响应面法优化新疆红肉苹果多糖的超声辅助提取工艺

以新疆红肉苹果为原料,采用超声辅助法提取新疆红肉苹果中的多糖物质。通过单因素实验,考察了提取温度、提取时间、超声功率、液料比四个因素对新疆红肉苹果多糖得率的影响;在单因素实验的基础上采用响应面法优化了超声辅助提取多糖的工艺条件。实验结果显示,新疆红肉苹果多糖的最佳提取参数为:提取温度65℃、提取时间71 min、超声波功率450 W、液料比为45∶1(m L/g),在该条件下,其多糖的得率最高达到4.53%,与理论预测的4.65%接近;实验获得的回归数学模型能够准确预测红肉苹果多糖的得率。该研究结果可为充分开发利用新疆红肉苹果资源提供实验依据。     

超声辅助吐温80提取发芽小米GABA和多酚的工艺优化

采用超声辅助吐温80优化发芽小米γ-氨基丁酸（gamma-amino butyric acid,GABA）和多酚提取工艺。以GABA和多酚得率为考察指标,通过单因素试验探究吐温80质量分数、超声温度、超声时间、料液比、超声功率对GABA得率的影响,设计正交试验优化GABA提取工艺;通过单因素试验探究吐温80添加量、超声温度、超声时间、料液比4个因素对多酚得率的影响,以响应面试验设计优化多酚提取工艺。结果表明：超声辅助吐温80提取GABA的最佳工艺条件为吐温80质量分数6%、超声温度35℃、超声时间25 min、料液比1∶18（g/mL）、超声功率126 W,此条件下GABA得率为4.70 mg/g;提取多酚的最佳工艺条件为吐温80质量分数9%、超声温度42℃、超声时间19 min、料液比 1∶12.5（g/mL）,此条件下多酚得率为 1.99 mg/g。     

响应面法优化超声波提取核桃青皮多酚的工艺研究

以核桃青皮为原料,利用响应面法优化超声波提取多酚的工艺条件。在单因素试验的基础上,选择对多酚得率影响较为显著的超声功率、超声温度、液料比3个因素为自变量,以多酚得率为响应值,进行Box-behnken试验和响应面分析,得出最佳工艺条件为:超声功率670W,超声温度57℃,液料比21:1(mL:g),超声时间5 s,超声间隙时间5 s,超声全程时间25 min,搅拌速度400 r/min。在此条件下,多酚得率可以高达55.473 mg/g。     

芜菁总多酚的提取工艺优化研究

目的 响应面法优化新疆芜菁中总多酚的提取工艺。方法 采用紫外分光光度法测定芜菁中总多酚的含量, 分别考察了乙醇浓度、料液比、超声时间、以及超声功率对芜菁总多酚得率的影响, 单因素的基础上进行了4因素3水平的设计, 以总多酚的得率为响应值, 分析数据, 优化新疆芜菁中总多酚的提取条件。结果 超声波提取新疆芜菁中总多酚的最佳工艺: 乙醇体积分数40%、固液比1: 30、时间30 min、功率 105 W时, 验证试验得出芜菁多酚的含量13.09 mg/g, 该值与预测值13.62 mg/g接近, 表明响应面法得到的工艺参数准确和可靠。结论 该方法提取时间短, 溶剂用量少, 提取效率高的优点, 可作为芜菁多酚提取工艺的一种有效手段。     

响应面法优化超声辅助提取牡丹籽粕中多酚工艺

采用超声辅助提取牡丹籽粕中多酚,分别考察液料比、乙醇体积分数、超声时间、超声温度、超声功率对多酚提取量的影响,在单因素试验的基础上,通过响应面法优化提取工艺。结果表明,超声辅助提取牡丹籽粕中多酚的最佳工艺条件为:超声功率300 W,液料比20∶1,超声时间98 min,乙醇体积分数80%,超声温度50℃。在最佳工艺条件下,牡丹籽粕中多酚提取量为17.42 mg/g。     

响应曲面法优化微波辅助提取苹果渣多酚工艺研究

为从苹果渣中提取具有生理活性的多酚物质,在单因素试验的基础上,采用响应曲面法优化微波辅助提取苹果多酚的工艺,建立该工艺的二次多项数学模型,研究微波功率、提取时间、乙醇体积分数和料液比4个因素及其交互作用对提取工艺的影响.试验结果表明,对苹果多酚得率的影响次序是:微波功率>料液比>提取时间>乙醇体积分数;微波辅助提取苹果渣多酚的最佳工艺条件是:微波功率650W、提取时间53 s、乙醇体积分数60%、料液比1:20(g/mL),多酚得率迭61.8286 mg/100 g干果渣.     

响应面法优化刺槐花多酚的超声提取工艺

目的：利用响应面法对刺槐花多酚的提取工艺进行优化。方法：在单因素试验的基础上,选择温度、超声功率、超声时间、液料比为自变量,多酚提取得率为响应值,利用响应面分析法,研究各自变量交互作用及其对多酚得率的影响,模拟得到二次多项式回归方程的预测模型。结果：刺槐多酚类化合物的提取工艺为温度35℃、超声功率110W、超声时间36min、液料比20:1(mL/g)。结论：在最佳工艺条件下多酚得率为7.891%。     

荸荠皮酚类物质超声波辅助提取工艺优化

采用超声波辅助提取荸荠皮中的酚类物质,考察溶剂种类、料液比、提取温度、超声功率及超声时间对酚类物质提取率的影响。在单因素试验的基础上,确定最佳提取溶剂,并利用响应面法优化工艺条件。结果表明,荸荠皮总酚的最佳提取工艺条件为:甲醇提取,料液比1:15 (g/mL),提取温度55℃,超声功率270 W,超声时间55 min,该条件下总酚含量的最大响应值为4. 42 mg/g;荸荠皮总黄酮最佳提取工艺条件为:甲醇提取,料液比1:20 (g/mL),提取温度60℃,超声功率240 W,超声时间55 min,该条件下总黄酮含量的最大响应值为15. 20 mg/g。     

响应面法优化超声辅助提取壶瓶枣多酚工艺研究

以壶瓶枣为原料,利用响应面法对提取壶瓶枣多酚的工艺条件进行优化。在单因素试验基础上,选取提取温度、超声功率、液料比为自变量,根据Box-Behnken中心组合设计原理,采用三因素三水平试验设计,以多酚提取率为响应值进行响应面分析。运用Design-Expert 8.0.6软件对试验数据进行多元回归拟合。试验结果表明,壶瓶枣多酚最佳提取工艺条件为:液料比26∶1(mL/g)、超声功率200 W、提取温度68℃。在该工艺条件下,壶瓶枣多酚提取率可达4.35%,与预测值4.33%基本一致,为壶瓶枣资源的深度开发与综合利用提供了理论依据。     

响应面法优化提取羊肚菌多酚及其HPLC鉴定分析

该研究采用响应面法对羊肚菌多酚的提取工艺进行了优化,对溶剂类型、乙醇浓度、料液比、超声时间、超声温度、超声功率等提取条件进行了单因素优化,并对影响较为显著的三个因素进行Box-Behnken设计,得出了最佳工艺参数：乙醇体积分数10%,料液比1:67（g/mL）,超声时间90 min,超声温度33 ℃,超声功率300 W,此工艺条件下提取羊肚菌多酚含量为22.39 mg/g。根据响应面实验数据分析,模型较为显著（P<0.000 1）,失拟项不显著（P>0.05）,拟合程度高（96.2%）,三因素对得率影响顺序为：超声温度>料液比>超声功率。同时对各提取条件下的羊肚菌多酚进行了HPLC检测,共检测出10种酚类物质,且各单因素条件下提取的10种酚类物质的含量曲线也与福林酚比色法测定数据基本一致。     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Detection of adulteration of locust bean gum with guar gum by capillary electrophoresis and polarized light microscopy

Capillary electrophoresis (CE) and polarized light microscopy (PLM) were utilized in the detection of the adulteration of locust bean gum with guar gum. For CE analyses, standards of locust bean and guar gums were extracted with 30% CH₃CN, removing the residual proteins from the gum matrix. A 8.75 mM NaH₂PO₄-20.6 mM Na₂B₄O₇ buffer, pH 9, was used to separate these proteins and to identify marker proteins that were present in the guar gum. These markers did not co-migrate with components in the extracts of mechanically processed locust bean gum, and are used as indicators of adulteration. Using PLM with toluidine blue and iodine staining techniques, unadulterated locust bean gum samples were distinguished from mixed samples through the differential staining of components in locust bean versus guar and tara gums. These experiments in the use of CE and PLM provide orthogonal and complementary methods for the verification of 'true' positives and the elimination of 'false' positives.