22个山核桃无性系果实营养成分的比较分析

为了比较22个山核桃无性系的经济性状与营养成分差异,对果仁的粗脂肪、粗蛋白、脂肪酸等进行了测定,旨在筛选果实经济性状和营养成分优良的栽培无性系。粗脂肪、蛋白质、脂肪酸的相对含量较稳定,变异系数均小于27%。在22个山核桃无性系油脂中共检测出8种脂肪酸,不饱和脂肪酸有油酸、亚油酸、亚麻酸、棕榈烯酸、顺-11-二十碳烯酸,饱和脂肪酸有棕榈酸、硬脂酸、花生酸,并且脂肪酸成分的相对含量之间存在差异,脂肪酸中的棕榈烯酸和花生酸变异系数较大,属于中等变异;其余六种脂肪酸的变异系数较小,性状较稳定。大源5号、高岭3号和徐坑2号为果实高不饱和脂肪酸的优良无性系。不饱和脂肪酸中,油酸与亚油酸呈极显著负相关,相关指数为-0.993**,且油酸和亚油酸总量的相对含量基本不变,即山核桃果实中的不饱和脂肪酸的相对含量比较稳定。对22个山核桃无性系果实的各性状进行比较,综合分析得出:大源2号、高岭3号、高岭7号、徐坑40号含水率、出壳率、粗蛋白等均高于其他无性系,可以作为优良山核桃干果重点利用品种。大源5号、高岭3号和徐坑2号果实不饱和脂肪酸均较高,是供食用的优良品种。     

薄壳山核桃油成分及抗氧化性研究

通过气相色谱法检测薄壳山核桃油中的脂肪酸组成及含量,用ABTS法测定薄壳山核桃油的抗氧化活性。结果表明:薄壳山核桃油中油酸含量最高,其次依次是亚油酸、棕榈酸、硬脂酸、亚麻酸,含量最小的是顺-11-二十碳烯酸,不饱和脂肪酸质量分数达到90%;品种ZL75的抗氧化活性最强(自由基清除率65.33%)。试验结果对抗氧化、防衰老植物的开发、利用以及薄壳山核桃优良品种的栽培和开发有一定的指导作用。     

薄壳山核桃油水酶法提取工艺优化及品质分析

为优化薄壳山核桃油水酶法提取工艺,以薄壳山核桃仁为原料,采用水酶法提取油脂,筛选出水酶法提油的适宜酶制剂。在单因素试验基础上,采用正交试验研究料液比、加酶量、酶解温度、酶解时间和酶解pH对薄壳山核桃油提取率的影响,并对比了水酶法、压榨法和溶剂浸提法3种方法制取的薄壳山核桃油的品质。结果表明：蛋白酶为适宜的酶制剂;水酶法提取薄壳山核桃油的最佳工艺条件为料液比1∶ 4、加酶量2.5％、酶解温度55 ℃、酶解时间2.0 h、酶解pH 8,在此条件下薄壳山核桃油提取率为68.44％;薄壳山核桃油中含有7种主要脂肪酸,分别是棕榈酸、硬脂酸、油酸、亚油酸、α-亚麻酸、花生酸和顺-11-二十碳烯酸,不饱和脂肪酸含量高达90%以上,且以油酸和亚油酸为主,油酸含量高达70%以上,亚油酸含量在15%以上。3种制油方法中,水酶法制取的薄壳山核桃油具有较高的油酸、生育酚、总酚、β-谷甾醇和角鲨烯含量,油脂品质最好。水酶法是一种较为理想的核桃油提取方法。     

湖南地区10个品种薄壳山核桃的坚果品质评价

为研究薄壳山核桃品种间坚果品质差异,筛选出在湖南地区表现优良的薄壳山核桃,以10个品种薄壳山核桃和2个品种普通核桃为材料,分别对各品种坚果表型性状[坚果横径、纵径、侧径、果形指数、果实形状、壳面、果壳颜色、果顶、果底(基)、缝合线、横隔膜]、经济性状(坚果质量、坚果含水率、果壳厚度、出仁率、取仁难易、核仁充实度、核仁饱满度、核仁颜色、核仁风味、核仁含油率)以及其油脂脂肪酸组成及含量进行测定,对薄壳山核桃品质指标进行了相关性分析和主成分分析,综合评价不同品种薄壳山核桃坚果品质。结果表明：在10个品种薄壳山核桃中,‘实生1号’‘德西拉布’‘实生3号’和‘福克特’果形指数较高,分别为2.24、2.15、2.15、1.99;单果质量较大的是‘金奥瓦’‘福克特’和‘德西拉布’,分别为9.24、8.30、8.06 g;出仁率较高的是‘实生4号’和‘金奥瓦’,分别为57.86%、57.08%;含油率较高的为‘福克特’‘佩洛奎’和‘德西拉布’,分别达到72.24%、70.66%、68.24%;薄壳山核桃绝大多数品质指标相互间都有相关性;主成分分析表明,‘德西拉布’的综合得分最高,其次是‘福克特’。综上...     

吕梁山核桃脂肪含量差异性的分析

使用主成分分析法对吕梁山核桃的脂肪品质的差异性进行分析评价，为吕梁山核桃脂肪品质评价提供参考。以吕梁15份山核桃为原材料，脂肪和各个脂肪酸均依据国标规定进行检测，在变异系数分析、相关性分析的基础上使用主成分分析法对山核桃脂肪品质差异性进行分析，最后使用聚类分析对试验结果进行分类及佐证。15份吕梁山核桃的脂肪质量分数平均值为63.21%,9个脂肪酸的变异系数为0.52%～16.14%,且亚油酸，油酸，亚麻酸等含量均达到了特级核桃油的标准。大部分脂肪酸之间呈极显著强相关性(P<0.01),根据主成分分析的特征值大于1得出2个主成分，累积贡献率为89.827%,综合评分前3的是孝义1号、汾阳1、2号核桃，得分分别为2.45、2.01、1.83,为高亚麻酸、亚油酸的核桃，最低的是石楼县3号的核桃，得分为-2.44,为饱和脂肪酸相对较高的核桃，对核桃脂肪品质差异影响程度前3的脂肪酸是亚麻酸、油酸和亚油酸。最后使用系统聚类法以欧氏距离D=15处将15个地区核桃分为了两类，对主成分分析综合得分进行佐证。     

不同品种桑蚕蛹脂肪酸组成分析

分析了93个品种桑蚕蛹的粗脂肪含量,并对其脂肪酸组成进行了比较分析。结果表明,桑蚕蛹不同品种间粗脂肪含量存在显著差异,变化幅度为19.1%~36.28%。桑蚕蛹油脂肪酸主要由软脂酸、硬脂酸、油酸、亚油酸、亚麻酸组成:软脂酸质量分数为22.24%~29.92%,硬脂酸质量分数为3.22%~11.85%,油酸为24.06%~37.36%,亚油酸为3.09%~7.07%,亚麻酸为24.55%~37.02%。不饱和脂肪酸占到总脂肪酸的61.61%~73.31%,n-6/n-3范围为0.102~0.235。2个桑蚕品种75和79粗脂肪含量分别为34.9%和36.28%,不饱和脂肪酸比例高达70%,是昆虫不饱和脂肪酸优良资源。     

泡核桃无性系油脂脂肪酸组成和营养成分的比较分析

核桃是我国重要的木本油料树种。为评选出脂肪酸及营养成分优良的核桃无性系,为油用型核桃良种选育奠定基础。本研究对11个泡核桃（Juglans sigillata）无性系的油脂脂肪酸组成、生物活性物质和矿质元素含量进行了测定,采用ASReml-R进行统计分析,并估算遗传力、遗传变异系数等遗传参数。结果表明,泡核桃油脂脂肪酸组分主要为不饱和脂肪酸和饱和脂肪酸,其中不饱和脂肪酸以亚油酸（49.60%～62.25%）、油酸（12.46%～22.31%）、亚麻酸（7.89%～10.03%）和棕榈油酸（0.55%～1.18%）为主;饱和脂肪酸主要为硬脂酸（3.77%～10.03%）、棕榈酸（4.53%～8.04%）和花生酸（2.32%～3.67%）。硬脂酸、棕榈酸、棕榈油酸和花生酸相对质量分数在无性系间差异显著,矿质元素中铜、锰和铁元素含量在无性系差异显著,黄酮和多酚含量在无性系间也存在显著差异。8个性状（棕榈油酸、硬脂酸、棕榈酸、多酚、黄酮、铜、锰和铁元素）遗传力均在0.7以上,表现出较强的受无性系遗传控制。各性状遗传变异系数和表型变异系数分别在0.10～0.83和0.05～0.51之间。硬脂酸、花生酸、棕榈酸、和黄酮含量具有较高的遗传相关和表型相关系数（0.527～0.979）,且都显著相关。采用BLUP法估算综合育种值,初步评选出高脂肪酸品质（C86、C72和C65）和高品质微量营养（C001、C72和C301）油用无性系各3个。本研究结果可为进一步开展核桃油营养功能评价、油用型良种选育、育种亲本选配以及核桃油开发利用等提供依据。     

海拔对巫山竹贤核桃果实表型和油脂品质的影响

分析研究了巫山竹贤3个海拔(1 300、1 600、1 800 m)处的核桃果实表型、油脂品质及其相关性。结果表明:巫山竹贤核桃平均含粗脂肪62.70%,其油中亚油酸48.33%、油酸25.90%、棕榈酸21.21%、硬脂酸2.41%、亚麻酸2.09%,以不饱和脂肪酸(76.37%)为主;海拔间果实质量、核果质量、仁质量、出仁率、棕榈酸、硬脂酸、油酸、亚油酸、饱和脂肪酸、单不饱和脂肪酸、多不饱和脂肪酸变异系数在10%以上,具有较大的选择潜力;海拔1 600 m以下时,海拔升高有利于核桃果实的果皮增厚、果壳增多、果实和核果增重,粗脂肪、油酸、亚油酸含量增加,而海拔增至1 800 m时,核桃的生长与不饱和脂肪酸的积累受到抑制;果实表型和油脂品质部分指标间存在显著相关,可根据果实表型初步推断油脂品质。3个海拔中,1 600 m处产出的核桃果实表型和油脂品质均最优,可作为进一步育种和栽培的备选材料。     

气相色谱-质谱法定性定量测定糜子中的脂肪酸

采用气相色谱-质谱法对糜子中脂肪酸进行定性、定量分析。结果共鉴定出14 种脂肪酸,相对含量为96.9%,其中不饱和脂肪酸8 种（64.533%）,主要有亚油酸（12.371%）、油酸（44.157%）、亚麻酸（1.173%）等。可见糜子中脂肪酸主要以不饱和脂肪酸为主,是优质脂肪酸。通过回归方程计算得出：糜子中棕榈酸、油酸、硬脂酸、亚油酸、亚麻酸的含量分别为100.261、165.309、23.402、52.181、17.516 mg/100 g。通过与其他杂粮进行比较,结果表明糜子和小米、高粱、小麦、燕麦、水稻一样均含有硬脂酸、油酸、亚油酸、亚麻酸和棕榈酸等,不饱和脂肪酸含量高,富含亚油酸和亚麻酸;本研究可为糜子品质的进一步开发和研究提供理论依据。     

18种大豆种子蛋白质、氨基酸和脂肪酸的组成成分分析

对18种大豆种子蛋白质和氨基酸、总脂肪及脂肪酸组成进行了分析。结果表明:榆林地区的横山老黑豆和神木连枷条的蛋白质含量较高,山西地区的汾豆79氨基酸含量最高,东北地区的吉育82的总脂肪含量最高;GC-MS共鉴定出7种脂肪酸,其中亚油酸和油酸的含量较高,不饱和脂肪酸的含量均在70%以上,其中子洲小黑豆、靖边黑豆和晋豆19所提取的油中不饱和脂肪酸含量在80%以上。研究结果可为筛选更适合种植的大豆品种提供理论依据。     

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.     

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.     

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.     

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.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.