棉籽油皂脚制备生物柴油的工艺优化研究

本文对棉籽油皂脚制备生物柴油的工艺进行了研究,并对原料水分含量、反应温度、甲醇与原料比（V/W）、硫酸与原料比（V/W）以及反应时间这5个影响皂脚制备生物柴油的因素进行了单因素和正交优化试验,试验表明：当原料水分含量低于5％,反应温度为60℃、甲醇与原料比（V/W）为4．5：1、硫酸与原料比（V/W）为0．75：1、反应时间为2h是棉籽油皂脚制备生物柴油的最佳反应条件。     

菜籽油脂肪酸在超临界甲醇中酯化反应工艺条件研究

以菜籽油在亚临界水解反应中制取的脂肪酸为原料,研究菜籽油脂肪酸在超临界甲醇中的酯化反应工艺条件及动力学模型。通过单因素试验考察了反应温度、醇酸体积比、反应压力、反应时间对酯化转化率的影响,并采用超高效液相色谱法分析油酸甲酯含量的变化情况。试验结果表明菜籽油脂肪酸在超临界甲醇中酯化反应的最佳工艺条件为:反应温度270℃,反应时间40 min,反应压力25 MPa,醇酸体积比2∶1。在最佳工艺条件下菜籽油脂肪酸酯化转化率超过了98%,动力学模型为-dCA/dt=62.98e-20.14/RTC1.8A。     

生物基炭质催化剂催化大豆皂脚酸化油制备生物柴油

选择大豆皂脚作为原料制备酸化油,并选用废弃的落叶松木屑,直接磺化制备生物基炭质催化剂,催化皂脚酸化油制备生物柴油.考察了生物基炭质催化剂催化皂脚酸化油生产生物柴油的工艺,得出最佳反应条件为:催化剂用量为皂脚酸化油的5.0%,反应温度70℃,甲醇与皂脚酸化油摩尔比7.5:1,醌化反应5 h,生物柴油酯化率为97.22%.与相同磺酸根基团当量的H2SO4相比,生物基炭质催化剂催化酯化反应能力更佳.     

脱臭馏出物提取VE的酶预处理

研究了以大豆油脱臭馏出物为原料,采用脂肪酶Novozym435为催化剂,催化脂肪酸与甲醇的酯化反应。反应最佳工艺条件为:反应试剂摩尔比(甲醇∶脱臭馏出物中游离脂肪酸)为2.2∶1,催化剂用量为2.5%,反应温度为35℃,反应时间为10 h。在最佳反应条件下酯化率为95.9%。     

亚临界醋酸法水解皂脚提取脂肪酸的研究

亚临界的条件下在高压磁力搅拌釜内,采用油脂厂精炼过程中的副产物皂脚,利用弱酸醋酸溶液的中和作用,使反应向正反应方向进行,从而制得有用物质脂肪酸 考察了料液比、反应温度、反应时间、反应压强对皂脚水解率的影响,采用单因素和响应面优化的方法,最终确定反应最优条件为:料液比为1∶2.2,反应温度为290℃,反应时间为45min,反应压强为14MPa,在最优条件下脂肪酸提取率为96.5％.亚临界醋酸水解法与传统提取方法相比,可明显缩短水解时间,无需添加强化学催化剂.     

离子液体催化工业脂肪酸酯化反应工艺研究

以B酸离子液体为催化剂,催化脂肪酸酯化制备生物柴油。考察了离子液体用量、反应温度、反应时间和甲醇流量对酯化反应的影响。结果表明:在反应温度120℃,反应时间4 h,甲醇流量50 mL/h,催化剂用量4%的最佳反应条件下,转化率达99.55%,脂肪酸酸值(KOH)由反应前的181.42 mg/g降到0.82 mg/g。     

酶促酯化合成多不胞和脂肪酸甘油酯

研究了在脂肪酶N435的催化作用下,游离多不饱和脂肪酸与甘油酯化合成的工艺,分别考察了甘油与脂肪酸的质量比、反应时间、反应温度、酶用量、初始加水量等单因素对酯化效果的影响。结果显示,较优的酶促酯化合成条件为:甘油与脂肪酸的质量比0.12∶1,反应时间48h,反应温度50℃,加酶量与底物游离脂肪酸的比例1∶4(w/w),初始加水量0。在此条件下,酯化率为96.58%,且反应前后各脂肪酸含量变化不大。     

棉籽油皂脚脂肪酸制备C21二元酸工艺的研究

以棉籽油皂脚为原料，经皂化、酸解及蒸馏得到富含亚油酸的皂脚脂肪酸，亚油酸经共轭化后和丙烯酸发生Didels-Alder反应合成了C21二元酸，共轭反应用碘为催化剂，催化剂碘的用量为亚油酸质量的0．1％：Didels-Alder反应的适宜反应条件为：丙烯酸／亚油酸为29％，反应温度230℃，反应时间2h。     

脂溶性茶多酚酯的制备及其复配油脂的抗氧化性能研究

以水溶性茶多酚和硬脂酸为原料,进行酯化反应制备脂溶性茶多酚酯。采用单因素结合正交实验,以茶多酚酯化率为考察指标,对反应温度、反应时间、茶多酚与脂肪酸摩尔比及催化剂用量进行了优选,发现反应时间和茶多酚与脂肪酸摩尔比对茶多酚酯化率影响显著,反应温度和催化剂用量对酯化率影响不显著。最优条件为:反应温度50℃,茶多酚与脂肪酸摩尔比1∶3,催化剂用量22.5%,反应时间7 h。在此条件下,茶多酚酯化率高达95.2%,并以红外光谱法对所制备的茶多酚酯进行了分析确证。将茶多酚酯复配添加至市售一级菜籽油中,发现茶多酚酯复配油脂的抗氧化性显著增强。     

鳀鱼油皂脚的酸化工艺优化

采用响应面实验对鳀鱼油皂脚的酸化工艺进行了优化,并对得到的高酸值粗鱼油进行了脂肪酸分析。结果表明:当皂脚酸化的工艺条件为:H2SO4用量4.18 mL/100 g、反应时间60 min、反应温度71℃、料液比3∶7(g∶mL),皂的转化率高达99.92%;粗鱼油中共检出26种脂肪酸,其中不饱和脂肪酸占51.69%,饱和脂肪酸占37.18%,必需脂肪酸占2.78%,EPA和DHA占21.89%。     

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