从猕猴桃中提取多酚的研究

研究提取猕猴桃中多酚的最佳工艺条件。考察了有机溶剂种类及其浓度、提取时间、温度、提取次数及料液比等5个单因素对总多酚提取率的影响,并在单因素的基础上进行正交实验得到多酚提取的最佳工艺条件:用30%的丙酮溶液,按1∶9的料液比,在35℃下提取30min。     

响应面优化超声波提取油松花粉多酚的工艺研究

研究了油松花粉多酚的超声波辅助提取工艺。在单因素实验结果的基础之上,通过Plackett-Burman筛选,确定出提取温度、料液比和提取时间为显著影响因子,选用3因素3水平的响应面分析法来优化油松花粉多酚的提取工艺。依据数据进行模型拟合和回归分析,确定影响油松花粉总酚得率的重要因素为提取时间和料液比,得出油松花粉多酚的最佳提取工艺条件为:乙醇体积分数80%、料液比1∶32 g/m L、提取时间为31 min、提取温度为51℃,在此工艺下总酚含量可达6.735 mg/g。实验结果显示,超声波辅助提取有效地优化了油松花粉多酚的提取条件,为其开发利用提供了理论支持。     

响应面法优化超声辅助提取红皮云杉多酚工艺

采用响应面法优化超声波辅助提取红皮云杉多酚工艺。在单因素实验的基础上,选择料液比、超声波功率、提取时间为自变量,以多酚得率为响应值,采用Box-Benhnken法设计三因素三水平的响应分析实验。结果表明,回归模型拟合度高,最佳工艺条件为:料液比1∶33、超声波功率301W、提取时间2.4h,乙醇浓度40%,温度60℃。在此条件下,红皮云杉多酚的得率为18.92%。     

茶树花多酚提取工艺的研究

用常规水浴浸提法和超声波辅助浸提法来提取茶树花中的多酚，研究了浸提温度、时间、料液比等因素对多酚得率的影响，比较得出超声波辅助浸提用时短，温度低的优点；通过正交试验设计，研究了各因素对多酚浸提影响的主次顺序，确定了最佳提取参数。实验结果采用统计软件（SPSS）进行分析，影响超声波辅助浸提各因素的主次顺序为料液比、温度、浸提时间,超声波辅助浸提最佳工艺为：温度50℃、提取时间10min、料液比1：30，在此工艺条件下多酚浸提得率75．13ms／g干花。为茶树花资源深度研究开发提供依据。     

响应面法优化杜仲叶中总多酚超声波辅助提取工艺研究

采用响应面法优化杜仲叶中总多酚超声波辅助提取工艺。考察了提取溶剂、液料比、提取时间、提取温度及提取次数对提取工艺的影响,在单因素实验分析的基础上采用Box-Benhnken中心组合进行4因素3水平的实验设计,以总多酚得率为响应值,进行响应面分析,建立二次多项回归数学模型,并优化提取工艺。结果表明杜仲叶中总多酚超声波辅助提取最佳工艺为:55%乙醇、液料比为25∶1mL·g-1、45℃下提取25min,提取两次,在此条件下,总多酚得率为4.678%。     

超声波提取苦菜叶、根中总多酚的工艺研究

以苦菜叶、根为原料,采用超声波辅助乙醇提取总多酚,福林-酚比色法在765 nm波长处测定总多酚的含量。通过单因素试验,正交试验确定最佳提取工艺。单因素试验表明:在提取温度为50℃、提取时间为1.5 h、料液比为1∶15(g/mL)、乙醇体积分数为50%时,苦菜叶、根中总多酚得率都达到最高。提取苦菜叶中总多酚的最佳条件为:提取温度为50℃、提取时间为2.0 h、料液比为1∶20(g/mL)、乙醇浓度为50%。提取苦菜根中总多酚的最佳条件为:超声波功率400 W、提取温度为40℃、提取时间为1.5 h、料液比为1∶15(g/mL)、乙醇体积分数为50%。     

响应面优化蒲公英多酚超声波辅助乙醇提取工艺及其抗氧化性

本实验以蒲公英全草为原料,选取超声波提取时间、超声波功率、料液比、超声提取温度四个因素为自变量,结合单因素实验结果,对蒲公英多酚超声波辅助提取工艺进行优化,最后对蒲公英不同部位多酚抗氧化活性进行评估。结果表明:四因素对提取率的影响大小依次是提取温度超声波功率超声提取时间料液比;超声波辅助乙醇提取蒲公英多酚的最佳工艺条件为提取时间37 min、超声功率380 W、提料液比1∶48、温度42℃,多酚平均提取率为3.68%±0.05%,与理论预测值3.72%误差值仅为0.94%。在优化条件下依次对蒲公英全草、叶片和根中的多酚进行提取并比较其抗氧化活性,三者均具有较强的抗氧化能力,蒲公英不同部位的抗氧化活性大小依次为蒲公英叶片蒲公英全草蒲公英根。     

柿果多酚提取工艺优化

采用单因素试验设计,研究乙醇体积分数、料液比、提取时间和提取温度4个因素对柿果总酚及缩合多酚超声提取效果的影响,并采用正交试验设计对提取工艺进行优化。结果表明影响因素对提取效率影响顺序为：乙醇体积分数＞料液比＞提取时间＞提取温度。最佳提取条件为：乙醇体积分数90%、料液比1:40(g/mL)、时间30min、提取温度40℃,在此条件下进行验证实验,总酚提取率为2.061%。     

几种不同提取方法对燕麦总多酚含量的影响

本文运用紫外-分光光度计法评价几种不同的提取方法对燕麦总多酚含量的影响,通过单因素和正交实验得到传统溶剂法提取燕麦总多酚的最佳工艺条件。其中传统溶剂法提取燕麦总多酚的最佳工艺条件为:乙醇体积分数55%,料液比1∶50 g/m L,水浴温度55℃,浸提时间2 h,燕麦总多酚含量为0.99 mg/g;超声波处理提取燕麦总多酚的最佳工艺条件为:超声波功率500 W,超声时间30 min,温度55℃,燕麦总多酚含量为1.32 mg/g;微波处理提取燕麦总多酚的最佳工艺条件为:微波功率500 W,微波时间7.5 min,温度55℃,燕麦总多酚含量为1.80 mg/g;超声波-微波处理提取燕麦总多酚的最佳工艺条件为:超声波-微波功率500 W,超声波-微波协同处理时间2.5 min,温度55℃,燕麦总多酚含量为2.02 mg/g。其中超声波-微波协同处理提取燕麦总多酚用时最短,得到的含量最高,可以选取该工艺为后续的实验提供科学依据。     

响应面优化超声波辅助提取葡萄籽油脂的工艺研究

该研究通过响应面法优化了超声波辅助提取葡萄籽油脂的最佳工艺条件。研究了提取时间、超声频率、提取温度、料液比对葡萄籽油脂得率的影响。以单因素实验为基础,采用响应面法优化了超声波提取葡萄籽油脂工艺。结果表明,超声波提取葡萄籽油脂的最佳工艺条件为提取时间73.97min,超声频率81.42kHz,提取温度33.48℃,料液比1∶12.42。在此工艺条件下,葡萄籽油脂得率为20.26%。     

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.