火鸡骨胶原多肽口服液的研究

以提取的火鸡骨胶原蛋白液为原料,探讨了影响火鸡骨胶原蛋白水解度的主要影响因素,优化了酶解工艺条件。得出火鸡骨胶原蛋白多肽口服液最佳配方。实验表明:火鸡骨胶原蛋白最佳酶解条件为底物浓度10%、酶用量30μl/g蛋白、酶解温度60℃、pH值7。火鸡骨胶原蛋白多肽口服液最佳配方:火鸡骨胶原蛋白多肽液40%、木糖醇1.0%、蜂蜜5%。     

PEF协同酶提取猪皮蛋白工艺条件的研究

研究高压脉冲电场(PEF)对枯草杆菌中性蛋白酶提取猪皮胶原蛋白的影响及提取的工艺条件。首先考查高压脉冲电场强度、脉冲数、酶用量、酶解时间等因素对生猪皮胶原蛋白提取效果的影响,然后以此为依据采用正交法优化提取条件。试验结果为,经高压脉冲电场处理的猪皮,其胶原蛋白的溶出率远高于未经高压脉冲电场处理的猪皮,而且酶解所用的时间短。在料液比1∶10(g/mL)、温度40℃、pH=6.5、酶用量10.0μkat/g、电场强度25 kV/cm、脉冲数40次、酶提时间30 min等条件下,胶原蛋白溶出率可达84.2%。     

猪跟腱胶原蛋白酶法提取工艺的研究

为更好利用猪跟腱资源、提高跟腱的附加值,探讨猪跟腱酶法提取胶原蛋白的最佳工艺条件。采用单因素试验法考察猪跟腱脱脂时间,酶法提取工艺中胃蛋白酶用量、提取时间、提取温度、pH和料液比对胶原蛋白提取率的影响,并用正交试验法优化酶法提取工艺。结果表明,40℃条件下水浴循环回流脱脂3 h就可以基本脱除猪跟腱中的脂肪(脱脂率为98.88%);酶法提取最佳工艺条件为:酶用量250 u/g、提取时间25 h、提取温度为25℃、pH1.6、料液比1︰20 g/g,此条件下每百克脱脂猪跟腱可获得45.8 g胶原蛋白;影响酶法提取效果的主次因素排序为:酶用量提取温度料液比提取液pH提取时间。进一步细化跟腱提取工艺的同时,与其他跟腱工艺比较有缩短了提取时间,节约能源,定量的明确了提取率等优点。     

黑木耳胶原蛋白酶法提取及分离纯化研究

为获得优质的黑木耳胶原蛋白，本研究通过单因素实验和响应面法对碱性蛋白酶法提取黑木耳胶原蛋白的工艺条件进行优化，并采用盐析、DEAE-52离子交换层析、Sephadex G-75凝胶过滤等方法对黑木耳胶原蛋白进行分离纯化。结果表明：在酶解温度55℃、pH 8.5条件下优化得到的黑木耳胶原蛋白最佳提取条件为：碱性蛋白酶（2240 IU/mg）添加量7%、料液比1∶68 g/mL、酶解时间2.0 h，此条件下，黑木耳胶原蛋白得率为0.65%；最佳盐析条件为：4 mol/L NaCl、24 h、15℃；最佳DEAE-52分离条件为：洗脱时间160 min、上样浓度300μg/mL、上样pH 7.2、NaCl洗脱浓度0.2 mol/L；经Sephadex G-75凝胶过滤层析后胶原蛋白纯度可达到72.6%，胶原蛋白回收率74.3%。因此，碱性蛋白酶法及盐析、DEAE-52、Sephadex G-75层析可有效提取纯化黑木耳胶原蛋白，为黑木耳胶原蛋白的深入研究及应用开发提供了理论依据。     

超声波辅助酶解提取鮟鱅鱼皮胶原蛋白的工艺优化

以鮟鱇鱼皮为原料,以料液比、超声时间、加酶量、酶解时间、酶解温度、提取pH为实验因素,用超声-风味酶法和超声-碱性酶法分别提取,并利用正交试验确定鮟鱇鱼皮胶原蛋白最佳提取工艺。结果表明,超声-风味酶法提取鮟鱇鱼皮胶原蛋白的最佳提取工艺条件为:超声时间80 min,酶解时间5 h,风味蛋白酶5000 U/g,酶解温度40℃,在此条件下胶原蛋白提取率为3.54%±0.21%;超声-碱性酶法提取鮟鱇鱼皮胶原蛋白的最佳提取工艺条件为:超声时间80 min,酶解时间6 h,碱性蛋白酶4000 U/g,酶解温度45℃,在此条件下胶原蛋白提取率为3.25%±0.68%,其中酶解时间比超声-风味酶法多1 h,但胶原蛋白提取率却不及超声-风味酶法。综上,选取超声-风味酶法提取鮟鱇鱼皮胶原蛋白。     

微波辅助提取猪皮胶原蛋白工艺优化

为了保持胶原蛋白的生物活性、提高得率,采用微波技术提取猪皮胶原蛋白。通过单因素试验研究微波处理温度、微波处理时间、固液比、提取时间4个因素对胶原蛋白提取率的影响,确定微波辅助提取胶原蛋白的最佳工艺条件。结果表明：微波时间2min、微波温度25℃、固液比1:30(g/mL)、提取时间35h条件下,猪皮胶原蛋白的提取率为76.72%。     

猪皮胶原蛋白酶解及其酶解产物的抗氧化活性

以新鲜猪皮为原料,利用Alcalase水解胶原蛋白,并对影响Alcalase水解过程的各个因素进行研究,通过对水解度和超氧阴离子自由基(O2－ ·)清除率的测定,确定Alcalase水解猪皮胶原蛋白的最适条件;研究在最适条件下制备的不同质量浓度的猪皮胶原蛋白酶解液对DPPH自由基和O2－ ·的清除效果。结果表明：Alcalase水解猪皮胶原蛋白的最适条件为：pH7.5、温度55℃、酶与底物比6000U/g、底物质量浓度40mg/mL,水解时间4h;在此水解条件下,水解度达到9.55%,O2－ ·清除率达到60.11%;在相应质量浓度10～50mg/mL范围内,猪皮胶原蛋白酶解液的DPPH自由基最大清除率为95.06%,IC50为3.89mg/mL;O2－ ·最大清除率为65.89%,IC50为16.43mg/mL。猪皮胶原蛋白酶解液具有较强的自由基清除能力。     

草鱼鱼鳞胶原蛋白提取及活性肽制备研究

以草鱼鱼鳞为原材料,探讨其胶原蛋白酸-酶组合提取工艺,并进一步研究相应抗氧化活性肽和血管紧张素转换酶抑制(ACEI)活性肽的制备方法。结果表明,草鱼鱼鳞胶原蛋白提取的最优工艺为:乙酸浓度0.3 mol/L、乙酸提取固液比1∶15(g/m L)条件下低温下提取24 h;离心后剩余残渣再按1∶10(g/m L)的比例浸入浓度为2%的胃蛋白酶溶液中低温下提取48 h;在该条件下鱼鳞胶原蛋白提取得率可达49.58%。以草鱼胶原蛋白粗提液为原料,制备抗氧化活性肽的最优工艺为:控制胶原蛋白浓度12.5 mg/m L,按10∶1(体积比)的比例加入浓度为4%的木瓜蛋白酶,60℃下酶解75 min,所得酶解液对ABTS~+自由基的抑制率可达45.7%;制备ACEI活性肽的最优工艺为:控制胶原蛋白浓度20 mg/m L,pH值调节为4.0,每10 m L加入6 000 U的酸性蛋白酶,37℃酶解3 h,所得酶解液对血管紧张素转换酶(ACE)的抑制活性可达98.8%。本研究结果,有望为水产品加工副产物的资源化利用提供参考。     

海蜇胶原蛋白肽的酶解制备工艺

以海蜇加工下脚料为原料提取胶原蛋白,以还原力(RP)和水解度(DH)为指标,采用响应面法研究了酶解温度、酶解时间、pH、料液比、酶添加量对还原力和水解度的影响,得到最佳酶解胶原蛋白的工艺条件;并进一步与复合酶水解工艺进行比较,确定海蜇胶原蛋白肽的最优制备工艺。结果表明:胰蛋白酶的最优酶解条件为:温度44℃、pH8.5、料液比0.50 g/mL、酶添加量3.0%和酶解时间4 h;风味蛋白酶的最优酶解条件为:温度44℃、pH7.5、料液比0.56 g/mL、酶添加量4.0%和酶解时间4 h;进一步进行复合酶实验,结果表明采用风味蛋白酶和胰蛋白酶分别在其最适条件下进行先后酶解获得的酶解液的DH和RP最高,分别为(71.56%±0.0076%)和(0.341±0.0101)。     

橘皮油溶性色素提取工艺研究

以干橘皮粉为原料,对橘皮油溶性色素的提取工艺进行研究.结果表明,其最佳提取工艺条件是:以pH 3.5的稀盐酸为酸解液,按料液比为1:10(w/V)的比例投料,在80℃下酸解2h,将滤渣烘干,加入0.8%(以底物质量计)果胶酶,按料谈比1:11(w/V)添加pH 4的盐酸,在50℃水浴下水解80 min,将滤渣烘干,以石油醚为浸提剂,按料液比1:12(w/V)的比例投料,在25℃下浸提7h,重复浸提3次.油溶性色素得率1.8%.     

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.