微波辅助提取仙人掌果红色素及稳定性研究

主要研究微波辅助提取仙人掌果红色素的最佳提取条件,并对红色素的稳定性进行了研究。通过单因素实验确定微波辅助提取仙人掌果红色素的最佳工艺条件为微波作用时间2min,微波功率119W,料液比1∶20,温度40℃,提取时间65min,仙人掌果红色素提取效果最好。pH,光照,氧化剂,还原剂对色素稳定性有显著影响,抗坏血酸的存在对色素的稳定性的影响不显著。     

仙人掌果红色素稳定性及抗氧化性的研究

仙人掌果含有丰富的营养物质及色素物质,且具有抗氧化功能。采用简单、高效的提取工艺获得仙人掌果红色素,研究了色素的稳定性;通过测定色素对羟自由基和超氧阴离子自由基的清除能力,研究色素的抗氧化性。结果表明:仙人掌果红色素在酸性条件下比较稳定,pH 5时颜色最深;食品添加剂、多数金属离子及光照条件对色素稳定性影响较小;而高温、铜离子对色素稳定性影响较显著;仙人掌果红色素具有很强的抗氧化性,表现在对羟自由基的清除能力略高于Vc,0.5mg/mL色素对超氧阴离子自由基的清除率可以达到90%。仙人掌果红色素可作为一种天然色素广泛应用于食品、药品及化妆品工业中,但使用时应注意温度、pH、光照等条件。     

樟树熟果红色素提取工艺及稳定性研究

为开发利用樟树果实的丰富资源,增加其经济附加值及为寻找新的天然食品着色剂提供依据,从提取工艺条件、pH、温度、时间等方面对樟树熟果红色素的提取方法及其稳定性进行了研究.结果表明,最佳的提取工艺条件为料液比1：25,pH1,提取温度60℃,提取时间90min;该色素在可见区最大吸收波长为509nm;该色素受pH值影响较大,在pH1时的A509nm较大,色泽鲜艳,对温度不稳定.在pH5时的A509nm较小,但对温度较稳定,在pH＞9时色素变色;色素对金属离子的稳定性较高,Fe^3＋使色素溶液变色,Cu^2＋对色素有增色效果,但加速了色素的降解,Ca^2＋对色素有一定的降解作用,Mg^2＋、Na^＋对色素无不良影响;食品添加剂VC、柠檬酸对色素有一定增色效果,苯甲酸钠对色素有降色效果,蔗糖和淀粉对色素的影响不大;氧化还原剂对色素有破坏作用.     

草莓色素的提取及稳定性的研究

对从草莓果实中提取红色素的方法和条件及该色素的稳定性进行了研究，结果表明最佳的提取工艺为：1.5mol/L的HCl溶液和97.5%的乙醇以体积分数1：9为浸提剂，料液比（质量浓度g/mL)为1：12，提取温度为40℃，提取时间为5h,pH对色素的影响明显，在酸性条件下该红色素较稳定。金属离子Na^ 、Ca^2 、Mg^2 、Zn^2 、K^ 对色素无不良影响，而Fe^3 、Al^3 、Cu^2 、Fe^2 对色素则有明显影响；草莓色素有一定的耐糖性；VC、H2O2、Na2SO3对色素有严重的破坏作用，低浓度的则有明显的降解作用。     

桑果红色素的提取及性能

对桑果红色素的提取及稳定性进行了研究，结果表明：桑果红色素的最大吸收波长为480nm，较适宜的提取剂为乙醇，最佳的提取条件为：提取剂体积分数为80％，提取剂pH值为6，提取温度为40℃，提取时间为2h。该色素耐光、耐热、抗氧化、抗还原性强，常用的食品添加剂蔗糖、食用香精、维生素C以及质量浓度小于0．1g／dL的金属离子Mg^2＋、Al^3＋、Ca^2＋、Cu^2＋、Fe^3＋等对色素无明显影响。     

天然美人蕉花红色素的提取及理化性质的研究

从美人蕉花中提取天然红色素的工艺条件是：以体积分数是0．1％HCI＋60％的乙醇-水溶液作提取剂，温度为70℃，时间为3h，原料与提取剂配比为1：8（g／mL）。对该色素的理化性质研究结果表明，美人蕉花红色素在pHi〈4的条件下对热的稳定性好，在此条件下加入果糖、葡萄糖、蔗糖、淀粉或Na^＋、K^＋、Mg^2＋、Ca^2＋、Al^3＋、Zn^2＋、Mn^2＋等金属离子时色素颜色不变，但Fe^3＋的存在会使该色素颜色改变。pH≥5时，色素颜色发生变化。     

大叶红草色素的提取及其稳定性研究

以大叶红草为实验原料,对大叶红草天然色素的提取工艺和稳定性进行研究。采用L（934）正交试验研究色素的最佳提取工艺;用紫外-可见分光光度分析法研究色素的稳定性。结果：得到常规法提取大叶红草红色素的优化工艺,蒸馏水为浸提剂,料液比1∶20;提取温度40℃;浸提次数3次,每次浸提时间是60min;结论：大叶红草色素为紫红色,颜色鲜艳,该色素适应pH（10≥pH≥4）较宽,光稳定性、耐氧化性较好,热稳定性、耐还原性较差,常用食品添加剂对色素的色泽无不良影响,Mg^2＋、Mn^2＋、Zn^2＋、Ca^2＋和低浓度的Cu^2＋对色泽无影响,Na^＋、K^＋和Fe^3＋有不良影响。     

木槿花红色素的提取及理化性质研究

本文研究了木槿花红色素的提取条件和理化性质，结果表明，用料液比1：30（g／mL）、pH1（10％盐酸调）的95％乙醇作提取剂，在80℃恒温浸提60min，提取效率较好。木槿花红色素属花青素类色素，pH值对色素影响明显，在酸性条件下色泽稳定且具有热稳定性。光照能加快色素降解。金属离子Na^＋、Ca^2＋、Al^3＋、Cu^2＋、Zn^2＋对色素色泽无影响，而Fe^3＋、Pb^2＋有不良影响。色素抗氧化能力较差而耐还原性能稍好。蔗糖、葡葡糖和盐等添加剂对色素无影响。     

扛板归红色素的提取及稳定性研究

研究了扛板归红色素的提取条件和稳定性，结果表明，用料液比1：50、pH1的95％乙醇作为提取剂，在60℃恒温浸提10min，提取效率较好。扛板归红色素属色素苷类色素，水溶性好，对热（60℃以内）的耐受性强，光照能加快色素降解。pH值对色素影响明显。金属离子Na^＋、Ca^2＋、Al^3＋、Cu^2＋、Zn^2＋对色素色泽无影响，而Fe^3＋、Pb^2＋有不良影响。色素的抗氧化能力较差，而耐还原性能较好。蔗糖、葡葡糖和盐等添加剂对色素无影响。     

郁金香红色素的提取及性质研究

研究了郁金香花红色素的提取条件和理化性质。结果表明，用料液比1：30（g／mL）、pH1（10％盐酸调）的95％乙醇作提取剂、在80℃恒温提取20min，提取效率较好。郁金香花红色素属花青素类色素，易溶于水和酸性乙醇；pH值对色素影响明显，在酸性条件下色泽稳定且具有热稳定性。光照能加快色素降解。金属离子Na^＋，Ca^2＋，A^13＋，Cu^2＋，Zn^2＋对色素色泽无影响，而Fe^3＋，Pb^2＋有不良影响。色素的色素抗氧化较好而抗还原性能较差。蔗糖、葡萄糖和盐等添加荆对色素无影响。     

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