我国玉米品种资源主要品质的鉴定与筛选

对１９９１－１９９４年入国家种质资源库的来自２２个省（区、市）的２５３７份玉米品种资源的主要品质进行了测定。测定结果表明，我国玉米种质资源的粗蛋白质平均含量为１１．６４％，粗脂肪平均含量为４．５％，总淀粉平均含量为６８．６８％，赖氨酸的平均含量为０．２８９％。粗蛋白质含量＞１５％，粗脂肪含量＞７％，总淀粉含量＞７４％，赖氨酸含量＞０．４％的优质玉米品种的总筛选率分别为０．９％、０．５５％、０．３２％和１．０２％。     

沙虫营养成分测定及营养学评价

测定沙虫中粗蛋白质、粗脂肪以及水分等主要营养成分和18种氨基酸。结果表明,沙虫中的粗蛋白、水分含量较高,粗脂肪含量适中;鲜味氨基酸在18种氨基酸中的含量最高,必需氨基酸的含量也较高;必需氨基酸占总氨基酸的比值为41.48%,必需氨基酸与非必需氨基酸的比值为70.87%,均高于FAO/WHO的标准;以FAO/WHO联合推荐的EAA模式和鸡蛋氨基酸模式为参比,计算沙虫中的AAS和CS,沙虫中必需氨基酸的组成相对比较平衡,富含高营养蛋白质。结果显示,沙虫是一种味道鲜美、营养价值丰富的水产品,具有广泛的养殖推广前景和市场。     

卫红花籽和卫红花籽饼的营养成分分析

对卫红花籽和卫红花籽饼的粗灰分、水分、粗蛋白、粗脂肪、氨基酸以及卫红花籽油的脂肪酸组成进行测定与分析。结果表明:卫红花籽和卫红花籽饼的粗灰分含量分别为4. 28%和3. 53%,水分含量分别为6. 50%和6. 68%,粗蛋白含量分别为18. 82%和20. 27%,粗脂肪含量分别为19. 84%和4. 32%。卫红花籽饼的氨基酸组成中脯氨酸和谷氨酸含量较高,其次为天冬氨酸、甘氨酸、亮氨酸、精氨酸和丙氨酸,赖氨酸及含硫氨基酸含量较低;卫红花籽油中含有丰富的不饱和脂肪酸,亚油酸含量高达77. 60%。卫红花籽油中既含有多种不饱和脂肪酸,饼中又含有优质蛋白质,是较理想的能量和蛋白质饲料源。     

湖南石门县地方品种鸡肉氨基酸组成分析及蛋白质营养价值评价

目的 探究湖南省石门当地7个品种鸡肉中的基本营养成分及氨基酸组成差异,并对其进行蛋白质营养价值评价。方法 采用相关国家标准测定7个品种鸡肉中水分、粗灰分、粗脂肪、粗蛋白含量,并利用高效液相色谱仪对鸡肉氨基酸含量进行测定,基于联合国粮食及农业组织和世界卫生组织(Foodand Agriculture Organization/World Health Organization, FAO/WHO)标准模式谱对不同品种鸡胸肉和腿肉蛋白质分别进行营养学评价。结果 7个品种鸡胸肉、腿肉中水分含量分别为71.20～74.97 g/100 g、72.65～76.22 g/100 g,粗灰分含量分别为0.90～1.38 g/100 g、0.91～1.28 g/100 g,粗脂肪含量分别为0.15～0.64 g/100 g、2.30～7.74 g/100 g,粗蛋白质含量分别为22.29～24.61 g/100 g、19.00～21.80 g/100 g,不同品种、部位间存在差异。7个品种鸡肉均检测出17种氨基酸,均以谷氨酸含量为最高;胸肉氨基酸含量高于腿肉(除壶瓶山鸡),其中青脚鸡胸肉和壶瓶山鸡腿肉的...     

盾叶木籽营养成分分析

为研究盾叶木籽的营养价值,依据国标及常规方法对其千粒质量、水分、粗脂肪、粗蛋白质、氨基酸、5种矿物元素及其油脂脂肪酸组成及相对含量进行测定。结果表明：盾叶木籽千粒质量为25.657 g,水分、粗脂肪和粗蛋白质含量分别为8.70、2.20 g/100 g和6.90 g/100 g;盾叶木籽检出16种氨基酸,7种必需氨基酸含量占总氨基酸含量的38.06%,必需氨基酸与非必需氨基酸的比值为61.44%,必需氨基酸比值系数分(SRC值)为61.83,营养价值较高;盾叶木籽中钙和铁含量较高,分别为7.84×10³ mg/kg和50.60 mg/kg;盾叶木籽油中共检出14种脂肪酸,其中饱和脂肪酸有6种,占脂肪酸总含量的14.26%,主要是棕榈酸(9.21%),不饱和脂肪酸有8种,占脂肪酸总含量的85.66%,主要是油酸(35.60%)和神经酸(18.10%)。综上,盾叶木籽有一定的经济价值,具有较好的开发前景。     

不同产地油莎豆性状及组成分析研究

从全国7个省份采集9个油莎豆样品,对其杂质、粒度、容重、千粒重、种皮颜色、果仁颜色、粒型、粗脂肪、粗蛋白、粗纤维、水分、灰分及油莎豆油的酸价、过氧化值和脂肪酸组成进行检测,分析不同产地油莎豆的品质差异。结果表明:不同产地油莎豆的粒度表现出较大差异,其中大粒油莎豆为10～15 mm,小粒为6～10 mm,与粒度对应的千粒重指标也存在较大差异,为362～821 g,但无论颗粒大小,油莎豆的容重差异较小,为580～621 g/L;油莎豆的水分含量为5.43%～10.92%,灰分含量为1.63%～3.11%,粗脂肪含量为18.71%～26.71%,粗蛋白含量为4.66%～8.46%,粗纤维含量为6.64%～11.00%;油莎豆油的主要脂肪酸组成为油酸67.71%～74.60%、棕榈酸12.42%～14.78%、亚油酸8.79%～12.01%、硬脂酸2.37%～4.91%;油莎豆毛油酸价(KOH)为1.06～3.46 mg/g,过氧化值为0.02～0.92 g/100 g。     

重阳木种子油的理化性质及脂肪酸组成分析

对重阳木种子的理化性质、种子油的理化性质及脂肪酸组成进行了分析。结果表明:重阳木种子千粒重、容重及水分、还原糖、总糖、粗蛋白质、粗脂肪和灰分含量分别为5. 69 g、936 g/L、7. 50%、0. 68%、1. 55%、3. 64%、30. 3%和4. 31%;重阳木种子油的酸价(KOH)为2. 29 mg/g、过氧化值为10. 7 mmol/kg、碘值(I)为132 g/100 g、皂化值(KOH)为159 mg/g、不皂化物含量为4. 83%;重阳木种子油主要由5种脂肪酸组成,饱和脂肪酸含量较低,仅占11. 72%,主要为棕榈酸(6. 91%)和硬脂酸(4. 81%),不饱和脂肪酸含量高达88. 28%,主要为亚麻酸(45. 32%)、亚油酸(28. 54%)和油酸(13. 21%)。重阳木种子油营养价值较高,是一种极具开发价值的营养保健油。     

玉米品种籽粒品质性状研究

对55个玉米品种籽粒品质性状研究.结果表明,不同玉米品种籽粒百粒重、百粒体积、粗脂肪、粗纤维、出珍率、皮渣率以及色泽体系中a＊值、b＊值差异较大.春玉米与夏玉米在百粒重、百粒体积、粗蛋白、灰分、粗纤维、亮度指数L＊上差异显著.玉米品种籽粒平均容重766.0g/L,百粒重34.48 g,百粒体积28.06 mL,籽粒密度1.23g/mL,淀粉含量69.55%,粗蛋白含量10.97%,粗脂肪含量4.51%,灰分含量1.46%,粗纤维含量2.19%,出珍率37.94%,出粉率56.48%,皮渣率5.58%.不同玉米品种间的糊化特性有一定差异.春玉米品种的峰粘度、破损值、回生值以及最终粘度显著小于夏玉米（a=0.05）,而糊化温度、冷糊稳定性高于夏玉米.玉米品种平均糊化温度72.8℃,峰粘度371 BU,破损值82 BU,回生值480 BU,最终粘度748 BU,冷糊稳定性21 BU.     

新疆巴旦姆种仁高级脂肪酸与氨基酸营养评价

以新疆巴旦姆28个品种为试验材料,采用超临界CO2萃取法萃取其种仁油脂。用气相色谱法测定脂肪酸的含量及组分;采用自动定氮法和连续累进提取法测定粗蛋白和分离蛋白,并对蛋白质和氨基酸进行了营养的分析。结果表明,巴旦姆种仁油脂含量高(平均为54.68%),油脂以不饱和脂肪酸为主要成分,平均占脂肪酸总量的92.3%(其中单不饱和脂肪酸平均占脂肪酸总量的72.19%),饱和脂肪酸含量较低。巴旦姆种仁粗蛋白质含量平均为22.55%,以清蛋白为主,平均占蛋白质总量的48.86%以上,其次为球蛋白,而醇溶蛋白和谷蛋白含量较低。其蛋白质均含18种氨酸酸,属完全蛋白质。氨基酸含量丰富,每百克蛋白质中18种氨基酸平均含量为92.5%,且富含人体所需的8种必需氨基酸,含量达27.5%～35.1%。谷氨酸含量最高(平均为21.0%),含硫氨基酸(Met Cys)和赖氨酸(Lys)为其限制氨基酸。     

米糠在食品工业中的应用

米糠是大米、小米加工过程中的主要副产物之一。营养丰富,富含蛋白质、纤维素、无机元素以及维生素B(V_(B1)、V_(B2)、V_(B6))、维生索E、菸酸等。其中含油脂26％;蛋白质15％(为玉米中蛋白质含量的1.8倍);粗脂肪21.21％;无氮浸出物34.44％;纤维10.05％;灰分9.40％;水分12.59％;硫氨基酸的含量几乎比玉米大2倍,而赖氨酸含量为玉米的2倍;其胱氨酸、蛋氨酸、赖氨酸、精氨酸和色氨酸的含量分别为0.40、0.29、0.75、1.10和     

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.     

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.     

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.     

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.