食用油中植物甾醇测定方法的优化及含量分析

研究了食用油中植物甾醇的检测方法,并将液相色谱法与薄层色谱法、实验室优化的方法进行了比较,结果表明,优化后的方法具有分析速度快、准确性高和精密度好的优点。同时,利用此检测方法,对油脂加工过程中植物甾醇的含量进行了追踪分析,考察了油脂在精炼过程中的甾醇损失情况。另外,还对不同种类植物油的毛油和脱臭馏出物中植物甾醇的组成及含量进行了分析,为将来相关领域开发应用方面的研究提供了参考数据。     

常见精练油中植物甾醇测定方法的建立及含量分析

为对我国常见的植物油中植物甾醇含量进行测定,建立了植物甾醇气相色谱分析方法,并对11类共25种精炼植物油中的β-谷甾醇、菜油甾醇、豆甾醇、β-谷甾烷醇、菜油甾烷醇及菜籽甾醇等的含量进行分析.本方法相对标准差为1.1%～6.9%;菜油甾醇、豆甾醇、β-谷甾醇的回收率的RSD值范围为3.0%～4.7%.玉米胚芽油中植物甾醇含量最高,其次是菜籽油和芝麻油.不同种类的植物油植物甾醇的含量和比例各不相同,同一种类不同品牌的植物油中各植物甾醇所占的比例基本接近.对我国居民植物油中植物甾醇的摄入量进行了初步估计.本研究建立的方法可靠,具有较高的准确度和精密度,可以作为精炼植物油中植物甾醇的测定方法.建议我国居民可以通过食用含植物甾醇较高的食用油来增加植物甾醇的摄入量。     

气相色谱-质谱联用法测定14种食用植物油中的植物甾醇

建立了气相色谱-质谱联用测定植物油中4种植物甾醇(豆甾醇、β-谷甾醇、菜籽甾醇和菜油甾醇)的方法。选用超高惰性J&W DB-5MS UI毛细管色谱柱,50%KOH-乙醇为皂化剂,进样量为1μL,分流比20∶1,程序升温,可在32 min内实现上述4种植物甾醇与其他不皂化组分的分离。豆甾醇、β-谷甾醇、菜籽甾醇和菜油甾醇的检出限分别为4.41、6.09、3.10、8.62 mg/L,线性相关系数R≥0.999 2。运用该法对14种25个植物油样品中4种植物甾醇的含量进行了分析,结果表明:玉米油和菜籽油中植物甾醇总量最高,其次是芝麻油;不同种类植物油中植物甾醇的含量和比例各不相同,同一种类不同品牌植物油中各植物甾醇所占的比例基本接近。     

天然维生素E和植物甾醇及其提取

植物油中含多种微量生理活性成分。天然维生素E(VitaminE)和植物甾醇(Phytosterin)仅是其中最具有代表的两种,经现代医学研究表明对人体具有重要的生理活性作用。此外,近来甾醇在国外已成为很多甾体激素、维生素D_3等生产的最重要原料。植物油无疑是生产天然维生素D和甾醇的重要资源。事实上,在油脂精炼过程中,近乎大部分维生素E和甾醇损失进入下脚即油脂碱炼皂脚、脂     

植物甾醇的发展前景

<正> 植物甾醇是一种类似于环状醇结构的物质,主要存在于植物油的不皂化物中,不同植物油中所含的植物甾醇是不一样的。植物甾醇及其衍生物由于其特有的生物学特性和物理化学性质被广泛应用于医药、食品、化妆品等行业。植物油精炼蒸馏脱臭物是植物甾醇的重要来源,在这些蒸馏脱臭物中一般含有10％～30％的不皂化物,其中大约40％是植物甾醇,15％是生育酚。造纸工业的副产品木浆油是回收植物甾醇的第二大原料。植物甾醇除了具有羟基甾醇和多羟基甾醇的活性外,还具有独特的生理功能,例如曾被广泛研究的     

植物甾醇提取方法研究进展

植物甾醇是一种天然生物活性物质,具有重要的应用价值.植物甾醇主要存在于植物油不皂化物中.随着科学技术发展,形成了各种各样的植物甾醇提取方法,概述了植物甾醇的结构、植物甾醇来源与植物甾醇提取方法.     

植物油甾醇

<正> 一、前言早在上世纪后期,在植物油中发现谷甾醇等植物甾醇以来,近百年中,人们对甾醇进行了广泛深入的探讨。尤其近三十年中,由于甾醇在应用理论和技术上的突破,甾醇研究进入了最盛时期。植物油中的甾醇,原来只知道几种或十几种,现在已分离签定出一百多种。谷甾醇和豆甾醇等主要植物甾醇在甾体药物合成、临床医药、药物配制、化妆品基剂和乳化剂、颜料分散剂、纺织柔软剂,以及化工、食品和饲料工业等方面的应用,已广泛开展或正在开拓。世界甾醇年产量已达千余吨。我国植物油甾醇资源丰富,几种主要大宗植物油品中蕴藏有甾醇一万多吨。从其副产品或下脚中可提取甾醇上千吨。为了开     

植物油精炼过程中微量成分变化

<正>植物油除主要成份-甘油三酯外,还含有磷酯、甾醇、色素、生育酚、游离脂肪酸等微量物质,这些微量物质会对植物食用油品质和贮存稳定性产生较大影响。本文拟对上述五种微量物质在油脂精炼加工过程中变化作一初步探讨。     

植物甾醇提取分离方法研究进展

正植物甾醇作为一种新资源食品,有较高的应用价值。植物甾醇主要存在于植物油不皂化物中,随着现代提取技术的发展,植物甾醇提取方法也更加多样化,本文概述了植物甾醇提取分离方法。植物甾醇来源(phytosterol)是植物中的一种有益的活性营养成分。甾醇按照其来源可分为:植物甾醇、动物甾醇和菌     

加工过程对苹果籽油中植物甾醇流向分布影响

采用GC-FIR法对苹果籽加工过程中的植物甾醇进行了成分分析。结果表明,苹果籽油中植物甾醇主要成分为菜油甾醇、豆甾醇和β-谷甾醇,其中以β-谷甾醇含量最高;压榨法制备的苹果籽油植物甾醇的含量(385mg/100g)高于索氏提取(288mg/100g)和超声提取法(318mg/100g);且随着苹果籽油精炼程度提高,油脂中的有益微量成分植物甾醇损失增大。     

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