荔枝核中总黄酮和多糖的连续提取工艺研究

采用微波—超声波协同萃取法对荔枝核中总黄酮和多糖进行连续提取,考察了料液比、微波—超声波功率、提取温度等因素对荔枝核总黄酮和多糖提取率的影响,得到荔枝核中总黄酮的最佳提取工艺为:乙醇浓度70%、料液比1∶30、微波—超声波功率600~800W、提取温度60℃、提取时间30min,此工艺条件下总黄酮提取率为8.201%。荔枝核多糖最佳提取工艺为:料水比为1∶35、微波—超声波功率700~900W、提取温度90℃、提取时间15min,多糖提取率为4.557%。     

响应面法优化薄荷全草总黄酮的提取工艺

以薄荷为材料,采用超声波辅助法提取薄荷全草总黄酮,研究乙醇体积分数、超声波处理时长、料液比、水浴温度对提取率的影响,在单因素实验的基础上,采用响应面法优化薄荷全草总黄酮的提取工艺条件,得最佳提取工艺,即:乙醇体积分数50%、料液比1∶20、水浴温度50℃、超声波提取时间30min,在此工艺下总黄酮提取率为3.11%±0.06%。     

辣木提取物的制备、抗氧化活性及其在饮料中的应用

通过考察乙醇浓度、温度、料液比、提取时间4个因素对总黄酮提取率的影响获得提取苦荞麦米黄酮的最佳工艺。利用单因素试验和正交试验确定超声波法辅助提取苦荞麦米中总黄酮的最佳工艺为:乙醇浓度70%,料液比1∶70(g/mL),温度为80℃,提取时间为50 min。在此条件下,苦荞麦米中总黄酮的提取率为4.128%;恒温水浴法提取苦荞麦米中总黄酮的最佳工艺为:乙醇浓度80%,料液比1∶70(g/mL),温度为70℃,提取时间为80 min。在此条件下,苦荞麦米中总黄酮的提取率为4.477%。通过比较发现,两种方法提取的黄酮含量相差不大,超声法辅助提取的时间相对较短,节能。因此,超声法辅助提取苦荞麦米中的黄酮比恒温水浴法的效果好。     

超声波法和微波法提取马齿苋中总黄酮的比较研究

采用超声波法和微波法分别对马齿苋中总黄酮的提取工艺进行了研究和对比分析.结果表明,超声波辅助萃取马齿苋黄酮的最佳工艺为料液比为1∶30,乙醇浓度为80％vol,作用温度为70℃,时间为30min,总黄酮萃取率为6.58％.微波辅助萃取马齿苋黄酮的最佳工艺为乙醇浓度为70％vol,微波功率为600W,作用时间为20min,料液比为1∶30,总黄酮萃取率7.65％.综合分析,在提取马齿苋中总黄酮的试验中,微波法萃取优于超声波法.     

超声波辅助法提取山黄皮果仁中的总黄酮

目的:确定山黄皮果仁中总黄酮最佳提取工艺。方法:采用超声波辅助法提取山黄皮果仁中的黄酮类化合物,通过单因素实验和正交实验,考察超声波提取条件(乙醇浓度、料液比、超声波功率、提取温度及超声波提取时间)对山黄皮果仁总黄酮提取率的影响。结果:山黄皮果仁总黄酮提取最佳工艺为:温度50℃,60%乙醇,料液比1:35,超声功率70 W,提取时间30 min。结论:在此工艺条件下提取,总黄酮提取率为1.159%。     

荸荠总黄酮不同提取方法的比较研究

研究了乙醇浸提法、超声波法和微波法提取荸荠总黄酮的最佳工艺.各方法均以乙醇浓度、料液比、提取功率和时间为影响因素,荸荠总黄酮提取率为指标,通过正交实验分别确定最佳工艺条件.结果显示,乙醇浸提法的总黄酮提取率为2.25%,超声波提取法为3.01%,微波提取法为3.43%.这三种提取方法对比分析表明,微波法具有高效、短时的优点,其最佳提取工艺为:乙醇浓度为60%,料液比为1:40,微波功率为400W,提取2次,每次2min.     

超声波-微波协同萃取芹菜黄酮的工艺研究

研究超声波-微波协同萃取芹菜黄酮的工艺条件.以远红外干燥的芹菜粉为原料,通过单因素和正交试验探讨乙醇浓度、液料比、微波功率、萃取时间及超声波等因素对萃取效果的影响.确定最佳的萃取工艺:80%乙醇为溶剂,液料比30∶1(mL/g),超声波和600 W微波功率协同萃取240 s,芹菜总黄酮和芹菜素提取率分别为1.051%和14.156 μg/g,均高于回流提取6 h时的提取率.     

超声微波协同萃取桃胶多糖的工艺研究

为了获得超声微波协同萃取桃胶多糖的最佳工艺,以多糖提取率为考察指标,通过单因素方法优化了乙醇含量、水浴温度、超声功率、微波功率、料液比、提取时间等条件。通过单因素实验得到的最佳条件:乙醇含量50%、水浴温度60℃、超声功率80W、微波功率500W、料液比1∶100g/mL、提取时间15min。在乙醇含量50%、水浴温度60℃的条件下,以超声功率、微波功率、料液比、超声时间为四因素,选择了3个水平,采用正交试验进行提取工艺的优化研究。正交试验结果显示:在超声功率70W、微波功率400W、料液比1∶150g/mL、提取时间15min的条件下,多糖的提取率为86.52%,三次平行提取的相对标准偏差为1.06%。     

响应面法优化超声辅助提取黄秋葵花总黄酮的工艺研究

目的采用响应面法对超声辅助提取黄秋葵花总黄酮的工艺进行优化。方法在提取剂浓度、液料比例、提取温度、水浴提取时间、超声波提取时间试验结果的基础上,采用Box-Behnken design试验设计原理,设计4因素3水平试验,以响应面分析法优化液料比例、乙醇浓度、提取温度、水浴提取时间4个因素对黄秋葵花总黄酮提取率的影响。结果黄秋葵花总黄酮提取率的最佳工艺条件为:液料比例160:1(mL:g)、乙醇浓度42%、提取温度80℃、水浴提取时间16 min和超声提取时间30 min。在此条件下,黄秋葵花总黄酮的提取率为(2.487±0.05)%,真实值与模型预测值相对误差为1.23%。结论该提取工艺提高了黄秋葵花总黄酮的提取率,为其开发利用提供理论支持。     

紫苏叶中总黄酮的超声波辅助提取工艺优化

以总黄酮提取率为指标,通过单因素试验考察液料比、超声时间、乙醇浓度、提取温度对紫苏叶总黄酮提取率的影响,采用响应面分析法对超声波辅助乙醇提取紫苏叶中总黄酮的工艺进行优化。结果表明,紫苏叶总黄酮最佳提取条件为:液料比29∶1(V∶m)、超声时间40min、乙醇浓度45%、提取温度51℃,该条件下紫苏叶中总黄酮的实际提取率为5.41%。     

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.