多重抗药性突变株中α－淀粉酶高产菌株选育

以解淀粉芽孢杆菌（Ｂａｃｉｌｌｕｓａｍｙｌｏｌｉｑｅｆａｃｉｅｎｓ）Ａ－４为出发菌株，经诱变处理，选育多重抗药性突变株。研究结果表明，抗药性突变株α－淀粉酶产量提高的正变率和正变幅度明显大于非抗药性突变株，负变率和负变幅度也较高。经ＮＴＧ和ＮＴＧ－ＵＶ诱变处理，获得一株林可霉素、Ｄ－环丝氨酸和万古霉素多重抗性突变株ＬＣＶ＿５（Ｌｉｎ￣ｒ，Ｃｓ￣ｒ，Ｖｍ￣ｒ），其α－淀粉酶活力比出发菌株Ａ－４提高３２．５％，发酵周期短，摇瓶为４０ｈ，酶活力达４６１ｕ／ｍｌ．     

阿舒假囊酵母过量合成核黄素性能的改良

以６０Ｃｏ的ｒ射线为诱变剂，核黄素合成途径的中间产物的结构类似物为“筛子”，筛选了阿舒假囊酵母（Ｅｒｅｍｏｔｈｅｃｉｕｍａｓｈｂｙｉ）的四种抗性突变株：杀结核菌素抗性突变株（Ｔｕｂｒ）、２－脱氧葡萄糖抗性突变株（２－ＤＧｒ）、８－氮杂鸟嘌呤（８－ＡＧｒ）和抗残液突变株。杀结核菌素抗性突变株Ｔ３０的摇瓶核黄素产量由出发菌的２．５～２．８ｍｇ／Ｌ提高并稳定在３．５ｍｇ／Ｌ以上，经初步优化（培养基配方）后，稳定在５．４ｇ／Ｌ以上。     

酿酒葡萄悬浮细胞游离原生质体

酿酒葡萄花丝在含６ＢＡ２ｍｇ／Ｌ、２，４－Ｄ１ｍｇ／Ｌ的Ｂ５培养基上诱导出胚性愈伤组织。胚性愈伤组织在含有２，４－Ｄ０．５ｍｇ／Ｌ、ＮＡＡ０．０１ｍｇ／Ｌ的Ｂ５液体培养基中振荡培养，得到细胞悬浮系。悬浮细胞在含ＣｅｌｕｌａｓｅＲｓ２％、ＰｅｃｔｏｌｙａｓｅＹ２３０．３％、５ｍＭＣａＣｌ２２Ｈ２Ｏ、０．６Ｍ甘露醇，ｐＨ５．６－５．８的酶液中游离得到原生质体。     

利用连续驯养方法选育优良啤酒酵母的研究

在对两株啤酒酵母进行紫外诱变、获得低双酰值菌株的基础上，采用双乙酰连续驯养手段，分离得到一株双乙酰还原能力强的菌株（２）。对（２）再次进行紫外诱变，获得一株谷胱甘肽（ＧＳＨ）产量和风味保鲜期预测值（ＲＳＶ）较高的突变株（２Ａ２７。对（２）Ａ２７进行蛋氨酸连续驯养后分离得到一株Ｍ４，５００ｍｌ锥形瓶发酵结束后，其主酵液的ＧＳＨＴ ＲＳＶ可比出发株（２）分别提高３７％和７４％，羰基化合物（ＴＢＡ）则下     

葡萄细胞诱变植株的培育

葡萄花丝在含有６ＢＡ２－３ｍｇ／Ｌ＋２，４－Ｄ０．５ｍｇ／Ｌ的Ｂ５培养上诱导出可分化愈伤组织。继代培养一个月之后，转入含有２，４－Ｄ０．５ｍｇ／Ｌ＋ＮＡＡ０．０１ｍｇ／Ｌ和６ＢＡｍｇ／Ｌ的Ｂ５液体培养基振荡培养，获葡萄体细胞悬浮系。用０．０１－０．８％的秋水仙素溶液诱变处理浮培养的胚状体堆，然后转入成苗培养基上胚状体发育成苗。通过茎端切片、气孔测量、叶片干物质含量和根尖细胞染色体观察，确认变异体为     

花生未成熟胚培养与植株再生

采用ＭＳ，Ｂ５，Ｗｈｉｔｅ，Ｎｏｒｓｔｏｇ四种培养基及六种植物激素，配制成多种培养基，对授粉后２０－２５天的花生幼胚进行离体培养和再生研究。结果显示：ＭＳ，Ｂ５为幼胚离体培养和发育较好的培养基。ＭＳ＋ＢＡ１．０ｍｇ／Ｌ（单位下同）＋ＮＡＡ０．００５＋ＧＡ３０．０２＋ＧＨ６００＋ＰＶＰ０．２％＋蔗糖５％能有效促进幼胚发育成熟。小苗通过ＭＳ＋ＢＡ２．０＋ＰＰ３３３０．２＋ＣＨ４００＋蔗糖２％中培养，诱     

几种激素对茶愈伤组织合成茶氨酸的影响

根据生长素（ＩＡＡ），吲哚丁酸（ＩＢＡ），萘乙酸（ＮＡＡ），以及２，４－二氯苯氧乙酸（２，４－Ｄ）和６－卞艹基腺嘌呤（６－ＢＡ），激动素（ＫＴ），玉米素（ＺＴ）及三十烷醇（ＴＡ）等的不同浓度和不同组合，测定茶愈伤组织生长和茶氨酸的积累情况，以求得茶愈伤组织生长和茶氨酸积累的较佳培养条件。试验证明，以４ｍｇ／Ｌ６－ＢＡ＋２ｍｇ／ＬＩＡＡ或３ｍｇ／Ｌ６－ＢＡ＋１．５ｍｇ／ＬＩＡＡ＋２ｍｇ／ＬＴＡ的组合，添加于ＭＳ培养基上，茶愈伤组织生长和茶氨酸积累均良好，茶氨酸含量最高可达１７０ｍｇ／ｇ．     

L—异亮氨酸产生菌的选育

以黄色短矸菌（Ｂｒｅｖｉｂａｃｔｅｒｉｕｍｆｌａｖｕｍ）ＡＴＣＣ１４０６７为出发菌株，经硫酸二乙酯（ＤＥＳ），紫外线（ＵＶ）和亚硝基胍（ＮＴＧ）逐级诱发处理，α－氨基－β－羟基戊酸（ＡＨＶ），Ｓ－２－氨基乙基－Ｌ－半胱氨酸（ＡＥＣ）磺胺胍（ＳＧ），乙硫氨酸（Ｅｔｈ）α－氨基丁酸（α－ＡＢ），异亮氨酸氧肟酸（ＩｌｅＨｘ）等氨基酸结构类似物及琥珀酸主碳源平板定向筛选，获得一株Ｌ－异亮氨酸高产菌ＺＱ－４     

山葡萄及其杂交品种组培脱毒技术的研究

１９９１－１９９５年，采用无病毒症状山葡萄及其２０个杂交后代的茎尖，进行培养。分化培养基为：ＭＳ附加ＮＡＡ０．０１－０．１ｍｇ／Ｌ、６－ＢＡ２ｍｇ／Ｌ、蔗糖３．０％、琼脂５．０％；生根培养基为：１／２ＭＳ附加ＩＢＡ０．２－０．４ｍｇ／Ｌ、蔗糖１．５％，     

L－脯氨酸产生菌的选育

以嗜乙酰乙酸棒杆菌ＡＴＣＣｌ３８７０为出发菌株，经硫酸二乙酯（ＤＥＳ）和亚硝基胍（ＮＴＧ）逐级诱变处理，结构类似物定向选育，获得一株Ｌ－脯氨酸高产菌ＺＱ－３（ＳＧｒ、Ｓｕｃｇ、ＤＨＰｒ）。在含１６％葡萄糖的培养基中，摇瓶发酵７２ｈ，产酸率为５．３％～５．５％。     

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.     

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.     

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.     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

Influence des ions sur le pouvoir hydratant de l'ure e: e tude sur peau de porc ex vivo

This study deals with the influence of ions (NaCl and MgSO4) in a W/O emulsion containing 10% urea. Moisturization kinetics are assessed by corneometry on pig skin ex vivo. The formula's influence on urea penetration is measured by infrared spectrometry with an ATR device and the stripping method. Corneometry and spectroscopy were chosen to record simultaneously the hydratation levels and urea localization into superficial cell layers. Urea crystallization after evaporation of emulsions and aqueous solutions is described. Results show that urea does not hydrate nor penetrate when applied to the skin through an aqueous gel. In a W/O emulsion, sodium chloride increases the ability of urea to moisturize without improving penetration. In vitro urea crystallization is disturbed by sodium chloride or magnesium sulphate for solutions and emulsions. This stabilization by ions is correlated with good moisturization values. The stabilization of urea in the solute state provided by ions increases its water epidermal binding capacity without enhancing penetration.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.