乳清蛋白的流变性质

主要研究了乳清蛋白溶液在升温过程中贮能模量G′与损耗模量G″的变化及其形成凝胶的温度。乳清浓缩蛋白（WPC-80）形成凝胶的临界质量分数为8％。质量分数为20％的WPI-90、WPC-80乳清蛋白的胶凝温度分别为76．9，77．6℃，相同质量分数的WPC-34不能形成凝胶。质量分数为20％的WPC-80添加质量分数0～1．5％无水氯化钙后，胶凝温度从77．6℃下降到71．0℃。     

乳清蛋白对脱脂发酵乳的流变特性及贮存稳定性的影响

研究了乳清蛋白对脱脂发酵乳流变学特性及贮存稳定性的影响，在VAYC-370为发酵剂的情况下，分别以质量分数为10％，20％，30％和40％的乳清蛋白替代脱脂奶粉进行发酵，结果表明，乳清蛋白会降低发酵乳凝胶的硬度、提高发酵乳的内聚性，同时发现乳清蛋白可提高搅拌型发酵乳的贮存稳定性．表明发酵乳凝胶的内聚性与贮存稳定性呈正相关关系。     

世界乳清产品贸易概况

乳清产品包括浓缩乳清、乳清粉、乳清蛋白浓缩物、低乳精乳清粉、脱盐乳清粉、乳清混合粉和乳糖。乳清的干制品是乳清产品的主要产品形式和销售形式。1995年世界乳清产品贸易量为35．6万吨（不包括欧盟内部贸易），价值约10亿美元。与五年前相比，贸易量增长了30％。同期的乳精     

乳清多肽的制备及乳清多肽酒的研制

采用蛋白酶水解乳清粉，对乳清多肽进行酵母菌发酵，并对发酵所得乳清酒进行风味调配。乳清粉最佳的水解条件为：酶浓度与底物浓度之比为1％、温度60℃、pH9．0、时间120min，水解度21．22％。乳清多肽酒的最优发酵条件：接种量5％、起始pH7．5、温度22℃、发酵60h，酒精度可达到3．9％。多肽乳清酒的最佳基本调配是总酸（苹果酸：柠檬酸=1：1）为0．1％、蔗糖为7％、环状糊精为0．6％。     

乳清的营养价值及乳清饮料的研究现状

乳清是工业生产干酪及干酪素的副产品,乳清的营养成分相当于除去酪蛋白的脱脂乳,约占牛乳营养成分的５５％,乳固体达６％－７％,其中粗蛋白１％,粗脂肪０．３％－０．４％,乳糖３％－５％。国外多利用乳甭生产乳清粉和乳清蛋白浓缩物等。乳清饮料有３种形式：１）乳清与果汁直接调配;２）制做无蛋白澄清饮料;３）发酵型乳清饮料。所以,乳清的合理开发利用十分重要。     

微生物转谷氨酰胺酶催化乳清蛋白聚合研究

采用SDS－PAGE分析，研究了不同条件下微生物转谷氨酰胺酶（MTGase）催化乳清蛋白（WPI）聚合。结果显示，MTGase可催化乳清蛋白的β－乳球蛋白（β-LG）和α－乳清蛋白（α－LA）聚合，形成低聚物或生物聚合物，其中β-LG更易受MTGase的催化，当TGase酶浓度一定时（0.5U/mL),TGase催化WPI聚合的最佳底物质量分数范围为2％－4％，对WPI进行加热预处理，同时添加还原剂，可明显提高MTGase对WPI的催化活性，MTGase催化WIP的最适PH值范围为6．5－7．5，当WPI经预热处理（85℃，15min），同时添加20mmol/L的DTT，TGase催化WPI聚合12h，可使质量分数为92％的β-LG和质量分数为75％的α－LA聚合。     

乳清蛋白在无添加剂酸奶中的应用

本实验采用乳清蛋白制备了一种不添加稳定剂的酸奶,为制作无添加剂酸奶提供理论依据。通过分析不同添加量的乳清蛋白对酸奶发酵终点,以及后熟和保质期内酸奶的酸度、粘度、脱水收缩作用敏感性（STS）、持水率（WHC）的影响,结果发现：乳清蛋白对发酵终点的影响不大;随着乳清蛋白添加量的增加,在后熟时酸奶的酸度变化加快;乳清蛋白可以提高酸奶在保质期内的稳定性,对STS和WHC都有促进作用,可保证产品最终质量。此外,结合感官测评,乳清蛋白添加量在3~4%时,产品口感及稳定性较佳,通过使用乳清蛋白可以使无添加剂的酸奶在保质期内稳定。     

响应面法优化低糖益生菌乳清发酵饮料的研究

在单因素试验的基础上结合响应面分析法,对影响益生菌乳清发酵饮料感官品质和pH值的蛋白糖质量分数、益生菌质量分数和后发酵时间的因素进行了研究,通过SAS软件分析建立了回归模型并进行了方差分析,最后优化得到最佳的工艺参数为:蛋白糖质量分数0.175%,益生菌质量分数3.852%,后发酵时间3.275 h,在此条件下得到的益生菌乳清发酵饮料的实际感官评分为97.68,pH值为4.96,二者与理论预测值差异均不显著。     

银杏酸奶的研制

以银杏果仁和脱脂牛奶为主要原料研制一种复合型发酵酸奶。从产品感官质量和稳定性入手，应用正交试验法，确定了合理的配方和适宜的发酵工艺条件，并对产品质量作了评价。结果表明，银杏酸奶的主要原料的最佳配比为脱脂牛奶：银杏果浆：1：1，同时加入6％的蔗糖和0．2％的复合稳定剂(琼脂：羧甲基纤维素纳=1：1)(均为质量分数)；最佳的发酵工艺条件为接种量6％，发酵温度为41℃，发酵时间为6h，该产品具有感官品质佳、稳定性好和营养丰富等特点。     

盐度和加曲量对罗非鱼片加工废弃物速酿鱼露的影响

对罗非鱼片加工废弃物速酿鱼露的发酵工艺进行了初步研究，从氨基酸态氮、总酸、TVBN、色度、感官5个指标分析了速酿鱼露在不同盐度（4，7，10，13g／dL）和不同加曲量（质量分数10％、15％、2S％、35%）下的发酵状况，综合各指标的影响确定适宜的速酿发酵条件为：7g／dL盐度和10％的加曲量，在此条件下的鱼露发酵液氨基酸态氮、总酸含量较高、腐败程度低，风味感官评价较好。     

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