丁香抑菌成分超声波提取工艺研究

天然植物提取物对多种果蔬采后致腐菌有抑制作用,实验证明丁香提取物对葡萄采后低温主要致腐菌灰葡萄孢有明显的抑制作用.采用超声波法对丁香中抑菌成分进行提取.以生长速率法测定抑菌率,通过单因素和正交设计考察了溶剂种类、溶剂浓度、料液比、超声温度、超声时间和超声功率等因素对丁香提取物抑菌效果的影响.结果表明:采用80%乙醇作为提取溶剂,料液比为1:15、超声温度55℃、超声时间60min、超声功率 210W的提取条件下测得的抑菌率最高、效果最好.     

红提葡萄致病菌的筛选及丁香抑菌成分提取工艺研究

以红提葡萄为试材,对采后致病菌进行了筛选和纯化;以筛选出的红提葡萄主要致病菌为目的菌,对丁香抑菌成分提取工艺进行了研究。研究表明:筛选出的2号病菌可导致红提葡萄黑点病,该菌属于半知菌亚门、丝孢纲、丝孢目、丛梗孢科、复端孢属;丁香抑菌成分的适宜提取条件为:乙醇浓度75%,料液比1:15,提取时间45min,提取温度40℃,在此条件下的抑菌圈直径为1.957cm。     

溪黄草水提取物及其抑菌效果研究

以水作为浸提溶剂,研究了溪黄草水提取物对大肠杆菌、沙门氏菌、青霉和黑曲霉的抑菌效果。通过单因素试验和正交试验优化了溪黄草抑菌物的提取工艺条件为:提取温度为90℃,提取时间为1.5h,料液比为1∶15(g/mL),在此条件下进行抑菌试验,溪黄草水提取物对大肠杆菌和沙门氏菌具有明显的抑制作用,其抑菌圈分别为13.8mm与15.4mm,对青霉和黑曲霉菌的抑制作用不明显。并采用光电比浊法验证了溪黄草水提取物的抑菌活性。结果表明在相同条件下,溪黄草水提取物对沙门氏菌的抑菌活性要强于大肠杆菌。     

超声辅助提取甘青虎耳草总黄酮工艺及其抑菌作用

目的：研究甘青虎耳草(Saxifraga tangutica Engl.)总黄酮的提取工艺及其抑菌作用。方法：用正交试验超声波辅助乙醇提取总黄酮;用琼脂扩散法和肉汤倍比稀释法研究不同质量浓度总黄酮提取物对6种供试菌的抑菌作用。结果：方差分析得各因素影响的顺序为提取次数＞乙醇体积分数＞超声时间＞料液比,最佳工艺为提取50℃、超声功率100W、乙醇体积分数80%、料液比1:25(g/mL)、超声时间35min、提取4次,在此条件下提取率达81.73mg/g;抑菌试验显示总黄酮提取物对细菌均有抑制作用,对金黄色葡萄球菌、枯草杆菌、大肠杆菌的最小杀菌质量浓度分别为0.156、0.313、0.625mg/mL;对酵母菌的抑制作用较弱;对霉菌没有抑制作用。结论：本实验结果可为甘青虎耳草总黄酮提取工艺的确定及在抑菌方面的应用提供实验依据。     

丁香乙醇提取物的抑菌效果及其在馒头保鲜中的应用

研究了丁香中抗菌抑菌成分的提取和抑菌效果。选择乙醇为提取溶剂,通过试验确定其最优提取条件为乙醇浓度85%、温度90℃、料液比1∶18、时间6 h;通过紫外分光光度法测定丁香中主要抑菌成分丁香酚的含量为329 mg/g;通过牛津杯法测定抑菌效果,丁香粗提液对毛霉、金黄色葡萄球菌、大肠杆菌,酵母菌和曲霉的平均抑菌圈直径分别为20 mm,27 mm,20mm,15 mm和18 mm;并对丁香提取物抑菌效果的应用方面进行了研究,通过测定放置一定时间的馒头样品的吸光度值、菌落总数及理化指标酸度,得出丁香提取物对食品中常见致病菌的抑制作用显著,为丁香可开发成安全有效的天然食品防腐剂做了进一步的研究工作。     

艾叶总三萜的提取工艺优化及其抑菌活性

本研究以湖北恩施艾叶为原料,考察溶剂种类、溶剂浓度、提取温度、液固比及超声时间对艾叶总三萜得率的影响。在单因素的基础上,根据Box-Behnken试验设计原理,选取四因素三水平,以艾叶总三萜得率为响应值进行响应面分析,确定最优工艺参数,并运用倍比稀释法研究艾叶总三萜提取物对7种常见致病菌的最小抑菌浓度(minimal inhibitory concentration,MIC),分析了艾叶中三萜类物质的抑菌活性。实验结果表明,超声波辅助提取艾叶总三萜的最佳提取工艺参数为:乙醇浓度72%,提取温度为73℃,液固比20:1 mL/g,超声时间42 min。此条件下艾叶总三萜实际得率为6.51%,其中超声时间、提取温度对艾叶总三萜得率影响较大。艾叶总三萜对所选7种致病菌均有较好的抑制作用,尤其是金黄色葡萄球菌和肺炎链球菌,最小抑菌浓度为3.00mg/m L。本研究提供的提取方法操作简单、结果稳定,且提取物具有一定的抑菌性能,为艾叶总三萜的进一步开发提供科学依据。     

蜂胶提取物的抑菌效果研究

用不同方法提取蜂胶有效成分,进行体外抑菌试验。结果表明:各种提取方法对食品中的常见菌都有不同程度的抑制作用,其中对革兰氏阳性菌抑菌作用较好;各种方法提取物对不同细菌的抑菌效果也不一样,其中以超声波提取效果最好,其最小抑菌浓度为:大肠杆菌:0.8%、沙门氏菌0.8%、金黄色葡萄球菌0.1%、蜡状芽孢杆菌0.1%、枯草杆菌0.2%、鸡蛋表面混合菌0.2%。     

溪黄草中抑菌物质的提取及抑菌效果的研究

主要对溪黄草抑菌物质的最佳提取条件以及抑菌性质进行了研究.实验结果表明,溪黄草中抑菌物质的最佳提取工艺条件是:浓度为70%的乙醇,回流时间为2 h,料液比1∶30.溪黄草乙醇提取物对大肠杆菌具有抑制作用,对霉菌抑制效果不明显.     

超声波辅助酶法提取香蕉皮多酚

采用超声波辅助酶法提取香蕉皮多酚,通过单因素试验和均匀试验优化了提取工艺,并通过滤纸片法检测了香蕉皮多酚提取物的抑菌性。结果表明,超声辅助提取香蕉皮多酚的最优提取工艺参数为：乙醇体积分数45%,纤维素酶添加量0.06%,酶解pH值2.5,酶解时间108 min,酶解温度70℃,在此条件下提取香蕉皮多酚,多酚提取率2.989 mg/g,该提取物对金黄色葡萄球菌和枯草芽孢杆菌具有良好的抑制作用。     

迎春花抑菌活性物提取工艺

目的：优化迎春花花中抑菌活性物质的提取工艺。方法：以抑菌效果为指标,在单因素试验的基础上,确定提取溶剂的体积分数、提取温度和提取时间进行4 因素3 水平正交试验。结果：最佳提取工艺条件为：溶剂为体积分数90% 乙醇溶液,60℃水浴加热2h;提取物对金黄色葡萄球菌、枯草芽孢杆菌、大肠杆菌、藤黄八叠球菌和变形杆菌的的最小抑菌浓度均为0.125g/mL,最小杀菌浓度均为0.25g/mL;提取物经强酸及高温处理后抑菌效果不明显,在碱性环境、紫外光、氧化还原剂处理后抑菌活性稳定;提取物的乙酸乙酯和正丁醇部位具有抑菌活性。结论：本实验所建立的工艺方法可应用于迎春花花中抑菌活性物质的提取。     

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