大豆低聚肽降胆固醇作用研究

目的:研究大豆低聚肽在降胆固醇方面的作用。方法:取5周龄SD雄性大鼠90只,随机分为6组(每组15只),即Ⅰ(对照组)、Ⅱ(蛋白组)、Ⅲ(多肽组)、Ⅳ(低聚肽组1)、Ⅴ(低聚肽组2)、Ⅵ(低聚肽组3),在实验环境下,构建高胆固醇模型,在对各组继续饲喂高胆固醇饲料的同时,对第Ⅱ组口腔灌喂大豆蛋白,对第Ⅲ组口腔灌喂大豆多肽,对第Ⅳ、Ⅴ、Ⅵ组分别灌喂不同剂量的大豆低聚肽,第Ⅰ组口腔灌喂同体积的饮用水。饲喂6周,分别收集粪便、血清和肝脏,测定血清和肝脏中的胆固醇和甘油三酯含量、粪便重量及其中的类固醇含量。结果:第Ⅱ、Ⅲ、Ⅳ、Ⅴ、Ⅵ组血清和肝脏中的胆固醇和甘油三酯含量均有不同程度的降低,大鼠粪便的排泄量及粪便中类固醇的含量增加。大豆低聚肽组有剂量依赖性,高剂量大豆低聚肽组效果极显著。结论:大豆低聚肽具有比大豆蛋白和大豆多肽更强的降低胆固醇的作用,且这种作用具有剂量依赖性。     

富硒大豆低聚肽的制备及其抗疲劳功能的研究

为探究富硒大豆低聚肽对抗运动性疲劳的影响,实验以富硒大豆为原料制备大豆分离蛋白,并以超滤萃取辅助中性蛋白酶和风味蛋白酶双酶酶解法制取富硒大豆低聚肽,并通过ICP-MS对硒含量进行鉴定,最后通过小鼠运动性疲劳实验综合评估富硒大豆低聚肽的抗疲劳活性。结果显示：富硒大豆低聚肽的总硒含量为90.03±3.23 mg/kg,主要形态为硒代蛋氨酸、硒代半胱氨酸。在运动性疲劳小鼠模型下,四组剂量组均能够延长小鼠负重力竭游泳时长,其中富硒大豆低聚肽高剂量组时间最长约为37.47±1.33 min,同时,血清生化指标显示小鼠的SOD酶、GSH-Px酶活性相较于模型组显著提高(P<0.05),MDA含量显著降低,肌糖原与肝糖原含量提高。综上,表明富硒大豆低聚肽对小鼠抗运动性疲劳具有积极作用,在100mg/kg.bw.d剂量组下抗疲劳效果显著。     

富硒大米肽体内抗氧化活性研究

目的:比较普通大米肽、富硒大米肽和硒代蛋氨酸的体内抗氧化活性。方法:将60只老龄(12月龄)雄性昆明小鼠和10只少龄(1月龄)雄性昆明小鼠分成7组(每组10只):老龄模型组(M组)、少龄对照组(YC组)、普通大米肽组(400 mg/kg·bw,Ⅰ组)、富硒大米肽组(400 mg/kg·bw,Ⅱ组)、硒代蛋氨酸组(2.5μg/kg·bw,Ⅲ组)、富硒大米肽+硒代蛋氨酸组(200 mg/kg·bw+1.225μg/kg·bw,Ⅳ组)和白藜芦醇组(10 mg/kg.bw,PC组),其中富硒大米肽组、硒代蛋氨酸组以及富硒大米肽+硒代蛋氨酸组中的硒含量一致,连续灌胃30 d。结果显示:与M组相比,YC组、Ⅱ组、Ⅲ组、Ⅳ组、PC组小鼠血清中超氧化物歧化酶(SOD)活性极显著提高(p0.01);YC组、Ⅰ组、Ⅳ组的还原型谷胱甘肽(GSH)含量显著增加(p0.05),Ⅱ组和PC组GSH含量极显著增加(p0.01);YC组、Ⅱ组、PC组的过氧化氢酶(CAT)活性显著增加(p0.05);Ⅲ组、Ⅳ组的肝匀浆中谷胱甘肽过氧化物酶(GSH-Px)活性显著提高(p0.05),Ⅱ组的GSH-Px活性极显著增加(p0.01);Ⅱ组、Ⅳ组、PC组的T-AOC显著增加(p0.05);YC组、Ⅱ组的丙二醛(MDA)显著减少(p0.05),PC组的MDA极显著减少(p0.01);YC组、PC组的GSH显著增加(p0.05),Ⅱ组的GSH极显著增加(p0.01),以及胸腺、脾脏指数等指标均有不同程度地改善。其中所有指标以富硒大米肽组效果最好,抗氧化活性显著高于同剂量的普通大米肽,大多数指标也显著优于同等硒含量的硒代蛋氨酸组。结论:富硒大米肽中的硒与肽对增强抗氧化能力有一定的增效作用。     

富硒发酵豆奶对CCl4急性肝损伤小鼠抗氧化功能的影响

用不同硒含量的富硒发酵豆奶给小鼠灌喂30d后用CCl4造模。24h后采用生化检测方法测定小鼠的GSH-Px、SOD酶活性和MDA浓度。结果表明，对于急性肝损伤小鼠，富硒发酵豆奶可以显著提高小鼠血清、肝脏中的GSH-Px和SOD酶活性，降低MDA浓度。证明富硒发酵豆奶可以增强机体拮抗氧化应激所导致的急性肝损伤能力。     

大豆异黄酮与Vc对糖尿病大鼠抗氧化能力影响的比较

比较大豆异黄酮(soybean isoflavone,SIF)与Vc对糖尿病大鼠抗氧化能力的影响。方法:用四氧嘧啶(ALX)建立糖尿病动物模型,正常对照组(N)和糖尿病对照组(DC)以蒸馏水灌胃,大豆异黄酮组(SIF)和Vc组(VC)分别以100mg/(kg·d)的SIF溶液和10.4mg/(kg·d)的Vc溶液灌胃。实验6周后,分别测血清及肝脏中总抗氧化能力(T-AOC)、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)和黄嘌呤氧化酶(XOD)活性以及丙二醛(MDA)含量。结果:DC组灌胃后血糖较灌胃前明显升高(P<0.05),SIF组和Vc组血糖均明显低于灌胃前和DC组(P<0.05)。与DC组相比,SIF组血清和肝脏GSH-Px和SOD活性及肝脏T-AOC明显增强(P<0.05),血清及肝脏MDA含量均明显降低(P<0.05)。Vc组血清GSH-Px和肝脏SOD活性、T-AOC明显高于DC组(P<0.05),MDA含量明显低于DC组(P<0.05)。SIF组和VC组在血清及肝脏T-AOC、SOD、GSH-Px、XOD活性和MDA含量上无明显差异(P>0.05)。结论:大豆异黄酮具有降血糖和增强机体抗氧化能力,其抗氧化效果与Vc相当。大豆异黄酮通过降低血糖、改善抗氧化酶活性和抑制脂质过氧化等作用发挥对糖尿病治疗作用。     

富硒大豆低聚肽降血压作用的研究

为了研究富硒大豆低聚肽在降血压方面的作用,本研究采用5周龄SD雄性大鼠60只,随机分为4组,按设计进行饲喂实验,测定各试验大鼠的体重和血压,饲喂4周,停喂次日处死所有大鼠,测定血清和肺组织中ACE活力及血清中K、Na、Se的含量。结果显示:富硒大豆低聚肽能促进试验大鼠的体重增加,降低大鼠血清中ACE活性,但对肺组织ACE活性无显著影响,能导致大鼠血清中Na离子浓度下降、Se含量增加。说明富硒大豆低聚肽具有降低SHR血压的作用,这种作用是Se和大豆低聚肽共同作用的结果,除与ACE活力被抑制有关外,还可能与导致大鼠体内Na+浓度下降、Se含量增加有关。     

菠萝蜜低聚肽对γ射线辐照小鼠氧化损伤的保护作用

目的:探究菠萝蜜低聚肽(JOPs)对γ射线辐照导致小鼠氧化损伤的保护作用。方法:选取96只SPF级雌性BALB/c小鼠,按体重随机分为空白组、模型组、乳清蛋白组(0.40 g/kg·BW)及3个JOPs干预组(0.20、0.40、0.80 g/kg·BW),每组随机分为2个亚组,8只/亚组。行灌胃干预第14 d除空白组外,小鼠接受60Coγ射线全身辐照,剂量3.5 Gy,剂量率1 Gy/min。两亚组分别在辐射后第3 d和第14 d检测小鼠血清和肝脏超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活性及丙二醛(MDA)水平。结果:辐照后第3 d及第14 d,相比空白组,模型组血清、肝脏SOD及GSH-Px活性均显著降低,MDA水平均显著增高,JOPs各剂量组小鼠血清及肝脏MDA水平均显著低于模型组与乳清蛋白组;辐照后第3 d,相比模型组,JOPs各剂量组小鼠血清及肝脏SOD、GSHPx活性均显著增高,且高剂量组小鼠血清SOD活性及血清、肝脏GSH-Px活性与中、高剂量组肝脏SOD活性均显著高于乳清蛋白组;辐照后第14 d,相比模型组,JOPs各剂量组小鼠血清及肝脏SOD、GSH-Px活性均显著增高,且JOPs各剂量组小鼠血清SOD活性与高剂量组肝脏SOD、GSH-Px活性均显著高于乳清蛋白组。结论:JOPs对γ射线辐照所致氧化损伤具有保护作用。     

复方杜仲对肉鸡抗氧化性的影响

研究复方杜仲对肉鸡抗氧化功能的影响.Ⅰ组为对照组,饮用自来水;Ⅱ、Ⅲ、Ⅳ组为试验组,分别饮用质量浓度为1.25、2.5和5 g/L复方杜仲水煎液,连续处理42 d.每周末每组随机抽样8只,心脏采血,分离血清,测定超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSH-Px)活性和丙二醛(MDA)含量.在整个试验期间,复方杜仲饮水各处理组血清中的SOD、GSH-Px、CAT的活性始终高于对照组(P＜0.05或P＜0.01),同时Ⅳ组高于Ⅱ、Ⅲ组(P＜0.05或P＜0.01),并随着周龄的增大其活性呈现波动性变化.血清中MDA的含量低于对照组(P＜0.05或P＜0.01);但随着周龄的增大,MDA的含量呈现上升的趋势.     

富硒玉米肽对四氯化碳致小鼠急性肝损伤的保护作用

研究富硒玉米肽对四氯化碳(Carbon tetrachloride,CCl4)诱导的小鼠肝损伤的保护作用。将健康的雄性昆明小鼠70只,随机分成7组:正常对照组、CCl4模型组、富硒玉米肽低、中、高剂量组(100、200、400mg/kg·bw)、普通玉米肽组(200 mg/kg·bw)、水飞蓟素阳性对照组(50 mg/kg·bw),每组10只。测定比较血清中谷丙转氨酶(ALT)活力、谷胱甘肽(GSH)、三酰甘油(TG)含量,同时测定肝组织中丙二醛(MDA)、谷胱甘肽(GSH)的含量及超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活力,肝脏指数,并观察肝组织病理学变化。结果显示富硒玉米肽低、中、高剂量组均能极显著抑制CCl4致肝损伤小鼠血清ALT活性和TG含量的升高、GSH含量的降低(P0.01);均能极显著提高肝组织中GSH含量和SOD、GSH-Px活力,并降低肝组织中MDA的含量(P0.01),极显著降低由于肝损伤引起的肝脏肿大(P0.01),改善肝组织损伤程度,并存在剂量效应关系。富硒玉米肽高剂量组的护肝效果与50 mg/kg·bw的水飞蓟素相当,相同剂量的富硒玉米肽的保肝作用极显著优于普通玉米肽(P0.01)。结果表明富硒玉米肽对CCl4所致小鼠急性肝损伤有显著的保护作用,且与普通玉米肽相比,富硒玉米肽的有效保肝剂量显著降低。     

大豆异黄酮抗氧化效能的研究

目的：观察大豆异黄酮对小鼠抗氧化效能的影响。方法：选用BALB／C雄性小鼠60只，体重18～22g，随机分为4组：空白对照组、低剂量组、中剂量组和高剂量组，空白对照组喂倒基础例料，其余3组分别喂饲添加25、100、200mg／kg大豆异黄酮的基础饲料。实验第8周末，将小鼠断头处死，取血、心脏、肝脏组织测定SOD、GSH-Px、CAT、MDA、H2O2和T-AOC等指标。结果：与空白对照组比较，小鼠肝脏中的MDA和H2O2含量显著降低（p〈0．01），小鼠全血和肝脏、心脏GSH-Px和CAT活性明显升高（p〈0．01），肝脏、心脏SOD活性，T-AOC含量明显升高（p〈0．01）。结论：大豆异黄酮具有明显的抗氧化作用。     

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.     

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.     

Influence des ions sur le pouvoir hydratant de l'ure e: e tude sur peau de porc ex vivo

This study deals with the influence of ions (NaCl and MgSO4) in a W/O emulsion containing 10% urea. Moisturization kinetics are assessed by corneometry on pig skin ex vivo. The formula's influence on urea penetration is measured by infrared spectrometry with an ATR device and the stripping method. Corneometry and spectroscopy were chosen to record simultaneously the hydratation levels and urea localization into superficial cell layers. Urea crystallization after evaporation of emulsions and aqueous solutions is described. Results show that urea does not hydrate nor penetrate when applied to the skin through an aqueous gel. In a W/O emulsion, sodium chloride increases the ability of urea to moisturize without improving penetration. In vitro urea crystallization is disturbed by sodium chloride or magnesium sulphate for solutions and emulsions. This stabilization by ions is correlated with good moisturization values. The stabilization of urea in the solute state provided by ions increases its water epidermal binding capacity without enhancing penetration.     

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.