蓓蕾蓝靛果花色苷对乙醇诱导小鼠氧化损伤的保护作用

探讨蓓蕾蓝靛果(Lonicera caerulea‘Beilei’)花色苷对乙醇诱导小鼠氧化损伤的保护作用。方法:将小鼠按体重随机分为对照组、模型组、VC阳性对照组(20 mg/kg bw)、花色苷低剂量组(50 mg/kg bw)、花色苷中剂量组(100 mg/kg bw)和花色苷高剂量组(200 mg/kg bw),每天经口灌胃,灌胃容量为0.2 m L/10 g,对照组和模型组经口灌胃等体积的生理盐水。30 d后,除对照组外,其他实验组灌胃乙醇造成氧化损伤模型,检测血液和组织中的丙二醛(MDA)、蛋白质羰基(PC)、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、还原型谷胱甘肽(GSH)的含量。结果表明蓓蕾蓝靛果花色苷可以极显著(p0.01)降低小鼠体内MDA和PC含量,极显著(p0.01)提高体内SOD、GSH-PX抗氧化酶的活力和抗氧化物质GSH的含量。蓓蕾蓝靛果花色苷具有防护乙醇诱导小鼠氧化损伤的功能。     

沙棘多糖清除自由基及抗脂质过氧化作用研究

目的:探讨沙棘多糖体外清除自由基及抗脂质过氧化作用。方法:采用体外抗氧化活性法测定沙棘多糖对DPPH自由基、羟自由基和超氧阴离子自由基清除能力及沙棘多糖总还原能力;制备5%小鼠肝脏匀浆,通过模拟建立体外小鼠肝匀浆自发性脂质过氧化模型、CCl₄体外诱导小鼠肝匀浆脂质过氧化模型、H₂O₂体外诱导小鼠肝匀浆脂质过氧化模型、Fe2+-V_C 体外诱导小鼠肝脏脂质过氧化模型,利用TBA显色法,观察沙棘多糖对脂质过氧化的抑制作用。结果:沙棘多糖对DPPH自由基、OH自由基和超氧阴离子自由基都具有一定的清除能力,其IC₅₀值分别为1.55、1.23、8.31 mg/mL,其浓度为2 mg/mL时,还原能力稍高于同浓度V_C。沙棘多糖对小鼠肝匀浆自发性脂质过氧化及CCl₄、H₂O₂、Fe2+-V_C所诱导的肝脏脂质过氧化均具有抑制作用,其IC₅₀值分别为1.10、1.59、9.13、1.39 mg/mL。结论:沙棘多糖具有一定的抗氧化活性及抗脂质过氧化作用。     

麦苗中超氧化物歧化酶(SOD)抗氧化活性研究

本研究探讨麦苗中超氧化物歧化酶(Superoxide Dismutase,SOD)在动物体内和体外的抗氧化活性。体外抗氧化试验中将麦苗中经过提取、纯化、干燥制成的SOD成品经蒸馏水配制成溶液,分别采用DPPH·清除法、Fenton反应法和Fe~(3+)还原法测定其对DPPH和羟自由基的清除率及其还原能力。通过饲养昆明种小鼠,经口灌胃受试物SOD酶液以及生理盐水、番茄红素,考察丙二醛(MDA)含量、过氧化氢酶(Catalase,CAT)活力和谷胱甘肽过氧化物酶(GSH-Px)活力。结果表明,体外试验中SOD酶液具有良好的抗氧化能力,SOD(1 mg/mL)酶液在1 mL水平下对DPPH、羟基自由基的清除率分别可达到96.95%、98%,还原能力随剂量的增加呈递增趋势;体内试验中SOD剂量组与对照组相比,小鼠肝组织中MDA差异显著(P0.05),且各个剂量组下MDA含量都有减少。与对照组比较,SOD高剂量组能提高小鼠肝组织中GSH-Px和CAT活力(P0.05)。麦苗中SOD在体外和体内均表现出良好的抗氧化作用。     

茶薪菇酚类提取物的抗氧化功效评价

目的:研究茶薪菇提取物的酚类物质对体外和体内抗氧化活性的影响。方法:在分析茶薪菇水提物、丙酮提取物、乙醇提取物的总酚、总糖含量以及体外抗氧化的基础上,以阿魏酸、维生素E为阳性对照组,以生理盐水为空白对照组,检测连续灌胃10 d茶薪菇水提物[以总酚含量计,12 mg/(kg bw·d)]对正常小鼠的抗氧化功效,采用D-半乳糖衰老小鼠模型评价茶薪菇水提物[以总酚含量计,12,20,40 mg/(kg bw·d)]对衰老小鼠的抗氧化功效。结果:茶薪菇水提物的总酚含量为1.25‰,介于丙酮提取物和乙醇提取物之间,当茶薪菇水提物质量浓度为60.00 mg/mL时,对羟自由基的清除率高达87.00%,对卵黄脂蛋白不饱和脂肪酸过氧化的抑制率高达65.31%。茶薪菇水提物对正常小鼠的抗氧化结果显示:茶薪菇水提物不影响正常小鼠体重增长,有调高肝脏指数和脾脏指数的趋势,茶薪菇水提物组的超氧化物歧化酶(SOD)活力最高达130.43 U/mL;丙二醛(MDA)含量明显低于生理盐水对照组(P<0.05),抗氧化能力与维生素E和阿魏酸相当。茶薪菇水提物对衰老小鼠的抗氧化结果显示:与D-半乳糖诱导的衰老小鼠比较,10,20,40 mg/(kg bw·d)的茶薪菇水提物极显著降低了衰老小鼠的MDA含量(P<0.01),20 mg/(kg bw·d)剂量组下降率高达94.53%;10 mg/(kg bw·d)剂量组谷胱甘肽过氧化物酶(GSH-Px)活力极显著提高22.98%(P<0.01)。结论:茶薪菇水提物中酚类物质是体外和体内抗氧化的主要功效成分,通过提高SOD、GSH-Px等抗氧化酶活力,降低MDA含量,发挥维持机体抗氧化稳态和拮抗D-半乳糖诱导的衰老损伤的作用。     

米糠抗氧化肽对D-半乳糖致衰小鼠肝线粒体的保护

目的:观察米糠抗氧化肽对D-半乳糖(D-gal)致衰小鼠肝线粒体的保护作用.并初步探讨其机制.方法:昆明小鼠60只随机分成对照组、衰老模型组、米糠抗氧化肽低、中、高剂量治疗组,衰老模型组每日颈背部皮下注射D-gal100mg/ks·bw;米糠抗氧化肽各组除注射D-gal外,分别灌胃抗氧化肽100、200、500mg/kg·bw;对照组每日皮下注射等量生理盐水,连续6w.利用试剂盒分别检测各组小鼠肝线粒体锰-超氧化物歧化酶(Mn-SOD)、谷胱甘肽过氧化物酶(GSH-Px)、过氧化氢酶(CAT)活性、总抗氧化能力(T-AOC)及丙二醛(MDA)含量.结果:与衰老模型组相比,米糠抗氧化肤可明显增强小鼠肝线粒体Mn-SOD、GSH-Px、CAT及T-AOC活性,显著抑制MDA含量的上升(P<0.05或P<0.01),并呈量-效关系.结论:米糠抗氧化肽能够显著提高致衰小鼠的抗氧化能力,减轻肝线粒体损伤,其机制可能与该肽直接清除体内自由基、提高机体抗氧化酶活性以及对抗脂质过氧化反应有关.     

卷丹乙醇提取物及其不同极性部位抗氧化活性的比较研究

对卷丹进行抗氧化活性研究,并筛选其主要的活性部位。采用体外抗氧化活性测试方法,以清除DPPH自由基和ABTS+ ·能力、还原Fe3+能力及抑制脂质过氧化能力为指标,评价卷丹乙醇总提取物及不同极性部位的抗氧化能力。卷丹及其乙酸乙酯部位和水饱和正丁醇提取部位具有较强的清除DPPH自由基和ABTS+ ·能力、还原Fe3+能力及抑制脂质过氧化能力。     

乳酸菌发酵大麦提取物增强肥胖大鼠的肝脏抗氧化能力

研究乳酸菌发酵大麦提取物(LFBE)对饮食诱导的肥胖大鼠肝脏脂代谢和抗氧化能力的影响。通过饲喂高脂饲料的方法建立营养型肥胖模型大鼠。模型大鼠在饲喂高脂饲料的同时,分别灌胃LFBE【1 000 mg/(kg bw)】和水【4 m L/(kg bw)】8周后,测定其体重、Lee’s指数、肝脏脂质水平、肝脏活性氧自由基和抗氧化酶活力等指标。结果显示,与模型对照组相比,LFBE能显著减缓肥胖大鼠体重和Lee’s指数的增加,降低肝脏甘油三酯、总胆固醇和低密度脂蛋白含量,增加肝脏高密度脂蛋白含量,从而减缓肝脏脂变。同时,LFBE可清除肝脏活性氧自由基,减少MDA含量,增加SOD和GSH-PX抗氧化酶活力。试验结果表明,LFBE具有抑制脂肪肝的形成,保护肝脏的作用,其作用机制可能与清除自由基,抑制脂质过氧化及增强肝脏的抗氧化能力有关。     

桑黄不同组分抗氧化活性的比较分析

采用铁离子还原/抗氧化力测定法(ferric reducing/antioxidant power assay,FRAP)、邻苯三酚法、水杨酸法,比较研究桑黄不同极性组分的抗氧化活性。结果显示,4种桑黄不同组分体外总抗氧化能力高低顺序依次是:水溶性组分乙酸乙酯组分乙醇组分。在清除羟自由基(·OH)试验中发现石油醚组分对羟自由基清除能力最强,远远高于水溶性成分,乙酸乙酯组分和乙醇组分也很强。在清除超氧阴离子(O~(2-)·)试验中发现乙醇组分活性最高,石油醚组分次之。     

体内和体外评价法分析川秋葵微粉的抗氧化活性

研究川秋葵微粉的体内和体外的抗氧化活性及可能的作用机制。将50只小鼠随机分为对照组、螺旋藻粉阳性药物组以及川秋葵微粉低、中、高剂量组(450、900、1800 mg/kg)。连续灌胃给药6周,末次灌胃后禁食12 h,颈椎脱臼处死后小鼠眼球取血,即刻取出肝脏组织和脑组织并测定相关指标。体外抗氧化功能评价采用体外·OH清除率、·O2—清除率、抑制脂质过氧化能力、ABTS+·清除率、DPPH·清除率、还原力、总抗氧化能力7个的指标。结果表明:川秋葵微粉具有良好的体外抗氧化活性,对DPPH·、·OH、ABTS+·的清除能力优于商品化的螺旋藻微粉。川秋葵微粉具有良好的体内抗氧化活性,与对照组相比,经高剂量川秋葵微粉干预后能够显著降低小鼠血清(p0.01)、脑和肝脏组织(p0.05)中MDA含量;提高小鼠血清(p0.05)、脑组织(p0.01)和肝脏组织(p0.05)中SOD活性;提高小鼠血清(p0.05)、脑组织(p0.01)和肝脏组织(p0.05)中GSH-Px活性;提高小鼠血清(p0.01)、脑组织(p0.01)和肝脏组织(p0.05)中CAT活性;提高小鼠血清(p0.01)、脑组织(p0.01)和肝脏组织(p0.05)中T-AOC能力。以上结果提示:川秋葵微粉能够提高机体的抗氧化能力,作用机制可能与清除自由基,抑制脂质过氧化及维持机体抗氧化酶系活性的正常进行有关;高剂量川秋葵微粉对脑组织和血清的抗氧化能力优于肝脏组织;高剂量川秋葵微粉对小鼠机体的抗氧化能力与阳性对照组(螺旋藻)相当。     

黑蒜多酚粗提物体内抗氧化功能研究

研究黑蒜多酚体内抗氧化功能。按《保健食品检验与评价技术规范》,将SPF级KM小鼠随机分为空白对照组、模型对照组和3个不同剂量的黑蒜多酚量组,以2.04,4.10,12.25 g/(kg·bw)剂量连续灌胃30 d后,取血。并制造溴代苯油灌胃氧化损伤模型,取黑蒜受试组与模型对照组小鼠的肝脏组织。分别测定造模损伤前血液及造模损伤后肝脏组织中的过氧化脂质丙二醛含量,超氧化物歧化酶、谷胱甘肽过氧化物酶活力和总抗氧能力活性。结果表明,随黑蒜多酚粗提物剂量增加可明显降低小鼠血清和肝脏组织中MDA含量,显著提高SOD、GSH-Px、T-AOC活力。根据"保健食品功能学评价程序和检验方法规范"判定标准,认为黑蒜多酚粗提物具有抗氧化功能。     

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.