南瓜籽油对大鼠血脂及抗氧化作用的影响

研究南瓜籽油对实验性高血脂大鼠的降血脂和抗氧化作用,采用高脂饮食构建高血脂大鼠模型,连续灌胃实验6周后,测定血清TG、TC水平及抗氧化指标。与高脂模型组相比,南瓜籽油各剂量组均有降低血清TG、TC及MDA水平和升高血清GSH-Px、SOD的作用,其中以中剂量组的降脂作用和抗氧化效果最好。中剂量组能显著降低血清TG和MDA水平的作用(P<0.05),降低血清TC和升高GSH-Px、SOD作用都达到极显著水平(P<0.01)。结果表明,南瓜籽油对大鼠有显著降低血脂和抗氧化作用。     

紫薯花青素降血脂及抗氧化效果

研究紫薯花青素（anthocyanins from purple sweet potato,PSPAs）对高血脂大鼠的血脂水平和抗氧化能力的影响,并对其主要成分进行分析。将Sprague-Dawley（SD）大鼠分为空白组和高脂组,分别喂养基础饲料和高脂饲料4 周,测定其体质量及血脂水平,判断大鼠高血脂模型是否建立成功。再将建模成功的高脂组大鼠分为模型组、阳性对照组和PSPAs低、中、高剂量组,测定大鼠体质量及脏体指数、血清中血脂水平、肝组织中的超氧化物歧化酶（superoxide dismutase,SOD）活性和丙二醛（malondialdehyde,MDA）含量。结果表明,PSPAs对大鼠体质量、肝脏指数和脾脏指数的增加有一定的抑制作用,而可以提高心脏指数;PSPAs能降低高血脂大鼠血清总胆固醇、甘油三酯、低密度脂蛋白胆固醇、载脂蛋白B水平,降低动脉粥样硬化指数（atherosclerosis index,AI）AI1、AI2和肝组织中MDA的含量,能提高大鼠血清高密度脂蛋白胆固醇、载脂蛋白AⅠ含量和肝组织SOD活性,其中以PSPAs高剂量组的降脂作用和抗氧化效果最好。以上结果表明PSPAs有降低大鼠血脂、抗氧化作用。     

不同分子质量小麦胚芽多肽的体内抗氧化活性

研究不同分子质量小麦胚芽多肽的体内抗氧化活性。利用超滤和纳滤技术对通过复合酶法制备的小麦胚芽多肽进行分级分段和纯化。通过建立小白鼠的氧化损伤模型,将170只小鼠随机分成17组(正常对照组、模型对照组、不同分子质量以及不同剂量的小麦胚芽多肽实验组),除正常对照组外,其余各组进行腹部注射600mg/(kg·d)D-半乳糖建立氧化损伤模型,5种不同分子质量的多肽组灌胃低、中、高剂量的小麦胚芽多肽,实验周期40d,眼球取血处死小鼠,测定血清、肝脏中的超氧化物歧化酶(SOD)活性、谷胱甘肽过氧化物酶(GSH-Px)活性、丙二醛(MDA)含量和总抗氧化能力(T-AOC),研究不同分子质量小麦胚芽多肽的体内抗氧化活性。结果表明：小麦胚芽多肽能够使小鼠血清和肝脏中SOD、GSH-Px以及T-AOC的指标升高,降低小鼠血清和肝脏中脂质过氧化物的MDA含量,具有良好的抗氧化活性。总体来说,随着多肽质量浓度的升高,抗氧化活性也随之增强,分子质量在2000D以下的小麦胚芽多肽具有较强的抗氧化活性。     

火麻仁油—藻油复配剂对混合型高脂血症大鼠的降脂及抗氧化作用

探讨火麻仁油—藻油复配剂对混合型高脂血症大鼠的降脂作用及抗氧化作用。将50只大鼠随机分为5组,每组10只,分别为空白对照组、模型对照组和复配剂低剂量组、中剂量组及高剂量组。高脂饲料喂养并给予相应药物灌胃后,测大鼠体重、睾脂肪垫重、肾周脂肪垫重、脂体比,检测血脂水平、血清的丙二醛(MAD)、谷胱甘肽(GSH)含量及过氧化超氧化物歧化酶(SOD)的活性。结果表明:模型组大鼠与正常组比较,体重、睾脂肪垫重、肾周脂肪垫重、脂体比显著增加,TG、TC含量显著升高,HDL-C显著降低,MDA显著升高,SOD、GSH、GSH-Px显著降低(P0.01或P0.05)。与模型组比较,火麻仁油藻油高、中、低剂量组大鼠体重、睾脂肪垫重、肾周脂肪垫重、脂体比显著降低,MDA含量显著降低,SOD、GSH、GSH-Px含量显著升高(P0.01或P0.05)。火麻仁油—藻油复配剂具有调节血脂和抗氧化作用。     

油茶对高脂饮食引起大鼠肝损伤的保护作用

本文主要研究了油茶对高脂饮食引起的大鼠肝损伤的保护作用。试验中将大鼠分为空白对照组、高脂模型组、油茶低、中和高剂量组,每组10只。经造模期15 d和给样期32 d后,腹主动脉采血,取肝脏。测定大鼠肝脏重量,观察肝脏组织病理;分别测定血清中ALT和AST活力,血清和肝匀浆中SOD、GSH-Px活力和MDA水平。结果表明,与高脂模型组相比,油茶组肝脏系数显著降低(p0.05);血清中ALT和AST活力显著降低(p0.05);血清和肝脏中SOD和GSH-Px活力显著升高,MDA含量显著降低(p0.05);肝脏组织病理显示,油茶组能够减轻肝细胞脂肪变性。由结果可知:油茶能够缓解高脂饮食大鼠肝脏肥大,增强机体抗脂质过氧化能力,缓解肝脏脂肪变性,对肝脏损伤起到有效的保护作用,其中油茶高剂量组作用最明显。     

亚麻籽提取物对高血脂症大鼠血脂和抗氧化作用研究

研究亚麻籽提取物对实验性高血脂症大鼠的降脂作用和抗氧化应激作用。48只大鼠随机分为六组,分别为正常组、模型组、阳性对照组、亚麻籽提取物高、中、低剂量组（0.6、0.3和0.15 g/kg）。正常对照组给予普通饲料喂养,其余各组给予高脂饲料喂养以建立高血脂症模型。造模成功后各位分别灌胃给药,共计6周。测定大鼠体重、肝肾指数,检测大鼠血清中总胆固醇（TC）、甘油三酯（TG）、低密度脂蛋白（LDL-Ｃ）和高密度脂蛋白（HDL-C）水平,检测大鼠肝和肾组织中谷胱甘肽过氧化物酶（GSH-Px）、超氧化物歧化酶（SOD）和丙二醛（MDA）的含量。HE染色考察肝脏组织病理学的改变。结果显示,与正常组相比,模型组大鼠的体重和肝肾指数显著增加,血清HDL-C降低,TC、TG和LDL-C升高,HE染色可见明显脂肪变性,肝肾组织中SOD和GSH-Px活性显著降低,肝组织中MDA含量显著增加。与模型组相比,亚麻籽提取物能显著抑制高脂饮食引起的大鼠体重增加,降低大鼠的肝肾指数;显著提高大鼠血清中HDL-C的含量,明显降低血清中TC、TG和LDL-C的含量;抗氧化指标SOD和GSH-Px在肝肾组织中的活性显著提高,肝组织中MDA含量降低。亚麻籽提取物低中高剂量组不同程度上减轻了大鼠肝细胞的脂肪变性情况。亚麻籽提取物对高血脂症大鼠具有降血脂作用,其机制可能是通过调节大鼠血脂水平,提高抗氧化能力有关。     

花生多肽的制备及其对氧化损伤模型小鼠抗氧化作用的研究

采用Alcalase蛋白酶水解花生蛋白制备花生多肽，将40只昆明小鼠随机分为四组（对照组、模型组、高低剂量多肽组），除对照组外，其余三组每日分别皮下注射400mg／kgbwD．半乳糖建立过氧化损伤模型；多肽组分别用花生多肽水溶液灌胃（400、800mg／kg bw），实验周期32d。实验结束，处死动物，取脾脏及胸腺称重，计算脏器指数；测定血清及肝脏中丙二醛（MDA）含量，超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH-PX）活性。结果表明，花生多肽使小鼠胸腺指数和脾脏指数升高，血清MDA含量明显下降，GSH-Px活力显著提高；并且使肝组织中MDA含量明显下降，SOD与GSH-Px活力明显提高，提示花生多肽具有较强的抗氧化作用。     

火麻仁油、藻油混合油软胶囊对高胆固醇血症动物模型血脂及脂质过氧化的影响

目的:探讨火麻仁油、藻油混合油软胶囊对高胆固醇血症大鼠血脂及脂质过氧化的影响。方法:50只大鼠随机分为5组,分别是空白对照组、模型对照组、火麻仁油藻油低剂量组(85mg/kg)、火麻仁油藻油中剂量组(170mg/kg)、火麻仁油藻油高剂量组(340mg/kg),饲喂以高脂饲料及不同剂量火麻仁油藻油,测大鼠体重、脂肪,计算Lee's指数、脂体比,检测血清中总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白-胆固醇(LDL-C)、高密度脂蛋白-胆固醇(HDL-C),以及血清和肝脏中丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性。结果:与正常组相比,模型组大鼠体重、Lee's指数、肾脂体比、睾脂体比、总脂体比显著增加(P0.01或P0.05),TG、TC、LDL-C含量显著升高,HDL-C显著降低(P0.01或P0.05),血清和肝脏中MDA显著升高,SOD显著降低(P0.01或P0.05)。与模型组比较,火麻仁油、藻油高、中剂量组大鼠体重、睾脂肪比、肾周脂肪比、总脂体比显著降低,TG、TC、LDL-C含量显著降低,HDL-C显著升高(P0.01或P0.05),血清和肝脏中MDA含量显著降低,SOD活性升高(P0.01或P0.05)。结论:对于高胆固醇血症模型大鼠,中、高剂量火麻仁油、藻油混合油的摄入能够有效起到调节血脂、抑制脂质过氧化学作用。     

蓝莓花色苷的降血脂和抗氧化作用

研究蓝莓花色苷(anthocyanins from blueberry fruits,ABBF)对实验性高脂血症大鼠的血脂水平和抗氧化能力的影响。将SD大鼠分成正常对照组,高脂组,低、中、高剂量蓝莓花色苷组,测定其血脂水平及血清和肝脏总抗氧化能力(T-AOC),谷胱甘肽过氧化物酶(GSH-Px)、超氧化物歧化酶(SOD)活性和MDA含量。结果表明:摄入蓝莓花色苷后高脂血症大鼠血脂水平和动脉粥样硬化指数(AI)均较高脂组显著降低,而血清和肝脏T-AOC、SOD和GSH-Px活性明显增强,MDA的生成量显著减少。     

木樨草素对高血脂大鼠抗氧化能力的影响

目的：探讨木樨草素对高血脂大鼠血清抗氧化功能的作用及其可能机制。方法：建立高血脂大鼠模型,观察给药后血脂水平和血清T-AOC、SOD、CAT 和MDA 变化。结果：各剂量药物组血清中TC、TG 和MDA水平显著低于模型对照组(P ＜ 0.05),HDL-C 水平显著高于模型对照组(P ＜ 0.05),T-AOC、SOD、CAT 活性显著高于模型对照组(P ＜ 0.05)。结论：木樨草素可提高高血脂大鼠血清抗氧化酶活性,降低脂质过氧化程度。     

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.     

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。     

Microbiology of food taints

Fresh and processed foods are often spoilt by the presence of undesirable flavours and odours caused by microbial action. The aim of this paper is to review the current knowledge of microbiologically induced taints that occur in a wide range of foodstuffs, including meats, poultry, fish, crustaceans, milk, dairy products, fruits, vegetables, cereals and cereal products. Examples have been chosen where the compounds responsible for the taint have been identified and sufficient data obtained to demonstrate the involvement of microorganisms. However, in some cases the full identity of the causative organism may not have been elucidated. The types of microorganisms covered by this review include bacteria, fungi, yeasts, actinomycetes and cyanobacteria. Although cyanobacteria do not in general infect foods, their presence in aqueous systems and water supplies can lead to off-flavours in aquatic organisms and processed foodstuffs. Several examples of each of these processes are discussed. Wherever possible, the likely biosynthetic pathway used by the microorganism to produce the offending compound in a foodstuff is indicated.     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. I: Interlaboratory studies of methods of analysis

This paper describes the first part of a project undertaken to develop mussel reference materials for Paralytic Shellfish Poisoning (PSP) toxins. Two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin (STX) and decarbamoyl-saxitoxin (dc-STX) in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the second part of the project: the certification exercise. In the first study, 18 laboratories were asked to measure STX and dc-STX in rehydrated lyophilized mussel material and to identify as many other PSP toxins as possible with a method of their choice. In the second interlaboratory study, 15 laboratories were additionally asked to determine quantitatively STX and dc-STX in rehydrated lyophilized mussel and in a saxitoxin-enriched mussel material. The first study revealed that three out of four postcolumn derivatization methods and one pre-column derivatization method sufficed in principle to determine STX and dc-STX. Most participants (13 of 18) obtained acceptable calibration curves and recoveries. Saxitoxin was hardly detected in the rehydrated lyophilized mussels and results obtained for dc-STX yielded a CV of 58% at a mass fraction of 1.86 mg/kg. Most participants (14 out of 18) identified gonyautoxin-5 (GTX-5) in a hydrolysed extract provided. The first study led to provisional criteria for linearity, recovery and separation. The second study revealed that 6 out of 15 laboratories were able to meet these criteria. Results obtained for dc-STX yielded a CV of 19% at a mass fraction of 3.49mg/kg. Results obtained for STX in the saxitoxin-enriched material yielded a CV of 19% at a mass fraction of 0.34mg/kg. Saxitoxin could not be detected in the PSP-positive material. Hydrolysis was useful to confirm the identity of GTX5 and provided indicative information about C1 and C2 toxins in the PSP-positive material. The methods used in the second interlaboratory study showed sufficiently consistent analysis results to undertake a certification exercise to assign certified values for STX and dc-STX in lyophilized mussel.