杏花总黄酮提取条件的研究

研究以乙醇为溶剂提取杏花总黄酮的工艺条件.在单因素试验的基础上,用正交实验法对杏花总黄酮的提取工艺进行优选,考察了乙醇浓度、提取温度、提取时间、料液比对杏花总黄酮提取率的影响.杏花总黄酮的最佳提取工艺条件为乙醇浓度60%,料液比1:30,提取温度为80℃,提取时间150 min,在此条件下杏花总黄酮提取率为97.40%.     

诺丽(NONI)果与叶中总黄酮的提取工艺

利用L9 (34) 正交试验法研究了Noni果与叶中总黄酮的提取工艺条件及其含量测定.结果表明:对Noni果中总黄酮的提取效果影响最大的因素是提取时间,其次是乙醇浓度和提取温度,影响最小的是料液比.总黄酮的最佳提取工艺条件为提取温度为75℃,提取时间为4.0h,提取溶剂为75%的乙醇,料液比为1 ∶ 30,Noni果粗提物中总黄酮的含量为22.91mg/g.对Noni果叶中总黄酮的提取效果影响最大的因素是提取温度,其次是料液比和乙醇浓度,影响最小的是提取时间.总黄酮的最佳提取工艺条件为提取温度为85℃,提取时间为4.0h,提取溶剂为80%的乙醇,料液比为1 ∶ 35,其总黄酮的得率为33.04mg/g.     

紫叶稠李叶中总黄酮含量的研究

采用分光光度法,以芦丁为标准品,测定紫叶稠李叶中的总黄酮含量.结果表明：紫叶稠李叶中总黄酮含量为0.875%.黄酮提取的最佳工艺条件为乙醇浓度60%,提取时间2.5h,提取温度60℃,料液比1g：30ml.     

超声波辅助提取油茶籽壳总黄酮及对猪油抗氧化能力研究

以油茶籽壳为试验材料,采用超声波辅助提取其中的总黄酮,通过单因素及正交试验确定超声波辅助提取油茶籽壳总黄酮的最优工艺条件,并对提取的总黄酮进行猪油抗氧化能力研究。结果表明:最优提取工艺条件为乙醇浓度40%(v/v)、温度65℃、料液比1∶30(w/v)、超声波功率480 W、提取时间30 min,油茶籽壳总黄酮提取得率为5.02%,添加0.15%(w/w)油茶籽壳总黄酮提取物对猪油具有较好的抗氧化能力。     

小米辣护色液的提取工艺研究

为了研究小米辣的绿色泡制方法,本文用中药提取液对小米辣进行护色.采用超声提取法提取中药,以总黄酮含量做指标,通过正交试验对总黄酮的提取工艺进行优化.结果显示:护色液总黄酮最佳提取工艺条件为:70%乙醇,提取温度80℃,固液比为20∶1,提取时问30 min,提取率达5.21%,护色效果最好.     

黄姜茎叶中总黄酮的提取工艺研究

采用超声渡法提取黄姜茎叶中的总黄酮类物质,在考察各影响因素的基础上设计正交实验,得出其提取最佳工艺条件.实验结果表明:黄姜茎叶总黄酮超声波提取的最佳工艺条件为:乙醇浓度为85%,料液比(g/mL)为1:30,超声波提取时间为60min.并采用紫外分光光度法测定其总黄酮含量,得率可超过1.7%.     

小麦麸皮中总黄酮微波辅助提取技术研究

应用微波辅助提取麦麸中的黄酮类化合物.通过正交实验的方法得到从小麦麸皮中提取总黄酮的最佳工艺为:微波功率560 W,微波辐射时间30 s,乙醇体积分数为80%,料液比为1:20.在该工艺条件下总黄酮提取率为0.351 2%.     

花生红衣中总黄酮的提取工艺

研究花生红衣中总黄酮的最佳提取工艺条件.以黄酮得率为指标,采用正交试验法考察乙醇浓度、料液比、提取时间、提取温度等4个因素对提取效果的影响.花生红衣中总黄酮提取最佳工艺为:80%的乙醇,料液比为1:15.提取时间为30min,提取温度为40℃,提取得率为1.242mg/100 g.此最佳工艺可用于花生红衣中总黄酮的提取.     

杜仲叶总黄酮的超声提取工艺

利用超声法对杜仲叶中总黄酮的提取工艺进行研究。单因素考察超声功率、超声时间、乙醇浓度、料液比、提取次数等因素对总黄酮得率的影响,并用正交试验对总黄酮的提取工艺条件进行优化。结果表明,杜仲叶总黄酮最佳提取工艺条件为:超声功率600 W,超声时间30 min,乙醇浓度60%,料液比1∶15(g/mL),提取2次,在最佳条件下总黄酮得率为2.04%。     

微波辅助提取鱼腥草叶总黄酮的工艺研究

采用微波辅助提取鱼腥草叶总黄酮,在单因素试验的基础上,用正交试验进行工艺参数的优化.其优化的工艺条件为:乙醇浓度50%,固液比1:50,预浸泡30min,微波作用时间30s,微波功率540W,总黄酮的提取率可达95%以上.与传统乙醇提取法相比,微波辅助提取可使每次提取时间由3h缩短为30.5min,提取率从92.14%增加到95.93%.微波辅助提取具有提取效率高、速度快、节能等优点.     

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.