贡菊多糖对D-半乳糖致衰老小鼠的抗衰老作用

目的:探讨贡菊多糖对D-半乳糖所致衰老小鼠的抗衰老的作用。方法:将小鼠随机分为5组:空白对照组,D-半乳糖衰老模型对照组(80mg/kg·d bw),贡菊多糖低、中、高剂量组(50、100、150mg/kg·d bw),考察血清和肝中SOD、GSH-Px、CAT、T-AOC和血清、肝及脑中的MDA等指标。结果:贡菊多糖能拮抗D-半乳糖所致的小鼠衰老,使小鼠血清及肝组织SOD、GSH-Px、CAT、T-AOC活性明显回升,血清、肝脏和脑组织中MDA的水平下降。结论:贡菊多糖具有延缓衰老的作用。     

新疆灰枣叶黄酮对衰老模型小鼠抗氧化活性的影响

目的:研究枣叶黄酮对衰老小鼠的心脏、肝、血清抗氧化功能的影响。方法:采用乙醇提取枣叶黄酮,测定灰枣叶总黄酮含量并对其抗氧化活性进行测定;由D-半乳糖连续皮下注射诱导亚急性衰老模型小鼠,以各组小鼠心脏、肝和血清总抗氧化能力,总抗氧化能力(T-AOC)、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶活力(GSH-Px)和丙二醛(MDA)含量为指标,评价枣叶黄酮在小鼠体内的抗氧化能力;做HE染色切片,观察其组织细胞状态。结果:灰枣叶总黄酮含量为(18.60±1.06)mg/g,清除DPPH自由基、羟基自由基、ABTS自由基、超氧阴离子自由基的IC50值分别是0.997、1.035、1.039、0.983 mg/m L,均与阳性对照组具有显著性差异(p0.05);与空白对照组相比,模型对照组小鼠心脏、肝、脑和血清中T-AOC、SOD、GSH-Px力均有不同程度的降低,MDA含量有不同程度的升高,且空白对照组与模型组差异显著(p0.05),说明小鼠衰老模型构建成功。与模型对照组相比,枣叶各剂量组能增强模型小鼠心脏、肝、脑和血清中T-AOC、SOD、GSH-Px活力,同时降低MDA值。从病理切片看,枣叶黄酮具有抗氧化能力。结论:枣叶黄酮能够显著增强亚急性衰老小鼠的抗氧化能力,具有延缓衰老的作用。     

洋葱槲皮素对衰老模型小鼠抗氧化作用的研究

利用洋葱槲皮素灌胃衰老模型小鼠,以小鼠心脏、肝、脑和血清中T-AOC、SOD、GSH-Px活力以及MDA含量作为评价指标,讨论洋葱槲皮素对衰老模型小鼠各组织抗氧化功能的影响。结果表明:与模型对照组比较,洋葱槲皮素每个剂量组均可对模型小鼠心脏、肝、脑和血清中T-AOC、SOD、GSH-Px活力起到增强作用,还可降低各组模型小鼠MDA含量,说明洋葱槲皮素可显著增强衰老小鼠的抗氧化功能,延缓衰老。     

金银花叶黄酮对衰老模型小鼠的体内抗氧化作用

目的:研究金银花叶黄酮对衰老小鼠体内抗氧化系统的调节作用。方法:采用颈背部皮下注射D-半乳糖法构建衰老小鼠模型,用不同剂量(低、中、高剂量分别为50、100、200 mg/(kg·d))的金银花叶黄酮灌胃小鼠,观察小鼠体质量变化,并计算肝脏、脑、肾脏、脾脏及心脏指数,测定小鼠血清及肝脏、脑、肾脏及心脏组织中总抗氧化能力(total antioxidant capacity,T-AOC)、超氧化物歧化酶(superoxide dismutase,SOD)、谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-Px)、过氧化氢酶(catalase,CAT)活力及丙二醛(malondialdehyde,MAD)、谷胱甘肽(glutathione,GSH)含量。结果:与空白组相比,模型组小鼠体质量和脏器指数显著下降,血清和各脏器组织中的T-AOC、SOD、GSH-Px、CAT活力及GSH含量均有所降低,MDA含量升高,且大部分差异显著(P0.05),说明衰老小鼠模型构建成功。与模型组相比,金银花叶黄酮各剂量组小鼠体质量和脏器指数均有所升高,血清和脏器中的T-AOC、SOD、GSH-Px、CAT活力及GSH含量均有不同程度的回升,MDA含量降低,高剂量组效果最显著。结论:金银花叶黄酮能有效提高衰老小鼠的抗氧化能力,其抗氧化机制可能与提高机体抗氧化酶活性和还原性保护物质含量、降低脂质过氧化物含量有关。     

蝇蛆肽对衰老小鼠的作用及机制的初探

目的:探讨蝇蛆肽对衰老小鼠的作用及其机制。方法:将60只小鼠随机分为6组,除空白组外,其余五组用D-半乳糖致衰老,分为衰老模型组、维生素C组以及蝇蛆肽低、中、高剂量组(2、4、8 g/kg)。测定小鼠的脾脏和胸腺指数。采用羟胺法测定小鼠肝脏和脑及血清中的超氧化物歧化酶(SOD)活力,可见光法测定过氧化氢酶(CAT)和谷胱甘肽过氧化物酶(GSH-Px)的活力,以硫代巴比妥酸(TBA)法测定丙二醛(MDA)的含量。结果:与空白组相比,模型组小鼠脾指数、胸腺指数及肝脏指数均有显著降低(p0.05),蝇蛆肽低、中、高剂量组脏器指数显著增高(p0.05)。与空白组比较,模型组肝、脑中SOD、CAT、GSH-Px均降低,且MDA含量增高(p0.05),血清中SOD、CAT降低、MDA含量增高(p0.05);与模型组比较,蝇蛆肽低、中、高剂量组肝、脑组织中SOD、CAT、GSH-Px均显著增高、MDA含量显著降低(p0.05),血清中SOD、CAT显著增高、MDA含量显著降低(p0.05)。结论:蝇蛆肽通过改变衰老小鼠的脏器指数而对其产生免疫调节作用,可显著提高小鼠肝脏和脑组织中的SOD、CAT、GSH-Px的活力,降低MDA的含量(p0.05),从而改变机体抗氧化能力。蝇蛆肽对衰老小鼠的影响机制可能与增强其体内抗氧化酶活力及改变脏器指数相关。     

黄秋葵果实粉对衰老模型小鼠抗氧化能力的影响

探讨黄秋葵果实粉(OFP)对D-半乳糖致衰老模型小鼠抗氧化能力的影响。以昆明种小鼠为研究对象,颈背部皮下注射D-半乳糖造模。正常对照组、模型对照组饲喂基础饲料,实验组小鼠饲喂含受试物低、中、高剂量(32.00、64.00、128.00 g/kg)饲料,实验期56 d,测定血清和肝组织匀浆中超氧化物岐化酶(SOD)、谷胱苷肽过氧化物酶(GSHPx)、过氧化氢酶(CAT)的活性及丙二醛(MDA)的含量。D-半乳糖致衰小鼠SOD活性、GSH-Px活性和CAT活性均明显下降,MDA含量明显上升,与正常小鼠比较差异显著;饲喂不同剂量的黄秋葵果实粉后均能提高小鼠血清、肝脏组织中的SOD、GSH-Px和CAT活性,同时降低血清、肝脏组织中MDA含量。适量摄入黄秋葵果实粉能显著提高衰老小鼠的抗氧化能力,具有一定延缓衰老的作用。     

银耳多糖抗氧化作用的研究

研究银耳多糖的抗氧化活性。以银耳为原料,经简单分离纯化,制得银耳多糖。将ICR小鼠随机分为空白对照组、模型对照组、银耳多糖低、中、高剂量组,通过每日皮下注射D-半乳糖建立亚急性衰老小鼠模型,空白对照组用生理盐水代替。剂量组小鼠灌胃剂量分别为100、200、400 mg/(kg·bw),空白对照组和模型对照组用生理盐水代替,每日一次,持续八周。测定比较血清、肝脏、脑组织中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)与谷胱甘肽过氧化物酶(GSHPx)活性、丙二醛(MDA)含量、总抗氧化能力(T-AOC)和皮肤中的羟脯氨酸含量的差异。与模型组相比,银耳多糖剂量组小鼠血清、肝脏、脑组织中的SOD、CAT、GSH-Px活性和总抗氧化能力显著增强,MDA含量的异常上升受到明显抑制,皮肤中的羟脯氨酸含量显著提高,且以银耳多糖中、高剂量组的效果更好。银耳多糖对D-半乳糖致亚急性衰老小鼠具有较强的抗氧化活性。     

蚕蛹多肽提高D-半乳糖致衰老小鼠的抗氧化及免疫能力

目的:研究蚕蛹多肽对D-半乳糖衰老模型小鼠抗氧化、提高免疫作用.方法:将昆明小鼠随机分为9组,包括空白组,衰老模型组,蚕蛹多肽(SPP)低、中、高剂量组,蚕蛹蛋白组,Vc组,谷胱甘肽组和鱼胶原蛋白肽组.除空白组外,其余8组腹腔注射D-半乳糖建立衰老模型,42d后眼球取血,颈椎脱臼处死小鼠,测定脑、肝脏中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSH-Px)活性、总抗氧化能力(T-AOC)和丙二醛(MDA)含量,测定胸腺指数,脾指数,血清中白细胞数(WBC).结果:与衰老模型组相比,Spp中、高剂量组肝和脑中CAT、SOD、GSH-Px和T-AOC活力提高显著(p＜0.05或p＜0.01),同时SPP组肝和脑中MDA含量均有不同程度降低(p＜0.05或p＜0.01).此外,SPP能提高胸腺指数、脾指数与WBC,可以缓解小鼠衰老导致的免疫低下症状.与阳性对照蚕蛹蛋白组和鱼胶原蛋白肽组相比,SPP表现出更强的减缓小鼠衰老的作用,相当于等体外抗氧化效果的谷胱甘肽组.结论:SPP有较强的体内抗氧化活性和提高免疫功能,也为蚕蛹资源的回收利用提供思路.     

农大4号’欧李果实花色苷对D-半乳糖致衰老小鼠保护作用研究

为了研究'农大4号'欧李果实花色苷对衰老小鼠保护作用,采用颈部皮下注射D-半乳糖构建衰老小鼠模型,用不同剂量(高、中、低剂量分别为500、250、125 mg·(kg·d)-1)的花色苷灌胃小鼠,计算小鼠心脏、肝脏、脾脏、肺脏及肾脏指数,并测定小鼠血清、心脏、肝脏、脾脏和肾脏中总抗氧化能力(total antioxidant capacity,T-AOC)、过氧化氢酶(catalase,CAT)、丙二醛(malondialdehyde,MDA)、超氧化物歧化酶(superoxide dismutase,SOD)、谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-Px)的指标变化情况。结果表明:与空白组相比,模型组小鼠肝脏指数、脾脏指数和肾脏指数显著下降(P<0.05),血清和各脏器组织中的T-AOC、SOD、GSH-Px、CAT均显著降低(P<0.05),MDA含量显著升高(P<0.05),说明衰老小鼠模型构建成功。与模型组相比,高剂量组的肝脏指数、脾脏指数和肾脏指数显著升高(P<0.05),血清和各脏器中的T-AOC、SOD、GSH-Px、CAT均有显著升高(P<0.05),MDA含量显著降低(P<0.05)。由此得出,'农大4号'欧李果实花色能有效增强小鼠的抗氧化能力,对衰老小鼠有较强的保护作用。     

辣木多肽对D-半乳糖致衰老小鼠抗氧化功能的影响

探讨辣木多肽(MOPP)对D-半乳糖致衰老小鼠抗氧化能力的影响。小鼠腹腔注射D-半乳糖(120mg/kg)建立衰老模型。建模成功后,分设正常组,D-半乳糖衰老组,维生素C组,MOPP低剂量(10 mg/kg)和高剂量(100 mg/kg)组。连续给药6周后,依试剂盒说明分别测定血清总抗氧化力(T-AOC),脑、心脏和肝脏及血清中超氧化物歧化酶(superoxide dismutase,SOD),过氧化氢酶(catalase,CAT),谷胱甘肽过氧化酶(glutathioneperoxidase,GSH-Px)和丙二醛(malondiadehycle,MDA)水平。q RT-PCR法测定肝内Mn-SOD、Gu/Zn-SOD和CAT的m RNA表达。与衰老对照组相比,MOPP能分别有效提高衰老小鼠血清T-AOC能力(至13.73～17.98U/m L),及血清SOD(8.04～11.65 U/mg protein)、CAT(4.56～6.45 U/mg protein)和GSH-Px(7.28～10.65 U/mg protein)活性,并显著提升脑、心脏及肝组织中抗氧化物酶(SOD、CAT、GSH-Px)活力(p0.05)。同时,高浓度MOPP还能使血清、脑、心脏和肝组织中MDA水平显著降低43.6%,44.7%,31.4%和56.0%(p0.05)。此外,MOPP干预还能增强肝脏中SOD、CAT和GSH-Px的m RNA转录。本研究结果提示MOPP能明显提高D-半乳糖致老龄小鼠体内的抗氧化状态。     

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.     

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.     

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.     

低温带皮菜籽粕微粉的不同粒级部分的功能特性

为研究低温带皮菜籽粕微粉的不同粒级部分的功能特性,以经低温脱脂的带皮菜籽粕为原料,经微粉碎后筛分成212~425μm、150~212μm和106~150μm的3个不同粒级的微粉样品,检测这些样品的吸水性、吸油性、乳化性和乳化稳定性、蛋白质体外消化率。结果表明:1 3个不同粒级的微粉样品之间的粗纤维含量存在显著差异,表明三者的结构组成成分有一定差异。23个微粉样品的乳化活性和乳化稳定性随粒度级别的减小而显著增加(P0.01)。33个微粉样品的蛋白质体外消化率随粒度级别的减小而显著增加(P0.01)。4不同粒级带皮菜籽粕微粉样品的吸水性与吸油性受其结构组成物质不同和粒度的双重影响,与粒度的相关性不明显。