超声辅助提取松仁蛋白工艺的响应面法优化

以脱脂红松松仁粉为原料,采用超声辅助技术提取松仁蛋白,研究超声时间、提取温度、溶液pH和料液比四因素对蛋白提取率的影响,进行响应面试验设计分析。以蛋白得率为指标,通过响应面法对提取工艺条件进行优化,最终确定超声波法提取松仁蛋白质的最优条件为：超声时间100min、提取温度48．38℃、溶液pH10．0和料液比1：24．61（g／mL）,在此条件下提取松仁蛋白的得率为233．23mg/g。     

超声波辅助碱提香菇柄中水溶性蛋白的工艺

以蛋白质得率为指标,研究液料比、pH、超声功率、超声温度及超声时间对蛋白质得率的影响,在单因素基础上,选取液料比、超声温度及超声时间为自变量,利用响应曲面法对超声波辅助碱提香菇柄中水溶性蛋白的提取工艺进行优化。结果表明,超声辅助碱提香菇柄中水溶性蛋白的最佳提取工艺条件为:液料比值16.8 mL/g,超声温度45.3℃,超声时间46.4 min。在此条件下,蛋白质得率达到2.87%。     

响应面法优化青豆蛋白提取工艺

响应面法优化青豆蛋白提取工艺,并研究最佳工艺条件下所得的青豆蛋白的纯度。以青豆为原料,采用超声波辅助法提取青豆蛋白,通过单因素试验研究料液比、超声波处理时间、超声波功率对青豆蛋白得率和蛋白质纯度的影响。在单因素试验的基础上,利用响应面分析法优化超声波辅助提取青豆蛋白的最佳工艺,并确定最佳工艺条件下青豆蛋白的得率及纯度。超声波辅助法提取青豆蛋白的最佳工艺为:料液比1∶20(g/mL)、超声功率为470 W、超声时间为27 min。在优化的最佳工艺条件下,所得的青豆蛋白得率为(41.90±0.43)%,纯度为73.56%,相比较传统碱溶酸沉法提取的青豆蛋白,虽然纯度有所降低,但得率提高了12.22%。     

响应面法优化黑木耳蛋白质的提取工艺

以黑木耳为原料,采用酶法进行前处理后用超声波辅助碱法提取黑木耳蛋白质,获得黑木耳蛋白质的最优提取工艺条件。以蛋白质得率为评价指标,进行单因素试验,并采用Box-Behnken响应面法优化黑木耳蛋白提取工艺。结果表明,纤维素酶和木聚糖酶混合酶解最佳前处理条件为:酶解温度50℃、酶解pH 4、酶解时间2 h、酶添加量(加酶量/木耳干质量)0.8%。黑木耳蛋白最佳提取条件为料液比1︰91(g/mL)、超声温度49℃、超声时间40min。最佳提取条件下黑木耳蛋白得率为4.84%。试验表明经酶法前处理后采用超声波辅助碱法能显著提高黑木耳蛋白质提取效率。     

超声波辅助醇提鹿茸蛋白的工艺优化

以吉林双阳梅花鹿茸为原料,采用超声波辅助乙醇法提取其中的鹿茸蛋白,以鹿茸蛋白得率为评价指标,考察液料比值、乙醇体积分数、超声时间和提取温度对鹿茸蛋白得率的影响,在单因素试验基础上,利用响应面法优化超声波辅助醇提鹿茸蛋白的工艺。结果表明:超声波辅助醇提鹿茸蛋白的最佳工艺条件为:液料比值16 m L/g,乙醇体积分数30%,超声时间30 min,提取温度9℃。在此条件下,鹿茸蛋白的得率为5.25%。     

响应面优化超声波辅助水酶法提取茶叶籽油工艺

利用响应面法(RSM)优化超声波辅助水酶法提取茶叶籽油工艺条件,在单因素试验基础上,选取复合酶用量、酶解pH、酶解温度、酶解时间为影响因子,茶叶籽油得率为响应值,应用Box-behnken中心组合试验设计建立数学模型,进行响应面分析。结果表明,超声波辅助水酶法提取茶叶籽油工艺优化条件为:高压蒸煮20min,超声处理20min,超声温度60℃,料液比1:5、复合酶用量1.75%,酶解pH4.6,酶解温度44℃,酶解时间6.9h。茶叶籽油得率为29.88%。     

核桃粕中蛋白提取工艺的优化

以冷榨核桃粕为原料,研究核桃粕中蛋白提取工艺及优化。采用超声波辅助提取核桃粕中蛋白,在单因素试验的基础上,进行正交试验及Box-Behnken试验设计,通过比较、分析确定核桃粕蛋白最佳提取工艺及其优化方法。结果表明,响应面法较正交试验更好的对核桃粕中蛋白提取工艺进行了优化,各因素对蛋白提取率的影响次序为碱溶pH值＞液料比＞超声温度＞超声时间,超声功率150 W时,核桃粕蛋白最佳提取工艺为超声时间60 min、超声温度48 ℃、液料比25∶1（mL/g）、碱溶pH 8.7,pH 5.0时进行沉淀,此条件下核桃粕蛋白质的提取率达69.62%。     

响应面法优化沙棘籽渣水溶性蛋白质提取工艺研究及其氨基酸组成分析

目的利用响应面法优化沙棘籽渣水溶性蛋白质的提取工艺条件,测定沙棘籽渣水溶性蛋白质的氨基酸组成。方法在单因素试验的基础上,以水溶性蛋白质提取率为试验指标,用响应面法研究液料比、提取温度、pH、提取时间及其交互作用对沙棘籽渣水溶性蛋白质提取率的影响。对所得蛋白质进行氨基酸组成分析。结果响应面法优化沙棘籽渣水溶性蛋白质最佳提取工艺条件为:提取时间88 min、提取温度60℃、pH 11、液料比15:1 mL/g。各因素对蛋白质提取作用的大小依次为:提取时间提取温度pH液料比。利用响应面法得到的二次多项式回归方程数学模型,沙棘籽渣水溶性蛋白提取率Y=38.29+0.44A-0.33B+3.49C+0.63D-0.56A~2-0.97B~2+1.09C~2-0.39D~2+0.0025AB-0.0025AC+8.414×10~(-3)AD+8.414×10~(-3)BC+8.414×10~(-3)BD-0.01CD,能较准确地预测试验结果。所得沙棘籽渣水溶性蛋白质由17种氨基酸组成。结论本研究结果可为沙棘籽渣水溶性蛋白质的提取和应用提供理论依据。     

超声辅助法提取黑豆中植酸工艺的研究

响应面法优化黑豆中植酸的超声波提取工艺。以10%硫酸钠-盐酸作为浸提液,植酸得率作为指标进行单因素试验,在此基础上,选择pH、料液比、温度、超声功率进行响应面试验设计。结果显示最佳提取条件为：提取液pH 2,料液比1:14 g/mL,温度60 ℃,超声功率240 W,时间20 min,植酸得率为12.39 mg/g。相对于振荡提取法,植酸得率提升13.56%,减少了溶剂的使用量,缩短了提取时间。所建立的超声波提取方法能够充分提取黑豆中的植酸,可为黑豆植酸的其他研究提供技术支持。     

响应面法优化超声波辅助提取辣木叶多糖工艺

以辣木叶为原料,采用响应面法优化超声波辅助提取辣木叶多糖工艺。在单因素试验的基础上,以料液比、提取时间、提取温度、超声功率为影响因素,辣木叶多糖得率为指标进行响应面优化试验,确定最佳提取工艺。结果表明,辣木叶多糖最佳提取工艺条件为:料液比1∶25(g/mL),提取时间43 min,提取温度83℃和超声功率105 W,在此条件下,辣木叶多糖得率预测值为7.39%,实际得率为7.36%。超声波辅助提取技术的应用能够显著缩短辣木叶多糖的提取时间,并提高其得率。     

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.