苹果渣果胶超声波辅助提取工艺优化与抗氧化性研究

目的 优化苹果渣中果胶超声波辅助提取工艺,并考查所提取果胶的抗氧化性.方法 在单因素实验的基础上,选取了料液比、pH、提取温度、超声波功率为因变量,以苹果渣中果胶得率为响应值,应用响应面设计方法建立数学模型并进行分析.结果 料液比、pH、提取温度、超声波功率对苹果渣中果胶得率的影响依次为:料液比＞pH＞提取温度＞超声波...     

响应面分析法优化超声波辅助提取柚皮果胶工艺的研究

在超声条件下,研究无机酸种类、p H、超声时间、液料比、提取温度、超声功率等因素对柚皮果胶提取率的影响,通过响应面设计确定最优的超声波辅助提取柚皮果胶工艺参数。结果表明:在选用盐酸作为水解酸时,最佳工艺参数为p H为2.5,液料比为1∶40(g/m L),超声波处理时间为55 min,提取温度为60℃,超声功率为320 W,实测柚皮果胶得率为24.02%。     

马铃薯渣中提取果胶的工艺优化及产品成分分析

为优化超声辅助提取马铃薯渣中果胶的工艺参数,在单因素试验基础上,采用五因素(1/2实施)二次回归正交旋转组合设计对影响果胶得率的5个主要因素(超声功率、提取温度、提取时间、pH值和料液比)进行优化。建立各因素与果胶得率关系的数学模型,并进行响应面分析。结果表明,超声波提取马铃薯渣中果胶的优化工艺为超声功率300W、提取温度80℃、提取时间47.6min、pH1.8、料液比1:21(g/mL),在此条件下,马铃薯渣果胶得率达到15.76%。测定最优工艺条件下提取的果胶产品的主要成分,各项指标均达到国标和行业标准的要求。     

超声波辅助提取柚皮中的果胶

我国柚子资源丰富,除果肉供食用外,柚皮常作为废弃物丢弃。柚皮中含有黄酮、果胶、香精油、膳食纤维素等多种活性成分。本文以柚皮为原料,在超声波辅助下,采用酸提醇沉法从柚皮中提取果胶。以果胶得率为指标,分别考察了超声波处理时间、超声波功率、液料比及提取温度等因素对果胶得率的影响。在单因素试验的基础上,进行正交实验设计,对柚皮果胶提取工艺进行优化。结果表明,超声波辅助提取柚皮果胶的最佳工艺条件为:超声波功率400W,超声波处理时间20min,料液比1∶25,提取温度85℃。该条件下,柚皮果胶平均得率为20.9%,比传统的酸提取法提高了43.1%。利用超声波辅助提取柚皮果胶,时间短、得率高,具有很好的实际应用价值,可为柚子资源的综合开发利用提供参考。     

响应面法优化超声波辅助提取南瓜皮中果胶的工艺

以南瓜皮为原料,采用响应面法优化超声波辅助提取南瓜皮中的果胶,通过单因素试验,分别讨论了超声功率、超声时间、pH及料液比对南瓜皮中果胶提取率的影响,对影响南瓜皮中果胶提取量的超声功率、超声时间和料液比3个主要因素进行中心组合试验优化.结果表明,响应面法优化超声波辅助提取南瓜皮中果胶的最佳提取工艺条件为:超声功率225W...     

山楂皮渣中总黄酮的超声波辅助提取工艺研究

为充分利用山楂资源,以山楂酒生产剩余的皮渣为试验材料,乙醇溶液为提取溶剂,采用正交试验优化山楂皮渣中总黄酮的超声波辅助提取工艺条件。结果表明,山楂皮渣中含有大量的黄酮类化合物,应用超声波辅助提取技术可实现其中总黄酮的快速提取。在100 W 超声功率下山楂皮渣中总黄酮的最佳提取工艺条件为：乙醇体积分数为60%、料液比1/10、提取时间30 m in、提取温度80℃、提取次数4次,山楂皮渣中总黄酮的提取得率可达到4.41%。     

菠萝蜜果皮中果胶的提取工艺优化

通过单因素和正交试验研究水提温度、pH值、提取时间、料液比4个理化因素对菠萝蜜果皮中果胶得率的影响,确定菠萝蜜皮果胶提取的最佳工艺参数。结果表明,酸提取最佳工艺为提取温度95℃、pH1.0、提取时间2.5h、液料比30:1(水:物料,m/m),果胶得率为12.46%;超声波辅助提取最佳工艺为80℃、50min、液料比40:1、pH1.0、450W,果胶得率为13.17%。超声波辅助提取可提高果皮中果胶得率和缩短时间。     

响应面优化提取血柚皮果胶的工艺研究

采用响应面法优化了血柚皮果胶的提取工艺,在单因素实验基础上,选取柠檬酸浓度、提取温度、液料比和提取时间为自变量,果胶得率为响应值,根据Box-Behnken实验设计方法,对提取血柚皮果胶的关键因素参数进行了优化,建立了血柚皮果胶得率的数学模型。结果表明:四个因素对血柚皮果胶得率的影响大小依次为提取温度>柠檬酸浓度>液料比>提取时间;血柚皮果胶提取的最佳工艺参数为:柠檬酸浓度1.5%,提取温度82℃、液料比32∶1m L/g、提取时间99min。在此条件下,血柚皮果胶得率达18.85%,与预测值仅相差0.32%,验证了数学模型的有效性。      

响应面法优化提取甜橙皮渣中果胶的研究

通过单因素试验研究料液比、提取温度、提取时间和pH 值4 因素对甜橙皮渣中果胶得率的影响。在单因素试验的基础上,采用三因素三水平的Box-Behnken Design(BBD)中心试验设计研究响应值以及最佳变量的组合。结果表明：随着pH 值的降低和温度的增加果胶得率增加;处理时间和料液比对果胶得率也有积极的影响。通过响应面法综合评价提取甜橙皮渣中果胶的最佳提取条件为温度90℃、时间1.3h、pH1.1,在此条件下的果胶得率预测值为0.998%。     

微波辅助提取柑橘鲜皮渣中果胶的工艺优化

应用微波辅助提取柑橘鲜皮渣中的果胶,探讨微波功率、料液比、微波时间和pH值4因素对柑橘鲜皮渣中果胶得率的影响。并利用响应面法对微波辅助提取果胶的工艺条件进行优化。回归方差分析结果表明：模型中一次项X1(pH值)、X2(微波时间)、X3(微波功率)对果胶得率的影响均达到显著水平;交互项X1X3的影响显著,但X1X2、X2X3不显著;二次项X12、X32均表现为极显著。表明各因素对果胶得率的影响不是简单的线性关系。考虑到实验的可行性以及效率等综合因素,确定微波辅助提取柑橘鲜皮渣中果胶的最佳工艺条件为微波功率626W、微波时间5.6min、pH1.5、料液比1:30(g/mL),模型预测果胶得率为7.1%,在此微波条件下进行3次重复实验,果胶的平均得率为7.05%。     

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.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the