留兰香精油的抗菌活性研究

采用扩散法对留兰香精油的抗菌活性进行定性测定,用紫外可见分光光度法确定精油的最小抑菌浓度(MIC值)。结果表明留兰香精油对3种试验菌株的抑菌性是枯草芽孢杆菌>金黄色葡萄球菌>大肠杆菌。对枯草芽孢杆菌、金黄色葡萄球、菌大肠杆菌3种菌的最小抑菌浓度(MIC)分别为0.5、1.0μL/mL和3.5μL/mL。     

粪鬼伞菌丝体提取液的抗菌活性

以深层发酵得到的粪鬼伞菌丝体为原料,分别用水和80%的乙醇溶液进行超声波浸提,对浸提液进行体外抗菌实验,然后用与总糖浓度相同的多糖溶液和水提液对比进行抗菌试验.结果表明,水提液对大肠杆菌和枯草芽孢杆菌的最低抑菌浓度(MIC) 为3.2 mg/mL, 对金黄色葡萄球菌的MIC为1.6 mg/mL;对大肠杆菌的最低杀菌浓度(MBC)为12.5 mg/mL,对金黄色葡萄球菌和枯草芽孢杆菌的MBC为25 mg/mL;对青霉和黑曲霉没有作用;醇提液对大肠杆菌和枯草芽孢杆菌的MIC为50 mg/mL,对金黄色葡萄球菌、青霉和黑曲霉没有作用;总糖质量浓度相同的多糖溶液和水提液具有等效的抑菌和杀菌能力.因此,粪鬼伞多糖就是水提液中的主要抗菌活性物质.     

柠檬草精油成分分析、抑菌性及对巨峰葡萄保鲜研究

采用中国西南地区的柠檬草,以水蒸气蒸馏法提取得到的柠檬草精油(lemongrass essential oil,LEO),通过气相色谱-质谱法(gas chromatography-mass spectrometry,GC-MS)分析柠檬草精油的成分和相对含量;通过测定抑菌圈直径和最低抑菌浓度研究对大肠杆菌、金黄色葡萄球菌和枯草芽孢杆菌的抑菌效果;研究不同浓度的柠檬草精油对新鲜采摘的巨峰葡萄产品品质和生理的影响,确定其保鲜作用。结果表明:当料液比达到1∶15(g/mL)时,出油量与得率达到最大,平均得率为0.91%。利用GC-MS分析柠檬草精油成分,其中有21种组分,主要成分为柠檬醛,占比为70.11%。柠檬草精油对3种供试菌均有较好抑制作用,对枯草芽孢杆菌、金黄色葡萄球菌和大肠杆菌抑菌圈大小分别为23.8、22.5 mm以及11.2 mm。其中对金黄色葡萄球菌和枯草芽孢杆菌的抑制效果较好,对金黄色葡萄球菌和枯草芽孢杆菌的最低抑菌浓度为0.1μL/mL,大肠杆菌的最低抑菌浓度为0.2μL/mL;与对照组相比,柠檬草精油处理能有效缓解可滴定酸、可溶性固形物含量和硬度的降低,减少烂果率和失重率,其中0.50%柠檬草精油处理组的保鲜效果明显好于其他处理组。由此可见,柠檬草精油具有抑菌和水果保鲜的作用。     

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。     

香菜茎叶精油的提取及其成分解析

以乙醚为溶剂,采用超声波法萃取香菜,以0.284%产率获得了香菜芳香精油,用GC-MS对精油进行了成分分析,解析出70种物质,占精油93.634%。其中,酯类化合物47.569%,饱和烃类化合物14.947%,醛类化合物和醇类化合物含量分别为13.406%和12.595%。与水蒸汽蒸馏法获得的精油以及香菜原汁的抗菌作用进行了比较,结果显示水蒸汽蒸馏法和超声波法提取的精油对大肠杆菌、白葡萄球菌、枯草芽孢杆菌,根霉菌的抑制作用大于香菜原汁。其中,水蒸汽蒸馏法获得的精油对大肠杆菌、白葡萄球菌的抑菌活性远远大于超声波法。对枯草芽孢杆菌和根霉菌的抗菌活性,两种提取方法获得的精油抑菌效果相近,但是,香菜精油和原汁对米曲霉、黑曲霉完全没有抑菌作用。     

川佛手精油抗氧化及抑菌活性的研究

为了研究川佛手精油的抗氧化和抑菌活性,以石油醚作为溶剂超声辅助提取得到川佛手精油,测定其抗氧化活性和体外抑菌活性,川佛手精油对金黄色葡萄球菌、大肠杆菌、枯草芽孢杆菌、苏云金芽孢杆菌、肠球菌5种常见食源性污染菌的抑菌效果。结果表明:川佛手精油含有丰富的多酚和黄酮类物质,具有一定的抗氧化活性,对DPPH和ABTS自由基清除能力较强,EC50分别为3.92,1.88mg/mL。体外抑菌试验表明川佛手精油对肠球菌有很好的抑菌效果,最低抑菌浓度(MIC)为24mg/mL,抑菌强弱顺序为:肠球菌、苏云金芽孢杆菌、枯草芽孢杆菌、金黄色葡萄球菌、大肠杆菌。     

覆盆子黄酮的抑菌特性研究

本文探讨了覆盆子黄酮的抑菌作用,研究了覆盆子黄酮对大肠杆菌、枯草芽孢杆菌、金黄色葡萄球菌、啤酒酵母、根霉、毛霉、青霉的抑菌作用。结果表明:覆盆子黄酮对试验菌的抑菌顺序为:金黄色葡萄球菌>枯草芽孢杆菌>大肠杆菌>青霉,对啤酒酵母、根霉、毛霉没有抑菌作用,最低抑菌浓度分别为:大肠杆菌0.16 mg/mL,枯草芽孢杆菌0.08 mg/mL,金黄色葡萄球菌0.04 mg/mL,青霉0.64 mg/mL,在100℃以内,温度对覆盆子黄酮的抑菌效果没有明显的影响,抑菌率随作用时间的延长而增加,随覆盆子黄酮浓度的增加而增加,且在pH值4~8范围内,覆盆子黄酮抑菌效果稳定。     

茵陈蒿水溶性抗菌物质提取工艺和抑菌效果研究

研究了茵陈蒿水溶性抗菌物质的提取工艺和抑菌效果。结果表明,以水为提取剂,最佳提取工艺条件是时间80min,温度60℃,加水比1∶15,且其中的主要有效成分绿原酸的含量为0.235%,茵陈蒿水提取物对枯草芽孢杆菌、青霉菌、黑曲霉、金黄色葡萄球菌和大肠杆菌都有抑菌作用,其最低抑菌浓度分别为:枯草芽孢杆菌为4%(含绿原酸0.188mg/mL),黑曲霉为5%(含绿原酸0.235mg/mL),青霉为5%(含绿原酸0.235mg/mL),金黄色葡萄球菌为8%(含绿原酸0.376mg/mL),大肠杆菌为12%(含绿原酸0.564mg/mL)。     

灵芝菌丝体中灵芝酸的体外抑菌作用

采用杯碟法试验灵芝菌丝体中灵芝酸对革兰阴性菌(大肠杆菌)、革兰阳性菌f金黄色葡萄球菌),以及芽孢杆菌(枯草芽孢杆菌)的体外抑菌作用.结果表明,灵芝酸组分对大肠杆菌和金黄色葡萄球菌的生长有较明显的抑制作用,而对枯草芽孢杆菌的抑制作用相对较弱;该灵芝酸对大肠杆菌和金黄色葡萄球菌的最小抑菌浓度为12.5 mg/mL;而对枯草芽孢杆菌的最小抑菌浓度为50 mg/mL.此外,该灵芝酸的抑菌成分在40℃和60℃下(处理2 h)较稳定,但在80℃和100℃温度下,热稳定性较差.     

菜籽多酚抑菌作用研究

采用滤纸片扩散法测定菜籽多酚溶液对大肠杆菌、金黄色葡萄球菌、枯草芽孢杆菌的抑制效果。结果表明:0.05%～0.80%的菜籽多酚对大肠杆菌、金黄色葡萄球菌、枯草芽孢杆菌均有抑制作用,并显示浓度-效应关系。最佳抑菌浓度在0.4%左右。菜籽多酚对3种微生物的最低抑菌浓度,大肠杆菌是1.00 mg/100 mL,枯草杆菌是0.50 mg/100 mL,金黄色葡萄球菌是0.25 mg/100 mL。以上结果表明:菜籽多酚有抑菌能力,可望用于食品贮存与加工。     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the