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。     

超声提取云南甜荞籽粒总黄酮工艺研究

以云南甜荞籽粒为研究对象,采用超声辅助醇提法提取荞麦总黄酮,并对工艺条件进行优化,为云南荞麦黄酮功能性成分的工业化提取提供科学依据。通过单因素试验,以总黄酮得率为考察指标,分别考察超声时间、温度、功率、乙醇浓度、料液比对荞麦总黄酮的影响,确定各因素的适宜水平。在此基础上,通过正交试验,确定云南甜荞籽粒中总黄酮提取的最佳工艺条件。结果表明:超声辅助醇提法对云南甜荞籽粒总黄酮具有良好的提取效果;超声提取甜荞籽粒总黄酮的最佳工艺条件为乙醇浓度80%、超声温度70℃、料液比1∶50(g/mL)、超声时间30min、超声功率150W;各因素的影响主次为乙醇浓度>料液比>超声温度。该条件下,荞麦总黄酮的得率为0.562%,是不经超声处理的乙醇浸提法的1.45倍。     

响应面分析法优化四药门花叶总黄酮提取工艺

研究四药门花叶中总黄酮提取工艺优化,采用单因素试验和响应面法考察了乙醇的体积分数、液料比、提取时间和提取温度对四药门花叶中总黄酮得率的影响。总黄酮提取最佳条件为:乙醇体积分数83%,液料比31 m L/g,提取时间80 min,提取温度59℃,四药门花叶中总黄酮的得率为4.145%。     

Plackett-Burman设计和响应面分析法优化香菜中总黄酮的微波提取工艺

为了确定香菜茎叶中总黄酮微波辅助提取最佳工艺条件,首先用Plackett-Burman设计对影响香菜总黄酮得率的因素进行评价,筛选出三个主要影响因素:液料比,微波温度,乙醇体积分数。以香菜总黄酮得率为响应值,采用响应面分析法优化提取条件,确定最佳提取条件为液料比35∶1,微波温度80℃,乙醇体积分数67%。在此条件下黄酮得率的预测值为1.33%,实测值为1.31%,误差为1.30%。表明Plackett-Burman设计结合响应面分析法可以很好的对香菜总黄酮微波提取工艺进行优化。     

响应面法优化苹果皮中总黄酮的提取工艺

以苹果皮为原料提取黄酮类物质。在单因素试验的基础上,采用响应曲面法研究提取温度、乙醇体积分数、料液比和提取时间对苹果皮总黄酮得率的影响,并建立该工艺的二次多项式模型。结果表明,回归模型具有高度显著性,可以对苹果皮总黄酮得率进行很好地分析和预测;对苹果皮总黄酮得率的影响顺序依次为乙醇体积分数>提取温度>提取时间>料液比;有机溶剂回流提取苹果皮总黄酮的最佳工艺条件为乙醇体积分数65%、提取温度45℃、料液比1:45(g/mL)、提取时间210min,在此条件下总黄酮得率为3.52%。     

白背三七类黄酮提取工艺条件的优化

采用乙醇提取法研究白背三七类黄酮化合物的提取工艺条件。通过单因素试验和正交试验,考察了乙醇体积分数、料液比、提取温度、提取时间等四个因素对类黄酮得率的影响;优化了白背三七类黄酮的提取工艺条件。结果表明,各因素对类黄酮得率的影响大小依次为乙醇体积分数＞提取温度＞料液比＞提取时间,白背三七类黄酮提取的最优工艺条件为：乙醇体积分数85%,料液比1∶25（g∶mL）,提取时间120 min,提取温度60 ℃。在此最佳提取工艺条件下,类黄酮平均得率为3.81%。     

响应面法优化油茶籽仁黄酮提取工艺

目的以总黄酮得率为指标,用响应面法对乙醇回流提取黄酮的工艺进行优化。方法通过对提取工艺中的液料比、提取温度、乙醇体积分数、提取时间4个因素进行单因素试验,筛选出主要的影响因素。以此为基础利用Box-Behnken设计正交试验,最后结果利用Design-Expert软件进行回归分析并对最佳工艺参数进行验证试验。结果得到优化提取工艺条件为:提取温度80℃,乙醇体积分数57%,液料比53 mL/g,提取时间2.5 h。在此条件下总黄酮得率的试验值3.91%,与最大预测值3.94%基本一致。结论通过响应曲面优化设计提高了油茶籽仁黄酮的得率,为进一步开发利用油茶籽提供了理论依据。     

响应面法优化密蒙花总黄酮的超声提取工艺

优化超声提取密蒙花总黄酮的工艺条件,在单因素试验基础上,考察乙醇体积分数、超声功率和提取温度3个因素对密蒙花总黄酮提取率的影响,并通过Box-Behnken试验设计和响应面分析法确定超声提取密蒙花总黄酮的最佳工艺条件。结果表明：最佳工艺条件为乙醇体积分数62%、超声功率410W、提取温度77℃、液料比50:1(mL/g)、提取时间35min,在此最佳提取条件下,总黄酮提取率为20.38%。     

超声辅助提取薄荷中总黄酮的工艺研究

以薄荷为原料,以总黄酮含量为指标,采用超声辅助工艺提取了薄荷中总黄酮。分别研究了乙醇体积分数、料液比、超声时间、超声温度对总黄酮提取率的影响,通过正交试验优化了提取工艺。结果表明总黄酮提取的最佳工艺条件为:乙醇体积分数50%、料液比1:25、超声时间25min、超声温度55℃。在此最佳条件下提取,总黄酮含量可达6.71%。     

响应面优化牡丹籽壳总黄酮超声波提取工艺及抗氧化活性研究

采用超声波法提取牡丹籽壳中总黄酮。通过单因素试验分别考察乙醇体积分数、料液比、超声功率、超声时间、提取温度对总黄酮得率的影响,在此基础上采用响应面法优化超声波提取工艺条件。以抗氧化剂V_C为对照,采用DPPH法测定牡丹籽壳总黄酮的体外抗氧化活性。结果表明:超声波提取牡丹籽壳总黄酮最佳工艺条件为乙醇体积分数60%、料液比1∶50、超声功率250 W、超声时间50 min、提取温度40℃,在此条件下牡丹籽壳总黄酮得率为13.66%;牡丹籽壳总黄酮对DPPH自由基的清除能力优于V_C,且其抗氧化活性与质量浓度呈一定的量效关系。     

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.