微波辅助提取洋葱黄酮类化合物的工艺研究

利用微波辅助提取洋葱中黄酮类化合物,采用正交试验优化工艺条件。结果表明：影响洋葱黄酮类化合物得率的主次因素顺序为微波萃取时间＞微波功率＞乙醇体积分数＞料液比。最佳的提取工艺参数为微波功率960W、萃取时间60s、乙醇体积分数70%、料液比1:60。在此条件下,黄酮类化合物的得率为1.81%。     

安梨皮渣中总黄酮微波辅助提取工艺优化

以安梨皮渣为原料,乙醇为浸提剂,研究了微波辅助提取安梨皮渣中黄酮类物质的工艺条件.采用单因素及正交试验,探讨乙醇体积分数、料液比、微波功率、微波时间等对黄酮类物质得率的影响.结果表明,安梨皮渣打浆磨细,加入体积分数50％乙醇作提取剂,料液比1∶10 （mL∶mL）,微波功率360 W条件下处理3min,总黄酮类物质得率最高达0.210％.     

响应面优化超声波-微波协同提取葡萄籽原花青素工艺研究

以衡水当地产葡萄籽为原料,利用超声波-微波协同提取葡萄籽原花青素。研究了乙醇体积分数、超声功率、超声时间、微波功率、微波时间、液料比对葡萄籽原花青素得率的影响。以单因素实验为基础,采用响应面法优化了超声波-微波协同提取葡萄籽原花青素工艺。结果表明,超声波-微波协同提取葡萄籽原花青素的最佳工艺条件为:乙醇体积分数50%,液料比21∶1,超声功率400 W,超声时间32 min,微波功率353 W,微波时间3.2 min。在最佳工艺条件下,原花青素得率为6.18%。     

超声波-微波协同萃取水芹叶总黄酮类化合物工艺的研究

本文研究了用超声波-微波协同萃取水芹叶总黄酮类化合物的工艺。考察乙醇体积分数、液料比、萃取功率和时间等因素对水芹叶总黄酮类化合物萃取得率的影响。在单因素实验的基础上利用Box-Behnken实验设计方法和响应曲面分析法,确定其较优萃取工艺条件。实验结果表明,当乙醇体积分数80%、液料比22∶1 m L/g、萃取功率563 W和萃取时间4.2 min时,水芹叶总黄酮类化合物萃取得率达44.7 mg/g。     

石榴皮多酚超声波-微波协同提取技术

探讨石榴皮加工副产品综合利用的基础因子。采用超声波-微波协同提取技术提取石榴皮中多酚类物质,研究了乙醇体积分数、料液比、微波功率、超声波功率、提取时间、浸提次数对石榴皮多酚提取得率的影响,并在单因素试验基础上进行正交试验,确定其较佳提取工艺为:以料液比1∶30 (g/mL)加入60%乙醇溶液浸泡20min后,在微波功率250W、超声波功率500W条件下提取1min,石榴皮多酚提取得率为(28.78±0.12)%,提高了提取效率。     

响应曲面法优化微波辅助提取苹果渣多酚工艺研究

为从苹果渣中提取具有生理活性的多酚物质,在单因素试验的基础上,采用响应曲面法优化微波辅助提取苹果多酚的工艺,建立该工艺的二次多项数学模型,研究微波功率、提取时间、乙醇体积分数和料液比4个因素及其交互作用对提取工艺的影响.试验结果表明,对苹果多酚得率的影响次序是:微波功率>料液比>提取时间>乙醇体积分数;微波辅助提取苹果渣多酚的最佳工艺条件是:微波功率650W、提取时间53 s、乙醇体积分数60%、料液比1:20(g/mL),多酚得率迭61.8286 mg/100 g干果渣.     

响应面法优化微波提取剑河双钩藤中的钩藤碱

为获得微波萃取剑河双钩藤中钩藤碱的最佳工艺参数,选取乙醇体积分数、料液比、萃取时间3个因素进行Box-Behnken试验设计,利用响应面法对剑河双钩藤中钩藤碱的提取工艺进行优化,建立钩藤碱得率的回归模型方程。结果表明,剑河双钩藤中钩藤碱的最佳提取工艺参数为:微波功率150 W、乙醇体积分数64%、料液比1︰169(g/m L)、微波萃取时间20 min、萃取3次,钩藤碱得率为49.553 8 mg/g。     

超声波辅助提取莲子心总黄酮的响应面优化

研究超声波辅助提取莲子心总黄酮的最佳工艺条件。单因素试验考察乙醇体积分数、超声温度、超声功率、料液比、超声时间对总黄酮提取得率的影响,在单因素试验基础上,采用Box-Benhnken响应曲面法考察乙醇体积分数、料液比、超声温度及其交互作用对总黄酮得率的影响。利用软件Design Expert 6.0.1对试验数据进行回归分析,得到二次多项式回归方程预测模型。结果表明,莲子心总黄酮的提取工艺最佳条件为乙醇体积分数80%,料液比1∶16(g/m L),超声温度50℃,超声功率120 W,超声时间20 min,此条件下总黄酮的提取得率为3.071 5%,与预测值基本一致。     

松籽壳总黄酮超声提取工艺响应面优化

为研究松籽壳总黄酮超声提取工艺,以超声波功率、乙醇体积分数、料液比、提取时间为考察因素,采用Box-Be-hnken试验设计进行工艺参数优化。结果表明,松籽壳总黄酮的最优提取工艺条件:超声波功率250W、乙醇体积分数50%、料液比1∶25(m∶V)、提取时间31min。该条件下,松籽壳总黄酮得率为15.37mg/g。     

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.     

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.