酶法提取香菇多糖

单因素实验确定了纤维素酶，果胶酶，木瓜蛋白酶提取香菇多糖最适工艺条件，在此基础上进行了正交实验，结果表明，多酶提取的最佳工艺条件是：纤维素酶0.5%，木瓜蛋白酶2.0%，果胶酶1.0%，温度50℃，pH=4.0。     

巴西菇多糖提取方法研究

本文探讨了巴西菇多糖的提取工艺，分别作了热水提取和酶法提取的正交试验，并对多糖提取率进行了比较分析。结果显示．热水提取巴西菇多糖的最佳工艺参数是：提取温度110℃，提取时间1．5h，料液比1：25，其多糖最高提取率5．80％。而采用酶法提取巴西菇多糖的最佳工艺参数分别是：木瓜蛋白酶酶用量0．20％，酶解温度55℃，酶解时间2h，作用pH值6．5；纤维素酶酶用量O．15％，酶解温度45℃，酶解时间3h，作用pH值4．5；果胶酶酶用量O．20％，酶解温度40℃，酶解时间3h，作用pH值4．0。其中木瓜蛋白酶提取巴西菇多糖提取率最高，可达到15．08％。     

高压热水-复合酶提取香菇多糖工艺研究

为提高香菇多糖提取率及质量,采用高压热水协同纤维素酶、果胶酶、菠萝蛋白酶的方法对香菇多糖进行提取。通过单因素及正交试验,研究了复合酶浓度、酶解温度、酶解时间、酶解pH四个因素对香菇多糖提取率的影响。研究显示:复合酶(1∶1∶1)浓度为3.25%,酶解温度40℃,酶解时间2.0h,酶解pH 4.5,在此条件下,香菇多糖的提取达到3.78%。     

超声波协同复合酶法提取香菇多糖的工艺优化

优化超声波协同复合酶法提取香菇中多糖成分的工艺。以香菇多糖提取率为评价指标,采用单因素试验和正交试验,确定最佳提取工艺参数。结果表明,超声波提取优化工艺条件为:料液比1∶15(g/mL),超声温度70℃,超声时间12 min。在此最佳超声提取条件下香菇多糖提取率为8.97%。在超声波优化的基础上,进行复合酶处理,最佳酶解工艺参数为:酶解时间50 min,复合酶(木瓜蛋白酶∶纤维素酶∶果胶酶=1∶1∶1,质量比)添加量3%,酶解温度60℃,酶解pH5.5,在此优化条件下香菇多糖提取率为12.46%。     

酶法提取金针菇多糖的研究

研究了酶法提取金针菇多糖的最佳工艺条件,采用木瓜蛋白酶处理,对酶量、作用温度、最适pH、作用时间进行正交试验。确定了酶法提取金针菇多糖的最佳工艺:酶解反应的温度为55℃,酶浓度为0.6%,pH为7.0,反应时间为3 h,提取率可以达7.6%。     

香菇多糖的酶法提取

利用果胶酶、纤维素酶和漆酶对香菇进行酶解,固定料水比(1∶15)和反应温度(40℃),以酶解后多糖提取率为指标,考察不同浓度的3种酶对香菇多糖提取的影响。在单因素试验的基础上,采用响应面法建立香菇多糖酶法提取的二次多项数学模型,并验证了该模型的有效性;探讨了果胶酶、纤维素酶、漆酶3个因子的交互作用及其最佳水平。响应面分析结果表明:果胶酶、纤维素酶、漆酶显著影响香菇多糖的提取效果,在果胶酶浓度为7.11%,纤维素酶浓度为6.82%,漆酶浓度为3.69%的优化条件下,香菇多糖的提取率达到37.07%。     

超声波辅助复合酶法提取Iota卡拉胶工艺优化

目的：优化Iota卡拉胶提取工艺，以期提高Iota卡拉胶产率。方法：采用超声波辅助复合酶技术从刺麒麟菜中提取Iota卡拉胶。通过单因素和正交试验，确定最佳复合酶（纤维素酶、半纤维素酶、木瓜蛋白酶）配比和复合酶酶解条件，并优化超声处理条件和煮胶工艺条件。结果：最佳复合酶配比为纤维素酶0.50%、半纤维素酶1.25%、木瓜蛋白酶0.20%；最佳酶解条件为酶解温度60 ℃，酶解pH 5.5、酶解时间2.5 h、酶解料液比1∶30 （g/mL）；最佳超声处理工艺为超声功率350 W、超声时间25 min、超声温度40 ℃；最佳煮胶工艺为煮胶温度90 ℃、六偏磷酸钠（SHMP）添加量0.04%、煮胶时间3 h。结论：在最优工艺条件下，提取的Iota卡拉胶产率高，可达到47.17%。     

复合酶解法优化黄精多糖提取工艺

采用复合酶解法优化黄精多糖提取工艺,苯酚-浓硫酸显色法测定黄精多糖质量浓度,以黄精多糖提取率为指标,对复合酶种类和配比进行筛选后,在单因素试验基础上,考察酶解温度、pH、料液比、加酶量对提取率的影响,并通过正交试验进行优化。结果表明,复合酶提取优于单酶提取和普通水提。酶用量配比为纤维素酶:木瓜蛋白酶=3∶7。酶解最佳条件为:pH值5.0,酶解温度50℃,料液比(g/mL)1∶20,加酶量1.5 g/dL,即纤维素酶0.45 g/dL,木瓜蛋白酶1.05 g/dL,酶解2 h后,沸水浸提2 h。在此工艺条件下,黄精多糖提取率可达21.55%,是普通水提法得率的2.75倍,比单酶水解高出12.06%。     

壳聚糖固定化木瓜蛋白酶提取牛蒡多糖的研究

以壳聚糖为载体、戊二醛为交联剂固定化木瓜蛋白酶，从牛蒡中提取多糖，考察固定化工艺的选择、固定化酶提取牛蒡多糖的优化条件及固定化酶的稳定性。结果表明：壳聚糖固定化木瓜蛋白酶的最佳条件为：壳聚糖浓度2.5%，加酶量0.3g/g载体，时间6h，温度15℃，pH7.5，酶活力回收率38.98%。提取牛蒡多糖的最佳条件为：固液比1：20，pH6.5，温度60℃，时间8h，加酶量1.8g/g载体，多糖提取率11.04%。固定化酶重复使用五次，酶活力仍保持50%以上。     

复合酶法提取鸡腿菇多糖的工艺优化

为优化鸡腿菇多糖的提取工艺,采用木瓜蛋白酶与纤维素酶复合处理,通过单因素试验研究了液料比、复合酶添加量、木瓜蛋白酶与纤维素酶质量比、酶解温度、pH值和提取时间对鸡腿菇多糖得率的影响。在单因素试验的基础上,采用Box-Benhnken中心组合试验设计,建立了具有较好预测性能的鸡腿菇多糖提取条件的回归模型,获得了复合酶法提取鸡腿菇多糖的最佳工艺,即酶解温度51.4℃、酶解pH值5.2、木瓜蛋白酶与纤维素酶质量比0.86,在此条件下鸡腿菇多糖得率可达6.42%。     

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.