蛹虫草黄豆对小鼠的抗氧化及免疫作用

研究不同剂量的蛹虫草黄豆对小鼠的抗氧化功能和免疫功能的影响。对小鼠分别喂食含有0(基础日粮),3%,6%,12%蛹虫草黄豆以及12%普通黄豆的日粮,以小鼠血浆和肝脏中MDA含量,CAT、GSH-Px、TSOD活力及抑制羟自由基能力为指标,研究其体内抗氧化活性(小鼠注射D-半乳糖建立衰老模型);测定血浆和肝脏组织中免疫球蛋白G、M含量及细胞因子白细胞介素4、γ-干扰素含量,研究小鼠免疫功能。研究结果表明,添加蛹虫草黄豆可显著提高小鼠血浆和肝脏中CAT、GSH-Px、T-SOD(P0.05)活力,抑制羟自由基能力以及IgG、IgM、IL-4、IFN-γ(P0.05)的含量,显著提高小鼠脾脏和肝脏指数,显著降低MDA(P0.05)含量,具有延缓衰老以及提高机体免疫功能的作用。     

重楼叶多糖改善D-半乳糖衰老模型小鼠脾脏免疫功能和抗氧化能力

采用D-半乳糖注射诱导衰老模型,探讨了重楼叶多糖(PPLPs)对小鼠脾脏免疫功能和抗氧化的影响。分别对小鼠D-半乳糖、D-半乳糖和PPLPs、D-半乳糖和VC以及生理盐水处理,持续42 d。结果显示:与模型组相比,灌胃PPLPs或VC均能显著增加小鼠脾脏指数(p0.05),显著上调脾脏免疫相关基因(T-bet、GATA、IFN-γ、IL-2、TNF-α、IL-4和IL-10)m RNA表达水平(p0.05),也显著增强了脾脏总超氧化物歧化酶(T-SOD)、铜锌超氧化物歧化酶(Cu Zn-SOD)、谷胱甘肽过氧化物酶(GSH-Px)和过氧化氢酶(CAT)活性(p0.05);同时,灌胃PPLPs或VC显著降低了脾脏丙二醛(MDA)含量(p0.05)。结果表明,PPLPs可增强脾脏免疫功能并提高小鼠的抗氧化活性。     

玉米皮多糖的组成及结构

采用紫外光谱、纸层析及比色等分析方法对分离纯化制得的玉米皮多糖A-1(CSPA-1)、A-2(CSPA-2)、B(CSPB)的总糖含量、单糖组成及基本结构进行初步研究。结果表明：CSPA-1、CSPA-2 和CSPB 皆为白色粉末,其中CSPB 微溶于水,其他易溶于水,不溶于高浓度的有机溶剂,不含蛋白质和淀粉,均含有糖醛酸。CSPA-1总糖含量为99.3%,糖醛酸含量为16.6%,糖基组成为葡萄糖、木糖及阿拉伯糖,可能还含有微量鼠李糖;CSPA-2 总糖含量为93.4%,糖醛酸含量为21.7%,糖基组成为葡萄糖、木糖、阿拉伯糖及鼠李糖;CSPB 总糖含量为83.3%,糖醛酸含量为6.82%,糖基组成为葡萄糖、木糖及阿拉伯糖。高碘酸氧化分析表明：CSPA-1 中1 → 2 糖苷键或1 → 4 糖苷键残基比例为25%,1 → 6 糖苷键残基比例为3%;CSPA-2 中1 → 2 糖苷键或1 → 4 糖苷键残基比例为25.7%,1 → 6 糖苷键残基比例为3%;CSPB 中1 → 2 糖苷键或1 → 4 糖苷键残基比例为34.1%,1 → 6 糖苷键残基比例为1%。     

免疫低下和食物过敏小鼠外周血中细胞因子的变化

建立小鼠免疫低下模型和食物过敏模型,采用ELISA法检测外周血中细胞因子(IL-4、IL-6、IL-10、IL-12、IFN-γ、TGF-β)的变化。结果表明：与空白对照组比较,腹腔注射环磷酰胺所建立免疫低下小鼠胸腺指数和脾脏指数均有显著降低(P≤0.05),且在第3天达到最低;经卵清蛋白致敏小鼠外周血IgE水平极显著升高(P≤0.01)。免疫低下小鼠外周血中IFN-γ(除第3天外)、TGF-β含量(除第3天外)和IFN-γ/IL-4比值均显著降低,而IL-10水平也有下降趋势;除第2天外IL-6水平显著升高,但IL-4水平只在第3天显著性增高,IL-12先是下降随后呈现增多的趋势;食物过敏小鼠的IL-4、IL-6、IL-10和TGF-β水平均有显著性增高,IFN-γ/IL-4比值有显著性下降,而IFN-γ和IL-12没有明显的变化。因此,免疫低下和食物过敏小鼠的Th1/Th2细胞平衡均向Th2细胞偏移,免疫低下对Th1细胞的影响大,食物过敏对Th2细胞的影响更明显。     

金线莲多糖协同ConA对小鼠脾淋巴细胞分泌Th1、Th2型细胞因子及其mRNA表达量的影响

目的:研究金线莲多糖(ARP)调节Con A刺激小鼠脾淋巴细胞细胞因子分泌水平及其m RNA表达影响,探讨其免疫调节作用机制。方法:小鼠脾淋巴细胞经不同质量浓度的金线莲多糖协同Con A体外刺激,ELISA法检测小鼠脾淋巴细胞上清液中Th1(IL-2、IFN-γ)、Th2(IL-4、IL-6)细胞因子的含量;q RT-PCR检测上述细胞因子及其转录因子T-bet、GATA-3 m RNA表达量。结果:在试验质量浓度范围,ARP能显著提高小鼠脾淋巴细胞Th1、Th2细胞因子的分泌量,促进Th1、Th2细胞因子及转录因子(T-bet、GATA-3)m RNA表达(P0.01)。结论 :ARP能协同Con A促进小鼠脾淋巴细胞分泌Th1、Th2型细胞因子及其m RNA表达,从而发挥免疫调节的作用,作用机制可能与上调核转录因子T-bet、GATA-3的m RNA表达水平有关。     

大豆肽免疫调节作用的研究

目的:研究大豆肽对正常及免疫低下小鼠免疫功能的影响。方法:腹腔注射环磷酰胺以引起小鼠免疫功能低下,观察大豆肽对正常及免疫功能低下小鼠胸腺指数、脾脏指数、脾淋巴细胞对ConA的刺激指数(SI)、抗体生成细胞含量(PFC)和血清溶血素(HC50)等指标的影响。结果:大豆肽不仅能增强正常小鼠免疫功能,而且能显著提高环磷酰胺致免疫功能低下小鼠的胸腺指数、脾脏指数、脾淋巴细胞对ConA的刺激指数、抗体生成细胞含量和血清溶血素的含量。结论:大豆肽对机体的免疫功能有一定的增强作用。     

葛氏鲈塘鳢鱼头多糖的制备、结构鉴定及体外生物活性分析

研究葛氏鲈塘鳢鱼头多糖(polysaccharide from Perccottus glenii head,PGP)和脱蛋白多糖(deproteinized polysaccharides from Perccottus glenii head,PGP-D)的制备工艺、单糖组成、结构和活性。结果表明:采用胃蛋白酶法脱蛋白效果最佳,其蛋白脱除率为86.0%,多糖损失率为3.7%,羟自由基半清除率为47.6%;扫描电镜显示脱蛋白前后多糖的微观形貌由粗糙球状变为光滑片状;气相色谱-质谱分析表明PGP-D的单糖组成为阿拉伯糖、鼠李糖、甘露糖、半乳糖、半乳糖醛酸和葡萄糖醛酸;紫外扫描光谱鉴定表明PGP-D不含核酸,含有微量蛋白;红外光谱分析表明PGP-D是一种含有β-糖苷键的酸性多糖;PGP及PGP-D均具有较强的抗氧化和抑制血管紧张素I转换酶活性;PGP具有抑制α-葡萄糖苷酶的活性。     

鸡腿菇子实体粗多糖理化性质及免疫活性研究

以小鼠巨噬细胞RAW264.7为免疫模型,探究鸡腿菇子实体粗多糖对免疫调节的作用。采用传统的水提醇沉的方法获得鸡腿菇子实体粗多糖,对其进行理化性质分析。首先,通过单糖组成分析,发现鸡腿菇子实体粗多糖主要由葡萄糖构成,其次是半乳糖、葡萄糖醛酸和甘露糖;从蛋白含量看,鸡腿菇子实体粗多糖中的蛋白含量占(5.04±0.10)%,推测成熟的鸡腿菇子实体中可能有一些蛋白与多糖结合形成糖蛋白。此外,红外光谱分析表明鸡腿菇多糖具有α构型的糖苷键,该种糖苷键对提高多糖的免疫功能有一定的作用。在体外免疫实验中,鸡腿菇子实体粗多糖不仅能促进小鼠巨噬细胞RAW264.7的增殖,还可以促进其产生NO,以及促进IL-1β、IL-6、IL-10和TNF-α等细胞因子的分泌。这些结果表明鸡腿菇子实体粗多糖能激活巨噬细胞,提高细胞的免疫调节功能。除此之外,抗肿瘤实验结果表明,鸡腿菇子实体粗多糖还能抑制人宫颈癌He La和肝癌Hep G2细胞的增殖,说明其具有抑制肿瘤的效果。总之,鸡腿菇子实体粗多糖不仅具有免疫调节的能力,还具有一定的抗肿瘤活性。     

枸杞多糖结构及其单糖组分的分析研究

枸杞经乙醚脱脂和Sevag法脱蛋白后,用热水提取并用乙醇沉淀多糖,采用紫外光谱、红外光谱、气相色谱和FID检测器对枸杞多糖结构和功效成分单糖进行光谱分析和气相色谱分析。结果表明:枸杞多糖属于蛋白多糖,构杞多糖存在有官能团如—OH,C—O—C,C=O,-NH_2等,其糖苷键存在β-型糖苷键和α-构型的吡喃糖和呋喃糖。多糖为杂多糖,粗多糖得率为2.04%,采用DB-1701毛细管柱对乙酰化后的单糖能进行很好的色谱分离,其单糖组分至少含有8种以上的单糖:鼠李糖、岩藻糖、阿拉伯糖、木糖、甘露糖、半乳糖、葡萄糖等,其中含量较多的是阿拉伯糖、葡萄糖和半乳糖,它们的摩尔比1.956:0.835:0.629,其余的单糖含量比较低。     

大蒜多糖的提取分离与分析

目的：提取、分离、纯化大蒜多糖，并对其进行分析。方法：依次用水提取、过滤、去蛋白、DEAE纤维素层析、冷冻干燥获得大蒜多糖：用薄板层析和气相色谱法测定单糖的组成和比例，高效液相色谱法测定分子量：结合IR和^13CNMR确定单糖组成、连接方式和端基碳构型。结果：从大蒜中得到了纯多糖，其含有85％果糖、14％葡萄糖、1％半乳糖，分子量7100道尔顿，糖苷键为β-2，1-糖苷键。结论：大蒜多糖是主要含有果糖，葡萄糖和少量半乳糖的大蒜中的β-杂聚糖。     

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.     

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.     

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.     

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.     

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.