微波辅助碱法提取花生粕蛋白质工艺条件的优化

采用微波辅助碱提酸沉法从花生粕中提取花生分离蛋白.相比于碱提法,采用微波辅助法可以将花生粕蛋白质的提取率提高18.00％,效果显著.在单因素实验基础上,以料液比、碱提pH、微波提取功率、微波提取时间为考察因素,采用正交实验优化最佳提取工艺.四因素对花生粕蛋白质提取率影响顺序为:微波提取功率＞碱提pH＞微波提取时间＞料液比,最佳工艺条件为:料液比为1∶10(g/mL),提取pH10,微波输出功率为480W,微波提取时间4min.在此条件下,花生粕蛋白质最高提取率可达85.43％.     

油茶籽粕中茶皂素和蛋白质同时提取工艺研究

介绍了以油茶籽粕为原料,分别采用传统的水浸法和碱溶酸沉法同时提取皂素和蛋白质的工艺研究结果。结果表明,所采用的工艺简单可行;水浸法提取茶皂素的最佳工艺条件为液料比11:1,pH11,提取时间8h,提取温度80℃,提取率最高可达36.38%;碱溶酸沉法提取提取油茶籽粕蛋白的最佳工艺条件为料液比1:25,pH10,浸提时间130min,浸提温度60℃,提取率最高可达48.59%。     

碱溶酸沉法提取梧桐子蛋白质的工艺

以梧桐子为原料,以蛋白质提取率为指标,通过单因素和正交试验,确定碱溶酸沉法提取梧桐子蛋白质的最佳工艺参数。结果表明,影响梧桐子蛋白质提取率的因素大小依次为:浸提时间、浸提温度、料液比和碱提液p H。碱溶酸沉法提取梧桐子蛋白质的最佳工艺参数为:碱提液pH 9、料液比1︰15 (g/mL)、浸提时间120 min、浸提温度40℃。此条件下,梧桐子蛋白质的提取率为31.36%;梧桐子中蛋白质提取液的最佳酸沉pH为3.8。     

响应面法优化山毛豆蛋白质提取工艺

通过响应面法优化山毛豆蛋白质碱溶酸沉法提取工艺。结果表明,碱溶酸沉法提取山毛豆蛋白质的优化工艺为碱溶pH=11.0、料液比为1∶36(g/mL)、提取温度40℃、提取时间143 min、酸沉pH=4.0;在此条件下山毛豆蛋白质的提取率为83.42%。     

牡丹籽粕蛋白提取工艺优化及其等电点分析

以牡丹籽粕为原料,对碱提酸沉法提取其蛋白的工艺条件进行优化,并对沉降蛋白质的等电点进行分析。研究结果表明,提取牡丹籽粕蛋白的最佳工艺参数为pH 11、提取时间100min、提取温度55℃、料液比1∶20(m∶V),蛋白提取率可达86.77%;牡丹籽粕蛋白质的等电点为pH 4.0,其沉淀率最高可达94.55%。     

碱提酸沉法提取紫花苜蓿干草叶蛋白初探

以北方寒冷地区紫花苜蓿干草为材料,将苜蓿干草粉碎后,采用碱提酸沉法提取苜蓿叶蛋白,并对提取的叶蛋白进行氨基酸含量的测定分析。本实验设计了料水比、pH、搅拌时间三个单因素进行碱提实验,并在单因素基础上设计了正交实验。正交实验结果表明,碱提法的最佳工艺条件为:料水比为1:35,pH为10,搅拌时间为12min。在最佳碱提实验的基础上进行酸沉,通过单因素实验,确定酸沉的最佳条件为提取液pH=4.2。此时样品粗蛋白含量为59.76%,粗蛋白提取率为42.52%。通过氨基酸分析结果表明,苜蓿叶蛋白氨基酸种类齐全,含量高,氨基酸比例协调,因此苜蓿叶蛋白是优质蛋白质。     

碱提酸沉法提取薏仁碎米中蛋白质的研究

采用贵州兴仁县产纯种小薏仁碎米作为研究对象,采用碱提酸沉法提取薏仁碎米中的蛋白质。通过单因素试验,确定各个因 素对薏仁碎米蛋白提取率的影响,然后用响应面法优化薏仁碎米蛋白的提取工艺,确定碱提酸沉法提取蛋白质的最佳工艺条件为 料液比1∶12（g∶mL）、碱提pH 10.1、碱提温度47.2 ℃、碱提时间4 h,理论蛋白提取率最大41.11%,验证此条件下薏仁碎米蛋白平均提取 率为38.75%,蛋白纯度为57.38%。     

巴旦木蛋白提取工艺

以巴旦木为原料,采用碱提酸沉法和超声波辅助碱液浸提法制备巴旦木蛋白,并对其理化性质进行研究。结果表明：碱提酸沉法提取巴旦木蛋白的最佳工艺条件是料液比1:25、pH10、60℃浸提40min;超声辅助碱液浸提法提取巴旦木蛋白的最佳工艺条件是pH9.0、料液比1:20、提取时间15min、超声功率125kW,在此条件下提取率为37.16%。与碱提酸沉法比较,超声波辅助碱液提取法时间短、得率高。     

酶法优化油茶粕蛋白提取工艺

为提高油茶粕蛋白的提取率,先对油茶粕进行淀粉酶、纤维素酶预处理,然后利用传统碱提酸沉法进行提取,并对初提取的油茶粕蛋白进行脱色处理。采用单因素和正交试验得出了酶预处理油茶粕的较佳工艺条件。结果表明:淀粉酶添加量2.0%、纤维素酶添加量0.7%,酶解温度50℃,酶解时间120 min,pH5;按碱提酸沉法在pH3时沉淀得到蛋白质,此时,蛋白质的提取率为80.83%。而未经酶处理蛋白质提取率为49.30%,表明酶法预处理可显著提高油茶粕蛋白的提取率。     

豌豆分离蛋白提取工艺的研究

主要研究了采用碱溶酸沉法提取豌豆分离蛋白的各个影响因素,同时采用超声波改进的提取工艺与传统工艺进行比较,通过实验得出传统的碱溶酸沉工艺提取豌豆分离蛋白的最佳工艺为:固液比为1∶25、pH为9.0、提取温度为45℃、提取时间为50min,在此提取条件下蛋白质的提取率为81.82%,其中蛋白质的含量为91.23%.采用超声波改进工艺后,蛋白质的提取率明显要高于传统工艺,其蛋白质的提取率可以达到83.21%.其最佳工艺为:料液比1∶15、功率为300W,时间为30min.     

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