藜麦皂苷提取及萌芽对皂苷含量的影响

利用响应面分析法对藜麦籽粒皂苷的提取条件进行探索,并研究萌芽对藜麦皂苷含量的影响。在单因素试验的基础上,选取乙醇提取分数、料液比和浸提温度进行三因素三水平的Box-Behnken试验设计,通过响应面分析法对提取条件进行了优化;同时在优化条件下测定萌芽144 h藜麦中的皂苷含量变化。结果表明,在560 nm波长下,最佳提取条件为乙醇体积分数65%,料液比1∶40,浸提温度60℃,皂苷提取量为5.56 mg/g。萌芽试验结果表明,萌芽初期(6 h内)皂苷含量迅速下降,在6~42 h期间含量保持平稳,42 h后逐渐升高直至96 h时达最高值7.80 mg/g,萌芽120 h后皂苷含量开始下降。     

响应面试验优化藜麦种子多酚提取工艺及其品种差异

利用响应面分析法对藜麦种子多酚的提取工艺进行优化。在单因素试验的基础上,选取乙醇体积分数、料液比、浸提温度进行三因素三水平的Box-Behnken研究,并运用Design-Expect 8.0软件对试验数据进行分析,通过响应面分析法对提取条件进行了优化。结果显示,藜麦种子多酚的最佳提取条件为：料液比1∶40（g/mL）、浸提温度84 ℃、乙醇体积分数56%。在此条件下品种“PI634920”多酚提取量为2.273 mg/g。各因素对多酚提取量的影响程度依次为：乙醇体积分数＞浸提温度＞料液比。同时发现藜麦种子多酚含量存在明显的品种间差异,其中品种“PI596293”的多酚含量最高,达2.72 mg/g。     

响应面法优化藜麦中生物碱的提取工艺

以藜麦为原料,研究藜麦生物碱的最优提取工艺。在单因素试验的基础上,选用液料比、提取温度、乙醇浓度进行三因素三水平的Box-Behnken研究,并运用Design Expert 8.0.6软件对试验数据进行分析,通过响应面分析法对提取条件进行优化。结果表明,液料比20∶1(mL/g),提取温度61℃,乙醇浓度86%,提取时间40min。在此条件下,藜麦生物碱得率为2.89mg/g。     

藜麦叶片多糖最佳提取工艺及抗氧化性研究

研究藜麦叶片多糖的最佳提取工艺条件以及体外抗氧化活性。采用水浴加热回流法,在单因素试验的基础上,选取提取温度、料液比、浸提时间进行三因素三水平的Box-Behnken中心组合研究。运用Design Expect8.0软件分析试验数据,通过响应面分析法优化提取条件,对藜麦叶片多糖类物质的DPPH·清除能力和·OH自由基能力进行分析,结果表明:藜麦叶片多糖的最佳提取工艺:提取温度90.8℃、浸提时间1.0 h、料液比1∶45.6,在此优化条件下,藜麦叶片多糖提取率达6.1013 g/100 g。各因素对多糖提取率的影响程度:提取温度料液比浸提时间。藜麦叶片多糖提取物具有较强的清除DPPH·和·OH自由基能力,其IC50(半抑制浓度)分别为31.96μg/m L和157.62μg/m L。各品种间,藜麦叶片多糖含量存在明显的差异,其中品种"NSL 92331"的多糖含量最高,达6.88 g/100 g。     

苦瓜皂甙的提取工艺优化研究

研究苦瓜皂甙的提取工艺和测定方法.以人参皂甙Rg1标准品为参照,采用分光光度法对苦瓜中皂甙进行定量分析;以料液比、浸提温度、乙醇的质量分数、提取时间为考察因素,采用二次回归正交旋转组合试验方法对苦瓜皂甙提取工艺条件进行优化.通过贡献率法分析表明,各因子对浸提率影响的相对大小依次为:提取时间＞料液比＞乙醇浓度＞浸提温度;经频率分析得到苦瓜皂甙浸提率＞2.18%的优化条件为:料液比10.190～11.016倍,浸提温度68.80～72.33℃,乙醇浓度71.32～74.32%,提取时间13.484～19.396h,且所建立的数学模型在此范围内能够较准确的预测皂甙的浸提率.料液比1:10,浸提温度70℃,乙醇浓度70%,提取时间为12h,这个条件比较贴近实际生产应用,且比较接近理论值.     

藜麦叶片多酚最佳提取工艺及其抗氧化性研究

以藜麦叶为原料,研究藜麦叶片多酚的最佳提取工艺及体外抗氧化活性。在单因素试验的基础上,选取乙醇浓度、料液比、提取时间进行三因素三水平的Box-Behnken中心组合研究,并运用Design Expect8.0软件进行分析,通过响应面分析法对提取条件进行了优化,并对藜麦叶片多酚类物质的DPPH·和·OH清除能力进行分析。结果表明,藜麦叶片多酚的最佳提取条件为:乙醇体积分数83%,物料比1:20,80℃水浴条件下浸提1.12 h;藜麦叶片多酚类物质具有很强的清除DPPH·和·OH清除能力,其IC_(50)分别为1.876μg/mL和6.520μg/mL;同时发现藜麦叶片多酚的含量存在明显的品种间差异,其中品种Temuco的多酚含量最高,达到0.675g/100 g。     

响应面法优化脱脂豆粕大豆皂甙提取工艺的研究

为优化脱脂豆粕大豆皂甙提取工艺,在单因素试验的基础上,选择提取温度、乙醇浓度及浸提时间为自变量,大豆皂甙提取率为响应值,采用中心组合设计、分析研究各自变量及其交互作用对皂甙得率的影响.利用响应面分析法确定大豆皂甙提取工艺:提取温度72℃、乙醇浓度72%vol、回馏时间7.2h、豆粕的粉碎度60目,料液比1∶7(g/mL),在此条件下大豆皂甙的得率为1.99%.     

响应面法优化超声波辅助提取藜麦多酚的工艺条件

以西藏地区种植的藜麦为原材料,探究超声波辅助提取工艺中料液比、提取时间、提取温度、提取功率、乙醇体积分数5个因素对3种藜麦多酚提取量的影响,在获取单因素影响结果的基础上,进行响应面条件优化研究。结果表明:3种藜麦多酚提取的最佳工艺条件均为料液比1∶24(g/mL)、提取时间42 min、提取温度42℃、提取功率205 W、乙醇体积分数为70%,在此条件下3种藜麦多酚提取量分别为(2.653±0.021)mg/g、(2.437±0.017)mg/g、(2.357±0.025)mg/g;3种藜麦多酚提取量模型均达到极显著水平(P 0.000 1),失拟项不具有显著性(P0.05),决定系数R2分别为0.948 3(白)、0.970 7(红)、0.962 0(黑),模型与实验值拟合度良好。     

响应面法优选大蒜中黄酮提取工艺研究

目的:利用响应面分析法优化大蒜中黄酮提取工艺条件.方法:以黄酮得率为指标,应用Design-Expert对影响黄酮提取效果的提取时间、料液比、乙醇体积分数、提取温度4个因素进行中心组合设计试验,并建立教学模型,研究这些因素对黄酮提取率的影响.结果:各因素对黄酮提取率的影响大小依次为提取温度＞乙醇体积分数＞提取时间＞料液比,最佳的提取工艺条件为提取时间3.98 h,料液比1 ∶ 40.19,乙醇体积分数68.63％,提取温度96.66℃,该条件下大蒜总黄酮的提取率为1.134mg/g.紫外分光光度法测得实际提取率为1.122mg/g,荧光法测得实际提取率为1.127mg/g.结论:响应面分析法优选黄酮提取工艺条件是合理、可行的.     

响应面法优化提取香菜根中总黄酮的工艺研究

目的:采用响应面法优化香菜根中总黄酮的提取条件。方法:采用乙醇热浸提法,在提取时间、提取温度、液料比和乙醇体积分数这些单因素试验基础上,选取试验因素和水平,运用Design-Expert V8.0.6软件采用三因素三水平进行响应面分析,将香菜根中总黄酮的含量作为响应值。结果:通过实验得到乙醇热浸提香菜根中总黄酮的最优工艺是提取温度71℃、液料比31∶1(mL/g)、乙醇体积分数71%。结论:该条件下总黄酮的提取量为0.1691mg/g。     

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.