ZTC1+1-Ⅱ澄清剂用于昆参片水提液的纯化研究

目的:研究纯化昆参片水提液的工艺.方法:以纯化前后昆参片水提液中总多糖含量和浸膏率为考察指标,比较乙醇沉淀法、壳聚糖澄清剂和ZTC1+1-Ⅱ澄清剂对提取液的纯化效果,并用单因素考察法确定ZTC1+1-Ⅱ澄清剂的最佳纯化工艺.结果:ZTC1+1-Ⅱ澄清剂优于乙醇沉淀法和壳聚糖澄清剂,最佳纯化工艺为澄清剂用量5%B+2.5%A,药液浓度0.2g/mL,搅拌速度100r/min.结论:ZTC1+1-Ⅱ澄清剂可用于纯化昆参片水提液.     

桦褐孔菌多糖口服液澄清工艺研究

优选ZTC1+1Ⅲ型澄清剂用于桦褐孔菌多糖口服液的澄清工艺.在单因素试验基础上,选择ZTC1+1Ⅲ型澄清剂用量、澄清温度、保温时间为自变量,吸光度为响应值,利用Box-Benhnken中心组合试验和响应面分析法,模拟得到二次多项式回归方程的预测模型.优化最佳澄清工艺参数为:ZTC1+1Ⅲ型用量(B/A)7.409%/3.71%,澄清温度(B/A)为73.63℃/53.63 ℃,保温时间为20.047 min. ZTC1+1Ⅲ型澄清剂的澄清工艺可用于桦褐孔菌多糖口服液的除杂.     

ZTC1+1-Ⅱ澄清剂用于昆参片水提液的纯化研究

目的研究纯化昆参片水提液的工艺。方法以纯化前后昆参片水提液中总多糖含量和浸膏率为考察指标,比较乙醇沉淀法、壳聚糖澄清剂和ZTC1+1-Ⅱ澄清剂对提取液的纯化效果,并用单因素考察法确定ZTC1+1-Ⅱ澄清剂的最佳纯化工艺。结果 ZTC1+1-Ⅱ澄清剂优于乙醇沉淀法和壳聚糖澄清剂,最佳纯化工艺为澄清剂用量5%B+2.5%A,药液浓度0.2 g/mL,搅拌速度100 r/min。结论 ZTC1+1-Ⅱ澄清剂可用于纯化昆参片水提液。     

猴头菇复合饮品澄清工艺研究

研究猴头菇复合饮品的澄清工艺。以壳聚糖、海藻酸钠、ZTC1+1Ⅱ及水提醇沉不同工艺制备饮品,比较总固体物、总多糖、三萜及腺苷的含量和澄清度,应用正交实验优选出ZTC1+1Ⅱ澄清剂最佳澄清工艺:浓缩液温度在30℃、浓缩液的浓度为1∶8(g/mL)、澄清剂的用量为先加入B8%(W/W),后加A4%(W/W)。结果表明,ZTC1+1Ⅱ澄清剂作为猴头菇复合饮品制备中的澄清剂能有效地保留饮品中的活性成分,且澄清效果稳定,工艺简便易行。     

ZTC1+1Ⅱ天然澄清剂在菊芋多糖提纯中的应用

采用L1(645)正交设计试验,以多糖含量为指标优选菊芋多糖的澄清工艺。确定澄清工艺以选用ZTC1+1Ⅱ天然澄清剂为宜,确定最佳工艺为50℃条件下,于料液比为1∶8的水提浓缩液中加入5%的澄清剂,絮凝时间30 min。优选得到的工艺稳定可行。     

芒果皮渣多糖脱蛋白和脱色工艺研究

探讨芒果皮渣多糖纯化过程中蛋白质和色素的脱除方法。以蛋白质脱除率和多糖保留率为评价指标,比较三氯乙酸法、三氯乙酸-正丁醇法、Sevage法、HCl法、木瓜蛋白酶法、三氯乙酸+Sevage法、木瓜蛋白酶+三氯乙酸法、木瓜蛋白酶+Sevage法和木瓜蛋白酶+三氯乙酸-正丁醇法对芒果皮渣多糖的脱蛋白效果;以脱色率和多糖保留率为评价指标,在单因素实验的基础上,通过正交实验优化活性炭对脱蛋白后多糖溶液的脱色工艺。结果表明:三氯乙酸-正丁醇法脱蛋白效果最佳,其条件为三氯乙酸-正丁醇与样液体积比2:1、三氯乙酸与正丁醇体积比1:20、振荡时间2 h,此时蛋白质脱除率为90.08%,多糖保留率率为94.40%;活性炭脱色最佳工艺条件为:样液pH3.0,活性炭添加量1.5%,脱色温度50℃,脱色时间75 min,此条件下脱色率为70.98%,多糖保留率为92.77%。本实验筛选的方法切实可行,可用于芒果皮渣多糖的脱蛋白和脱色。     

牡丹叶多糖的提取纯化、分级制备及抗氧化性能研究

以牡丹叶为实验对象,建立牡丹叶多糖的提取及分离纯化方法,再采用不同体积分数(25%、45%、65%、85%)乙醇分级沉淀,得牡丹叶多糖PW-25、PW-45、PW-65、PW-85,采用红外光谱分析各组分的光谱学特征,并通过DPPH自由基和羟自由基清除实验对各组分体外抗氧化活性进行研究。结果表明:采用ZTC1+1-Ⅱ型天然澄清剂法脱蛋白和过氧化氢脱色法联用进行牡丹叶粗多糖的分离纯化,在此方法下牡丹叶粗多糖中蛋白脱除率为89.66%,色素脱除率为79.35%,多糖保留率为61.41%,得到PW-25多糖纯度达91.23%,得率为1.29%;4种牡丹叶多糖组分均具有一定体外抗氧化能力,其中PW-25对DPPH自由基和羟自由基具有明显清除能力,且半数抑制浓度(IC50)分别为15.36、65.77μg/m L,但均略差于VC(IC50分别为7.89、46.46μg/m L)。研究结果为牡丹叶多糖开发和应用提供基础。     

五味子多糖脱蛋白工艺的研究

为建立五味子多糖脱蛋白工艺,对三氯乙酸-正丁醇法、Sevag法、酶法+三氯乙酸-正丁醇、酶法+Sevag处理脱除蛋白进行了研究,并测定处理后多糖液中蛋白质含量。结果表明:酶法+三氯乙酸-正丁醇脱蛋白效果最好,即蛋白酶用量为1%、处理温度为50℃、处理时间为140min、pH为5,酶处理后再用等体积的三氯乙酸-正丁醇溶液重复处理4次,蛋白质含量低于0.005mg/mL。     

啤酒花多糖的提取及脱蛋白工艺研究

以超临界液态二氧化碳萃取后的啤酒花残渣为原料,采用正交实验和单因素实验,确定了啤酒花多糖的热水微波辅助萃取的最佳工艺条件:提取时间2h,料液比1∶10,提取温度90℃,微波功率750W作用时间12min;此条件下多糖提取率为2.76%。对得到的粗多糖,以蛋白脱除率和多糖保留率为指标,在比较Sevag法,盐酸-正丁醇法,三氯乙酸-正丁醇法,木瓜/菠萝蛋白酶法对粗多糖中蛋白质的脱除效果的基础上,考察了酶法和化学法联用脱蛋白工艺,并最终确定菠萝蛋白酶-三氯乙酸-正丁醇的脱蛋白效果最好,最佳条件为温度45℃,酶解时间0.5h,酶添加量22.5U/mL,pH5.5,三氯乙酸-正丁醇法除蛋白1次,蛋白脱除率和多糖保留率分别为86.77%和77.37%;而木瓜蛋白酶-盐酸-正丁醇的脱蛋白工艺在有效脱除蛋白质的同时,多糖损失最少,最佳条件为温度55℃,酶解时间0.5h,酶添加量36U/mL,pH5.5,盐酸-正丁醇法除蛋白1次,蛋白脱除率和多糖保留率分别为77.37%和84.43%。     

天然吸附澄清剂在板栗壳棕色素精致中的应用

色泽是构成食品感官质量的一个重要因素,保持或赋予食品良好色泽是食品工业中亟待解决的重要问题.板栗壳棕色素是一种稳定性好,无毒副作用,甚至对人体具一定保健作用的天然色素,故可作优良的食品添加剂.然所含杂质则大大地降低其色价和品质,本文将板栗壳棕色素分别用101果汁澄清剂、ZTC1+1Ⅱ型澄清剂和壳聚糖进行絮凝处理,确定了各自的作用条件,并对其絮凝效果进行比较.101果汁澄清剂法:101果汁澄清剂1/125(v/v),温度室温(约15℃),色价7.27;ZTC1+1Ⅱ型澄清剂法:先B后A,B1/500(v/v),A1/1000(v/v),温度约40℃,色价9.39;壳聚糖法:1/125(v/v),温度约50℃,色价6.67.实验结果表明,三种方法对棕色素色价提高均有较好的效果,但总体上看,ZTC1+1Ⅱ型澄清剂法效果最好,色价高达9.39,故ZTC1+1Ⅱ型澄清剂法明显优于其它两种方法.     

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