核桃油氧化及抗氧化调控研究进展

摘要：核桃油富含多不饱和脂肪酸（PUFA）、单不饱和脂肪酸（MUFA）和多种营养素,具有多种生物活性。核桃油的稳定性较差,易发生氧化酸败,为提高核桃油的品质,延长其货架期,综述了近年来有关核桃油氧化劣变的影响因素和核桃油抗氧化调控措施的研究进展。核桃油氧化劣变的影响因素有内部因素,如脂肪酸组成、内源性物质的抗氧化能力,也有外部因素,如储藏条件、提取工艺。可以采用微胶囊技术、复配调和其他抗氧化性强的油脂,以及添加抗氧化剂的方式延缓核桃油氧化酸败。     

核桃油的研究进展

核桃油中丰富的油酸、亚油酸和亚麻酸等多不饱和脂肪酸具有重要的生理作用。目前有多种提取核桃油的方法,对这些方法的优缺点进行总结,并介绍核桃油的功能特性。     

核桃油绿色提取技术的研究进展

核桃油具有良好的脂肪酸结构，富含生育酚、甾醇、磷脂等多种药理活性物质，具有较高的食用及营养价值，能够起到抗氧化、抗炎、抗肿瘤、预防心脑血管疾病等作用。该文对核桃油的成分组成、功能活性和理化性质等方面特征进行分析，对核桃油传统提取技术以及绿色提取技术进行综述，并对未来的发展方向提出展望。     

水酶法提取核桃油研究进展

核桃油富含不饱和脂肪酸和多种脂肪伴随物, 对人体健康十分有益。由于核桃油的营养价值高, 如何实现核桃油的高效提取和适度加工越来越受到学者的关注。传统提取核桃油的方法存在蛋白质大量浪费、出油率不高和生物活性物质利用不充分等问题, 因此推进新型绿色的核桃油提取方法显得极为重要。水酶法(Aqueous enzymatic extraction, AEE)是一种新兴的植物油提取技术, 通过充分破碎油料, 在生物酶的辅助作用下破乳, 实现植物油分离, 具有出油率高和环境友好等优点。本文综述了核桃油主要营养成分与脂肪伴随物、核桃油的水酶法提取的关键工艺(预处理方法、酶解过程和破乳等)及存在的问题。同时, 本文提出了如何实现核桃油水酶法出油率的提高、核桃油品质提高和实现工业化生产的建议, 为水酶法提取核桃油实现工业化生产提供理论和技术支撑。     

核桃油与葡萄籽油的营养价值及其理化特性影响因素分析

<正>一、核桃油与葡萄籽油的营养价值1.1核桃油的营养价值(1)、核桃油含有大量的亚油酸,高达63%。而亚油酸中的亚油脂亚麻油酸能减少肠内胆固醇的吸收,促进体内胆固醇在肝内降解为胆汁酸,随胆汁排出体外。对于防治动脉硬化,高血脂等疾病十分有益。(2)、核桃油中含有多种矿物质元素。所含的微量元素锌与锰是脑垂体的重要成分,常食有益于脑的营养,有健脑益智作用。此处核桃油中还含有钙、磷、铁等人体必须的微量元素。     

鸡蛋中的生物活性蛋白质和肽

鸡蛋富含生物活性蛋白质,经酶解后也会产生多种生物活性肽,具有多种生理功能,如抑菌、抗高血压、抗氧化、促生长和增强免疫等作用。该文综述了鸡蛋中的生物活性蛋白和肽的研究进展。     

核桃油的特性及营养价值的研究

报道了核桃油的特性及经测试得出的碘值、皂化值、不皂价值、酸值分别为95、185、3.5、0.4。而且它还含有多种微量元素,如Ca、P、K、Zn、Na、Fe、Cu、Mn及维生素A、D、E、P、K核黄素、硫胺素、尼克酸等。其不饱和和脂肪酸含量高达80%以上,其中主要成分--亚油酸含量为62.20%,而亚麻酸含量为13.45%,核桃油具有很好的营养价值。     

气相色谱结合化学计量在核桃油、菜籽油掺伪混合物含量判别分析中的应用

目的：识别核桃油中同时掺入多种其他植物油的多元掺伪。方法：采用气相色谱技术分析核桃油、菜籽油掺伪混合物中脂肪酸含量,结合化学计量方法对气相色谱数据进行建模,并对不同比例核桃油、菜籽油混合物进行判别分析。结果：主成分分析法（PCA）能快速鉴别出纯核桃油和掺伪核桃油,并在一定程度上反映样本的掺伪比例;Bayes判别分析将83.33%的样品归入正确的分类;偏最小二乘判别分析法（PLS-DA）的判别准确率达87.50%;基于BP神经网络模型的判别分析,其训练集的正确率为84.21%,测试集的正确率为80.00%;基于遗传算法优化支持向量机（SVM-ga）的判别分析,其训练集和测试集的正确率均为100%。结论：多种分析模型均能不同程度地识别核桃油、菜籽油掺伪比例,其中SVM-ga模型的预测精度最佳。     

生物活性肽的制备及分离纯化方法研究进展

目前,含有生物活性肽的功能性制剂越来越受关注。生物活性肽作为多种食物蛋白的水解产物,是当前功能食品和膳食补充剂等领域的研究热点。生物活性肽是指一类对机体的功能或状况具有积极作用,并可能最终影响人体健康的特殊蛋白质片段,具有免疫调节、抗菌、抗氧化、降血压、抗衰老、抗肿瘤等多种生物学功能。因具有安全性高、来源丰富、生理功效明显和易于消化吸收等优点,生物活性肽在功能性食品成分和配料领域具有广阔应用前景。本文重点综述了生物活性肽的制备及分离纯化方法,并对其发展前景进行了展望。     

基于UPLC-Triple-TOF/MS核桃油酚类物质的鉴定与区分

针对机械压榨法（MP）、溶剂萃取法（SE）、水酶法（AEE）等制备的核桃油,本研究测定三种油的总酚含量（TP）并分析鉴定其酚类化合物;通过酚类物质差异对三种萃取方法的核桃油进行分类、鉴定。研究发现,三种萃取方法制得核桃油TP具有显著差异;SE核桃油TP最高（15.75 mg/kg）,AEE核桃油TP次之（11.05 mg/kg）,MP核桃油TP最低（9.20 mg/kg）;基于HPLC和UPLC-Triple-TOF/MS分析,核桃油共鉴定出15种酚类化合物,且三种核桃油酚类物质类别、丰度与含量差异显著;其中,MP核桃油的酚类化合物种类最丰富。基于代表性酚类化合物的含量及酚类物质类别的相对含量开展主成分分析,能成功区分三种萃取方法的核桃油。因此,本研究成功构建了核桃油酚类化合物数据库,并提出一种基于酚类化合物对植物油掺假鉴定的可行方案。     

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.     

The Ministry of Environmental Protection Issued "Feasible Technology Guidelines for Pollution Prevention and Control in Wood Pulping Process of the Paper Industry (Trial)" and Two Other Guiding Technical Documents

On December 27t＂, 2013, the Ministry of Environmenta Protection announced that, in order to implement ＂The Environmental Protection Law of the People＇ s Republic of China＂, improve the working system in environmenta protection technologies, and promote technologica advancement in pollution prevention, the Ministry of Environmental Protection sponsored the formulation of three guiding technical documents including ＂Feasible Technology Guidelines for Pollution Prevention and Contro n Wood Pulping Process of the Paper Industry （Trial）＂     

1~(st) Intelli-Tissue~ EcoEc Tissue Machine Supplied by PMP Group Successfully Put into Operation in China

正On April 29th,2014,Intelli-Tissue EcoEc tissue machine supplied by PMP Group successfully put into operation at Hebei Xuesong Paper Co.,Ltd.,this is the first such kind of paper machine of PMP Group in China.