龙眼粗多糖提取的影响因素及工艺的研究

本文以龙眼干果肉为原料,对龙眼粗多糖提取的影响因素及工艺技术进行了研究,采用单因素试验和L9(33)正交试验,研究了料液比、温度、时间对多糖提取率的影响,采用水浸提、Sevag法结合酶法脱蛋白、乙醇醇析提取、离心等方法来提取龙眼粗多糖.结果表明:料液比和温度是影响多糖提取率的主要因素;最佳工艺为:料液比1:40、温度80℃、时间4h,在最佳提取工艺时,龙眼的粗多糖提取率可高达21.94%.     

吴茱萸粗多糖的碱法提取及脱蛋白方法研究

本实验采用正交设计研究了提取温度、提取时间、料液比和NaoH浓度等对用碱法提取吴茱萸中多糖得率的影响。结果表明,影响最为显著的因素是料液比,最佳提取工艺条件为提取温度80℃、NaoH浓度0.6mol/L、料液比1:20、提取时间3h,此时多糖提取率为12.58%。比较两种脱蛋白方法,Sevag法的优点在于多糖损失率较低,但比较复杂费时,TCA法优点在于其可溶性蛋白脱除相对较为彻底,同时节约大量试剂和时间。综合考虑,TCA法优于Sevag法。     

西红花花瓣粗多糖提取纯化工艺及体外抗氧化研究

研究西红花花瓣粗多糖的提取纯化条件及抗氧化活性。采用L9(34)正交试验设计,考察了提取温度、时间、料液比、提取次数等因素对西红花花瓣粗多糖提取效果的影响。进一步用酶法、Sevag法比较其除蛋白效果,并研究对羟自由基、DPPH自由基的清除能力。最佳提取条件为:料液比1︰50,提取温度为100℃,提取时间为3 h,提取次数为3次。酶法与Sevag法均有较好的除蛋白效果;抗氧化结果表明,西红花花瓣粗多糖对羟自由基、DPPH自由基均有一定的清除作用。最优条件下粗多糖得率达(19.346±0.029)%;酶法除蛋白效果要优于Sevag法;西红花花瓣粗多糖对两种自由基均有不同程度的清除作用。     

正交试验法优选繁枝蜈蚣藻粗多糖的提取工艺

本文对繁枝蜈蚣藻中可溶性粗多糖的提取工艺进行了研究,通过单因素试验和L9(33)正交试验,研究了料液比、温度、时间对多糖提取率的影响,结果显示温度和料液比是影响多糖提取率的主要因素,最佳工艺为料液比1:60,温度100℃,时间3h,在最佳提取工艺时,繁枝蜈蚣藻的多糖提取率为22.527%。采用紫外检测和茚三酮法检测未见多糖含有核酸、蛋白质。     

羊栖菜多糖的提取工艺研究

为了开发利用羊栖菜资源,对羊栖菜中多糖的提取工艺进行了研究。对羊栖菜多糖提取工艺中的参数:提取介质、料液比、提取温度、提取时间、pH值、提取次数、醇沉倍数分别进行了单因素试验,并且在单因素实验的基础上,通过对其中3个主要影响因子(温度、料液比、时间)进行正交试验,以及比较几种粗多糖脱蛋白和脱色方法,最终确定了羊栖菜多糖的最佳提取工艺,即:pH=3.0、浸提温度85℃、料液比1∶30、浸提时间5h、提取次数2次、3倍体积醇沉、大孔树脂脱色、酶解与Sevag法结合除蛋白。     

五味子红色素超声波辅助提取工艺优化

目的:通过单因素和正交试验研究五味子红色素最优提取工艺。方法:采用超声波辅助提取法,以红色素提取率为指标,测定红色素的吸光度。pH为3的乙醇为提取溶剂,在单因素试验基础上,以乙醇浓度、料液比、超声时间、超声温度因素进行正交试验。结果:影响五味子红色素提取率的主要因素为料液比,其次为乙醇浓度和超声时间,最后为超声温度。最佳提取工艺为:pH 3的75%乙醇,料液比1∶50g/mL,超声时间30min,超声温度40℃。对比两种提取方法,超声波辅助提取法比浸提法所用温度低,且缩短了提取时间,提高了色素提取率。结论:该方法提取率高,简单易行,最佳工艺条件下提取率可达到1.5520%。     

正交试验法优化超声提取黄米中多糖

通过单因素试验研究料液比、超声功率、提取时间、提取温度对黄米中多糖提取率的影响,再利用正交试验法优化最佳提取工艺条件,得出最佳提取工艺参数:料液比1∶23 (g/mL)、超声功率100 W、提取温度70℃、提取时间40 min,该条件下黄米中多糖的提取率为7.35%。     

灰树花子实体多糖和蛋白的同步提取工艺优化

对同步提取制备灰树花子实体多糖和蛋白的工艺进行研究,采用单因素实验研究料液比、提取温度、提取液pH、提取时间对灰树花子实体中多糖和蛋白提取率的影响,并通过正交实验法对提取工艺进行优化。结果表明,影响灰树花蛋白提取率的主次因素依次为:料液比提取温度提取时间pH;影响灰树花多糖提取率的主次因素依次为:提取温度pH提取时间料液比;确定灰树花多糖和蛋白的同步提取最佳工艺条件为提取温度85℃,浸提时间4 h,液料比为60:1,提取液pH为11。在此条件下,蛋白的提取率为29.33%,提取率为36.42%,多糖的提取率为20.34%,提取率为23.52%。     

落葵水溶性多糖的提取工艺研究

对传统药食两用植物落葵的水溶性多糖提取工艺进行研究。采用热水浸提、石油醚脱脂、Sevage法脱蛋白、乙醇沉淀等方法来提取落葵粗多糖。采用单因素试验和正交试验L9（3^4）研究料液比、温度、时间对多糖提取率的影响,以苯酚一硫酸显色法测定多糖浓度。结果表明,料液比和提取温度为影响落葵多糖提取的主要因素。正交设计得到最佳提取工艺为：料液比1：50,提取时间5h,提取温度85℃。多糖提取率最大为4．0％;超声波提取在温度70℃,超声功率160w,时间120min时可达最大,其提取率为17．02％,是热水浸提法的4．25倍,这表明超声提取法是一种更为有效的落葵粗多糖提取方法。     

均匀设计法优化超声提取泰山赤灵芝多糖工艺

试验采用超声波技术提高泰山赤灵芝子实体多糖的提取率。利用单因素试验和均匀设计试验,考察料液比、提取时间、提取温度对多糖提取率的影响,并确定最佳提取工艺条件。结果表明,影响超声辅助提取泰山赤灵芝多糖的主次因素为:提取温度提取时间水料比;最佳工艺条件为水料比23 m L:g,提取时间40 min,提取温度58℃,在该工艺条件下泰山赤灵芝子实体多糖提取率达2.13%。试验同时证明,均匀设计用于研究超声辅助提取泰山赤灵芝多糖工艺条件是可行的。     

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.