草莓澄清汁的加工技术研究

本文采用复合果胶酶酶解的方法,研究了草莓澄清汁的加工工艺,得到草莓澄清汁最佳的酶解工艺条件为:复合果胶酶添加量0．015%,酶解时间90min,酶解温度35℃,此时草莓的出汁率为81．10%,透光率可达96．1%。     

发酵型草莓蜂蜜酒的工艺优化研究

以草莓为主要原料,用蜂蜜调整糖度,通过单因素实验与正交实验对复合酶法提取草莓汁的工艺条件和草莓蜂蜜酒的发酵工艺进行优化研究.结果表明,草莓的最佳酶解工艺条件为:复合酶添加量0.2％(果胶酶与纤维素酶添加量比例为1∶4),酶解温度50℃,pH4.5,酶解时间4.0h,草莓出汁率可达90.2％.草莓蜂蜜酒的发酵工艺条件为:发酵初始糖度16％,酵母菌直投用量0.4％,发酵温度30℃,发酵时间4d,酒精度可达8.4％vol.     

草莓汁澄清工艺研究

草莓汁的澄清是草莓汁加工工艺的重要环节,澄清效果会影响草莓汁的品质和货架期。以红颜草莓为原料,首先采用单因素及正交试验对果胶酶、壳聚糖澄清草莓汁的条件进行了优化,确定了果胶酶、壳聚糖澄清草莓汁的最佳作用条件,再使用果胶酶-壳聚糖复合法澄清草莓汁。结果表明,果胶酶最佳用量为0.015 g/L,壳聚糖处理草莓汁的最佳工艺条件为壳聚糖添加量0.6 g/L,水浴时间25 min,水浴温度55 ℃,草莓汁pH值3.3。采用果胶酶-壳聚糖（果胶酶0.015 g/L和壳聚糖0.6 g/L）复合法澄清草莓汁,透光率为97.3%,澄清效果优于单一澄清法,因此果胶酶-壳聚糖复合澄清法可作为一种良好澄清方法使用。     

复合酶对草莓出汁率和澄清度的影响

为提高草莓的出汁率和草莓汁的澄清度,该文以新鲜草莓为原料,研究单一酶（果胶酶、纤维素酶、木聚糖酶）和复合酶对出汁率和澄清度的影响。在单因素试验基础上,对复合酶添加量、复合酶质量比、酶解温度、酶解时间进行响应面优化,得到最佳酶解条件,并对酶解的草莓汁进行感官评价。结果表明,果胶酶和纤维素酶具有协同作用,可明显提高草莓的出汁率和澄清度,出汁率从64.16%（对照组）提高到87.38%,澄清度从2.34%提高到72.83%;经响应面优化试验,得到草莓汁最佳酶解条件为复合酶添加量0.17%、复合酶（果胶酶∶纤维素酶）质量比3∶1、酶解温度41℃、酶解时间35 min,此条件下草莓的出汁率为90.84%,草莓汁的澄清度为84.61%;与对照组相比,复合酶组的感官评分最高,整体风味及口感更优,表明果胶酶和纤维素酶可以有效提高草莓的出汁率和澄清度,且所得草莓清汁感官风味更佳。     

酶法生产草莓汁的研究

研究了直接榨汁、解冻后榨汁、纤维素酶酶解、果胶酶酶解四种方法对生产草莓汁品质的影响,结果表明,果胶酶酶解生产草莓汁效果最佳。通过正交实验研究了酶加入量、酶解温度、酶解时间对草莓汁出汁率、花色苷及Vc的影响。结果表明,果胶酶制取草莓汁的最佳工艺是:酶加入量0.005%、酶解时间1h、酶解温度50℃。此条件下生产的草莓汁色泽鲜艳、营养丰富,而且美味可口。     

草莓胡萝卜复合果蔬汁澄清工艺研究

澄清是复合果蔬汁加工过程核心技术之一,处理不好直接影响果蔬汁品质。果胶酶作为常用澄清剂,具有简便、快捷、效果好等特点。本文以果胶酶为澄清剂,研究了果胶酶用量、酶解温度、酶解时间和复合果蔬汁pH对草莓胡萝卜复合果蔬汁的澄清效果。单因素试验显示:果胶酶用量为0.65 0.75g/L、酶解温度为40 50℃、酶解时间为3.5 4.5h、复合果蔬汁pH为3.5 4时,草莓胡萝卜复合果蔬汁的出汁率和透光率均较好。通过正交试验获得的最佳工艺条件为:果胶酶用量0.7g/L、酶解温度50℃、酶解时间5h、复合果蔬汁pH值3.75,此条件下澄清后草莓胡萝卜复合果蔬汁透光率为80.34%,出汁率为88.73%,可溶性固形物含量为10.8%。本研究结果表明,在合适的工艺条件下,果胶酶能有效的去除草莓胡萝卜复合果蔬汁中的果胶物质。     

红枣枸杞菠萝复合饮料的加工工艺研究

以红枣为主料,枸杞、菠萝等为辅料,对红枣枸杞菠萝复合饮料的加工工艺进行了研究。结果表明,果胶酶浸提红枣汁的最佳工艺条件为：果胶酶用量0.08％、酶解温度55℃、酶解时间3h、酶解pH4.0;红枣汁的最佳澄清条件是果胶酶添加量0．02％、55℃下澄清1．5h;红枣枸杞饮料的最佳配比为：红枣汁55％、枸杞汁8％、菠萝汁12％、50％蔗糖溶液25％。     

复合澄清草莓汁生产工艺研究

本文介绍了以草莓为主要原料,经酶解处理得到草莓清汁,再辅以其它蔬菜清汁,得到复合澄清草莓果汁饮料的生产工艺。解决了草莓汁褐变、沉淀及与其它蔬菜汁营养、口味配合等问题,研究得到关键步骤酶解的最佳条件,生产工艺过程合理、科学、高效。     

复合澄清草莓汁生产工艺研究

本文介绍了以草莓为主要原料,以酶解处理得到草莓清汁,再辅以其它蔬菜清汁,得到复合澄清草莓果汁饮料的生产工艺。解决了草莓汁褐变、沉淀及与其它蔬菜汁营养、口味配合等问题,研究了得到关键步骤酶解的最佳条件,生产工艺过程合理、科学、高效。     

澄清草莓汁制作工艺的研究

对澄清草莓汁的制作工艺进行了探讨,确定了适宜的工艺条件和参数.结果表明,采用微波中火40s热烫,节省时间,色泽和Vc损失较小,出汁率达75%以上.采用果胶酶澄清草莓汁的最佳工艺条件为:45℃,pH=3,果胶酶添加百分含量为0.015%,酶解时间为40min,得到的果汁透光率可达95%以上.     

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