猪血粉酶解液脱色工艺研究

利用活性炭对猪血粉酶解液进行脱色,研究了活性炭用量、pH值、脱色温度和吸附时间对猪血粉酶解液脱色效果的影响。试验结果表明:活性炭对猪血粉酶解液具有理想的脱色效果,最佳脱色工艺参数为活性炭用量2.5%,pH 4.0,脱色温度60℃,吸附时间1.0h,在此最佳脱色工艺条件下脱色率达92.20%,同时氮损失率为10.42%。     

氮-磷系阻燃型复鞣剂的脱色与应用

利用活性炭、双氧水对一种新合成的氮一磷系阻燃型复鞣剂进行脱色研究,选择脱色剂用量、脱色pH、脱色温度、脱色时间作为四个影响因素.通过试验得到最佳工艺条件分别为:活性炭用量0.12 g/mL,pH 3.5,脱色温度55℃,脱色时间0.5 h,脱色率可达56.6%;y(双氧水)/v(试样)=1:2,脱色温度50℃,脱色时间...     

苹果渣果胶树脂吸附静态与动态脱色工艺研究

以XDA-7大孔树脂为吸附剂,研究了苹果渣果胶的脱色工艺.分别探讨了在静态与动态条件下,XDA-7型树脂对苹果渣果胶的吸附脱色能力.实验结果表明:XDA-7树脂对果胶提取液有较好的吸附脱色效果,损失率较低,静态脱色的最佳工艺参数为:XDA-7树脂用量14g/100mL(果胶液),pH1.0,温度40℃,时间630min,脱色率为36.17%,损失率为3.70%;动态脱色的最佳工艺参数为:流速4.5BV/h,处理量2.5BV,上柱液pH1.0,温度35℃,脱色率为61.66%.损失率为3.05%.在最佳动态工艺条件下脱色的果胶提取液经醇沉和冷冻干燥后,其成品色泽符合QB2484-2000标准.     

响应面分析法优化碱蓬多糖的脱色工艺

为了优化活性炭对碱蓬多糖的脱色工艺条件,在单因素实验基础上,选取碱蓬多糖脱色过程中的活性炭用量、脱色温度、脱色时间和pH为影响因素,根据Box-Behnken中心组合设计原理,进行响应面法分析,确定碱蓬多糖的最佳脱色工艺条件为:活性炭用量3.3%,脱色温度53 ℃,脱色时间43 min,pH5.4,脱色率为65.38%,RSD为1.74%。该优化工艺简单、稳定、具有良好的可行性。     

L-缬氨酸发酵液脱色工艺的研究

本文探讨了活性炭对经金属膜分离得到的L-缬氨酸（L-γa1）发酵液脱色效果的影响,并考察了脱色过程中主要影响因素。以活性炭用量、发酵液pH、脱色温度、脱色时间为考察因素,色素去除率和L-缬氨酸回收率为考察指标,采用正交试验法对脱色工艺进行优化,确立了最佳的工艺条件为：活性炭用量2%,脱色料液pH5.4,脱色温度50℃,脱色时间20min,料液浓度35g/L~60g/L。     

双酶直接催化玉米粉中的淀粉糖化工艺参数的研究

通过双酶直接催化玉米粉中的淀粉糖化工艺参数的研究,为玉米粉糖浆混合物生产和使用单位提供参数指导。通过试验得出最佳工艺参数为：糖化温度55～60℃,最佳点为60℃,液化液pH值为4.0～4.5范围,要得到较高DE值的糖浆混合物需60h的糖化时间,糖化酶用量在280～320U/g淀粉。     

味精生产中陈糖大米糖化工艺的研究

研究了液化温度和时间、糖化温度和时间、酶用量、pH和底物浓度在糖化过程中对糖化质量和DE值的影响,确定了陈粮大米糖化工艺的最适条件为:液化pH5.8-6.0,α-淀粉酶10-12U/g干物质,105-108℃维持5-8min,闪冷到95-97℃,保持90-120min;糖化pH4.2-4.4,糖化酶100-120U/g干物质,温度60 2℃,时间28-32h。     

紫薯渣果胶提取工艺研究

该试验以紫薯渣为原料研究果胶提取工艺,对预处理后的紫薯渣以果胶含量为考察指标,研究酸提取条件及脱色条件。结果表明,紫薯渣在pH 7.0,温度75 ℃时,α-淀粉酶用量60 U/g原料,酶解时间30 min条件下除去淀粉;酸提取工艺条件为盐酸提取液pH值1.5,温度85 ℃,时间105 min;脱色条件为活性炭用量1%,脱色温度70 ℃,时间30 min;在此条件下制备的果胶含量为3.979%。     

超声波辅助复合酶法酶解木薯淀粉工艺优化

以木薯淀粉为原料,采用超声波协同复合酶解技术研究其糖化工艺。在单因素实验(超声时间、超声功率、糖化时间、糖化温度、糖化酶添加量、糖化pH、料液比)基础上,选取糖化时间、糖化温度、糖化酶添加量、糖化pH四因素,以糖化率(DE值)为指标,通过4因素3水平的Box-Behnken实验设计,优化了木薯淀粉的糖化工艺参数,结果表明:超声时间15 min,超声功率900 W,糖化时间100 min,糖化温度65 ℃,糖化酶用量5 g/L,糖化pH4.7,料液比9:20 (g/mL)时,DE值达到98.98%。SEM结果显示木薯淀粉超声前后形貌有差异,FT/IR检测显示,木薯淀粉主要组成单糖为葡萄糖,且经GC-MS对木薯淀粉水解后糖化液分析得出其成分只有葡萄糖,这可为木薯淀粉糖化工艺提供一定的理论依据。     

菊芋中提取菊粉的纯化工艺研究

采用石灰乳-磷酸法除杂和脱色剂脱色,对菊芋菊粉粗提液进行纯化研究。结果表明:石灰乳-磷酸法对菊粉粗提液除杂的最佳工艺条件为:pH12.0,温度60℃,时间10min,在此最佳条件下体系的透光率从46.5%上升到87.3%;比较几种脱色剂的脱色效果,活性炭的脱色效果最好;当活性炭用量为0.7g/100mL(除杂液),脱色温度80℃,脱色时间30min,透光率高达96.7%;当活性炭用量为0.3g/100mL(除杂液),脱色温度40℃,脱色时间10min,菊粉损失率仅为4.05%。     

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.     

Focus on China's Paper Industry

In the English section of this issue, 〈China Paper Newsletters〉 will introduce ＂National Development and Reform Commission Issued Announcement for Selection of Major Preliminary Research Projects for the ＇13th Five-Year Plan＇＂, ＂2013 Annual Report of China＇s Paper Industry＂, and news of projects and other policies.     

Listen to downstream & search for innovation

正Nowadays,textile enterprises are all taking efforts in transformation and upgrading,like improving producing capacity and optimizing production structure to face market downturn.It claimed a higher request to the standard of textile equipments.In the upcoming of ITMA ASIA+CITME 2014exhibition,this magazine have interviewed several branch associations and a series of relative enterprises,to summarize industrial developing status