提高啤酒非生物稳定性的措施

1。选用蛋白质含量低的大麦和新鲜酒花。2．适当增加大米用量。3．煮沸强度要大，控制PHS．2左右，但煮沸时间不能过长。4．在发酵过程中，对麦汁充Q。5．啤酒风味成熟后，向贮酒罐中添加适量单宁，以促进蛋白质与单宁结合，然后通过过滤除去。6添加聚乙烯聚吧咯烧酮等吸附剂，以吸附啤酒中的单宁成分。7．在滤酒、灌酒前采取措施防止氧溶入。如滤酒时用除氧水和硅藻土，充分搅拌，尽可能排除空气，灌酒时用水充满管道与灌酒机的酒槽，排除空气。8．在低温、避光处保存啤酒。提高啤酒非生物稳定性的措施@苗敬芝$江苏徐州市彭城职业大学!22…     

低压煮沸工艺降低麦汁中可凝固氮含量

采用低压煮沸工艺，可提高煮沸麦汁温度至100．5℃，加强蛋白质凝聚，麦汁可凝固氮下降0．5mg／100mL；煮沸过程加强了美拉德反应、“棕色反应”，类黑精、类黑素化合物增加，麦汁色度增加，麦汁的抗氧化能力增强；煮沸强度从9％～12％降至7％～8％，煮沸时间缩短10～20min，提高生产效率，节约能源20％；改善啤酒非生物稳定性。（孙悟）     

缩短煮沸时间对啤酒质量的影响

众所周知，麦汁煮沸是啤酒酿造过程中的一个重要环节。在原有设备和煮沸强度不变的基础上，验证缩短煮沸时间对啤酒非生物稳定性和风味的影响。     

麦汁煮沸工艺对凝固氮含量的影响

延长煮沸时间和增加煮沸温度可降低麦芽汁凝固氮含量，但会增加麦汁色度；单宁的理想添加浓度为60mg／kg；添加复合硅胶可吸附沉淀部分蛋白质颗粒，降低啤酒色度，提高啤酒非生物稳定性。     

麦汁煮沸时影响蛋白质凝聚的因素

麦汁煮沸的目的之一，是尽可能将麦汁中可凝固蛋白南凝聚并分离出来，以改善啤酒风味和非生物稳定性。文章从麦汁组成、煮沸强度、煮沸时间、煮沸方式，麦汁ｐＨ及酒花添加等方面分析了麦汁煮沸时影响蛋白质凝聚的因素。     

瓶装啤酒巴氏灭菌泡沫环成因及预防

啤酒泡沫环主要成分为高分子肽、多酚物质、碳水化合物、金属离子等。形成因素有：原料麦芽质量、酒花、酿造用水含Fe^2 高；麦汁的煮沸强度、煮沸时的pH值；发酵工艺等。预防措施有：选择优良的原辅料；工艺选择及工艺过程中的参数控制。（孙悟）     

影响酒花α-酸异构化的因素

α-酸是啤酒酒花的主要成分，也是啤酒苦味的主要物质，啤酒中的α-酸异构物可提高啤酒的泡沫稳定性。提高啤酒质量。影响α-酸异构化的因素有：煮沸时间、煮沸方法、煮沸温度、煮沸压力、酒花添加量及酒花品种、煮沸时含氧量、煮沸pH值、麦汁浊度和添加的辅料物质。(孙悟)     

Vb-Na在啤酒酿造中的应用--取代甲醛、偶合双乙酰、抗氧化

生物和非生物沉淀均严重影响啤酒的质量。提高啤酒非生物稳定性可通过控制大麦质量、制麦工艺、糖化工艺、煮沸工艺得以改善；实现生产场地、工具等的有效灭菌，可提高非生物稳定性。Vb-Na新型天然抗氧化保鲜稳定剂可有效除去啤酒中的溶解氧和啤酒中的金属离子，防止啤酒中多酚类物质的氧化聚合，消除金属离子催化作用。阻止双乙酰回升，提高啤酒非生物稳定性、啤酒风味质量，延长啤酒保质期。     

论啤酒中二甲基硫

控制啤酒中二甲基硫的措施：①控制大麦浸度，缩短发芽时间，延长凋萎时间。②大麦发芽时添加溴酸钾。③高温长时间焙焦。④采用煮出糖化法较浸出糖化法DMS含量低。但对色泽、口味不利。⑤提高煮沸强度，延长煮沸时间。⑥缩短热麦汁在沉淀槽中停留时间。⑦提高发酵温度。⑧运输、贮存、销售过程避光照射。⑨搞好工艺卫生，防止腐败微生物污染。⑩选用蛋白质含量适中，收获时间短的大麦。     

影响麦汁煮沸强度的主要因素

<正>煮沸强度是麦汁煮沸过程的重要技术参数,其含义为麦汁煮沸时,每小时蒸发出的水分相当于混合麦汁的百分数。麦汁煮沸强度直接影响麦汁组分、浓度、色度及可凝固氮的含量。合理控制煮沸强度对啤酒的非生物稳定性及口感具有重要意义。本文将结合煮沸强度公式煮沸强度=[混合麦汁量(L)-最终麦汁量(L)]/[混合麦汁量(L)×煮沸时间(h)]×100%,以及生产实际对影响煮沸强度的各种因素进行     

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.