微波萃取花生壳天然黄色素及其稳定性研究

本文对福建产花生壳进行微波萃取天然黄色素及其稳定性研究。研究表明微波萃取的工艺条件是：以pH=3,体积分数70％的乙醇水溶液作提取剂，原料与提取剂配比为1g:5ml，微波辐射功率120W辐射时间200s。对该色素稳定性研究的结果表明，该色素为水溶性色素，属黄酮类以素，适用pH值范围比较广，尤其性状态效果最佳，对光、热稳定性好，大多数食品添加剂对色素稳定性影响不大，对氧化剂H2O2的耐受能力较差，对还原剂Na2SO3的耐受能力强。     

微波辅助提取密蒙花黄色素及稳定性分析

采用微波辅助提取黔产密蒙花黄色素,得到最优的提取条件为:微波功率250 W、料液比1:50、提取时间30 min。此外,密蒙花黄色素稳定性研究表明:密蒙花黄色素在中性及弱酸性的环境中较为稳定,在碱性环境中不能稳定存在;在光照以及50℃以上,密蒙花黄色素易分解;密蒙花黄色素具有一定的抗氧化能力,其抗还原能力较弱。     

火龙果果皮色素提取工艺及稳定性研究

以红皮白肉火龙果为原料,采用溶剂萃取法探讨不同萃取剂、料液比、时间、温度、pH对其色素提取率的影响;同时研究不同温度、pH、光照、糖浓度、盐浓度、金属离子及氧气对该色素稳定性的影响.结果表明,火龙果果皮色素最适提取工艺条件:萃取剂为蒸馏水,料液比1∶20(m∶V),提取时间50 min,提取温度30℃,提取pH 6.火龙果红色素的热稳定性差,温度越高越不利于色素稳定;pH在5～6时色素最稳定;光照和氧气都可降低色素的稳定性;糖和食盐对色素稳定性影响不显著;Ca2+可降低色素的稳定性,Zn2+有护色作用,K+、Fe2+、Mg2+对色素稳定性的影响不显著.     

微波萃取红花羊蹄甲花红色素的研究

确定微波萃取红花羊蹄甲花红色素的最佳试验条件.以家用微波炉为微波萃取装置,采用正交试验确定微波萃取红花羊蹄甲花红色素的最佳试验条件.微波萃取红花羊蹄甲花红色素的最佳试验条件为提取剂为酸性乙醇,固液比1:15,微波功率560W,萃取时间30 8,提取级数2级.最佳试验条件下色素的提取率30.31%,色价C(1%,547 nm)为2 6.332.应用微波技术提取红花羊蹄甲花红色素是可行的.     

菠萝皮色素的提取及其稳定性研究

研究了菠萝皮色素的提取工艺,并采用正交试验对其进行了优化,确定菠萝皮色素的最佳提取工艺条件为:微波温度50℃、时间150s、功率300W、料液比1∶10(g/ml)。同时研究了微波温度、pH、金属离子及常见食品添加剂对菠萝皮色素稳定性的影响,结果表明:抗坏血酸,金属离子Fe2+、Fe3+和Cu2+对该色素的稳定性有显著影响,菠萝皮色素在酸性、中性环境中稳定性较好,而在强碱性环境中稳定性较差。     

超临界CO2和微波萃取核桃油的比较研究

通过超临界CO2萃取核桃油的正交实验和微波萃取核桃油的均匀设计实验,考察影响核桃油萃取的主要因素,寻求最佳萃取工艺条件.研究结果表明,超临界CO2萃取的最佳工艺条件为:萃取压力35 MPa,萃取温度45℃,萃取时间2.5 h,分离温度50℃,CO2流量25 kg/h;在此条件下油脂得率为59.2%.微波萃取最佳工艺条件为:以环己烷为萃取剂,溶料比为3.5:1(W/W),微波功率735 W,每次微波辐射时间60 s,微波辐射累计时间6 min,在此条件下得率为60.4%.比较了不同提取方法对油脂得率和油脂品质的影响.结果表明,微波萃取油脂得率最高,时间最短;超临界CO2萃取的核桃油品质最优,是萃取优质核桃油的首选方法.     

橘皮色素加盐-微波法提取新工艺的优化及稳定性研究

用加盐-微波法提取橘皮色素,通过正交实验优化提取工艺条件。结果表明,橘皮色素在330.0 nm处吸光度有最大值。最佳提取工艺为:微波时间90 s,料液比1:15,加盐量(盐/橘皮质量比)4%,水浴温度50℃,水浴浸提2 h。同时,橘皮色素溶液稳定性研究表明,金属离子Al~(3+),Co~(2+),Cu~(2+),Fe~(3+)对橘皮色素稳定性有一定影响,其中Fe~(3+) 影响最大;食品添加剂中,仅碳酸氢钠会降低橘皮色素稳定性;碱性条件下,橘皮色素稳定性明显下降;该橘皮色素对还原剂稳定,强氧化剂KMn O_4对其稳定性影响较大;橘皮色素对光比较稳定。     

石榴皮原花青素的微波提取工艺及其稳定性研究

采用微波法提取野生石榴皮中的原花青素,同时考察光照、温度、金属离子、PH及食品添加剂对原花青素稳定性的影响。通过单因素试验和正交试验得出微波提取石榴皮原花青素的最佳工艺条件为：乙醇浓度80％、料液比1：50、提取温度65℃、微波功率500W、提取时间120s、提取2次,原花青素的得率为2．62％。稳定性研究表明,光照条件下色素稳定性较差;高温对色素有降解作用,60℃以下稳定性良好;pH值为5时色素稳定性好;金属离子Cu^2＋和Al^3＋对原花青素的稳定性影响显著;苯甲酸对原花青素稳定性影响显著。     

超声波-微波协同萃取紫草总色素及紫草素的制备

以新疆紫草为原料,乙醇作萃取剂,考察了超声波-微波协同萃取紫草总色素的工艺条件.并采用Cu2络合纯化方法将萃取所得的总色素水解制备成了紫草素.在超声波功率内置为50W的仪器条件下,采用分光光度法测定提取液吸光度的方法考察了萃取剂浓度,料液比,微波功率、提取时间对色素提取效果的影响.通过单因素实验和L9(34)正交实验确定了萃取紫草总色素的优化工艺条件为:乙醇浓度90％,料液比1:12,微波功率70W,提取时间7min.在此优化条件下紫草素及其衍生物的得率可达5.36％.总色素经Cu2络合纯化水解为紫草素的得率为29.25％.这是一种实验室中简单、快速、高收率的由天然紫草分离制备紫草素的有效方法.     

微波法提取红花黄色素的工艺研究

对红花黄色素的提取条件进行了系统研究.通过采用MAS-I型常压微波辅助合成/萃取反应仪,以羟基红花黄色素A为对照品,以蒸馏水为萃取溶剂,对微波萃取红花黄色素的影响因素,包括提取温度、提取时间、提取溶剂体积等进行单因素的考察.在单因素的实验基础上通过正交实验得出微波萃取红花黄色素的优化工艺条件:提取温度70℃,提取时间20 min,液固比为100(mL/g),提取次数为3次.     

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.