黄鳍鲷骨骼肌α-辅肌动蛋白的分离纯化及抗体制备

目的黄鳍鲷骨骼肌α-辅肌动蛋白的分离纯化及多克隆抗体制备.方法采用低温抽提、硫酸铵分级沉淀及两次DEAE-Sepharose离子交换等方法获得α-辅肌动蛋白,并通过免疫大鼠制备了抗α-辅肌动蛋白多克隆抗体.结果经SDS-PAGE检测得到高纯度的α-辅肌动蛋白,分子质量约为100kDa.Western blot检测结果显示,制备的多克隆抗体具有较高的效价和良好的特异性.结论从海水黄鳍鲷骨骼肌中得到高度纯化的α-辅肌动蛋白,并制备了滴度高、特异性好的多克隆抗体,为研究鱼类保鲜储藏过程中α-辅肌动蛋白的分解变化提供了重要的手段.     

不同温度贮藏对黄鳍鲷鱼肉鲜度与品质的影响

以黄鳍鲷（Acanthopagrus latus）为研究材料,通过测定鱼肉菌落总数、pH值、挥发性盐基氮（total volatile basic nitrogen,TVB-N）值、硫代巴比妥酸（2-thiobarbituric acid,TBA）值和剪切力等指标,结合感官评定,设立4℃冷藏为对照组,研究0℃和微冻（-4℃）贮藏对黄鳍鲷鱼肉鲜度和品质的影响。结果表明：在贮藏期间,各贮藏组黄鳍鲷鱼肉的菌落总数、TVB-N和TBA值均呈现上升趋势,鱼肉pH值呈先稍下降后再上升的趋势,而鱼肉剪切力和感官评分均呈逐渐下降趋势。0℃和微冻两贮藏组黄鳍鲷鱼肉各项指标的变化速率均小于4℃冷藏对照组,0℃和微冻保鲜效果明显优于4℃冷藏保鲜;0℃和微冻贮藏组,黄鳍鲷贮藏7 d后鱼肉菌落总数分别为6.88 lg（CFU/g）和5.72 lg（CFU/g）,TVB-N值分别为20.54 mg/100 g和11.40 mg/100 g,TBA值分别为0.88 mg/100 g和0.38 mg/100 g,剪切力分别为4.96 N和5.51 N,说明微冻贮藏能更好地抑制鱼肉微生物繁殖,有效地减缓鱼肉蛋白质分解和脂肪氧化,较好地保持鱼肉嫩度和品质;相比于4℃冷藏,0℃和微冻下贮藏的黄鳍鲷鱼肉货架期至少可延长2 d和8 d。     

气相色谱-质谱法分析六种鲈形目海水鱼脂肪含量和脂肪酸组成

分析六种鲈形目海水鱼脂肪酸组成,为海水鱼的生产加工提供理论依据。通过氯仿-甲醇法提取六种海水鱼肌肉的脂肪,运用气相色谱-质谱联用法对脂肪酸组成进行分析。六种鲈形目海水鱼肌肉粗脂肪含量为4.40%~8.72%,其中黄鳍鲷含量最高,总共检测出21种脂肪酸,包括6种饱和脂肪酸(saturated fatty acids,SFA)和15种不饱和脂肪酸(5种单不饱和脂肪酸(monounsaturated fatty acids,MUFA)和10种多不饱和脂肪酸(polyunsaturated fatty acids,PUFA)),粗脂肪和脂肪酸总体含量均有显著差异(P<0.05),其中SFA含量为26.63%~33.97%,MUFA含量为23.07%~29.13%,PUFA含量为41.06%~44.35%。6种鲈形目海水鱼EPA和DHA占脂肪酸总量为21.17%~35.73%,除了黄鳍鲷,其他5种海水鱼占比均在30%以上,其中马拉巴笛鲷中占比最高,为35.73%。六种鲈形目海水鱼中MUFA/SFA总体有显著差异(P<0.05),其中黒鲷最高(1.43),马拉巴笛鲷次之(1.36)。6种鲈形目海水鱼中多不饱和脂肪酸比较丰富,其中马拉巴笛鲷的EPA+DHA含量较高,按照人们对于必需脂肪酸的需求,马拉巴笛鲷的营养价值最高。     

黄鳍金枪鱼食用品质的研究

取斐济岛黄鳍金枪鱼背部肌肉,分别测定其营养成分,氨基酸及脂肪酸组成和游离氨基酸,对其进行营养价值与食用价值评价。结果显示,黄鳍金枪鱼背肉粗蛋白含量高达24．88％,脂肪含量仅为0．0387％,灰分含量为1．71％。根据1973年FAO／WHO推荐的必需氨基酸需要量模式对黄鳍金枪鱼背肉进行评价,氨基酸评分为95,第一限制性氨基酸为缬氨酸。赖氨酸含量为81．02mg／g,甲硫氨酸含量为54．81mg／g。游离的呈味氨基酸如组氨酸（肉香味）、甘氨酸（甜味）、谷氨酸（鲜味）,分别占氨基酸总量的75．94％、1．25％和1．73％。不饱和脂肪酸含量占总脂肪酸含量的60．95％,其中EPA和DHA分别占6．90％和36．38％。此外,还检测到奇数碳脂肪酸,如十五碳脂肪酸和十七碳脂肪酸。可见新鲜黄鳍金枪鱼背肉是营养丰富、味道鲜美的上等原料。     

黄鳍金枪鱼头酶解蛋白粉营养评价及其应用

对黄鳍金枪鱼头酶解蛋白粉的营养成分进行了分析,对其蛋白质营养价值进行了评价,并研制了黄鳍金枪鱼头酶解蛋白粉营养片。结果显示,黄鳍金枪鱼头酶解蛋白粉粗蛋白含量(干基)为92.1%,脂肪含量0.44%,灰分7.2%,具有高蛋白、低脂肪、矿物元素含量丰富的特点;18种氨基酸含量为85.1%,必需氨基酸占氨基酸总量的37.2%。以黄鳍金枪鱼头酶解蛋白粉为主要原料,添加大豆蛋白粉等辅料研制的营养片必需氨基酸之间比例适宜,符合FAO/WHO推荐的理想蛋白质模式。     

不同钙离子浓度体外条件下磷酸化对肌联蛋白降解的影响

以羊背最长肌中肌联蛋白为原料,添加蛋白激酶A和碱性磷酸酶体外孵育使肌联蛋白发生磷酸化和去磷酸化反应。反应后添加μ-钙蛋白酶,在钙离子浓度分别为0.05 mmol/L和2 mmol/L条件下,4 ℃孵育2 d。测定孵育体系pH值、肌联蛋白磷酸化水平及其降解程度。结果表明：不同处理组孵育体系pH值差异不显著（P＞0.05）;蛋白激酶A组肌联蛋白磷酸化水平显著高于对照组,对照组肌联蛋白磷酸化水平显著高于碱性磷酸酶组（P＜0.05）;当钙离子浓度为0.05 mmol/L时,蛋白激酶A组和对照组未检测到分子质量为1 200 kDa的降解条带,而碱性磷酸酶组在孵育12 h检测到该条带;当钙离子浓度为2 mmol/L时,蛋白激酶A组和对照组均在孵育12 h检测到1 200 kDa降解条带,而碱性磷酸酶组在孵育0.5 h时检测到该条带。结论：蛋白激酶A和碱性磷酸酶能够促进肌联蛋白发生磷酸化和去磷酸化反应;随着钙离子浓度增加,肌联蛋白降解速率加快;并且在相同钙离子浓度下,肌联蛋白在碱性磷酸酶组降解较快,表明去磷酸化可以促进肌联蛋白的降解。     

超声波辅助黄鳍金枪鱼免疫活性肽酶解工艺优化

本文以黄鳍金枪鱼肉为原料，通过超声波辅助酶解黄鳍金枪鱼肉制备免疫活性肽。以小鼠巨噬细胞相对增殖率为指标，筛选出最适蛋白酶为胰蛋白酶，并在单因素实验基础上，通过响应面优化试验确定了黄鳍金枪鱼肉的酶解条件。结果表明，酶解时间5 h、酶解温度37.6℃、超声波时间为11 min，在此条件下，小鼠巨噬细胞的相对增殖率最佳，为43.04%±2.03%，与线性回归模型的预测值相近。对最佳酶解条件下的黄鳍金枪鱼免疫活性肽进行氨基酸组成与分子量分析，其必需氨基酸为41.42%±1.24%，疏水氨基酸含量为26.49%±0.79%，分子量集中分布在4.7～6.5 kDa。研究结果为黄鳍金枪鱼的高值化利用提供了理论指导与技术支持。     

六种鳞鲀亚目鱼肌肉脂肪酸分析和比较

从广东湛江市场收集到6种鳞鲀亚目鱼：丝背细鳞鲀、圆斑疣鳞鲀、双棘三刺鲀、中华单角鲀、黄鳍马面鲀、单角革鲀,采用国家标准方法测定组织中的水分和粗脂肪,经毛细管气相色谱法测定了肌肉中的24种脂肪酸组分,分析和比较了其饱和脂肪酸（SFA）、单不饱和脂肪酸（MUFA）和多不饱和脂肪酸（PUFA）的含量,结果显示,6种鳞鲀亚目的鱼体含水量67.2%~72.9%,粗脂肪占干重1.05%~1.42%,肌肉饱和脂肪酸含量为34.21%~43.45%,单不饱和脂肪酸含量为11.84%~19.43%,多不饱和脂肪酸含量为34.39%~48.86%。6种鳞鲀亚目鱼有较高含量的多不饱和脂肪酸,其ω-3系脂肪酸高于ω-6系脂肪酸,ω-3/ω-6为1.0~4.7,具有较高的脂肪酸营养价值,其中圆斑疣鳞鲀和黄鳍马面鲀的ω-3/ω-6分别为3.3和4.7。6种鳞鲀亚目鱼均具有较高的EPA（二十碳五烯酸）+DHA（二十二碳六烯酸）,含量为17.20%~37.49%,按鱼中肌肉的EPA+DHA含量,黄鳍马面鲀（37.49%）>圆斑疣鳞鲀（30.29%）>中华单角鲀（25.73%）>丝背细鳞鲀（23.82%）>双棘三刺鲀（18.82%）>单角革鲀（17.20%）,其中黄鳍马面鲀EPA+DHA高达37.49%±2.67%,具有较高的食用价值和医用价值。     

马齿苋多糖提取、纯化工艺的初步研究

实验以多糖提取率为指标成分，采用正交试验对马齿苋多糖的提取工艺进行优选，并进行了初步纯化。结果显示最佳工艺为：温度100℃，时间9h，醇沉比4：1，浸提次数3次，在最佳提取工艺时，马齿苋的多糖提取率为268％用光谱分析鉴定初步纯化的多糖：红外光谱分析具有典型的多糖特征吸收峰，紫外光谱分析未见蛋白质（280nm）与核酸（260nm）的特征吸收峰。     

2种大洋性金枪鱼赤身营养价值分析与评价

对黄鳍和长鳍2种金枪鱼赤身部位肌肉的营养成分进行分析与评价。结果表明:黄鳍和长鳍金枪鱼赤身水分含量分别为72.43%和72.73%,脂肪含量分别为0.54%和0.19%,蛋白质含量为25.21%和26.63%,灰分含量为1.32%和1.53%,均含有丰富的矿物质元素;黄鳍和长鳍金枪鱼赤身多不饱和脂肪酸含量高,尤其是DHA含量可高达28.84%和29.83%。黄鳍和长鳍金枪鱼赤身氨基酸配比合理,必需氨基酸含量分别为40.70%和41.70%,必需氨基酸指数(EAAI)分别为92.62和95.00,并含有丰富的呈味氨基酸,其含量分别为40.81%和42.31%。因此,2种金枪鱼赤身肌肉蛋白含量高,脂肪含量低,具有较高的营养价值。     

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.