美味牛肝菌黄酮类提取物体内抗氧化作用研究

目的:研究长白山美味牛肝菌黄酮类提取物体内抗氧化作用。方法:将实验小鼠随机分为空白对照组和低、中、高3个剂量组,分别灌胃生理盐水和提取物,4周后眼眶取血及各组织,用试剂盒分别测定小鼠血清、心脏、肝脏及肾脏中蛋白质含量、T-AOC、MDA含量、SOD和GSH-Px活力。结果:血清、心脏、肝脏中蛋白含量中、高剂量组显著高于空白对照组;心脏中SOD活性中、高剂量组显著高于空白对照组;血清、心脏、肝脏中GSH-Px三剂量组显著高于空白对照组;血清、心脏中MDA中、高剂量组显著低于空白对照组;心脏、肾脏T-AOC中、高剂量组显著高于空白对照组。结论:美味牛肝菌提取物一定剂量有助于增强机体清除自由基的能力,具有一定的抗氧化作用。     

桦褐孔菌多酚在小鼠血清中的抗氧化作用研究

通过测定小鼠血清中总抗氧化能力(T-AOC)、丙二醛(MDA)的含量、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、甘肽过氧化物酶(GSH-Px)的活性,探讨了桦褐孔菌多酚在小鼠血清中的抗氧化作用。结果表明,灌胃桦褐孔菌多酚的小鼠,与对照组小鼠相比,血清中的T-AOC明显增加(p0·01),MDA含量明显减少(p0·01),SOD、CAT、GSH-Px酶活性明显增加(p0·01)。桦褐孔菌多酚具有一定的抗氧化作用。     

大豆异黄酮对糖尿病大鼠抗氧化能力的影响

目的：观察大豆异黄酮（soybean isoflavone，SIF）对糖尿病大鼠抗氧化能力的影响。方法：以四氧嘧啶（ALX）为诱导剂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（SI）每日以100mg／kg·d的SIF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）活性及丙二醛（MDA）含量。结果SI组实验后血糖较实验前和DC组明显降低（p〈0．05），DC组实验前血糖较实验后则明显升高（p〈0．05）。与DC组相比，SI组血清和肝脏GSH-Px和SOD抗氧化酶活性明显增强（p〈0．05）接近和超过正常水平，肝脏T．AOC能力明显高于DC和N组（p〈0．05），而血清及肝脏MDA含量均低于DC组（p〈0．05），血清XOD活性较DC组略有降低。结论：大豆异黄酮具有降血糖和增强机体抗氧化能力，其降糖机理与阻止胰腺B细胞和肝脏表面胰岛素受体进一步氧化损伤，修复其功能有关。     

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。     

金针菇废菇柄发酵物对衰老模型小鼠氧化应激损伤的影响

以D-半乳糖致衰老模型小鼠为研究对象,采用试剂盒测定不同组别(空白对照组,金针菇废菇柄发酵物低、中、高剂量组,D-半乳糖模型组和金针菇废菇柄对照组)中小鼠血清、肝脏、心脏和脑组织中谷胱甘肽过氧化物酶(Glutathione peroxidase,GSH-Px)、超氧化物歧化酶(Superoxide dismutase,SOD)及过氧化氢酶(Catalase,CAT)的活性和总抗氧化能力(Total antioxidant capacity,T-AOC),丙二醛(Malondialdehyde,MDA)含量指标,探讨金针菇废菇柄发酵物对衰老模型小鼠氧化应激损伤的影响。实验表明:金针菇废菇柄发酵物能显著(p0.01)提高D-半乳糖致衰老小鼠体内肝脏、脑、心脏和血清的GSH-Px、SOD、T-AOC、CAT活性,并显著(p0.01)降低MDA 含量。研究显示,金针菇废菇柄发酵物能有效提高衰老小鼠体内多种抗氧化酶活力,催化对机体有害物质的分解,有效地防止氧化损伤等产生的衰老作用,金针菇废菇柄在医药或保健功能性食品领域具有广阔的应用空间。     

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。     

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。     

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。     

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。     

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.     

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.     

Analysis for organic residues from aids to polymerization used to make plastics intended for food contact

Polymers intended for food contact use have been analysed for organic residues which could be attributed to a range of substances employed as polymerization aids (e.g. initiators and catalysts). A wide range of polymers was extracted with solvents and the extracts analysed by gas chromatography-mass spectrometry (GC-MS). The overwhelming majority of substances identified were not derived from aids to polymerization but were oligomers, additives and adventitious contaminants. However, a small number of substances were identified as initiator residues. These included tetramethylsuccinonitrile (TMSN) which was observed in two polymers and it derived from recombination of two azobisisobutyronitrile (AIBN) initiator radicals. Methyl benzoate, benzoic acid, biphenyl and phenyl benzoate were detected in one poly(methyl methacrylate) sample and in two polyvinylchlorides and they are thought to be derived from benzoyl peroxide initiator. TMSN was subsequently targeted for analysis of poly-(methyl methacrylate) plastics using proton nuclear magnetic resonance spectrometry (¹     

Tests of potential functional barriers for laminated multilayer food packages. Part II: Medium molecular weight permeants

Experiments were performed to characterize the kinetics of the permeation of different medium molecular weight model permeants: bisphenol A, warfarin and anthracene, from liquid paraffin, through a surrogate potential functional barrier (25 microns-thick orientated polypropylene--OPP) into the food simulants olive oil and 3% (w/v) acetic acid. The characterization of permeation kinetics generally observed the permeation models previously reported to explain the experimental permeation results obtained for a low molecular weight group of model permeants. In general, the model permeants exhibited behaviour consistent with their relative molecular weights with respect to (a) the time taken to attain steady-state permeation into the food simulant in which they were more soluble, (b) their subsequent steady-state permeation rates, and (c) their partition between liquid paraffin and the OPP membrane.     

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.     

Focus on China's Paper Industry

In the English section of this issue, 〈China Paper Newsletters〉 will introduce ＂National Development and Reform Commission Issued Announcement for Selection of Major Preliminary Research Projects for the ＇13th Five-Year Plan＇＂, ＂2013 Annual Report of China＇s Paper Industry＂, and news of projects and other policies.     

Listen to downstream & search for innovation

正Nowadays,textile enterprises are all taking efforts in transformation and upgrading,like improving producing capacity and optimizing production structure to face market downturn.It claimed a higher request to the standard of textile equipments.In the upcoming of ITMA ASIA+CITME 2014exhibition,this magazine have interviewed several branch associations and a series of relative enterprises,to summarize industrial developing status