荞麦槲皮素对高胆固醇饮食大鼠的降脂及肝损伤修复作用

研究荞麦槲皮素对高胆固醇大鼠脂质代谢及肝损伤的防治效果。将54只SD大鼠随机分为对照组、模型组、阳性组、荞麦槲皮素低(50 mg/kg)、中(100 mg/kg)、高(200 mg/kg)剂量组。建立高脂血症大鼠模型5周后,灌胃荞麦槲皮素干预治疗,测定各组大鼠血清脂质、抗氧化水平,以及肝脏抗氧化水平,并观察肝脏组织病理切片。结果表明：与模型组相比,荞麦槲皮素能够降低TC、TG、LDL-C的含量,回调HDL-C的含量,较模型组差异极显著;荞麦槲皮素各剂量组的ALT、AST活力有不同程度降低,剂量越高,下降幅度越大。同时,荞麦槲皮素高剂量组上调了血清中141.17 U/mgprot的SOD酶活力,下调了血清中1.21 U/mgprot的MDA含量,肝脏中SOD、MDA含量亦出现此趋势,HE染色结果表明,荞麦槲皮素各剂量组肝细胞排列整齐,脂肪滴变小,肝脏病变减轻。由此可见,荞麦槲皮素能显著调节高胆固醇膳食大鼠血脂异常,降低体内脂质蓄积,提高肝脏抗氧化能力,修复肝损伤。     

荞麦槲皮素对高脂饮食大鼠脂代谢及脂肪因子的调节作用

该文研究了荞麦槲皮素（QYE）对高脂饮食大鼠脂质代谢及脂肪因子的影响。将54只SD大鼠随机分为对照组、模型组、阳性组、荞麦槲皮素低（50 mg/kg）、中（100 mg/kg）、高（200 mg/kg）剂量组,建立高脂血症大鼠模型5周后,灌胃荞麦槲皮素干预治疗,测定各组大鼠血清、肝脏脂质水平,以及血清抗氧化、脂肪因子水平,并观察肝脏组织病理切片。结果表明,与模型组相比,荞麦槲皮素能够降低血清和肝脏TC、TG的含量,其中QUE高剂量组血清中TC、TG含量分别下降了33.47%和28.66%,较模型组差异极显著（P<0.01）;荞麦槲皮素高剂量组的Chemerin水平下降12.3%,CMKLR1水平下降19.83%,TLR4水平下降15.87%,NF-κB水平下降14.12%。同时荞麦槲皮素高剂量组上调了血清中33.87U/m L的GSH-Px酶活力,差异极显著（P<0.01）,荞麦槲皮素高剂量组下调了血清中79.56U/m L的CHE含量。由此可见,荞麦槲皮素能显著调节高脂膳食大鼠血脂异常,降低Chemerin及其受体CMKLR1、TLR4、水平,抑制NF-κB通路活化,减少...     

均匀设计优化制备槲皮素固体脂质纳米粒

目的制备槲皮素固体脂质纳米粒。方法采用高温乳化-低温固化法制备槲皮素固体脂质纳米粒,以包封率为考察指标,均匀设计法优化处方与制备工艺。结果按最优工艺条件制得的纳米粒均匀圆整,粒径为(203±75)nm,包封率为48.5%。结论优选的槲皮素固体脂质纳米粒制备工艺稳定可行。     

以亚麻籽油为基质的槲皮素固体脂质载体的制备和表征

固体脂质载体是作为一类安全的口服剂型,在食品、制药等领域被广泛应用于提高难溶性成分的生物利用度。试验选择了具有多种生物活性的槲皮素和亚麻籽油分别作为固体脂质载体的活性成分和脂质材料,经过物理吸附方法制备了负载槲皮素的亚麻籽油固体脂质载体,同时对其进行了表征和体外评价。实现两种活性物协同应用,充分发挥其生物利用度。     

槲皮素和芹菜素对高尿酸血症大鼠血尿酸及抗氧化能力的影响

目的：研究同等剂量的槲皮素和芹菜素对腺嘌呤+盐酸乙胺丁醇诱导高尿酸血症大鼠血尿酸及抗氧化能力的影响。方法：SD大鼠随机分为5组,空白对照组、模型对照组、别嘌醇组、槲皮素组和芹菜素组。利用腺嘌呤加盐酸乙胺丁醇片灌胃诱导SD大鼠制备高尿酸血症模型,槲皮素和芹菜素预防治疗3周,测定肝脏和血清中相关的酶活性及生化指标。结果：与模型组相比,槲皮素和芹菜素均能显著降低高尿酸血症大鼠血尿酸(SUA)、尿素氮(SUN)、血肌酐(SCr)和丙二醛(MDA)的水平,提高超氧化物歧化酶(SOD)、总抗氧化能力(T-AOC)的水平。结论：槲皮素和芹菜素均能很好的控制高尿酸血症大鼠血清尿酸水平,并且能够增强高尿酸血症大鼠的抗氧化和清除氧自由基的能力,减少脂质过氧化。     

黑果枸杞叶槲皮素的制备及其体外抗氧化活性研究

采用超声波-微波协同提取黑果枸杞叶醇提物,利用大孔吸附树脂分离富集黑果枸杞叶总黄酮,采用Sephadex LH-20,分离纯化槲皮素。利用高效液相色谱-质谱联用法(high performance liquid chromatography and mass spectrometry,HPLC-MS)对所得的槲皮素进行结构鉴定。通过考察槲皮素的总抗氧化活性、清除DPPH自由基、ABTS+自由基、超氧阴离子自由基以及脂质过氧化体系中脂质过氧化抑制率5个指标,由此评价槲皮素的体外抗氧化活性。研究结果表明,槲皮素在5种自由基中清除ABTS+自由基能力最强,浓度在300 nmol/L～400 nmol/L时清除率达68.0%。清除DPPH自由基能力和清除超氧阴离子自由基能力基本持平。     

苦荞黄酮的抗脂质过氧化和红细胞保护作用研究

目的:研究苦荞总黄酮的体外抗脂质过氧化和红细胞保护作用,分析其抗氧化的主要成分。方法:将苦荞总黄酮用200～300目硅胶柱层析分离,氯仿-甲醇-水梯度洗脱,紫外检测,得到18个Rf值不同部位;DPPH活性示踪,得到2个活性较强部位(Fr4、Fr9);采用大鼠肝组织脂质过氧化、红细胞溶血模型比较苦荞总黄酮、Fr4、Fr9、槲皮素及芦丁的抗氧化效应;用薄层色谱分析Fr4、Fr9的化学组成。结果:苦荞总黄酮、Fr4、Fr9、槲皮素及芦丁DPPH抑制率(IR)分别为53.13%、66.15%、68.55%、71.99%、63.08%;抑制大鼠肝脏自发性脂质过氧化半抑制浓度(IC50)分别为:27.78、16.05、14.28、8.74和7.4mg/mL;抑制H2O2诱导大鼠肝脂质过氧化IC50分别为:0.37、3.60、0.07、0.07和0.41mg/mL;抑制H2O2诱导大鼠红细胞溶血IC50分别为:13.00、0.48、0.20、0.08和4.10mg/mL。Fr4、Fr9均含有槲皮素,另有3个组分待定。结论:槲皮素是苦荞总黄酮在体外表现抗脂质过氧化和红细胞保护作用主要活性成分之一。     

蜂胶黄酮及其功效成分对脂代谢的调节作用

目的 研究蜂胶黄酮及其功效成分对脂质代谢紊乱的调节作用及机制.方法 建立高脂血症大鼠模型,研究蜂胶黄酮对大鼠血脂水平及脂质代谢关键酶活性的影响;同时,在体外观察蜂胶黄酮功效成分对胰岛素抵抗的改善作用.结果 蜂胶黄酮可显著降低高脂血症大鼠的血清甘油三酯(TG)和总胆固醇(TC)水平(P＜0.05);在体外试验中,蜂胶黄酮可上调肝酯酶(HL)和7α-羟化酶(7CYP7A1)的活性水平(P＜0.05);在胰岛素抵抗的L6肌管细胞中,蜂胶黄酮功效成分7-甲基白杨素、槲皮素-3-O-新橙皮糖苷和咖啡酸可明显提高细胞对葡萄糖的消耗(P ＜0.05);7-甲基白杨素0.4 μg/ml以及槲皮素-3-O-新橙皮糖苷10 μg/ml能显著降低L6肌管细胞对游离脂肪酸(FFA)的摄取.结论 蜂胶黄酮可有效改善脂质代谢紊乱,其作用机制可能是增强脂质代谢关键酶活性以及改善胰岛素抵抗状况.     

蜂胶对脂质过氧化的抑制作用

采用Fe2+诱导卵黄脂蛋白多不饱和脂肪酸发生脂质过氧化反应为模型,以硫代巴比妥酸反应物的光密度值为指标,观察了蜂胶对Fe2+诱导的脂质过氧化反应的抑制作用,结果表明,蜂胶可以抑制Fe2+诱导的脂质过氧化反应,呈现量效关系,同时对已受Fe2+诱导的脂质过氧化反应有一定的延缓和阻断作用,效果优于同浓度的芦丁和槲皮素。     

槲皮素和NaCl添加量对牦牛肉饼蛋白质和脂质氧化的影响

为研究槲皮素（Quercetin,Q）和不同NaCl添加量（0%、2%、4%、6%,m/m）对牦牛肉饼在贮藏过程中蛋白质和脂质氧化的影响,测定了牦牛肉饼在冷藏15 d期间的pH值、色差、羰基含量、表面疏水性、色氨酸荧光强度、二聚酪氨酸含量、过氧化值（Peroxide Value,POV）和硫代巴比妥酸反应物（Thiobarbituric Acid Reactive Substances,TBARS）值。结果表明,随着NaCl添加量增加,pH值增加（P<0.05）,L*、a*和b*值先增加后降低（P<0.05）;添加槲皮素后咸肉饼的pH值（P<0.05）、a*和b*值增加（P<0.05）、L*值降低（P<0.05）。添加NaCl使肉饼的羰基、表面疏水性、二聚酪氨酸、POV值和TBARS值增加（P<0.05）,色氨酸荧光强度减小（P<0.05）;但槲皮素处理使咸肉饼的色氨酸荧光强度、二聚酪氨酸、POV值及TBARS值降低,使4% NaCl（质量分数）肉饼的羰基含量降低了27.80%;表面疏水性在0~2% NaCl（质量分数）添加量下进一步增加（P<0.05）,而在4%~6% NaCl添加量下降低（P<0.05）。该研究表明,NaCl能促进牦牛肉饼蛋白质和脂质氧化,但加入槲皮素可有效缓解肉饼氧化。该结果可为槲皮素作为肉制品天然抗氧化剂提供参考。     

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.     

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.