不同饱和度脂肪酸豆甾醇酯的体外生物可给率北大核心CSCD

为了探究脂肪酸饱和度对其植物甾醇酯生物可给率的影响,采用体外模拟消化静态模型,系统研究了油酸豆甾醇酯、亚油酸豆甾醇酯和亚麻酸豆甾醇酯的体外模拟消化规律。结果表明:体外模拟消化结束后(120 min),亚油酸豆甾醇酯游离脂肪酸(FFA)释放率最高,为78.51%,其次是亚麻酸豆甾醇酯,为74.21%,油酸豆甾醇酯FFA释放率最低,为69.15%;3种豆甾醇酯的水解速率由大到小为亚麻酸豆甾醇酯>亚油酸豆甾醇酯>油酸豆甾醇酯;3种豆甾醇酯的水解度由大到小为亚油酸豆甾醇酯>亚麻酸豆甾醇酯>油酸豆甾醇酯;油酸豆甾醇酯、亚油酸豆甾醇酯和亚麻酸豆甾醇酯生物可给率分别为14.01%、11.11%和10.19%,总体差异较小。综上,豆甾醇酯中结合态的脂肪酸(相同碳链长度)饱和度影响其水解速率,但对豆甾醇酯生物可给率影响较小。     

HPLC-UV法测定植物甾醇中3种甾醇单体的含量

本文建立了一种利用紫外高效液相法(HPLC-UV)测定植物甾醇中菜油甾醇、豆甾醇和β-谷甾醇的方法。采用 Waters Symmetry C₁₈柱(4.6 mm×250 mm,5 μm),以乙腈和水为流动相等度洗脱,柱温30 ℃,流速1.0 mL/min,紫外检测波长为208 nm。实验结果表明:菜油甾醇、豆甾醇和β-谷甾醇在38 min内均能实现基线分离,线性范围分别为2.52~50.30、5.08~101.60、5.10~102.00 μg/mL时,甾醇单体的线性关系良好,相关系数r分别为0.9971、0.9989、0.9991,检测限为2.5 μg/mL;日内精密度在0.06%~3.06%范围内,日间精密度介于1.56%~6.61%;加样回收率介于92.74%~106.25%之间。本方法能够准确测定4种植物甾醇中3种甾醇单体的含量,其中大豆甾醇和木甾醇中3种甾醇单体的含量组成差异较大,大豆甾醇中菜油甾醇和豆甾醇的含量分别为163.80~251.23 mg/g和134.89~235.04 mg/g,远高于木甾醇中的菜油甾醇和豆甾醇含量,而木甾醇中β-谷甾醇含量为(685.10±7.55) mg/g,则明显高于β-谷甾醇在大豆甾醇中的含量。相对现有的高效液相方法,本方法实现了对混合甾醇中菜油甾醇、豆甾醇和β-谷甾醇3种甾醇单体的精确定量分析。     

葡萄籽油中植物甾醇的提取与鉴定

以4种酿酒葡萄(美乐、赤霞珠、龙眼、霞多丽)的种籽为原料,提取葡萄籽油,经皂化、萃取制得植物甾醇。采用GC-MS方法首次分析了葡萄籽油中植物甾醇的组成及含量,结果从葡萄籽油中检测到6种植物甾醇(菜油甾醇、豆甾醇、β-谷甾醇、岩藻甾醇、豆甾烷醇、环木菠萝烯醇),其中白葡萄品种(龙眼、霞多丽)籽油中总甾醇含量高于红葡萄品种(龙眼、霞多丽)。在鉴定出的6种植物甾醇中,β-谷甾醇含量最高,其次是豆甾醇和菜油甾醇,岩藻甾醇含量最低。     

植物甾酸和甾烷醇的生理功能

<正>在精炼植物油时脱胶产生油脚和脱臭副产馏出物内富含植物甾醇,这些副产物系为制取植物甾醇良好来源;所含植物甾醇主要有β-谷甾醇、菜油甾醇、豆甾醇等,其中,尤以β-谷甾醇量最丰。其化学结构与胆固醇相似,但在侧链上有部分不同。另外,与植物甾醇共存的还有一种天然微量的双链饱和型甾醇,即甾烷醇。由于从植物甾醇内难以分离精制甾烷醇,一般是通过将植物甾醇加氢饱和而成。制取β-谷甾烷醇以β-谷甾醇、豆甾醇为原料,菜油甾烷醇以菜油甾醇为原料。     

UPLC-MS法测定烤后烟叶中的5种游离态甾醇

为考察国内不同类型、品种、产地和部位烟叶样品中游离态甾醇质量分数的分布情况,采用UPLC-MS联用法测定了国内烤烟、雪茄烟和晒烟共47个烟叶样品中5种甾醇(豆甾醇、β-谷甾醇、菜油甾醇、胆甾醇、麦角甾醇)的质量分数。结果表明:(1)烟叶样品中游离态甾醇的总质量分数呈现特定规律,其中豆甾醇质量分数最高,其次是β-谷甾醇、菜油甾醇、胆甾醇和麦角甾醇;(2)烤烟和晒烟中β-谷甾醇的质量分数大于菜油甾醇,而雪茄烟中菜油甾醇的质量分数大于β-谷甾醇;(3)不同品种、部位和产地的烟叶中游离态甾醇的质量分数存在差异。     

黑果枸杞油中脂肪酸、植物甾醇的组成及维生素A、维生素E的分析

对黑果枸杞油中脂肪酸、植物甾醇组成及维生素A、维生素E的含量进行测定。结果表明:黑果枸杞油中不饱和脂肪酸含量为90.0%,其中油酸、亚油酸、亚麻酸含量分别为17.9%、67.6%和4.0%;植物甾醇由β-谷甾醇、菜油甾醇和豆甾醇组成,总含量为489.2 mg/100 g;维生素A和维生素E的含量分别为0.3 mg/100 g和46.3 mg/100 g。黑果枸杞油是一种具有开发价值的新型植物油。     

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。     

苹果籽油中脂肪酸及植物甾醇成分分析

采用冷榨法制取苹果籽油,并对制取的苹果籽油进行脂肪酸和植物甾醇成分分析.结果表明:苹果籽油中的主要脂肪酸为亚油酸(48.38％),油酸(38.32％),棕榈酸(7.15％)和硬脂酸1.83％;植物甾醇为β-谷甾醇,豆甾醇和菜油甾醇.苹果籽油中不饱和脂肪酸含量高达86.92％,植物甾醇含量达384.7 mg/100 g,是一种具有开发价值的特种油脂.     

植物甾醇琥珀酸酐酯化产物的分析表征

采用差示扫描热分析法、红外光谱分析法、紫外可见分光光度法和反相高效液相色谱法对混合植物甾醇中豆甾醇、β-谷甾醇与琥珀酸酐反应生成的酯化产物进行了分析表征.分析测定结果表明,在实验条件下豆甾醇、β-谷甾醇分别与琥珀酸酐反应生成产物为甾醇琥珀酸单酯,豆甾醇琥珀酸单酯和β-谷甾醇琥珀酸单酯的熔点分别为154.8℃和131.3℃左右.     

亚麻籽油中植物甾醇含量的测定

以32种亚麻籽油为原料,采用GC-MS测定其植物甾醇的组成与含量,确定亚麻籽油中含有6种植物甾醇,分别为菜油甾醇、豆甾醇、β-谷甾醇、Δ5-燕麦甾醇、环阿屯醇、2,4-亚甲基环阿屯醇。总甾醇含量范围为321.65~1 028.5 mg/100 g,其中β-谷甾醇含量最高。将植物甾醇各组分含量与亚麻籽油氧化诱导时间进行相关性分析,结果表明豆甾醇含量与亚麻籽油氧化诱导时间有显著正相关性。     

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.     

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.