低温酸性淀粉酶在酒精发酵中的应用

低温酸性淀粉酶可以将液化过程中没有水解的生淀粉颗粒直接进行水解。试验研究低温酸性淀粉酶在酒精发酵中的应用,发现将低温酸性淀粉酶添加到发酵环节可以提高原料出酒率。     

樟芝真菌发酵动力学研究

对樟芝真菌菌体及胞外多糖发酵过程和发酵动力学进行了研究.基于Logitic方程和Luedeking-Piret方程,得到了描述发酵过程的动力学数学模型和模型参数,同时对实验数据与模型进行了验证比较.模型计算与实验结果拟合良好,模型正确地反应了樟芝真菌菌体及胞外多糖的发酵过程及其动力学机制.     

灰树花发酵动力学研究

对灰树花真菌发酵过程和发酵动力学进行了研究。基于Logitic方程和Luedeking-Piret方程,得到了描述发酵过程的动力学数学模型和模型参数,同时对实验数据与模型进行了验证比较。模型计算与实验结果拟合良好,模型正确地反应了灰树花真菌的发酵过程及其动力学机制。     

黑曲霉生产葡萄糖酸钠的分批发酵动力学模型

对黑曲霉发酵生产葡萄糖酸钠的分批发酵动力学特性进行了研究,通过对Logistic方程,Luedeking-Piret方程和Luedeking-Piret/Like方程进行最优参数估计和非线性拟合,得到了描述发酵过程中菌体生长、葡萄糖酸钠合成、葡萄糖消耗的动力学模型.对实验数据与模型预测值进行比较,发现模型预测值与实验数据能较好地拟合,基本上反映了黑曲霉分批发酵过程的动力学特征,结果还表明葡萄糖酸钠的发酵合成是部分生长偶联型的.     

利用大豆秸秆酶解液发酵制备L-乳酸的动力学研究

对乳酸菌发酵大豆秸秆酶解液制备L-乳酸的动力学特性进行了研究,基于monod方程,提出了固定化乳酸菌生长动力学模型;基于gaden方程,提出了乳酸生成动力学模型,得到了描述发酵过程的动力学模型及模型参数,同时对试验数据与模型进行了验证,模型计算值与实验数据拟合良好,模型基本上反映了乳酸发酵过程的动力学特征.     

产胞外多糖芽胞杆菌的发酵动力学研究

对芽胞杆菌胞外多糖发酵动力学进行了研究.基于Logistic和Luedeking-Piret方程,得到了描述芽胞杆菌发酵过程菌体生长、多糖形成、底物消耗的动力学数学模型和模型参数.模型反映了该菌株发酵过程的动力学特征,模型值与实验数据拟合良好,平均误差小于10%.     

液体发酵灰树花胞外多糖动力学研究

通过对灰树花胞外多糖的发酵研究,根据Logistic方程,提出了发酵过程中菌体生长、胞外多糖合成、基质消耗的动力学模型.采用数据分析软件对实验数据进行处理,得到了灰树花发酵合成胞外多糖的动力学模型参数,并对实验数据与模型进行了比较,结果表明模型与实验数据能较好地拟合,基本上反映了灰树花分批发酵胞外多糖过程的动力学特征.     

减压处理下泡菜发酵动力学初探

利用DPS软件,通过Logistic方程、Luedeking-Piret方程和Luedeking-Piret-like方程对减压处理下泡菜的发酵过程进行了动力学分析,研究了其发酵过程中菌体生长、产物生成和基质消耗等特性,得到了描述泡菜分批发酵过程的动力学模型和模型参数.模型计算值与实验值的拟合度分别为0.9924、0.9688和0.8971,该模型基本反映了减压处理下泡菜分批发酵过程的动力学特征.     

圆弧青霉发酵右旋糖酐酶过程动力学模型的建立

为了研究圆弧青霉发酵生成右旋糖酐酶的过程及动力学,测定发酵过程的菌体质量浓度、右旋糖酐酶酶活以及总糖(底物)质量浓度随时间的变化,分别采用Logistic方程、Luedeking-Piret方程和类Luedeking-Piret方程对实验数据进行非线性拟合,获得了圆弧青霉菌菌体生长、右旋糖酐酶生成和底物消耗的动力学模型,相关系数R2分别为0. 994、0. 992、0. 991。对获得的动力学模型进行分析,计算值与实验值的误差合理,所建立的发酵动力学模型能较好地反映出圆弧青霉菌发酵产右旋糖酐酶的过程,为控制和预测发酵过程提供了理论基础。     

耐高温α-淀粉酶在淀粉质酒精生产中的应用研究

概述了酒精行业形势及生产工艺,对采用赛诺耐高温α-淀粉酶(酒精发酵专用型),分别运用95℃低温蒸煮液化、105℃中温蒸煮液化的酒精甲乙生产企业生产过程液化、发酵及产品指标进行了研究分析,结果表明赛诺耐高温α-淀粉酶(酒精发酵专用型)是一种良好的酒精液化用酶,应用于低温蒸煮可以显著提高酒精质量以及出品率。     

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.