黑胡萝卜色素酸水提取工艺条件的研究

以黑胡萝卜为原料,采用酸水提取的方法,通过单因素及正交实验研究诸多因素对黑胡萝卜色素提取效率的影响.结果表明,各因素对黑胡萝卜色素提取效果的影响程度依次为浸提液酸度＞浸提温度＞料液配比＞浸提时间.确定了酸水提取黑胡萝卜色素的最佳工艺条件为浸提液酸度pH=1、浸提温度70℃、料液比1 ∶ 6、浸泡时间1.5h、浸提级数1.     

黑胡萝卜色素酸水提取工艺条件的研究

以黑胡萝卜为原料,采用酸水提取的方法,通过单因素及正交实验研究诸多因素对黑胡萝卜色素提取效率的影响.结果表明,各因素对黑胡萝卜色素提取效果的影响程度依次为浸提液酸度＞浸提温度＞料液配比＞浸提时间.确定了酸水提取黑胡萝卜色素的最佳工艺条件为浸提液酸度pH=1、浸提温度70℃、料液比1∶6、浸泡时间1.5h、浸提级数1.     

紫山药色素提取工艺研究

加工过程中削落的紫山药皮富含紫色素,是提取天然色素的理想原料。以紫山药皮为原料,采用单因素和正交实验法,研究了提取剂浓度、浸提温度、浸提时间、料液比对紫山药色素提取效果的影响。用AB-8大孔吸附树脂对紫山药色素粗品进行吸附纯化得到紫山药色素纯品。结果表明:通过对比不同溶剂提取效果,确定乙醇为提取剂。色素提取过程中,浸提温度和料液比对提取效果的影响最大,其次是提取剂浓度,最小是浸提时间。最佳提取条件为:40%乙醇作浸提剂,温度70℃,浸提时间2h,料液比1∶10。提取液经吸附纯化后,干燥制得紫黑色粉末,色价为51.2。研究表明,紫山药皮可以作为提取紫山药色素的来源。     

超级黑糯玉米芯色素提取工艺的研究

采用浸提法提取超级黑糯玉米芯中的色素,考察不同溶剂、乙醇体积分数、浸提温度、浸提时间和液料比等因素对浸提效果的影响。通过单因素试验和正交试验,确定超级黑糯玉米芯色素的最佳提取工艺条件为:以95%乙醇与0.1mol/LHCl混合提取剂,料液比1:20(m:v),在50℃下浸提60min,在此条件下色素提取率达93.18%,产率达15.62%。     

红心萝卜色素提取工艺的研究

研究并优化了红心萝卜色素的提取条件.结果表明影响红心萝卜色素提取的因素依次是液固比、酸度、浸提时间、浸提温度.液固比5:1,浸提时间2 h,浸提温度50℃,浸提剂酸度为pH 2是提取红心萝卜色素的最佳条件.     

紫薯花色苷提取工艺研究

本文研究了紫薯色素的最佳提取方法以及紫薯色素的稳定性。通过单因素试验对紫薯色素最大吸收波长、最佳提取溶剂、料液比、pH、浸提时间、浸提温度进行探讨,通过料液比、pH、温度三因素三水平试验获取最优提取条件,并对紫薯色素的稳定性做了研究。结果表明,紫甘薯色素的最佳提取条件为:最大吸收波长531nm、最佳提取剂为5%柠檬酸、料液比为1∶100、pH为2、浸提温度60℃、浸提时间1h。色素的颜色和稳定性易受pH值的影响,酸性是较稳定;色素含量易受温度影响,温度升高易使色素降解。正交实验表明:pH为1,料液比1∶50,温度70℃提取效果最好。以上研究结果为紫薯色素的工业化提取及规模化应用奠定了基础。     

紫甘薯色素水提工艺参数的研究

采用水溶液提取紫甘薯色素.选择pH值、料液比、浸提时间和浸提温度作为单因素进行梯度试验,确定其条件范围,通过正交试验确定紫甘薯色素提取的最佳工艺条件:pH值3(HCl)、料液比1∶2(g/mL)、浸提时间2h、温度25℃,共提取3次,紫甘薯色素提取率可达94.85％.     

黑糯玉米(Zea mays L.ceretina kulesh)穂芯中黑色素的提取工艺研究

鲜食的黑糯玉米的下脚料穂芯,其黑色素含量丰富,原料丰富易得,以黑色素含量作为指标,利用紫外分光光度法,通过单因素试验和正交试验对黑糯玉米芯中色素的提取工艺进行优化筛选。结果表明,该色素为水溶性色素,特征吸收峰大约在511nm处,易溶于稀酸介质中并呈紫黑色;影响提取黑糯玉米芯色素的主次因素为:浸提固液比>浸提温度>浸提时间;优选最佳提取工艺为:粒径120目,浸提液为0.5mol/L盐酸,固液比为1∶20,浸提时间为4h,浸提温度为80℃。在此最佳条件下,黑糯玉米芯色素提取率可达70.2%,二次平行试验证明最佳工艺黑色素含量和浸出率基本稳定,工艺可行。     

黑花生衣色素的提取工艺条件研究

以黑花生皮为原料,采用酸水浸提的方法,对黑花生皮的提取工艺条件进行研究.通过单因素及响应面试验研究诸多因素对黑花生皮色素提取效率的影响,确定黑花生皮色素提取最佳工艺条件为浸提液酸度pH1、浸提温度80℃、料液比1:50、浸泡时间2 h、提取级数2.     

醇溶法提取黑米色素的工艺研究

以黑米为原料,利用乙醇为浸提剂,研究了黑米色素的提取工艺,分别考察了料液比、浸提p H、浸提温度和浸提时间各单因素水平对提取效果的影响,并通过正交试验确定了醇溶法提取黑米色素最佳的工艺条件。结果表明,影响黑米色素提取的因素主次顺序为:浸提时间料液比浸提温度浸提p H。最佳提取工艺参数为:用体积分数95%的乙醇浸提,料液比1∶45(g∶m L),浸提p H3.0,浸提温度80℃,浸提时间90 min。     

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.