丁香酚对金黄色葡菌球菌抗菌作用的探究

为了寻找代替化学防腐剂的绿色安全天然添加剂,研究了丁香酚对金黄色葡萄球菌的抑菌作用。以丁香酚为原材料,采用96孔板微量稀释法和琼脂平板稀释法确定最低抑菌浓度(MIC)和最低杀菌浓度(MBC),通过菌落数直观地确定丁香酚对金黄色葡萄球菌的MIC值和MBC值;并以分光光度计法探究不同质量浓度丁香酚对金黄色葡萄球菌中苹果酸脱氢酶(MDH)和琥珀酸脱氢酶(SDH)酶活性的影响。结果表明,丁香酚对金黄色葡萄球菌的最低抑制浓度(MIC)为600μg/mL,最低杀菌浓度(MBC)为700μg/mL,其可将金黄色葡萄球菌菌体蛋白质质量浓度、苹果酸脱氢酶(MDH)酶活、琥珀酸脱氢酶(SDH)酶活分别降至0.033 mg/mL、8.28 U/mg、2.40 U/mL,原因可能是抑制了菌体三羧酸循环和电子链传递中相关关键酶的活性。     

木芙蓉(Hibiscus mutabilis)叶提取物对大肠杆菌O1和金黄色葡萄球菌91053的外抗菌效果研究

研究不同浓度木芙蓉(Hibiscus mutabilis)叶提取物对大肠杆菌(E.coliO1)和金黄色葡萄球菌(Staphylococcus aureus 91053)的体外抗菌效果.利用二倍稀释法和涂布平板法,确定提取物对两种菌种的最低抑菌浓度(MIC)和最低杀菌浓度(MBC),并绘制杀菌曲线.结果为:提取物对大肠杆菌的MIC和MBC浓度均为0.25 g/mL,8、4、2、1 MIC浓度的木芙蓉叶提取物分别在第6、14、18h能完全杀灭细菌该菌;提取物对金黄色葡萄球菌的MIC和MBC浓度均为0.5g/mL,4、2、1 MIC浓度的木芙蓉叶提取物对金黄色葡萄球菌的杀菌效果更佳,分别能在第6、10、14 h完全杀灭该菌.木芙蓉叶提取物对大肠杆菌和金黄色葡萄球菌均具明显的杀菌效果.     

木芙蓉（Hibiscus mutabilis）叶提取物对大肠杆菌O1和金黄色葡萄球菌91053的体外抗菌效果研究

研究不同浓度木芙蓉(Hibiscus mutabilis)叶提取物对大肠杆菌(E.coliO1)和金黄色葡萄球菌(Staphylococcus aureus91053)的体外抗菌效果。利用二倍稀释法和涂布平板法,确定提取物对两种菌种的最低抑菌浓度(MIC)和最低杀菌浓度(MBC),并绘制杀菌曲线。结果为:提取物对大肠杆菌的MIC和MBC浓度均为0.25g/mL,8、4、2、1MIC浓度的木芙蓉叶提取物分别在第6、14、18h能完全杀灭细菌该菌;提取物对金黄色葡萄球菌的MIC和MBC浓度均为0.5g/mL,4、2、1MIC浓度的木芙蓉叶提取物对金黄色葡萄球菌的杀菌效果更佳,分别能在第6、10、14h完全杀灭该菌。木芙蓉叶提取物对大肠杆菌和金黄色葡萄球菌均具明显的杀菌效果。      

桫椤茎中牡荆素的抑菌活性

从体外试验的角度观察牡荆素的抑菌作用。以大肠杆菌、金黄色葡萄球菌、枯草芽孢杆菌为供试菌种,采用滤纸片法和试管内药液2倍稀释法测定牡荆素的抑菌圈直径和最低抑菌浓度(Minimal inhibitive concentration,MIC)。牡荆素对大肠杆菌、金黄色葡萄球菌、枯草芽孢杆菌均有明显的抑制作用,对大肠杆菌的最低抑菌浓度(MIC)为100μg/mL,对金色葡萄球菌的最低抑菌浓度(MIC)为25μg/mL,对枯草芽孢杆菌的最低抑菌浓度(MIC)为100μg/mL。牡荆素具有良好的体外抑菌作用。     

丁香酚对金黄色葡萄球菌抗菌作用的探究

为了寻找代替化学防腐剂的绿色安全天然添加剂,研究了丁香酚对金黄色葡萄球菌的抑菌作用。以丁香酚为原材料,采用96孔板微量稀释法和琼脂平板稀释法确定最低抑菌浓度（MIC）和最低杀菌浓度（MBC）,通过菌落数直观地确定丁香酚对金黄色葡萄球菌的MIC值和MBC值;并以分光光度计法探究不同质量浓度丁香酚对金黄色葡萄球菌中苹果酸脱氢酶（MDH）和琥珀酸脱氢酶（SDH）酶活性的影响。结果表明,丁香酚对金黄色葡萄球菌的最低抑制浓度（MIC）为600 μg/mL,最低杀菌浓度（MBC）为700 μg/mL,其可将金黄色葡萄球菌菌体蛋白质质量浓度、苹果酸脱氢酶（MDH）酶活、琥珀酸脱氢酶（SDH）酶活分别降至0.033 mg/mL、8.28 U/mg、2.40 U/mL,原因可能是抑制了菌体三羧酸循环和电子链传递中相关关键酶的活性。     

葡萄籽和苹果原花青素对变形链球菌和金黄色葡萄球菌的抑制作用

研究苹果原花青素和葡萄籽原花青素对变形链球菌(Streptococcus mutans)和金黄色葡萄球菌(Staphylococcus aureus)的抑制作用,采用试管液体稀释法和琼脂稀释法抑菌实验测定其最低抑菌质量浓度(MIC)和质量最低杀菌质量浓度(MBC),并通过测定培养基pH值的变化,研究葡萄籽原花青素对变形链球菌产酸能力的影响。结果表明：苹果原花青素、葡萄籽原花青素对变形链球菌和金黄色葡萄球菌生长都有抑制作用;苹果原花青素对变形链球菌的MIC和MBC分别为1.25、4.00mg/mL,葡萄籽原花青素对变形链球菌的MIC和MBC分别为1.75、2.00mg/mL;苹果原花青素对金黄色葡萄球菌的MIC和MBC分别为4.00、9.00mg/mL,葡萄籽原花青素对金黄色葡萄球菌的MIC和MBC分别为2.00、6.50mg/mL。葡萄籽原花青素质量浓度大于1.00mg/mL对变形链球菌的产酸能力有显著抑制效果。     

香旱芹精油对金黄色葡萄球菌抑菌机理的研究

采用微波辅助水蒸气蒸馏提取出香旱芹精油,对其成分进行GC-MS分析,通过测试其对金黄色葡萄球菌的抑菌圈直径、最低抑菌浓度(MIC)和最低杀菌浓度(MBC)评价其抑菌效果。分别从菌体微观形态、细胞溶出物、蛋白质和钾离子泄漏等方面研究香旱芹精油对金黄色葡萄球菌的抑菌机理。实验结果表明香旱芹精油的主要成分为百里香酚(45.85%)、对伞花烃(20.72%)和γ-松油烯(23.57%),其对金黄色葡萄球菌的抑菌圈直径为75mm,MIC为0.25μL/mL,MBC为0.5μL/mL。香旱芹精油可使金黄色葡萄球菌细胞膜受到损伤,使细胞膜表面出现塌陷和破裂,并引起菌体细胞溶出物、蛋白质以及钾离子的泄露,从而导致菌体的死亡。     

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.     

复合生物保鲜剂对金黄色葡萄球菌的抑菌作用研究

研究了壳聚糖、溶菌酶与茶多酚配制而成的复合保鲜剂对金黄色葡萄球菌的抑菌作用。采用琼脂平板打孔法确定复合保鲜剂对金黄色葡萄球菌的最小抑菌浓度(MIC)与最小杀菌浓度(MBC),结合抑菌率、抑菌活力、细菌生长曲线、膜完整性、AKP活性与细菌超微结构,综合评价复合保鲜剂对金黄色葡萄球菌的影响。结果得出,复合保鲜剂对金黄色葡萄球菌的MIC与MBC分别为0.8 mg/mL与1.6 mg/mL,随着作用时间的延长,复合保鲜剂对金黄色葡萄球菌的生长抑制明显,菌体的细胞壁与细胞膜完整性受到破坏,菌体细胞中的AKP量增多,影响菌体细胞的代谢循环,菌体内部的核酸与蛋白质外泄,抑制其正常生长。由细菌超微结构观察发现,菌体细胞经复合保鲜剂处理后,造成菌体扭曲变形,细胞壁破裂,细胞质外渗。表明复合保鲜剂可破坏菌体的细胞壁,影响胞膜稳定性与胞内环境,最终导致菌体死亡。     

乳酸对三种食源性致病菌的抑菌及杀菌作用

选用金黄色葡萄球菌、蜡样芽孢杆菌、埃希氏大肠杆菌3株常见的食源性致病菌,用于测定乳酸的抑菌效果、最小抑菌浓度(MIC)及最小杀菌浓度(MBC),并研究乳酸对3株致病菌细胞对数期代时的影响,同时研究不同浓度乳酸对大肠杆菌膜电位的影响.试验结果表明:乳酸对3株食源性致病菌均有不同程度的抑制作用,并得出最小抑菌浓度(MIC)及最小杀菌浓度(MBC),分别是金黄色葡萄球菌MIC 1.8 mg/mL,MBC3.6 mg/mL;蜡样芽孢杆菌MIC 3.6 mg/mL,MBC 7.2 mg/mL;大肠杆菌MIC 0.9 mg/mL,MBC 1.8 mg/mL;乳酸在最小抑菌浓度下显著(p≤0.05)延了3株食源性致病菌对数生长期的代时.大肠杆菌对乳酸的敏感性较强,代时增加128%.采用流式细胞仪测定大肠杆菌的膜电位.发现乳酸对大肠杆菌细胞膜电位有一定的影响,随着乳酸浓度的增加,细胞膜电位逐渐增加,导致细胞的超极化程度越来越严重直至细胞死亡.     

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.     

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.     

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.     

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