普通法焦糖色-NaCl溶液体系的颜色特性

以焦糖色质量分数、Na Cl含量、保温时间为因素,探究普通法焦糖色-Na Cl溶液体系颜色特性在常温条件及95℃保温过程的变化。常温条件下,体系的Na Cl含量增加,色率明显下降,红色指数基本不变;体系的焦糖色质量分数增加,对色率有影响,对红色指数无明显影响。保温过程中,不同焦糖色质量分数的体系色率都呈上升趋势,红色指数总体呈下降趋势,焦糖色质量分数越高的体系色率增长速度越慢,相同保温时刻焦糖色质量分数越高的体系色率越低、红色指数越高;不同Na Cl含量的体系色率均呈上升趋势,红色指数呈下降趋势,相同保温时刻Na Cl含量越高的体系色率越低,红色指数基本不变。保温过程中,Na Cl含量越高、焦糖色质量分数越低,体系发生絮凝现象的时间越早。     

普通法焦糖色存储特性的研究

焦糖色在食用色素领域占有重要地位,因为普通法焦糖色具有高安全性,正日渐成为当下研究的热点。本文以普通法焦糖色为对象,探究了保温时间、样品浓度、热处理等因素对其理化性质的影响,试验结果显示:保温时间越长,p H越低且下降幅度越小,并最终趋于平衡;色率随保温时间的延长呈先增后减的趋势,120 min后基本稳定;红色指数、黄色指数随保温时间的延长呈先减后增的趋势,120 min后保持稳定;色率、红色指数、黄色指数的热处理前后变化基本遵循随保温时间延长变化值增加的趋势,保温超过90 min,变化值接近;样品制备终止后,保温促进物质的后续反应,促使物质稳定,利于各指标的稳定;样品浓度影响焦糖色的稳定性,高浓度焦糖色抑制物质的传递,因此稳定性更高。     

莱赛尔/棉混纺织物的染色同色性北大核心

由于莱赛尔纤维和棉纤维在结构和性能上的差异,其混纺织物在同浴染色时存在竞染。为实现染色同色性,使用专用活性染料和常规活性染料对纯棉机织物和莱赛尔机织物进行染色,分析了硫酸钠用量、碳酸钠用量、保温时间、染色工艺、丝光条件以及染料类别对同色性效果的影响。结果表明:硫酸钠用量、保温时间对同色性影响较小,碳酸钠用量、染色工艺及丝光条件可提高莱赛尔/棉混纺织物的同色效果。在加碱固色前增加一道90℃保温10 min工艺,有利于提高混纺织物的同色效果。当丝光碱液的质量浓度在180 g/L以上时,6只染料染色织物的同色效果较好。DCS系列活性染料可有效提高同色性效果。     

对苯基苯酚在涤纶染色中的应用研究

将对苯基苯酚用于涤纶织物分散染料载体染色中,测试并分析了对苯基苯酚用量、染色温度、保温时间对染色效果的影响,并采用正交试验法进行染色工艺优化。探讨了三原色染色效果以及染色后织物的耐水洗色牢度和断裂强力。结果表明,涤纶分散染料对苯基苯酚载体染色时,织物上染率提高;分散蓝E-R加载体染色最佳工艺为:对苯基苯酚用量30%,染色温度95℃,保温时间45 min;分散蓝E-R、分散黄E-3GB染色时得色量较大,分散红E-FB染色时得色量较小;对苯基苯酚载体染色后织物的耐水洗色牢度不受影响,断裂强力有所下降。     

保温后熟及陈酿条件与玫瑰醋色泽形成的相关性研究

研究引入了色率、黄色指数、红色指数、玫瑰紫指数的概念,建立了对玫瑰醋色泽进行量化评价的方法。即将食醋稀释50％后,5000r／min离心30min,取上清液分别测其在波长460nm、510nm、530nm、610nm处的吸光度值,分别用10×lg（OD460nm／OD610nm）、10×lg（OD510nm／OD610nm）、10×lg（OD530nm／OD610nm）、OD610nm×20000／0．076来表示食醋的黄色指数、红色指数、玫瑰醋紫指数和色率,并用这种方法评价了保温后熟及保藏条件对食醋色泽的影响。通过试验发现在试验设计的保温时间范围内,色率随保温时间的增加呈下降趋势;黄色指数、红色指数、玫瑰紫指数随着保温时间缓慢增大;常温保藏比4℃保藏样品的色率更高,而黄色指数、红色指数、玫瑰紫指数则是4℃保藏样品比常温保藏的高。     

正交实验法优化酱油用焦糖色素的制备工艺

以葡萄糖和碳酸铵为原料,优化酱油用焦糖色素的制备工艺。采用正交实验法,研究保温温度、保温时间、助剂质量分数及糖液质量浓度对焦糖色素的色率和红色指数的影响。结果表明:在保温温度140℃,保温时间70min,助剂质量分数7%,葡萄糖质量浓度为50%(w/v)的条件下可获得具有较好色率的产品,色率可达76579BEC。在保温温度130℃,保温时间60min,助剂质量分数5%,葡萄糖质量浓度为40%(w/v)的条件下可获得具有较好红色指数的产品,红色指数可达5.569。在保温温度135℃,保温时间60min,助剂质量分数6%,葡萄糖质量浓度为50%(w/v)的条件下可获得同时具有高色率和高红色指数的产品,色率可达43632BEC,同时红色指数达到5.34,优于市售焦糖色素。     

纯棉针织物冷轧堆染色小样仿色的改

采用烘箱保温法改进纯棉针织物的活性染料冷堆小样仿色工艺,探讨了混合碱剂比例、反应温度、保温时间等因素对冷堆染色工艺的影响。优化的烘箱保温法工艺为：以烧碱与水玻璃的混合碱剂,混合比例（1∶5）,保温温度为70～80 ℃,保温时间为12～15 min。结果表明,小样仿色织物的表面得色量与同处方冷堆12 h工艺的相近,可大大缩短小样仿色时间,提高仿色效率。     

染色条件对羊绒织物起毛起球的影响

分析了染色温度和保温时间对山羊绒长度和强力的影响,以及山羊绒长度和强力与织物起毛起球现象的关系。结果表明,山羊绒纤维长度随着温度的提高或保温时间的延长而缩短;山羊绒纤维的强力也随着温度的提高或保温的时间延长呈下降趋势,保温时间以不超过50 min为宜。另外,通过对试验色绒和毛、梳毛后再随机对梳理毛网中的山羊绒抽检发现,平均单纤维强力低的色绒经过梳理后纤维长度会变短,长度变异（CV）值提高;控制山羊绒染色后平均纤维强力在3.0 cN以上或长度变异值在11.0%左右才能保持织物抗起毛起球等级在3级以上。     

肉葡萄球菌对香肠发色的影响

研究硝酸盐、异VC-Na和肉葡萄球菌冻干粉添加量以及保温温度和时间对香肠发色效果的影响,并进行贮藏实验。利用响应曲面法和单因素试验对肉葡萄球菌的发色条件进行优化,确定香肠最佳发色工艺条件：硝酸盐0．005％、异VC-Na0．01％、肉葡萄球菌冻干粉0．25％、保温温度30℃和保温时间3h;香肠贮藏两个月后菌落总数小于10CFU／g,表明香肠中添加肉葡萄球菌是安全的。结果表明,接种肉葡萄球菌并添加少量硝酸盐替代直接添加亚硝酸盐进行香肠发色是可行且安全的。     

毛/粘混纺织物留白染色

采用Lanasol CE系列染料对毛/粘交织物进行留白染色,分析染色工艺中各因素对毛/粘混纺织物留白染色效果的影响,确定了毛/粘混纺织物留白染色的最佳染色工艺为:pH值5.5,保温时间50 min,保温温度95℃,匀染剂用量1.0%(owf)。结果表明,该染色工艺混纺中的羊毛纤维上色率高,色光稳定,色牢度优良,匀染性好,粘胶纤维的损伤小且不沾色,留白染色效果好。     

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