑菌效果

为了研究6种植物精油对常见的导致果蔬腐烂的灰霉菌和青霉菌的抑菌效果。通过滤纸片法、最小抑菌浓度法(Minimal Inhibit Concentration,MIC)、最小杀菌浓度法(Minimum Bactericidal Concentration,MBC)、体外直接接触法和熏蒸法测定了6种植物精油对灰霉菌和青霉菌的抑菌效果。结果表明:6种精油对灰霉菌和青霉菌的抑菌效果从大到小依次为:牛至精油、反式-2-己烯醛、肉桂精油、丁香精油、冬青精油、柠檬精油;其中,柠檬精油对灰霉菌和青霉菌均无抑菌效果;在体外直接接触和熏蒸中,牛至精油对灰霉菌和青霉菌的抑菌率均为100%;其对灰霉菌和青霉菌的MIC分别为0.5μL/mL和0.25μL/mL,MBC分别为0.5μL/mL和0.25μL/mL。结论:牛至精油对灰霉菌和青霉菌具有较强的抑菌效果。     

植物精油对食品中常见有害微生物的抑菌活性研究

通过测定抑菌圈、气相熏蒸法等体外抑菌试验研究了罗勒精油、茶树油、百里香精油、丁香精油、小茴香精油、依兰油、甘牛至精油、肉桂精油、桉叶油、芫荽籽精油、香茅油、鼠尾草油、甘松精油十三种植物精油对六种食品常见有害微生物抗菌作用。结果表明:十三种植物精油均对细菌、霉菌和酵母具有一定的抑杀能力。百里香精油和肉桂精油抗菌活性最强,均表现程度不等的抗菌活性。六种供试菌种对百里香精油、肉桂精油极敏感,抑菌圈直径均大于20 mm;当两种精油空间体积浓度达到300μL/L时,两种精油对多数供试菌表现出强抑菌效果。肉桂精油与百里香精油复配后对供试菌没有表现出强的协同增效效果,部分出现相加作用和无关作用。复配精油中肉桂精油占80%时,对供试菌效果最好。     

10种植物精油对圣女果中三种致病菌抑制效果的研究

通过研究植物精油对圣女果致病菌的抑制效果,筛选出对圣女果有良好贮藏保鲜效果的植物精油。使用不同浓度的10种植物精油,采用体外熏蒸法和直接接触法,筛选出对圣女果中三种致病菌具有较强抑制效果的精油,并研究其最低抑菌浓度(MIC)和最低杀菌浓度(MBC)。结果显示植物精油对三种致病菌的体外熏蒸法优于直接接触法;肉桂精油、山苍子精油、丁香精油、牛至精油对白地霉菌的最低抑菌浓度分别为0.05×104、0.1×104、0.5×104、0.5×104μL/L,最低杀菌浓度分别为0.05×104、0.1×104、0.5×104、1.0×104μL/L;肉桂精油、丁香精油、牛至精油对赤霉菌的最低抑菌浓度分别为0.05×104、0.2×104、0.2×104μL/L,最低杀菌浓度分别为0.05×104、0.2×104、0.5×104μL/L;肉桂精油、丁香精油、牛至精油、山苍子精油对毛霉菌的最低抑菌浓度分别为0.1×104、0.5×104、1.0×104、1.0×104μL/L,最低杀菌浓度分别为0.1×104、0.5×104、1.0×104、1.0×104μL/L。肉桂精油、山苍子精油、丁香精油、牛至精油对白地霉菌均有较好抑制作用;肉桂精油、丁香精油、牛至精油对赤霉菌具有良好的抑菌及杀菌作用;肉桂精油、丁香精油对毛霉菌有较好抑制作用,牛至精油对毛霉菌有一定的抑菌作用,但杀菌效果不明显,山苍子精油对毛霉菌的抑菌杀菌效果最差。     

罗勒精油和Nisin复配抑菌剂抑菌效果的研究

以肉制品中的致腐微生物大肠杆菌和金黄色葡萄球菌为试验菌株,采用滤纸片扩散法研究罗勒精油及乳酸链球菌素(Nisin)的抑菌效果,并探索二者的联合抑菌性能,采用三因子二次正交旋转设计确定天然抑菌剂的最佳配比。结果表明:罗勒精油及Nisin对大肠杆菌的MIC分别为3.75μL/mL和7.5mg/mL,对金黄色葡萄球菌的MIC分别为1.875μL/mL和0.9375mg/mL,复配后二者联合抗菌指数FIC为0.75,表现为强烈相加作用,优于罗勒精油与Nisin的单独抑菌效果,且罗勒精油(μL)与Nisin(mg)的最佳配比为3∶1。     

植物精油对铜绿假单胞菌抗菌作用的研究

采用气相熏蒸法研究了松针油、香茅油、依兰油、康酿克油、山苍子油、莪术油、鼠尾草油、沉香木油、艾叶油、迷迭香油十种植物精油对铜绿假单胞菌的气相抗菌活性,通过测定各种植物精油的最低抑菌浓度比较其抗菌效果。实验结果表明：山苍子精油和香茅精油的抑菌效果最好,其最低抑菌浓度均为250 μL/L;鼠尾草油和依兰油的最低抑菌浓度均为500 μL/L;艾叶油、莪术油和迷迭香油的最低抑菌浓度均为1000 μL/L;松针油、康酿克油和沉香木油未表现明显抗菌活性。山苍子油和香茅油以2:3和3:2进行复配时表现出显著协同增效效果,复配物空间体积浓度为100 μL/L时就能完全抑制铜绿假单胞菌的生长。不同溶剂对复配精油抗菌活性有所影响,以冰乙酸为溶剂抗菌效果最好,乙醇其次,甘油和丙二醇稍差。     

复合精油对黄曲霉联合抑菌作用研究

采用联合抑菌评价方法,通过测定植物精油抑菌圈直径、最低抑菌浓度(Minimum Inhibition Concentration,MIC)、最低生长下降浓度(Reduction Concentration,RC)、联合抑菌指数(Fractional Inhibitory Concentration,FIC),对植物精油单独及联合使用后的抑菌效果进行评价,筛选最佳抑制黄曲霉活性作用的复合精油种类及配比。结果表明:大蒜、肉桂、丁香、薄荷精油单独或复合使用均有较强抑制黄曲霉活性的作用。大蒜与肉桂精油联合抑菌评价为相加作用。当大蒜精油与肉桂精油复合体积比为1∶3时,复合精油具有最佳抑制黄曲霉活性的效果。因此,复合精油作为有效防霉保鲜成分具有良好的研发与应用前景。     

不同植物精油对大米青霉和黑曲霉的抑菌效果

为探明部分植物精油对大米的防霉效果,选取提自蓝桉叶、薄荷、山苍子、孜然、丁香、肉桂、花椒、香茅以及迷迭香的9种精油为研究对象,以大米青霉和黑曲霉为目标菌,通过测定抑菌圈直径、最小抑菌浓度、最低生长下降浓度和联合抑菌效果,以确定单一精油的抑菌效果、复配精油的协同抑菌效果及其最佳配比。结果表明,在所选9种精油中,肉桂和丁香精油对大米青霉和黑曲霉的抑菌效果最好,山苍子和蓝桉叶精油次之。在两两复配精油中,当肉桂精油与山苍子精油的比例为3:1(v/v)时,对大米青霉和黑曲霉的抑制效果最佳,其最小抑菌浓度为0.1 μL/mL,比单一精油的浓度下降了20~180倍。研究表明按适当比例复配的肉桂与山苍子复合精油是具良好应用前景的大米防霉保鲜剂。     

18种芳香植物精油抑菌活性的比较研究

目的:研究18种芳香植物精油对5种细菌的体外抑菌活性。方法:采用滤纸片法、肉汤稀释法测定18种芳香植物精油对金黄色葡萄球菌、枯草芽孢杆菌、大肠杆菌、铜绿假单胞菌和肺炎克雷伯氏菌的敏感度、最低抑菌浓度(MIC)及最低杀菌浓度(MBC)。结果:体外抑菌活性试验中月桂、百里香、天竺葵、罗勒、依兰、香茅和马郁兰精油对5种细菌有较强的药敏活性,均为中度和高度敏感。18种芳香植物精油对5种细菌的最低MIC值均为0.49mg/mL。月桂精油、罗勒精油和马郁兰精油对肺炎克雷伯氏菌具有较强的杀菌作用,MBC值均为0.49mg/mL。结论:18种芳香植物精油对5种细菌的抑菌效果不同,其中对肺炎克雷伯氏菌的抑菌效果最好,部分精油表现出良好的抑菌和杀菌活性。     

鲜切西兰花贮藏期病原菌分离鉴定及植物精油对其抑制效果

以‘冬至绿’西兰花为试材,分离、纯化并鉴定鲜切西兰花贮藏期病原菌,筛选出抑制病原菌效果较好的植物精油。通过分离、纯化及致病性实验得到病原真菌菌株AB01,以病原菌内源转录间隔区序列进行进化树分析,鉴定该病原菌为链格孢菌（Alternaria alternata）。选用肉桂、茴香、牛至、丁香、百里香和香茅6 种精油对AB01进行抑菌性实验,通过体外抑菌和活体抑菌筛选出最优的精油种类及含量。结果发现,肉桂精油对AB01的抑菌效果最好,其最低抑菌浓度和最低杀菌浓度分别为0.05 μL/mL和0.15 μL/mL,其次是茴香和牛至精油。0.15 μL/mL肉桂精油用于鲜切西兰花可有效降低花球黄花率和切面褐变率。     

植物精油对微生物的抑菌效果评估研究

本实验以大肠杆菌(Escherichia coli)8099、金黄色葡萄球菌(Staphylococcus aureus)ATCC6538、枯草杆菌黑色变种(Bacillus subtilis)ATCC9372、白色念珠菌(Candida albicans)ATCC10231和黑曲霉(Aspergillus niger ATCC16404)为指示菌,采用纸片法和试管法评估了42种植物精油的抑菌效果,结果显示植物精油对真菌和革兰氏阳性细菌的抑杀效果好,其中有11种精油对5种指示菌的抑杀效果较好,由强至弱的顺序为:肉桂、百里香、柠檬草、香茅、香茅油、雪松、山鸡椒、天竺葵、桂皮油、芫荽、罗勒、山苍子油、欧薄荷、茴香。     

Mechanism of action of Spanish oregano, Chinese cinnamon, and savory essential oils against cell membranes and walls of Escherichia coli O157:H7 and Listeria monocytogenes

The mechanism of the antimicrobial action of Spanish oregano (Corydothymus capitatus), Chinese cinnamon (Cinnamomum cassia), and savory (Satureja montana) essential oils against cell membranes and walls of bacteria was studied by the measurement of the intracellular pH and ATP concentration, the release of cell constituents, and the electronic microscopy observations of the cells when these essential oils at their MICs were in contact with Escherichia coli O157:H7 and Listeria monocytogenes. E. coli O157:H7 and L. monocytogenes, two pathogenic foodborne bacteria, were used as gram-negative and gram-positive bacterial models, respectively. Treatment with these essential oils at their MICs affected the membrane integrity of bacteria and induced depletion of the intracellular ATP concentration. Spanish oregano and savory essential oils, however, induced more depletion than Chinese cinnamon oil. An increase of the extracellular ATP concentration was observed only when Spanish oregano and savory oils were in contact with E. coli O157:H7 and L. monocytogenes. Also, a significantly higher (P < or = 0.05) cell constituent release was observed in the supernatant when E. coli O157:H7 and L. monocytogenes cells were treated with Chinese cinnamon and Spanish oregano oils. Chinese cinnamon oil was more effective to reduce significantly the intracellular pH of E. coli O157:H7, whereas Chinese cinnamon and Spanish oregano decreased more significantly the intracellular pH of L. monocytogenes. Electronic microscopy observations revealed that the cell membrane of both treated bacteria was significantly damaged. These results suggest that the cytoplasmic membrane is involved in the toxic action of essential oils.     

Antimicrobial efficacies of essential oils/nanoparticles incorporated polylactide films against L. monocytogenes and S. typhimurium on contaminated cheese

Polylactide based films were formulated by incorporating polyethylene glycol, selected nanopowders (zinc oxide, silver-copper), and essential oils (cinnamon, garlic, and clove) by solvent casting method. Films were tested against three foodborne pathogens (one gram-positive and two gram-negative) for their antibacterial activity. The effectiveness of selected cinnamon oil-based film was ascertained by performing a challenge test with cheese as a food model. In vitro antibacterial efficacies of nanopowders and essential oils were also determined by the decimal reduction concentrations and the minimum bactericidal concentrations for those foodborne pathogens. It was observed that nanopowders exhibited considerably poorer decimal reduction concentrations and minimum bactericidal concentration values in comparison to the essential oils. Silver-copper alloy nanopowders exhibited lower decimal reduction concentrations and minimum bactericidal concentrations values than ZnO against tested pathogens whereas essential oils showed distinct antimicrobial effectiveness against all those pathogens with in vitro decimal reduction concentration values of 87–157 and 77–220 µg/mL for cinnamon and clove oils, respectively. Among the various formulations, it was observed that only essential oils (especially cinnamon and clove) incorporated films exhibited a significant antimicrobial activity against the selected microorganisms. These results indicate that the poor antibacterial activity of the nanopowders and the hydrophobicity of polylactide could be responsible for the ineffectiveness of nanopowders in polylactide based films. Furthermore, the challenge test indicated the polylactide/polyethylene glycol/cinnamon oil film was appropriate to inhibit the growth of L. monocytogenes and S. typhimurium on cheese up to 11 days at refrigerated storage.     

肉桂精油-玉米淀粉基抗菌膜的制备及其性能

为研究新型抗菌降解包装材料,筛选肉桂精油等4?种植物精油,以玉米淀粉、壳聚糖和魔芋葡甘露聚糖为成膜基质,甘油为增塑剂,吐温-80为表面活性剂,研究肉桂精油添加对复合膜机械性能、光学性能、阻水性能和抑菌性能的影响。结果表明：4?种精油对金黄色葡萄球菌、大肠杆菌和沙门菌的抗菌活性依次为肉桂精油＞牛至精油＞百里香精油＞迷迭香精油。随着肉桂精油质量浓度增加,复合膜的抗拉强度和水蒸气透过系数降低,断裂伸长率和不透明度升高。当肉桂精油质量浓度在15.0～20.0?g/L时,复合膜色泽指数a*值无明显差异（P＞0.05）,L*值显著降低,b*值和ΔE值显著增加（P＜0.05）。添加肉桂精油显著提高了玉米淀粉基膜的抗菌能力（P＜0.05）,精油与吐温-80相互作用对革兰氏阴性的大肠杆菌具有协同作用,而对革兰氏阳性的金黄色葡萄球菌具有拮抗作用。当肉桂精油质量浓度为20.0?g/L时,膜具有较好的物理性能和抗菌效果。本研究可为肉桂精油-玉米淀粉基可降解抗菌膜生产工艺参数的进一步优化提供参考。     

Antimicrobial Wine Formulations Active Against the Foodborne Pathogens Escherichia coli O157: H7 and Salmonella enterica

ABSTRACT:  We developed wine formulations containing plant essential oils and oil compounds effective against foodborne pathogenic bacteria Escherichia coli O157:H7 and Salmonella enterica. HPLC was used to determine maximum solubility of antimicrobials in wines as well as amounts of antimicrobials extracted by wines from commercial oregano and thyme leaves. Activity of essential oils (cinnamon, lemongrass, oregano, and thyme) and oil compounds (carvacrol, cinnamaldehyde, citral, and thymol) in wines were evaluated in terms of the percentage of the sample that resulted in a 50% decrease in the number of bacteria (BA₅₀). The ranges of activities in wines (30 min BA₅₀ values) against S. enterica/E. coli were carvacrol, 0.0059 to 0.010/0.011 to 0.021; oregano oils, 0.0079 to 0.014/0.022 to 0.031; cinnamaldehyde, 0.030 to 0.051/0.098 to 0.13; citral, 0.033 to 0.038/0.060 to 0.070; lemongrass oil, 0.053 to 0.066/0.059 to 0.071; cinnamon oil 0.038 to 0.057/0.066 to 0.098; thymol, 0.0086 to 0.010/0.016 to 0.022; and thyme oil, 0.0097 to 0.011/0.033 to 0.039. Detailed studies with carvacrol, the main component of oregano oil, showed that antibacterial activity was greater against S. enterica than against E. coli and that wine formulations exhibited high activities at low concentrations of added antimicrobials. The results suggest that wines containing essential oils/oil compounds, added or extracted from oregano or thyme leaves, could be used to reduce pathogens in food and other environments.     

天然精油协同等离子体对盐水鸭杀菌保鲜及脂质氧化的调控

为调控等离子体处理对肉类造成的脂质氧化现象，研究复合精油协同低温等离子体（cold plasma，CP）处理对盐水鸭保鲜及脂质氧化的影响。采用牛至精油、肉桂精油和迷迭香配制复合精油，研究CP处理对复合精油抑菌性、总酚含量和1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl，DPPH）自由基清除率的影响。此外，将复合精油协同CP处理盐水鸭，对18 d贮藏期内盐水鸭的菌落总数、大肠杆菌菌落数、色泽及脂质氧化进行测定。结果表明：CP处理未对复合精油的总酚含量和DPPH自由基清除率造成显著影响，但当复合精油质量分数为0.100%～0.125%且协同CP处理大肠杆菌菌液时，大肠杆菌菌落数可降低8（lg（CFU/mL））；同时，复合精油协同CP处理可使盐水鸭保质期显著延长，且对盐水鸭的色泽无显著影响，并能使样品硫代巴比妥酸反应物值从CP处理组的6.87 mg/kg降至4.58 mg/kg。     

植物复合精油对5种稻谷霉变优势菌株抑菌作用研究

为了研究天然植物精油(百里香、丁香、肉桂)对霉变稻谷的抑菌效果,以5种稻谷霉变优势菌株为受试菌,以霉菌抑菌圈直径大小和最低抑菌浓度（MIC）为指标,通过混料设计方法建立复合精油抑菌模型,结合方差分析得到抑菌效果最佳的植物精油配比。研究结果表明,单一精油抑菌活性对亮白曲霉（A. candidus）,杂色曲霉（A. versicolor）和聚多曲霉（A. sydowii）为肉桂精油>丁香精油>百里香精油;对稻黑孢霉（N. oryzae）为肉桂精油=丁香精油>百里精香油;对布罗克青霉菌（P. brocae）为丁香精油=百里香精油<肉桂精油。当肉桂精油:丁香精油:百里香精油的体积比为55.2%︰26.9%︰17.9%时,3种植物精油对5种菌株抑制效果最佳,复合抑制值大于90.9%。     

7种芸香科植物精油抑菌活性的研究

通过水蒸气蒸馏法提取了花椒、柠檬、脐橙、蜜柚、砂糖橘、丑柑以及椪柑7种芸香科植物的挥发性成分。采用肉汤稀释法测定了上述7种单种精油以及2组复配精油对金黄色葡萄球菌、表皮葡萄球菌、白色葡萄球菌、枯草芽孢杆菌等6种常见致病细菌的抑菌活性。结果表明,7种芸香科精油对金黄色葡萄球菌、表皮葡萄球菌、白色葡萄球菌、大肠杆菌、伤寒杆菌和枯草芽孢杆菌的生长均表现不同程度的抑制活性。除了丑柑精油外,其余6种精油对大肠杆菌均表现出了杀灭活性,MBC值在20~40mg/mL之间。精油按照不同比例复配后,抑制活性表现出差异性,柠檬与蜜柚或花椒精油存在拮抗作用。研究结果有助于了解单种精油和复方精油的抑菌性能,为芸香科植物精油的开发应用提供依据。