莽吉柿果壳不同萃取物中总黄酮、总酚含量及抗菌活性

研究莽吉柿果壳提取物不同溶剂萃取物抑菌作用。以莽吉柿果壳为原料,经95%乙醇回流提取,总提取物分别用不同极性溶剂进行萃取,得到石油醚、氯仿、乙酸乙酯萃取物和水层。测定各萃取物中总黄酮、总酚含量,比较各部位对大肠杆菌、金黄色葡萄球菌、鲍曼不动杆菌、肺炎克雷伯菌、铜绿假单胞菌的抑菌活性。结果表明:莽吉柿果壳提取物的不同溶剂萃取物中,乙酸乙酯萃取物的总黄酮和总酚的含量最高(黄酮含量135.57±0.021 mg RE/g、总酚含量138.09±0.380 mg GAE/g);乙酸乙酯萃取物、水层的抗菌活性最佳,对金黄色葡萄球菌MIC值均为0.125 mg/mL,表现为极度敏感,对另外4种试验菌的MIC值均在0.5～2 mg/mL之间,表现为高度敏感;石油醚萃取物和氯仿萃取物仅对金黄色葡萄球菌有明显抗菌活性, MIC分别为0.5 mg/mL和0.25 mg/mL,表现为极度敏感。莽吉柿果壳提取物的萃取物中乙酸乙酯萃取物和水层对所有试验菌均有较强的抗菌活性,石油醚萃取物和氯仿萃取物仅对金黄色葡萄球菌有明显抗菌活性。     

白刺果实提取物的体外抑菌活性研究

探讨白刺果实提取物的体外抑菌活性,以期为白刺果实的综合利用及天然食品防腐剂的开发提供依据。用石油醚、氯仿、乙酸乙酯和正丁醇分别对白刺果实95%乙醇提取物进行萃取,纸片法测定各萃取部分对大肠杆菌、枯草芽孢杆菌、金黄色葡萄球菌、酵母菌、青霉、根霉和黑曲霉7种常见的食源性污染菌的抑菌效果,并通过倍比稀释法测定乙酸乙酯部分对其中3种细菌的最低抑菌浓度。结果表明:白刺果实乙酸乙酯部分、乙醇部分和氯仿部分对3种供试细菌均有抑菌作用,其中乙酸乙酯部分抑菌效果最好,且乙酸乙酯部分对3种细菌的抑制强弱顺序为:枯草芽孢杆菌>大肠杆菌>金黄色葡萄球菌;其中乙酸乙酯部分对枯草芽孢杆菌和金黄色葡萄球菌的最低抑菌浓度(MIC)均为25mg/mL,对大肠杆菌的MIC是50mg/mL。各萃取部分对供试真菌均无明显抑制作用。     

菠萝叶乙醇提取物的抑菌活性及其稳定性研究

采用96孔板法和倾注平板法研究菠萝叶总提物及其不同溶剂萃取物的抑菌活性,同时考察温度、光照和pH对乙酸乙酯萃取物抑菌活性稳定性的影响。结果表明,乙酸乙酯萃取物的抑菌效果最佳,其对金黄色葡萄球菌、蜡状芽孢杆菌、枯草杆菌、藤黄八叠球菌的最小抑菌浓度(MIC)分别为3.12、3.12、6.25、6.25mg/mL,对黑曲霉和青霉的最小抑菌浓度(MIC)分别为5、10mg/mL。在设定的温度范围、光照条件和不同酸度条件下,乙酸乙酯萃取物的抑菌活性较稳定。因此,菠萝叶乙酸乙酯萃取物的抑菌活性具有一定的光热稳定性和酸稳定性。     

侧柏球果体外抑菌作用初探

目的：观察侧柏球果乙醇提取物的体外抑菌活性。方法：运用渗漉法提取并制备石油醚、乙酸乙酯、正丁醇和水萃取物,用滤纸片法对粗提物及各萃取物进行粗筛,有抑菌作用的萃取物进一步用微量肉汤稀释法测定其最低抑菌浓度（MIC）。结果：侧柏球果乙醇提取物及石油醚和乙酸乙酯萃取物具有抑制金黄色葡萄球菌等3种孳兰氏阳性菌和大肠埃希菌等3种举兰氏阴性菌生长繁殖的活性,乙醇提取物抑菌作用最强,对金黄色葡萄球菌、大肠埃希菌和肺炎克雷伯菌的MIC均为19．6μg·mL-1,对地衣芽孢杆菌、无乳链球菌和铜绿假单胞菌的MIC均为39．1μg·mL-1;石油醚萃取物对6种测试菌的MIC均为78．2ug·mL-1,乙酸乙酯萃取物对铜绿假单胞菌的MIC为625μg·mL,对无乳链球菌和肺炎克雷伯菌的MIC为312．5ug·mL-1,对其余3种测试菌的MIC为156．3ug·mL-1结论：侧柏球果乙醇提取物及石油醚和乙酸乙酯萃取物能湿著抑制金黄色葡萄球菌、地农芽抱杆菌、无乳链球菌、大肠埃希菌、肺炎克雷伯菌和铜绿假单胞菌的生长繁殖。     

阳荷不同极性部位体外抑菌活性研究

为研究阳荷的体外抑菌活性,采用70%乙醇回流提取阳荷粉末,依次用石油醚、乙酸乙酯、正丁醇萃取乙醇提取物,得到乙醇提取物、石油醚萃取物、乙酸乙酯萃取物、正丁醇萃取物和水萃取物;用滤纸片对乙醇提取物及不同极性萃取物进行抑菌活性测定,有抑菌活性的部位进一步测定其最低抑菌浓度(minimum inhibitory concentration,MIC)和最低杀菌浓度(minimum bactericidal concentration,MBC)。试验结果表明阳荷乙醇提取物、石油醚萃取物、乙酸乙酯萃取物和正丁醇萃取物,MIC值在3.125 mg/mL~12.5 mg/mL之间,MBC值为25 mg/mL;阳荷乙醇提取物、石油醚萃取物、乙酸乙酯萃取物、正丁醇萃取物和水萃取物对枯草芽孢杆菌有较强的抑菌效果,MIC值在3.125 mg/mL~12.5 mg/mL之间,MBC值为25 mg/mL;阳荷乙醇提取物和石油醚萃取物对大肠杆菌、肺炎克雷伯菌、粪肠球菌、铜绿假单胞菌和鲍曼不动杆菌均有抑菌效果;阳荷乙醇提取物、石油醚萃取物、乙酸乙酯萃取物、正丁醇萃取物和水萃取物对苏云金芽孢杆菌没有抑菌作用。阳荷对革兰氏阳性菌和革兰氏阴性菌具有广谱抑菌活性。     

山豆根提取物抗氧化和抑菌活性的研究

研究山豆根不同溶剂(氯仿、乙酸乙酯、正丁醇、乙醇)提取物的抗氧化活性和抑菌活性,通过测定四种提取物的DPPH自由基、ABTS自由基、羟自由基的清除能力以及还原能力来评估其抗氧化能力;并通过测试各提取物对7种实验菌的最低抑菌浓度(MIC)来评估它们的抑菌活性。结果表明:山豆根四种溶剂提取物均具有一定的抗氧化能力和抑菌活性,其中,对DPPH自由基的清除效果最佳,EC50均小于0.2mg/m L;乙酸乙酯提取物对金黄色葡萄球菌有明显的抑菌作用,其MIC为0.313mg/m L。     

菝葜提取物抑菌作用研究

用石油醚、氯仿、乙酸乙酯、正丁醇分别萃取经50%乙醇超声处理后的菝葜提取液。用四种供试菌,采用滤纸片法、最小抑菌浓度、半数抑菌浓度比较各萃取物的抑菌活性。结果:各萃取物对实验菌均有抑制作用,萃取物抑菌活性大小为:乙酸乙酯相正丁醇相水相醇提物石油醚相氯仿相,与萃取物中的总多酚、总黄酮含量有关。其中乙酸乙酯相的抑菌效果最好,当其浓度为80mg/m L时,对金黄色葡萄球菌、枯草芽孢杆菌、大肠杆菌和沙门氏菌抑菌圈分别为13.6±0.12、13.2±0.10、12.9±0.07、(12.5±0.01)mm。乙酸乙酯相对四种菌的最小抑菌浓度分别为5、5、5、10mg/m L,其半数抑菌浓度分别为12.5、13.6、18.2、18.7mg/m L。结论:菝葜提取物有抑菌作用,特别是乙酸乙酯萃取物的抑菌效果最好。     

汉麻叶提取物抑菌活性及抑菌稳定性研究

目的研究汉麻叶提取物的抑菌活性及抑菌稳定性。方法用乙醇对汉麻叶成分提取并依次用石油醚、乙酸乙酯、正丁醇分级萃取,以4种常见食源性致病菌:金黄色葡萄球菌、大肠杆菌、单核细胞李斯特菌、沙门氏菌为指示菌,用牛津杯法和微量2倍稀释法测定汉麻叶提取物的抑菌活性并分别对其热稳定性、酸碱稳定性、紫外线稳定性、金属离子稳定性、蔗糖稳定性进行考察。结果汉麻叶提取物对大肠杆菌和沙门氏菌无抑制作用,但对金黄色葡萄球菌和单核细胞李斯特菌具有良好的抑菌作用,活性成分主要分布于乙酸乙酯相,其对2种细菌的最小抑菌浓度(minimum inhibitory concentration,MIC)分别为7.81mg/mL和15.63mg/mL;汉麻叶乙酸乙酯相经紫外线照射、蔗糖添加和不同温度处理仍表现出良好的稳定性,酸性条件使其对金黄色葡萄球菌和李斯特菌的抑菌活性增强,Ca~(2+)使其抑菌活性提高,Fe~(3+)使其抑菌活性降低,Na~+能够增强其对单核细胞李斯特菌的抑菌活性,K+使其对金黄色葡萄球菌的抑制作用有所增加。结论汉麻叶提取物具有良好的抑菌活性和抑菌稳定性,具备作为一种天然防腐剂进行开发和利用的前景。     

微波辐射预处理提取花叶滇苦菜总黄酮工艺及其乙酸乙酯萃取物的抑菌活性研究

为了探讨微波辐射预处理提取花叶滇苦菜总黄酮的工艺优化及其总黄酮提取液乙酸乙酯萃取物的抑菌活性,在单因素实验基础上,采用正交试验定总黄酮提取最佳工艺;参照CLSI标准测定乙酸乙酯萃取物对铜绿假单胞菌(ATCC9027)、铜绿假单胞菌耐药菌(PA1)、金黄色葡萄球(ATCC29213)、金黄色葡萄球菌耐药菌(SA1)、大肠杆菌(ATCC25922)等5种细菌的抑菌活性。结果表明,花叶滇苦菜地上部分总黄酮提取的最佳工艺为:微波辐射时间为120 s,微波功率为350 W,乙醇浓度为60%,水浴温度70℃,料液比1:40 g/mL,水浴时间为60 min,此时,黄酮得率为38.328 mg/g。地下部分总黄酮提取的最佳工艺为:微波辐射时间为90 s,微波辐射功率为490 W,乙醇浓度为70%,料液比1:30 g/mL,水浴温度为80℃,水浴时间为90 min,其黄酮得率为7.232 mg/g。乙酸乙酯萃取物具备一定抑菌活性,对金黄色葡萄球菌耐药菌的MIC分别为4(地上部分)和8 mg/mL(地下部分)。当浓度低于16 mg/mL时,对铜绿假单胞菌、铜绿假单胞菌耐药菌和大肠杆菌均无抑制作用。微波辐射预处理对花叶滇苦菜总黄酮的提取具有指导意义,总黄酮提取液乙酸乙酯萃取物对金黄色葡萄球菌具有一定的抑制作用。     

辣木叶醇提物不同极性部位抑菌活性研究

测定辣木叶醇提物不同极性部位的总黄酮含量及抑菌活性。以石油醚、乙酸乙酯、正丁醇依次萃取辣木叶醇提物,得不同极性部位并测定各部位总黄酮含量;以树脂天青法研究不同极性部位对8种试验菌的最小抑制浓度(minimum inhibitory concentration,MIC)和最小杀菌浓度(minimum bactericidal concentration,MBC),确定其抗菌活性大小。结果表明:辣木叶乙酸乙酯部位总黄酮含量明显高于其他部位达到(326.19±2.35)mg/g,而石油醚相不含黄酮。抗菌结果表明,不同极性部位的抑菌活性顺序为:乙酸乙酯相正丁醇相醇提物,其中,乙酸乙酯相对肺炎克雷伯菌(Klebsiella pneumoniae)、金黄色葡萄球菌(Staphylococcus aureus)、粪肠球菌(Enterococcus faecalis)、苏云金杆菌(Bacillus thuringiensis)的MIC均为0.625 mg/mL,对鲍曼不动杆菌(Acinetobacter baumannii)、大肠埃希氏菌(Escherichia coli)的MIC为1.25 mg/mL,对铜绿假单胞菌(Pseudomonas aeruginosa)、枯草芽孢杆菌(Bacillus subtilis)的MIC为2.5 mg/mL。表明乙酸乙酯部位总黄酮含量丰富,是辣木叶抗菌的主要活性部位。     

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.     

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     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press