Hartley方法优化菠萝皮渣多酚化合物提取工艺

在单因素试验基础上,采用SAS9.2中的响应曲面分析-Hartley方法对菠萝皮渣中的多酚类化合物提取工艺进行优化,建立提取温度、提取时间、乙醇体积分数和液料比4个因素与总多酚得率(Y)之间的编码水平回归模型,并得出各因素对菠萝皮渣总多酚得率的影响顺序为提取温度>提取时间>液料比>乙醇体积分数。在提取温度48.4℃、提取时间73.6min、乙醇体积分数41.6%、液料比46.8:1(mL/g)的条件下,菠萝皮渣总多酚得率最高,可达7.77mg/g,与理论值7.80mg/g基本吻合。响应面法所得的优化提取条件工艺参数可靠,可用于菠萝皮渣中多酚产品的开发。     

石榴籽中多酚的醇提取工艺优化

运用正交试验对石榴籽多酚的乙醇提取条件进行了优化。研究了提取温度、提取时间、乙醇体积分数和料液比四因素对石榴籽多酚提取效果的影响。结果表明石榴籽多酚的最佳提取条件:提取温度60℃,提取时间120min,乙醇浓度60%,料液比1∶20。在最佳提取条件下的石榴籽多酚得率为2.431mg/g干物质。     

薄荷多酚的提取及其在卷烟嘴棒中的应用研究

为了更好的开发利用薄荷,研究使用超声波辅助萃取技术从薄荷中提取薄荷多酚,通过单因素试验考察乙醇体积分数、超声温度、超声时间、超声功率、固液比对薄荷多酚得率的影响,并结合响应面分析法对提取工艺进行了优化,然后将制备的薄荷多酚施加于卷烟滤棒中,研究其对卷烟感官品质的影响。研究结果表明超声波辅助乙醇提取薄荷多酚的最佳工艺参数为:乙醇体积分数60%,超声温度74.14℃、超声时间28.05 min、超声功率165.57W、固液比1∶36.35(g/m L),此工艺条件下理论得率为1.24%,实际得率为1.29%;薄荷多酚添加于卷烟滤棒中具有提高生津感、缓解刺激、掩盖杂气的功效。     

石榴皮总多酚的微波辅助提取工艺及抗氧化活性研究

利用响应面分析法优化石榴皮总多酚的微波辅助提取工艺,以总多酚得率为指标,通过单因素试验及响应面分析,研究了乙醇体积分数、提取时间、提取功率和液固比4个主要因素对石榴皮总多酚得率的影响。采用BoxBenhnken中心组合设计和响应面分析法,建立了回归方程的预测模型,确定最佳提取条件为乙醇体积分数58%、提取时间98 s、提取功率235 W、液固比49∶1(m L/g)。此条件下总多酚得率为(23.26±0.15)%。试验结果与模型预测值基本相符。用红外光谱对总多酚提取物进行了表征。石榴皮总多酚对DPPH自由基的半清除质量浓度为0.28 mg/m L,具有较强的抗氧化作用。     

响应面法优化燕麦多酚提取工艺

以燕麦为实验材料,在单因素的基础上,以乙醇体积分数、温度、料液比、提取时间等因素为自变量,多酚得率为响应值,通过Box-Behnken实验设计的方法,研究各自变量及其交互作用对多酚得率的影响,采用响应面分析法,模拟得到二次多项式回归方程的预测模型,确定燕麦总多酚的最佳提取工艺参数为:乙醇体积分数60%,温度39℃,液料比14∶1,提取时间59min。验证实验结果显示,此条件下燕麦粗多酚提取得率为4.59%。     

白背三七类黄酮提取工艺条件的优化

采用乙醇提取法研究白背三七类黄酮化合物的提取工艺条件。通过单因素试验和正交试验,考察了乙醇体积分数、料液比、提取温度、提取时间等四个因素对类黄酮得率的影响;优化了白背三七类黄酮的提取工艺条件。结果表明,各因素对类黄酮得率的影响大小依次为乙醇体积分数＞提取温度＞料液比＞提取时间,白背三七类黄酮提取的最优工艺条件为：乙醇体积分数85%,料液比1∶25（g∶mL）,提取时间120 min,提取温度60 ℃。在此最佳提取工艺条件下,类黄酮平均得率为3.81%。     

石榴皮中多酚的醇提取工艺优化

为确定最优的提取条件,以提高石榴多酚的得率,采用四因素二次回归正交旋转组合设计试验,研究了提取温度、提取时间、料液比和乙醇体积分数对石榴多酚得率的影响,建立了各因子与石榴多酚得率关系的数学回归模型;最后确定了最佳的提取条件为:提取温度为70℃,液料比25:1,提取时间1.5h,乙醇体积分数50%,石榴皮多酚得率为16.28%。     

湿法粉碎辅助溶剂提取葡萄皮渣中多酚的研究

通过正交试验,优化分析确定湿法粉碎辅助溶剂提取葡多酚的最佳工艺条件。通过单因素试验研究了粉碎时间、固液比、乙醇体积分数、提取温度和时间对葡多酚产量的影响,利用正交试验优化得出各因素的最佳条件:粉碎时间30 s、料液比1∶20(m/v)、乙醇体积分数60%、提取温度60℃、提取时间1.5 h,在该条件下葡多酚产量可达到64.26 mg GAE/g,IC_(50)(DPPH)值为59.08 mg/L。     

超声波辅助提取苹果皮中总黄酮工艺条件的优化

采用超声波辅助法对苹果皮中的总黄酮进行提取和条件优化。在单因素实验的基础上,用响应面研究了乙醇体积分数、液固比、提取时间对黄酮得率的影响。并由此确定了超声波辅助提取苹果皮中总黄酮最佳提取工艺条件:乙醇体积分数50.3%、液固比28.9∶1、时间49.1min,黄酮得率为19.32mg/g。     

柿果多酚提取工艺优化

采用单因素试验设计,研究乙醇体积分数、料液比、提取时间和提取温度4个因素对柿果总酚及缩合多酚超声提取效果的影响,并采用正交试验设计对提取工艺进行优化。结果表明影响因素对提取效率影响顺序为：乙醇体积分数＞料液比＞提取时间＞提取温度。最佳提取条件为：乙醇体积分数90%、料液比1:40(g/mL)、时间30min、提取温度40℃,在此条件下进行验证实验,总酚提取率为2.061%。     

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