酸性蛋白酶和纤维素酶联合水解蘑菇柄蛋白的研究

对蘑菇柄蛋白采用纤维素酶与酸性蛋白酶双酶联合水解处理,探索出最适工艺条件为先加纤维素酶,温度50℃,pH 4.5,固液比1∶9,酶用量9.0%,水解时间4 h;后加酸性蛋白酶:温度42℃,pH 3.2,酶用量9.0%,水解时间3 h。双酶联合水解后蘑菇蛋白水解率可达51%。     

应用纤维素酶解和酸洗法从米渣中提取蛋白质的研究

该文研究了纤维素酶水解和酸洗法相结合，从大米糖化渣中提取食用蛋白质的新工艺。纤维素酶水解最佳条件为温度50℃，pH4．8—5．0，纤维素酶用量2μ/g—40μ／g米渣，酶解时间30min-60min；酸洗法以二级酸洗提取效果较好，提取最佳条件为温度30℃，时间6min，料液比1：6；用纤维素酶水解和二级酸洗两步法提取，得到产品蛋白含量最高达86．8％。     

纤维素酶水解糖化木薯秆的影响因素分析

通过对纤维素酶水解糖化木薯秸秆工艺条件的优化,对纤维素酶水解糖化木薯秸秆的影响因素进行分析。结果表明,最佳反应条件为：在温度为45℃,反应体系pH为4．5,酶用量为2g／L,反应时间为42h,还原糖得率最大。     

慈竹硫酸盐浆酶水解条件研究

对影响慈竹硫酸盐浆纤维素酶水解的主要影响因素作了探讨,包括PH、温度、液比、酶用量、时间、打浆度和吐温80用量;还对吐温80影响酶水解的原因进行了探讨。结果表明：在PH值4．8、温度45℃、底物质量浓度28．6g／L、酶用量25FPU馆、吐温80用量1mg／g的条件下水解52h,打浆度13°SR的浆料酶水解得率为82．39％。吐温80用量对慈竹酸盐浆酶水解的影响表现为：一方面影响酶的活性,另外一方面降低纤维素酶与木素的无效吸附,使游离酶的数量增加。     

纤维素酶水解玉米芯的研究

研究了影响纤维素酶水解玉米芯的各个因素(pH、温度、酶添加量、底物浓度)，得到纤维素酶水解玉米芯的最佳条件——pH4．5，温度35℃，酶添加量10U／g玉米芯，底物浓度100g／L。在最佳条件下纤维素酶水解玉米芯的葡萄糖产率为27．1％。     

罗非鱼鱼皮胶原蛋白降血压酶解液的制备与活性研究

本文研究了单酶和复合酶水解罗非鱼鱼皮胶原蛋白制备抑制帆管紧张素转换酶抑制剂（ACEI）的工厂艺条件。通过正交试验确定了菠萝蛋白酶和Alcalase 2．4L蛋白酶单独水解鱼皮胶原蛋白的最适酶解条件。菠萝蛋白酶和Alcalase 2．4L蛋白酶的最适酶解温度，pH，酶，底物，时间，底物浓度分别为45℃，pH4．5，4000U／g，4h，6％和55℃，pH7．5，6000μ／g，2h，4％。在甲．酶水解的基础上，进行复合酶水解实验，结果表明：先采用菠萝蛋白酶水解，再用Alcalase2．4L蛋白酶水解，效果更佳。采用该双酶复合水解工艺，所得水解产物的水解度为30．43％，体外对ACE的抑制率达68．6％。采用Sephadex G-25，HPLC的分离方法对酶解液进行分离纯化，得到了高抑制活力的组分。所得水解原液，Sephadex G-25过柱所得高活力组分的IC50分别为2．82mg／ml利0．65mg／ml。     

大豆蛋白酶解制寡肽过程中蛋白酶再利用的研究

研究了在水解大豆蛋白反应中采用吸附法回收再利用蛋白酶的可行性。结果表明：吸附法可有效回收Akalase碱性蛋白酶。首次大豆蛋白水解反应中黑曲霉酸性蛋白酶的加入量为6％g/g蛋白,Alcalase加入量为15眺蛋白。用大豆蛋白原料吸附回收蛋白酶进行二次大豆蛋白水解反应,酶的补加量为：酸性酶的加入量为5％(g／g),AlcalaseIsn入量为2．5μl/g。     

不同酶类提取米糠蛋白的研究

我国米糠资源丰富，米糠蛋白的营养价值高。本文采用不同酶类提取米糠蛋白，比较蛋白收率．从中选出最佳水解用酶及确定酶用量。不同的酶水解米糠有不同的作用方式。本文对水解米糠所用的细胞破壁酶类和蛋白酶类进行选择,以蛋白收率为指标，水解度为参考指标，比较各种酶水解米糠制蛋白的效果，认为纤维素酶和复合蛋白酶水解效果较好，蛋白收率分别达54．75％和58．93％，因此选择这两种酶为水解用酶。分别对纤维素酶、复合蛋白酶的水解效果进行分析。在pH、温度为各酶最适条件，水解时间、底物浓度相同的条件下，采用酶添加量的单因素试验，选择各酶的最适用量并比较在最适添加量的情况下其蛋白收率。结果当纤维素酶添加量为[E]／[s]=2％时，蛋白收率达最高为56．12％；复合蛋白酶添加量为[E]／[s]pro=2％时，蛋白收率达最高为62．04％。     

酶法水解牛胎盘下脚料

以牛胎盘下脚料为原料，试验5种蛋白酶对其进行水解，根据水解液综合效果确定中性蛋白酶为最适单酶，其最佳水解条件为温度40℃，pH7．5，酶添加量4000u／g，料水比1：3，水解时间4h；响应面分析方法知，中性蛋白酶与胰蛋白酶混合水解牛胎盘下脚料的最佳水解条件为：温度46．4℃，pH值为8．17，酶比1：1(酶量为4000u／g)，料水比为1：3。氨基酸分析结果表明：混合酶水解液的游离氨基酸2483.6mg／L，而中性酶水解液的游离氨基酸493.8mg／L。     

纺织用酸性蛋白酶的性质及其在羊毛处理中的应用

以蛋白酶水解羊毛的能力来衡量自制酸性蛋白酶的活力，对自制酸性蛋白酶的性质及其在羊毛细化处理中的应用进行研究。发现所用酸性蛋白酶最适作用温度为40℃，最适作用pH值为3．0；一些金属离子在一定条件下可提高蛋白酶的活力，促进蛋白酶对羊毛纤维的减量细化．除温度、pH值外，酶用量、浴比、表面活性剂JFC的用量对蛋白酶水解羊毛的效果也有一定的影响。用所制得的酸性蛋白酶处理64支内蒙古羊毛的最佳条件为温度40℃，pH值3．0，酶用量4％，浴比1：25．JFC0．9％。     

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