花生露制备条件对可溶性蛋白溶出率的影响

以花生仁为原料,可溶性蛋白溶出率为评价指标,采用考马斯亮蓝法研究液料比、磨浆温度、磨浆pH和磨浆时间对花生可溶性蛋白溶出率的影响。采用正交试验法优化制备工艺,得到制备花生乳的最佳工艺条件:液料比4∶1(mL/g)、磨浆温度60℃、磨浆时间8 min、磨浆pH 7。结果表明:液料比、磨浆温度、磨浆pH和磨浆时间对花生可溶性蛋白溶出率影响显著。     

超声波提取缢蛏多糖及脱蛋白工艺

采用超声波法对缢蛏多糖进行了提取,正交试验确定了最佳提取工艺条件:超声功率440W,提取时间60 min,提取温度80℃,料液比1∶30(g/mL).在此条件下,缢蛏粗多糖提取率为8.31％.对比了Sevag法和三氯乙酸法对缢蛏粗多糖脱蛋白的影响,实验结果表明三氯乙酸法在蛋白质脱除率和多糖损失率两个方面的综合指标较理想,三氯乙酸法处理3次后,蛋白质脱除率达到69.75％,缢蛏多糖损失率为26.68％.     

从花生蛋白粉中提取花生分离蛋白的条件优化

采用碱提酸沉法从脱脂花生蛋白粉中提取花生分离蛋白,通过单因素试验和正交试验优化了提取工艺条件,确定最佳工艺条件为:浸提温度60℃,料液比1∶9,pH 9.0,浸提时间90 min,酸沉pH 4.5.在此条件下,蛋白质提取率达42.5%,产品纯度为95.65%.所得花生分离蛋白具有良好的功能特性.     

碱性蛋白酶提取花生水解蛋白的研究

利用碱性蛋白酶从冷榨花生饼中提取花生水解蛋白.研究了温度、pH值、加酶量、液固比、水解时间对蛋白质提取率的影响,在此基础上通过正交实验对花生水解蛋白提取工艺条件进行优化.确定最佳工艺参数为温度55℃、pH9.0、加酶量0.8%、水解时间3 h、液固比7:1,在此条件下蛋白质提取率为81.32%.     

碱提酸沉法提取牡丹籽饼中蛋白质的研究

以牡丹籽饼为原料,采用单因素试验和正交试验优化碱提酸沉法提取牡丹籽饼中蛋白质的工艺条件。结果表明:牡丹籽饼中蛋白质的最佳提取工艺条件为料液比1∶12、碱液pH 8. 5、提取时间60 min、提取温度45℃,在此条件下牡丹籽蛋白提取率为(78. 23±0. 04)%;牡丹籽蛋白最佳酸沉条件为pH 4. 0,此时蛋白沉淀率达(90. 90±0. 11)%。     

板蓝根多糖的提取与脱蛋白工艺优化

通过Box-Behnken组合实验设计,考察了料液比、提取温度及提取时间对板蓝根多糖提取率的影响。利用响应面分析方法,模拟得到二次多项式回归方程的预测模型,并确定最佳提取条件为:料液比为1∶55,提取温度80℃,提取时间3.5 h。在此条件下,板蓝根多糖的提取率为3.55%。以蛋白脱除率和多糖损失率为指标,比较了Sevag法、三氯乙酸法和胃/胰蛋白酶法对粗多糖中蛋白质的脱除效果。结果表明:采用胃/胰蛋白酶脱蛋白工艺,蛋白脱除率较高,分别可达63.5%和52.9%,多糖损失较少,且操作简便,无污染,是较好的脱蛋白方法。     

醇法生产花生浓缩蛋白的工艺条件研究

以脱脂花生蛋白粉为原料,通过单因素实验和正交实验优化乙醇浸提法生产花生浓缩蛋白的工艺条件,并通过放大实验进行验证。结果表明,花生浓缩蛋白生产的最佳工艺条件为:乙醇体积分数65%,料液比1∶8,浸洗温度60℃,浸洗时间40 min,浸洗次数3次。在最佳工艺条件下所得花生浓缩蛋白产品的蛋白质含量为72%,氮溶解指数为42%。100 g放大实验所得花生浓缩蛋白产品的蛋白质含量为70%,氮溶解指数为40%。     

膜技术分离纯化牛蒡多糖的研究

研究了膜技术分离纯化牛蒡多糖的过程.首先,以蛋白脱除率、多糖损失率为指标,比较了三氯乙酸法、鞣酸法、Sevage法几种常用的除蛋白方法,结果表明:鞣酸法除蛋白的效果最佳,蛋白质总去除率为67.87%,糖损失率为18.18%;其次,以膜通量和透过液中糖浓度为指标,研究了不同分子量的超滤膜、超滤压力、料液温度对超滤效果的影响.结果表明:采用截留相对分子质量10万的超滤膜,在压力为0.25MPa,料液温度为40℃时,膜通量最大,而且膜污染较轻,多糖得率为25.8%,多糖纯度为73.27%.     

吴茱萸粗多糖的碱法提取及脱蛋白方法研究

本实验采用正交设计研究了提取温度、提取时间、料液比和NaoH浓度等对用碱法提取吴茱萸中多糖得率的影响。结果表明,影响最为显著的因素是料液比,最佳提取工艺条件为提取温度80℃、NaoH浓度0.6mol/L、料液比1:20、提取时间3h,此时多糖提取率为12.58%。比较两种脱蛋白方法,Sevag法的优点在于多糖损失率较低,但比较复杂费时,TCA法优点在于其可溶性蛋白脱除相对较为彻底,同时节约大量试剂和时间。综合考虑,TCA法优于Sevag法。     

响应面法优化木瓜蛋白酶脱除茁霉多糖发酵液蛋白质工艺

对木瓜蛋白酶脱除茁霉多糖发酵液蛋白质工艺进行研究。在单因素实验的基础上,通过响应面设计进行工艺优化。结果表明:pH、酶解温度、酶添加量以及pH与酶解时间、pH与酶添加量的交互作用对蛋白脱除率有显著影响。木瓜蛋白酶脱除茁霉多糖发酵液蛋白质的最佳工艺条件为:pH5.2,酶解时间2.5h,酶解温度49℃,酶添加量1.5%,在此条件下蛋白脱除率为64.09%,多糖损失率为13.05%。     

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.