不同屠宰工艺(剥皮和烫毛)对猪胴体表面微生物的多样性影响及关键点的控制研究

应用变性梯度凝胶电泳(Denaturinggradientgelelectrophoresis(DGGE))和经典微生物培养相结合的方法研究了剥皮和烫毛工艺中猪胴体表面污染的微生物数量和细菌多样性的变化以及3.5%乳酸处理后细菌总数和大肠菌群的变化。结果显示:不同猪胴体屠宰工艺中的微生物种类并不完全一致,微生物的污染多是由于前期的屠宰工艺引入;与剥皮工艺相比,烫毛后污染的微生物种类多,初始污染程度也较为严重;乳酸处理显著降低了剥皮工艺中的细菌总数,使出库猪胴体表面细菌总数降低到2.95logCFU/cm2,完全达到HACCP微生物的控制要求,但是没有降低烫毛工艺出库时的细菌总数,因此对不同的屠宰工艺应采取不同的关键点控制措施。     

基于不同提油工艺的薏米糠重金属流向及安全评价

采用超临界CO_2萃取法(SPE)、正丁烷亚临界浸出法(BSE)和石油醚索氏抽提(PSE)3种工艺提取薏米糠油,检测As、Pb、Cd、Hg、Cu、Zn和Mn在薏米糠、薏米糠油及薏米糠粕中的含量。结果表明:3种提油工艺中,超临界CO_2萃取法的薏米糠油中Hg、Cu、Zn和Mn含量较低,尤其Cu含量显著低于其他两种工艺,而石油醚索氏抽提的薏米糠油中Hg、Zn和Mn含量最高;3种提油工艺中,薏米糠油重金属迁移率均以Hg最高,分别达24.47%、31.91%和89.36%,其次为Cu,分别达为14.65%、23.79%和16.83%,而其余重金属迁移率较小;经重金属安全评价,除超临界CO_2萃取法和正丁烷亚临界浸出法的薏米糠油Pb为轻度污染外(污染指数分别为1.074和1.017),其余重金属均在安全范围内;3种薏米糠粕中均存在As、Pb、Cu和Mn污染。     

锯屑亚铵法制浆工艺条件探讨

在大力倡导节约原料,降低成本,减少污染的制浆方法下,本实验采用污染较小的亚铵法对锯屑进行蒸煮,找出了较佳的蒸煮工艺条件。其较佳蒸煮工艺条件为:最高蒸煮温度165℃,亚铵用量(18—20)%,液比1:2.5,尿素用量2%.AQ用量0.05%。在此条件下,所得浆耐破度165 kPa,裂断长4 768 m.撕裂指数8.7 mN·m2·g-1。     

杠板归中提取天然酒石酸氢钾的方法研究

杠板归(Perfoliate Knotweed)是蓼科植物,味酸,富含酒石酸氢钾(potassium hydrogentartrate)。杠板归广泛分布于我国南北各地,为了避免资源浪费,合理利用天然资源,研究了用物理工艺方法提取杠板归中天然酒石酸氢钾,提取收率为85%,含量达到99.51%。提取方法简便,无任何污染,是一种提供天然食品添加剂酒石酸氢钾的有效方法。     

皮革工业鞣前工段可持续发展的生态友好废物处理方法

皮革工业生产过程中产生的皮蛋白类材料和大量的固体和液体废弃物造成的污染,需要通过可持续的清洁技术来解决。本文综述了生态友好面临的各种挑战和皮革生产中减少污染的主要成就。讨论了原皮保存、浸水、脱毛等工序中的清洁技术方法。使用化学和生物制剂的清洁保存技术,已经发展到在很大程度上减少了皮革生产过程中盐的污染问题。通过强化工艺操作有助于化学品更好的吸收和解决污染载荷。酶脱毛可降低40%的COD和50%的BOD。     

减少铬用量

云南蒙自皮革厂自去年六月以来,针对轻革鞣制中铬的耗量高、污染重的问题,改革工艺,先后对黄牛正面革、牛油浸革、山羊正面革、山羊鞋面革等产品进行了试验并逐步投入生产。实践证明,浸酸后加10%的铬液初鞣(计红矾2.5%),再用5%的铬液进行复鞣的工艺,是成功的。这个工艺较原工艺有很多好处:(1)减少了红矾用     

实验制粉去除小麦中脱氧雪腐镰刀菌烯醇(DON)的研究

采用自然污染脱氧雪腐镰刀菌烯醇(DON)毒素不同程度的9种小麦为材料,通过检测其经实验制粉工艺得到麸皮、细麸、不同出粉点面粉包括最后统粉的DON含量,探索小麦实验制粉工艺去除DON的效果。结果表明:经过小麦实验制粉工艺后,能够重新分配小麦中的DON毒素,存留在面粉中的DON总量仅为原来小麦的31.03%～50.39%,并主要分布在小麦的表皮中,在小麦胚乳中也呈从内到外逐渐升高。制得面粉统粉中DON含量减少23.67%～58.97%,心磨粉最高能减少70.51%。小麦籽粒DON含量与制得面粉中DON含量之间呈幂函数回归关系,回归方程为y=0.498x1.206(R2=0.991),随着DON污染程度越低,DON含量减少率越大。以上实验证明,小麦制粉工艺是一种有效的去除小麦中DON毒素的方法。     

逆流提取工艺中浆料浓度对黑液提取率的影响

为定量探究碱回收工艺中浆料浓度对黑液提取率的影响,本研究以烧碱法红松浆和黑液为原料,采用逆流提取工艺,对不同浆浓的黑液提取率及浆料洁净度进行研究。结果表明,相比于15%浆浓,35%浆浓的黑液提取率从75.61%显著增加到98.19%。高浓提取不仅能有效促进碱回收,还可明显提高纸浆洁净度。浆料经过三段提取后35%浆浓的总残碱去除率、COD_(Cr)和BOD_5提取率分别为96.01%、95.0%和98.0%。浆中残余COD_(Cr)和BOD_5的大幅降低,不仅从源头上减少了污染物进入后续漂白和造纸工艺,还可提高漂白效率、降低漂白废水的污染负荷和毒性。     

由大豆浓缩蛋白(SPC)乳清制备高纯度异黄酮苷元的研究

以价格低廉、易污染环境的大豆浓缩蛋白(SPC)乳清为原料,采用等电点结合盐析法沉淀蛋白质、活性炭脱色、离子交换树脂脱盐、HPD-100型非极性大孔树脂吸附纯化、盐酸水解等工艺,制备高纯度的大豆异黄酮苷元产品。经高效液相色谱(HPLC)等方法分析,大豆异黄酮的纯度为(58.4±2.5)%(w/w),总回收率为(78.3±2.6)%;异黄酮苷元的相对含量≥95%(w/w),其中染料木素(Genistein)与大豆甙元(Daid-zein)的含量分别为(23.4±0.8)%和(31.2±0.9)%,而黄豆黄素(G lycitein)的含量极低。产品纯度和附加值高,既能克服当前异黄酮提取工艺中原料成本高、预处理方法繁琐、产品纯度低等缺点,又能实现废物利用,具有良好的推广应用与产业化前景。     

2007—2014年绍兴地区蔬菜中重金属污染调查

目的了解绍兴地区蔬菜中铅、镉和总汞的含量水平及污染程度,为制定蔬菜中重金属污染控制措施提供依据。方法 2007—2014年在绍兴地区7个调查点的农贸市场、超市等地点随机抽取7类共984份蔬菜样品,采用国家标准方法检测蔬菜中铅、镉和总汞的含量,按GB 2762—2012《食品中污染物限量》统计超标情况。采用单因子污染指数和内梅罗综合污染指数评价蔬菜中重金属污染程度。结果 984份蔬菜样品铅、镉和总汞的检出率分别为68.4%(673/984)、92.0%(905/984)和37.6%(370/984),超标率分别为2.9%(29/984)、1.2%(12/984)和5.8%(57/984),平均值分别为0.040、0.017和0.004 0 mg/kg;2009—2011年蔬菜中总汞超标率较高,超标率分别为17.3%(19/110)、24.7%(19/77)和10.1%(12/119);鳞茎类蔬菜中铅和镉超标率分别为14.0%(6/43)和11.6%(5/43),均为各类蔬菜中最高。所有种类蔬菜的综合污染指数均小于0.7。结论绍兴地区蔬菜中重金属总体污染水平不高,但部分蔬菜中重金属污染相对较突出,应继续加强监管和控制。     

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.