亚临界水提取豆渣中可溶性大豆多糖工艺研究

考察了亚临界水提取豆渣中可溶性大豆多糖的最佳工艺条件。结果表明最佳提取条件为:亚临界水温度150℃,液料比35∶1,提取时间11 min,该条件下可溶性大豆多糖得率达22.8%。与传统提取方法相比,亚临界水提取法可明显缩短提取时间,并提高可溶性大豆多糖得率。     

响应面法优化北五味子水溶性糖蛋白提取工艺

为探讨碱提酸沉法提取北五味子水溶性糖蛋白的最优条件,采用响应面分析法,在单因素试验的基础上,选择料液比、浸提时间、浸提温度和碱提液p H值为影响因素,以蛋白得率和糖得率为响应值,采用中心组合Box-Benhnken法建立数学模型,进行响应面分析。结果表明,碱提酸沉法提取北五味子水溶性糖蛋白的最佳工艺条件为:料液比1∶35(g/m L),碱提液p H 9.5,浸提温度35℃,浸提时间3 h,该条件下蛋白质得率为7.72%,糖得率为19.24%。     

亚临界水提取大豆胚芽中异黄酮及低聚糖的研究

以大豆胚芽为原料、高压反应釜为反应容器,应用亚临界水为溶剂、采用高纯氮气加压提取大豆胚芽中异黄酮及大豆低聚糖。利用紫外分光光度法测定大豆异黄酮的含量。选取液料比、提取时间、提取温度、压力4个因素进行单因素试验,再进行正交试验优化亚临界水提取大豆异黄酮的条件。结果表明:在液料比25:1,浸提温度120℃,浸提时间40 min,浸提压力1.9 MPa的条件下,大豆异黄酮的得率是1.09%,大豆异黄酮粗提物的产率为6.52%,粗提物纯度是2.60%;大豆低聚糖粗提物产率是35.2%。     

小麦胚芽多糖的亚临界水萃取的工艺研究

以小麦胚芽为原料,研究亚临界水萃取小麦胚芽多糖的工艺流程及条件,探讨水料比、pH、萃取时间和萃取温度对小麦胚芽多糖提取得率的影响。结果表明,通过单因素试验和响应面试验优化得到的最佳提取条件为:pH 6,水料比20︰1(mL/g),提取温度150℃,浸提时间10 min。在这个条件下小麦胚芽多糖的提取得率为7.26%。而传统热水浸提法多糖得率为3.29%,与传统热水浸提法相比,亚临界水浸提法具有明显的优势。红外光谱分析表明亚临界水萃取对小麦胚芽多糖的结构无影响,亚临界水萃取可用于小麦胚芽多糖的提取。     

超声波预处理协同黑曲霉水解玉米芯糖化工艺

以玉米芯为原料,采用超声波预处理和黑曲霉协同水解玉米芯制备还原糖。探讨了经过超声波预处理后原料的粒度、酶液用量、水解温度和水解时间对还原糖得率的影响,并采用响应面法建立二次回归模型对水解工艺进行了优化,在反应温度为56℃、反应时间为22.4 h、酶液用量为26 U/g时,还原糖的得率可达到36.58%,比在相同工艺条件下未经超声波处理的得率提高了13.41%。     

豆渣中可溶性多糖的不同提取方法比较和工艺优化

该研究分别利用超声辅助提取法和复合酶解提取法对豆渣中可溶性多糖进行提取,以多糖得率为考察指标,对提取工艺进行了优化。超声辅助提取法利用超声辅助热水浸提多糖,其最佳工艺条件为超声功率140 W、浸提温度70℃、浸提时间3 h、料液比1∶20,此条件下多糖得率为6.13%。复合酶解提取法利用纤维素酶与酸性蛋白酶进行酶解提取多糖,其最佳工艺条件为酶添加量2.5%、浸提温度60℃、浸提时间1 h、料液比1∶30,此条件下多糖得率为7.72%。通过化学组成分析,两种方法提取的多糖的单糖组成基本相似,主要由甘露糖、葡萄糖和半乳糖组成,但复合酶解提取法所得多糖的总糖含量和糖醛酸含量均高于超声辅助提取法。由红外光谱分析可知,两种提取方法均未对豆渣中可溶性多糖的特征官能团产生破坏。综合比较分析,复合酶解提取法提取时间短,提取温度低,多糖得率较高,是提取豆渣可溶性多糖的最佳方法。     

苦金甘陈凉茶总黄酮热水煎煮工艺优化

探讨提高苦瓜、金银花、甘草和陈皮复合凉茶中总黄酮得率的最佳工艺条件。考察了浸提温度、浸提时间、料液比和β-CD环糊精添加量等因素对苦金甘陈凉茶饮品中总黄酮得率的影响,通过响应面优化提高总黄酮得率的浸提条件。结果表明,浸提时间、温度和料液比显著影响总黄酮得率。建立了提高苦金甘陈饮品中总黄酮得率的浸提最佳工艺:浸提温度为85℃,浸提时间112 min,料液比为1︰43 g/mL,在此条件下总黄酮得率为4.75%。     

微波与纤维素酶协同水解杨木制备还原糖的研究

以速生杨木为原料,采用微波辐射和纤维素酶协同水解制备还原糖.探讨了经过微波辐射处理后原料的粒度、酶液用量、水解温度和水解时间对还原性糖得率的影响,并采用响应面法建立二次回归模型对水解工艺进行了优化,在反应温度为50.5℃、反应时间为20.7h、酶液用量为27U/g时,还原糖的得率可达到32.40%.比在相同工艺条件下未经微波处理的得率提高了11.87%.     

亚临界萃取椒样薄荷精油的工艺

利用亚临界技术萃取椒样薄荷精油,通过正交试验优化液料比、萃取压力、萃取温度、萃取时间四因素对椒样薄荷精油得率的影响,结果表明,亚临界萃取椒样薄荷精油的最佳工艺条件为:液料比1.5∶1(m L/g)、萃取压力0.4 MPa、萃取温度45℃、萃取时间60 min,椒样薄荷精油得率为3.108%。     

石榴叶中提取茶多酚工艺研究

以石榴叶为原料,采用乙醇浸提工艺,并结合过滤、浓缩、沉淀、萃取、干燥等技术,制成茶多酚成品.着重研究了浸提工艺对茶多酚得率的影响,对浸提工艺中的料液比、浸提时间、浸提温度3个因素进行正交实验,并对茶多酚得率进行分析,为高得率、高品质荼多酚提取工艺提供参考数据,同时也为大规模生产奠定一定的基础.经研究确定最佳浸提工艺条件为料液比1:10、浸提时间50min、浸提温度80℃,在此浸提条件下浸提茶多酚得率可达27.28%.     

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.