龙脑樟鲜叶挥发油成分及其抗菌活性的研究

目的:研究龙脑樟鲜叶中挥发油的化学成分和抗菌活性。方法:采用水蒸汽蒸馏法提取龙脑樟叶中挥发油;通过气相色谱-质谱(GC-MS)联用技术分析挥发油化学成分;采用K-B纸片琼脂扩散法和微量肉汤稀释法分别测其对细菌、酵母菌和霉菌的抑菌圈直径和最小抑菌浓度(MIC值),以评估挥发油的抑菌性能。结果:GC-MS结果表明该挥发油有27种组成成分,占整个挥发油的98.14%,其中以右旋龙脑(81.58%)、樟脑油(2.96%)和α-蒎烯(2.03%)为主要成分;该挥发油及其主要成分右旋龙脑对实验所选的细菌、酵母菌和霉菌三类微生物均表现出一定的抗菌效果。其中,挥发油对所测菌的抑菌直径范围为(9.21±0.6)～(22.12±1.30)mm,而右旋龙脑组分对所测菌的抑菌直径范围为(7.32±0.5)～(20.42±1.40)mm;对应两种物质对所测菌的最低抑菌浓度(MIC值)范围分别为(31.25～125)μg/mL和(62.5～125)μg/mL。结论:该研究为龙脑樟叶的综合利用及天然右旋龙脑药用资源的研究开发提供参考依据。     

余甘子果实粗提物的抑菌活性研究

本实验研究并探讨了余甘子果实70%乙醇提取物的抗菌谱和抑菌特性,结果表明：70%的乙醇提取物对供试霉菌几乎没有抑菌活性;对啤酒酵母有一定的抑菌活性;对金黄色葡萄球菌、大肠杆菌、枯草芽孢杆菌、变形杆菌和嗜热脂肪芽孢杆菌有很强的抑菌活性,抑菌活性强弱顺序为：嗜热脂肪芽孢杆菌＞变形杆菌＞金黄色葡萄球菌＞大肠杆菌＞枯草芽孢杆菌,其MIC值分别为：2.0%、2.0%、2.0%、4.0%、4.0%,啤酒酵母的MIC值为8.0%。     

银杏叶提取物(EGb)抗菌特性的研究

测定了银杏叶提取物(EGb)对食品常见污染菌的抗菌活性,探讨了热处理和pH值对EGb抗菌活性的影响,阐明了银杏叶提取物(EGb)的抗菌特点以及作为食品天然防腐剂的开发价值。结果表明:银杏叶提取物的抑菌作用显著,其抗菌活性随着其浓度增加而增强,对细菌和真菌的最低抑菌浓度(MIC)为1.25%和5.0%;EGb的抗菌活性具有热稳定性,能忍受高温短时的热处理;EGb在pH5～9的范围内均具有抗菌活性。本研究为EGb在食品天然防腐剂领域中的开发利用提供实验依据。     

10种中草药提取物对常见果蔬致腐真菌的抑制作用及有效成分分析

研究了陈皮、肉桂、丁香、五倍子、艾叶、辛夷、姜黄、川芎、虎仗和蜂胶10种中草药提取物对果蔬致腐真菌扩展青霉和黑曲霉的抑制作用,结果表明:中草药丁香提取物具有较强的抗菌活性,对扩展青霉和黑曲霉的MIC分别为25%和50%;通过GC-MS从丁香挥发油中分离分析出14种化合物,其中丁香酚的相对含量最高,达68%;抑菌试验还表明,丁香挥发油中含有削弱丁香酚抗菌性能的成分。     

柿叶抗菌活性的研究及活性成分的分离鉴定

首次以柿叶提取物对七种常见的食品腐败菌及致病菌进行抑菌试验。结果表明，柿叶具有较强的拮抗食品腐败菌与致病菌的活性，对各供试菌的最低抑菌浓度（MIC）和最低杀菌浓度（MBC）为0．313g/ml和0.625g/ml，抑菌率达到90％以下。对柿叶的活性成分进行分离与鉴定，它们分别为挥发油，总黄酮，香豆素及有机酸。     

天山花楸叶抗菌作用研究

用一系列细菌和真菌试验了天山花楸叶乙醇提取物的抑菌作用。结果表明一定浓度的天山花楸叶乙醇提取物对供试细菌和真菌都显示出一定的抑制作用，MIC和MBC均较低，其抑菌活性随着提取物浓度的增大而逐渐增强。提取物对高温、紫外线都具有良好的稳定性。因此天山花楸叶乙醇提取物可用于食物防腐、保鲜等领域，具有广泛的使用范围。     

金银花挥发油及残渣浸膏的抗菌活性研究

以山东和广东两地金银花为原料,利用二氧化碳超临界萃取法从中分离挥发油,并利用分离挥发油后的残渣制备浸膏。采用GC-MS联用分析挥发油组成,采用高效液相色谱测定金银花浸膏中的绿原酸和木犀草苷含量,通过琼脂片扩散法和最小抑菌浓度法(Minimum Inhibitory Concentration,MIC)检测金银花挥发油和浸膏的抗菌活性。分离得到的金银花挥发油主要成分为反丁烯二腈(61.5%)和乙酸戊酯(37.7%)。山东产地的金银花水溶相浸膏中绿原酸和木犀草苷的含量在四种浸膏中最多。金银花挥发油和浸膏对6种致病菌表现出不同程度的抑制作用,两类提取物对革兰氏阳性菌的抗菌作用优于革兰氏阴性菌。山东产金银花的挥发油对金黄色葡萄球菌抑菌作用最强,抑菌圈直径为9.3 mm,MIC值为64μL/m L;广东产金银花水相浸膏对枯草芽孢杆菌抑菌作用最强,抑菌圈直径达到15 mm以上,MIC值为16μL/m L。两地金银花提取物的抗菌活性无明显差异。     

丁香和肉桂挥发油的提取、主要成分测定及其抗菌活性研究

本文采用水蒸汽蒸馏法提取丁香和肉桂的挥发油,并对所得挥发油主要成分进行气相测定,通过体外抗菌试验,比较了这两种挥发油及其主要成分和目前常用化学防腐剂苯甲酸钠和山梨酸钾对金黄色葡萄球菌、大肠杆菌、枯草芽孢杆菌、沙门氏菌和志贺氏菌等5株食品中常见污染菌的抗菌作用。结果表明丁香油中丁香酚含量为78.1%,肉桂油中肉桂醛含量为86.8%;这两种挥发油及其主要成分丁香酚和肉桂醛的抗菌作用均强于两种化学防腐剂,其中肉桂油与其主要成分肉桂醛表现出的抗菌活性最强,最小抑菌浓度(MIC)为200～1600mg/L;仅为苯甲酸钠和山梨酸钾MIC(6400～25600mg/L)的1/64～1/16;丁香油及其主要成分丁香酚的抗菌活性次之,MIC为800～1600mg/L,相当于苯甲酸钠和山梨酸钾MIC的1/16～1/8。     

荸荠皮提取物的抗菌性及其应用研究

用平板稀释法测定荸荠皮提取物的抗菌性。用平板菌落 计数法测定荸荠皮提取物作为食品防腐剂的应用效果。 结果表明,荸荠皮提取物具有较强的抗菌效力,对大多数 细菌的最低抑菌浓度(MIC)为0.3％,对多数真菌的最低 抑菌浓度为1.25％;在pH4.4～8.1的基质中,荸荠皮提取 物都具有较强的抗菌效力;而且其热稳定性能良好,经 121℃湿热灭菌处理15min,仍具有较强的抗菌效力。荸荠 皮提取物在食品中可明显抑制细菌的生长,使食品的保 质期延长。     

树头发提取物抑菌作用研究

用树头发(pterula umbrinella Bres.)的乙醇水溶液提取物对三种细菌、两种酵母菌和两种霉菌进行抑菌研究。结果表明,树头发提取物对大肠杆菌、枯草芽孢杆菌、金黄色葡萄球菌、啤酒酵母、赤酵母、黑曲霉和桔青霉等都有抑制作用,对上述供试菌的最低抑菌浓度(MIC)分别为0.5%、0.5%、1.0%、3.0%、3.0%、2.5%、2.5%;热处理对提取物的抑菌效果无影响。     

基于HS-SPME-GC-MS和OAV分析不同干燥方式菊花脑的挥发性物质差异

通过顶空固相微萃取结合气相色谱-质谱（headspace solid phase microextraction-gas chromatography-mass spectrometry,HS-SPME-GC-MS）联用法对热风干燥、真空冷冻干燥、微波-热风联合干燥菊花脑挥发性物质进行定性以及定量,明确干燥方式对菊花脑挥发性物质的影响,并探索菊花脑的关键呈香物质。结果表明：菊花脑中共分离出140种物质,新鲜菊花脑中检出112种物质,热风干燥样品中检出86种物质,微波-热风联合干燥样品中检出83种物质,真空冷冻干燥样品中检出85种物质,分别为萜烯类、酯类、醛类、醇类、芳香族化合物以及其他类共六大类物质。萜烯类含量最高,分别在新鲜菊花脑中检出229 474.33μg/kg,热风干燥样品中检出64 629.68μg/kg,微波-热风联合干燥样品中检出56 469.88μg/kg,真空冷冻干燥样品中检出70 832.87μg/kg。与另两种干燥方式对比,真空冷冻干燥较好地保留了挥发性物质的丰度。真空冷冻干燥菊花脑与新鲜菊花脑风味相似,主要呈樟脑、松节油以及花草的清香。GC-MS结合气味活度值分...     

新疆圆柏枝条乙醇提取物体外抗菌活性测定

对新疆圆柏枝条乙醇提取物的抑菌特性进行了研究,测试了提取物对食品中主要致病、致腐细菌的最低抑菌浓度和最低杀菌浓度、实验了提取成分对热、压力、紫外光和金属离子的稳定性,并选择了有代表性的食品进行食物实验。结果表明:新疆圆柏乙醇提取物对受试菌均有较低的最低抑菌浓度和最低杀菌浓度,分别为:枯草芽孢杆菌MIC0.5%、MBC0.75%;大肠杆菌MIC0.125%、MBC0.25%;金黄色葡萄球菌MIC0.25%、MBC0.25%;苏云金杆菌MIC0.0625%、MBC0.25%;产气肠杆菌MIC0.0625%、MBC0.125%;普通变形杆菌MIC0.25%、MBC0.5%;酵母菌MIC0.5%、MBC1%;黑曲霉MIC1%、MBC2%;青霉MIC1%、MBC2%;根霉MIC1%、MBC2%;毛霉MIC1%、MBC2%。抑菌成分对热、压力、紫外光及金属离子稳定,且食物防腐实验结果良好。     

侧柏叶挥发油抑制真菌实验研究

应用水蒸汽蒸馏法提取侧柏叶挥发油,通过体外抑制真菌实验比较挥发油和常用食品防腐剂山梨酸钾对3种常见真菌的抑菌活性,同时考察两者对这3种真菌的最低抑菌浓度(MIC)。结果显示,侧柏叶挥发油对上述3种常见真菌表现出明显的抑制活性,侧柏叶挥发油的抑菌作用强于山梨酸钾。侧柏叶挥发油对黑曲霉和青霉的最低抑菌浓度均为25.00 mg/mL;对根霉的最低抑制浓度为12.50 mg/mL。山梨酸钾对黑曲霉和青霉的最低抑菌浓度均大于50.00 mg/mL;对根霉的最低抑制浓度为40.00 mg/mL。由此可见,侧柏叶挥发油在天然防腐剂开发方面将有良好的应用前景。     

Antimicrobial Effect of Malpighia Punicifolia and Extension of Water Buffalo Steak Shelf‐Life

In the present study, a multiple approach was used to characterize Malpighia punicifolia extract and to evaluate its inhibitory activity against several meat spoilage bacteria. First, volatile fraction, vitamins and phenolic compounds of the extract obtained by supercritical fluid extraction were determined by GC‐MS and HPLC. Then, the antimicrobial action of the extract was in vitro evaluated against Pseudomonas putida DSMZ 291^T, Pseudomonas fluorescens DSMZ 50009^T, Pseudomonas fragi DSMZ 3456^T, and Brochothrix thermosphacta DSMZ 20171^T by the agar well diffusion assay and by the agar dilution test. Based on the results of the minimum inhibitory concentration (MIC) against the assayed bacteria, 4 different concentrations of the extract were used in a challenge test on water buffalo steaks stored for 21 d at 4 °C. Results of chemical analyses showed that M. punicifolia extract is characterized by the presence of several compounds, already described for their antimicrobial (phenolic acids, flavonones, and furanes) and antioxidant (ascorbic acid) properties. The in vitro detection of antimicrobial activities highlighted that the extract, used at 8% concentration, was able to inhibit all the target bacteria. Moreover, very low MIC values (up to 0.025%) were detected. In situ tests, performed on water buffalo steaks treated with the extract in the concentration range 0.025% to 0.05%, showed a strong inhibition of both intentionally inoculated bacteria and naturally occurring microorganisms. Positive results, in terms of color and odor, were also observed during the entire storage of steaks preserved with the extract.     

贮藏温度和包装方式对菊花脑贮藏期间生理特性的影响

研究了常温、10+1℃和0+1℃三种贮藏温度及相应温度下敞口和挽口两种包装方式对菊花脑贮藏期间生理特性的影响。结果表明,0℃贮藏可有效抑制菊花脑的呼吸强度、超氧阴离子和丙二醛的生成速率及电导率的上升速度,同时降低了多酚氧化酶和过氧化物酶的活性,延长了菊花脑的贮藏寿命;结果同时显示10℃和0℃下挽口包装菊花脑贮藏保鲜效果优于敞口包装,而在常温下效果则相反。     

Biological activities of the essential oil and methanolic extract of Micromeria fruticosa (L) Druce ssp serpyllifolia (Bieb) PH Davis plants from the eastern Anatolia region of Turkey

The in vitro antimicrobial and antioxidant activities of the essential oil and methanolic extract of Micromeria fruticosa ssp serpyllifolia as well as the composition of the essential oil were examined. The essential oil exhibited activity against 14 bacteria, three fungi and a yeast, with minimal inhibitory concentration (MIC) values ranging from 31.25 to 125 µl ml^?1, whilst the methanolic extract was inactive. Antioxidant activity was measured by two methods, namely scavenging of the free radical DPPH and inhibition of linoleic acid oxidation. The methanolic extract exhibited significant antioxidant activity in both assays, providing 50% inhibition at 70.9 ± 0.5 µg ml^?1 concentration in the DPPH assay and inhibiting linoleic acid oxidation to 59% at 2 mg ml^?1 concentration, whilst the essential oil showed activity only at higher concentrations. The gallic acid equivalent total phenolic content of the methanolic extract was found to be 55.2 ± 2.00 µg mg^?1 dry weight extract (5.5% w/w). The chemical composition of the hydrodistilled essential oil was analysed by means of GC/MS. Twenty‐nine constituents were identified, the main ones being piperitenone (50.61%) and pulegone (29.19%). Copyright © 2004 Society of Chemical Industry     

植酸对腐败希瓦氏菌的抑菌机理

结合植酸对南美白对虾的保鲜,以虾体优势腐败菌一腐败希瓦氏菌为研究对象,利用植酸溶液处理后,通过对细菌的抑菌效果及最小抑菌浓度、细菌生长曲线、碱性磷酸酶（AKP）等的测定研究其抑菌机理。结果表明,植酸对腐败希瓦氏菌有较强的抑菌效果,最低抑菌浓度（体积分数）为0.2％。同对照组相比,植酸能够影响细菌的生长规律,使细胞破损。细胞壁和细胞膜遭到破坏,AKP及电导率均增大,初步阐述了植酸对腐败希瓦氏菌的抑菌机理。     

响应面法优化菊花脑黄酮提取工艺

采用Box-Behnken试验和响应面分析法研究菊花脑黄酮的提取工艺。结果表明,菊花脑黄酮的最佳提取工艺条件为乙醇体积分数78%、提取时间89min、水浴温度68℃、液料比41:1(mL/g),黄酮提取得率2.88mg/g。     

Damage inhibition during refrigerated storage of mackerel (Scomber scombrus) fillets by a presoaking in quince (Cydonia oblonga) polyphenolic extract

The effect of quince (Cydonia oblonga Miller) polyphenolic extract on preserving mackerel (Scomber scombrus) fillets during refrigerated (4 °C) storage for 11 days was investigated. The quince extract, mainly consisted of procyanidin B dimer (50.8%) and hydroxycinnamic acids (36.62%), was found to quench 2,2‐diphenyl‐1‐picrylhydrazyl radicals by nearly 59.3%. As deduced from the lower peroxide value of the fillet fat fraction and the inhibition of thiobarbituric acid reactive substances formation, the quince extract (8.9 ± 0.4 mg phenolics mL^?1) was found to prevent fish oil from oxidative deterioration compared to control samples. Moreover, the extract was found to be active for in vitro inhibiting the growth of a range of food‐borne bacteria, including Vibrio fluvialis, a halophilic bacterium responsible for a relevant number of sporadic gastroenteritis attributed to contaminated seafood. The minimal inhibition and bactericide concentration (MIC, MBC) values were about 0.37–1.2 mg of polyphenols mL^?1. In a second experiment, following cold smoking of fillets, sensory attributes firmness, astringency, acidity, colour and odour were analysed. The use of multivariate statistical methods (cluster analysis and principal component analysis) revealed no significant differences between samples pre‐treated and non‐pre‐treated (control) with the quince‐phenolic extract.     

吊瓜皮提取物抑菌活性的研究

研究了吊瓜皮提取物的抑菌作用.探讨了吊瓜皮活性物质的提取方法并且测定其对各种常见菌的抑菌圈大小、MIC和MBC.结果表明,吊瓜皮提取物时常见菌有显著的抑制效果,乙酸乙酯直接提取和95%乙醇提取后用石油醚、乙酸乙酯逐级萃取的提取液内富含有抑制细菌和霉菌生长的活性物质.MIC和MBC测定结果表明,各个样品在不同浓度下可以有效抑制或杀死细菌和霉菌.