葵花籽油挥发性风味物质研究进展

葵花籽油风味独特,深受大众喜爱。概述了冷、热榨葵花籽油中的主要挥发性风味物质及原料品种、炒籽、精炼、储藏、煎炸等因素对葵花籽油挥发性风味物质的影响。葵花籽油中主要挥发性风味物质包括萜烯类、吡嗪类和醛酮类,赋予葵花籽油独特的清香、坚果香、焙烤香等气味特征。炒籽中通过美拉德反应和脂质氧化反应形成多种风味产物,而脱色和脱酸处理可使大部分挥发性风味物质损失殆尽。储藏和煎炸过程中脂肪酸氧化产生的以醛类和酸类为主的物质导致了油脂异味的产生。高油酸葵花籽油比普通葵花籽油表现出了更好的风味稳定性。今后可利用分子感官科学的手段揭示葵花籽油的香气形成机理和调控机制,为风味品质控制提供理论依据,促进葵花籽油产业的健康发展。     

大豆脂肪氧合酶强化香菇风味基料的风味成分研究

研究大豆脂肪氧合酶(LOX)强化香菇风味基料风味成分的影响因素。SDE装置抽提、GCMS分析鲜香菇的主要风味成分,并以此作为考察指标,研究LOX酶促过程的因素条件对香菇风味基料风味成分产生的影响,优化其工艺条件。结果表明,鲜香菇中八碳化合物占挥发成分的44.13%、含硫化合物为21.53%、酯类化合物为7.60%。八碳化合物中1-辛烯-3-醇、1-辛醇、3-辛酮、2-辛烯-1-醇等对鲜香菇风味的贡献率为最大,1,2,3,5,6-五硫杂环庚烷等含硫化合物也是香菇的重要风味组成。酶促体系的pH、温度、搅拌速度、通氧速率等因素条件对风味成分产生有一定影响,试验确定酶促强化风味的工艺条件为:质量分数0.5%LOX粗酶液、质量分数0.4%葵花籽油水解液、pH 5.0、温度40℃、搅拌速度500 r/min、通氧速率50 mL/min、时间40min。添加葵花籽油水解液和LOX酶处理可明显提升香菇风味基料的风味成分组成。     

氨基酸对浓香葵花籽油美拉德反应风味的贡献北大核心CSCD

通过研究比较脱脂葵花籽粕烘烤前后的氨基酸组成及风味变化,建立了以浸出一级葵花籽油为基质的氨基酸与葡萄糖美拉德反应风味模拟模型,比较分析了12种氨基酸与葡萄糖美拉德反应风味模拟模型体系中形成的挥发性化合物与浓香葵花籽油风味化合物的异同。结果表明:赖氨酸、精氨酸、组氨酸对浓香葵花籽油美拉德反应风味的贡献最大,是浓香葵花籽油美拉德反应风味形成的主要前体物质。赖氨酸、精氨酸、组氨酸3组模型体系中美拉德反应挥发性化合物与浓香葵花籽油风味化合物相同的共有12种,其中吡嗪类化合物8种、醛类化合物2种、醇类化合物1种、呋喃类化合物1种。     

氨基酸对浓香葵花籽油美拉德反应风味的贡献

通过研究比较脱脂葵花籽粕烘烤前后的氨基酸组成及风味变化,建立了以浸出一级葵花籽油为基质的氨基酸与葡萄糖美拉德反应风味模拟模型,比较分析了12种氨基酸与葡萄糖美拉德反应风味模拟模型体系中形成的挥发性化合物与浓香葵花籽油风味化合物的异同。结果表明:赖氨酸、精氨酸、组氨酸对浓香葵花籽油美拉德反应风味的贡献最大,是浓香葵花籽油美拉德反应风味形成的主要前体物质。赖氨酸、精氨酸、组氨酸3组模型体系中美拉德反应挥发性化合物与浓香葵花籽油风味化合物相同的共有12种,其中吡嗪类化合物8种、醛类化合物2种、醇类化合物1种、呋喃类化合物1种。     

葵花籽油中吡嗪类风味化合物形成机理的研究进展

吡嗪类化合物是葵花籽油Maillard反应形成风味的重要物质,Maillard反应的前体物质(游离氨基酸和肽)与葵花籽油中主体特征性风味化合物形成密切相关。游离氨基酸在一般食品体系中含量较少,肽的种类及肽的结构在吡嗪类化合物的形成方面发挥着重要的作用。本文对形成葵花籽油风味的化合物进行分析,重点综述了葵花籽油特征风味化合物吡嗪类风味物质的形成机理,突出肽尤其是小分子量多肽的作用。从二肽的结构角度展望,结合稳定同位素示踪法和碳模块标记技术深入探究吡嗪类化合物的形成机理,为食用油生产过程中风味化合物的控制奠定技术和理论基础。     

香菇热风干燥过程中香气形成机理初探

通过感官分析香菇香味形成的非挥发性成分的变化,对香菇热风干燥过程中的香气形成机理进行了研究。香菇热风干燥过程的香气形成可分为2个阶段:即干燥初期和中期的酶的作用产生香味物质以及前驱体,和干燥后期的美拉德反应产生香味物质。     

基于PLSR鹰嘴豆蛋白美拉德风味肽最适底物的研究

本实验以鹰嘴豆蛋白为原料,通过双酶定向酶解制备一系列不同水解度(DH%)鹰嘴豆蛋白酶解液,以此为底物采用描述性感官分析(DSA)和气质联用技术(GC-MS)分析比较经模式美拉德反应体系制备所获得风味肽产品的风味特征,以期获得美拉德风味肽最适鹰嘴豆蛋白酶解体系。结果表明:由不同DH%鹰嘴豆蛋白酶解液为底物制备的美拉德风味肽产品在感官属性和形成的香气成分上呈现显著差异,当添加DH%为23.03%~26.02%的酶解液制得的美拉德风味肽其所形成的香气种类和数量相对较多,同时呈现明显的肉味、鲜味和较长的持续感。结合偏最小二乘回归(PLSR)对其香气物质、感官分析数据和电子鼻响应值进行相关性分析,进一步表明DH%为23.03%~26.02%的鹰嘴豆蛋白酶解液可作为风味肽产品热反应最适反应底物。     

海洋磷脂氧化及其对食品风味的影响

海洋磷脂因其独特的结构和生物活性引起人们的关注。海洋磷脂广泛存在于水产品中,由于多不饱和脂肪酸含量高,在加工和储运过程中易发生脂质氧化反应、非酶促褐变反应等,这一系列反应生成的产物一方面引起水产品的酸败,降低食品的品质;另一方面适当的磷脂氧化,提供了脂质来源的风味前体物质,是水产品特征香气物质产生的关键。在水产品的挥发性风味物质中已鉴定出醇、醛、2-戊基呋喃、苯甲醛等特征香气成分,此类风味物质的形成来源于脂质氧化以及非酶褐变等反应,受这些反应共同作用的影响,形成了食品独特诱人的品质和风味。该文综述了海洋磷脂氧化及其在食品风味中的作用,为深入理解食品特征风味物质形成提供参考。     

SDE-GC-O-MS鉴定浓香葵花籽油香气活性物质

采用同时蒸馏萃取法（SDE）萃取浓香葵花籽油中的挥发性风味物质,利用气相色谱-质谱-嗅闻技术（GC- O-MS）对香气活性物质进行分离鉴定。SDE的最佳萃取条件为：二氯甲烷40 mL,加油量40 g,水添加量 200 mL,萃取时间3 h。经GC-MS分析共鉴定出96种挥发性风味物质,主要为醛类（29.29%）、杂环类（29.10%）、萜烯类（26.79%）、醇类（3.08%）、烯烃类（1.78%）、酮类（1.47%）、烷烃类（0.57%）、酯类（0.43%）和酸类（0.25%）。GC-O鉴定出24种香气活性物质,主要包括吡嗪类物质,赋予浓香葵花籽油烤香味;萜烯类物质,赋予其包括松针味的植物清香。     

双孢蘑菇风味的强化与胶囊化研究

为制备具有浓郁蘑菇风味的方便调味料,通过在双孢蘑菇体系中添加富含亚油酸的葵花籽油水解液对其风味进行强化,然后采用乙醇浸渍、复合酶处理提取风味及鲜味物质;再以提取物为心材,以大豆水解蛋白、糊精、阿拉伯胶为壁材,经喷雾干燥制成粉末状调味料。风味强化的正交实验结果表明:在实验取值范围内pH和温度对风味强化效果影响显著,最优水平组合为pH6.5、温度35℃,混合脂肪酸添加量因对风味影响不显著,可取最小水平值0.3%。     

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