桔梗多糖Sevag法除蛋白工艺的研究

采用水提醇沉法得到桔梗多糖,优化Sevag法除蛋白的工艺条件,通过单因素实验确定振摇时间、Sevag试剂添加量、氯仿正丁醇体积比、脱蛋白次数对脱蛋白效果的影响。采用四因素三水平正交试验确定脱蛋白的最优工艺。最优工艺为振摇时间25min,Sevag试剂添加量1/3,氯仿正丁醇体积比4∶1,脱蛋白次数4次。     

甘薯糖蛋白脱游离蛋白的研究

研究了用Sevage法脱除甘薯糖蛋白中游离蛋白的工艺条件，通过单因素试验，提出了影响甘薯糖蛋白脱游离蛋白的主要因素，并通过正交试验进一步优化工艺条件，确定影响甘薯糖蛋白脱游离蛋白的主次因素分别为样液与试剂的比例、脱蛋白次数、氯仿与正丁醇的比例、脱蛋白时间，试验结果表明，样液与试剂的体积比为2：1，氯仿与正丁醇的体积比为2：1，脱蛋白次数为3次，脱蛋白时间为20min时，脱游离蛋白的效果较好。     

粪鬼伞多糖脱蛋白方法的研究

探讨粪鬼伞多糖提取过程中的脱蛋白方法与工艺.以蛋白质去除率和多糖损失率为考察指标,比较Sevag法、酶法、三氯乙酸法、酶-Sevag法脱蛋白效果.结果表明,酶-Sevag法脱蛋白效果较好且多糖得率较高,脱蛋白的最佳工艺条件为:酶用量2%,温度40 ℃,脱蛋白时间2 h,pH值5.0;Sevag试剂浓度20%,脱蛋白次数3次,在此条件下,蛋白质去除率和多糖损失率分别为70.95%和6.58%.     

金樱子粗多糖的脱蛋白研究

采用Sevag法、酶法、酶法与Sevag法相结合对金樱子多糖进行脱蛋白研究。结果表明,酶法与Sevag法结合脱蛋白效果最佳,具体操作条件为酶用量为底物浓度的1%、pH为6.0时、60℃水浴3h,再加入占总体积1/5的氯仿-正丁醇(5∶1)溶液进行脱蛋白,重复操作5次,此时蛋白脱除率为80.5%,多糖含量为84.3%。     

牛蒡菊糖提取工艺的研究

以水提醇沉工艺,采用单因素和正交试验设计研究料液比、提取时间、提取温度和提取次数对牛蒡菊糖提取率的影响,得到牛蒡菊糖提取的最佳工艺条件组合为料液比1:10(m/V)、提取时间120min、提取温度80℃、提取两次提取液经乙醇沉淀、真空浓缩得到粗菊糖,菊糖提取率为63.36%。采用Sevag 法、木瓜蛋白酶法、Sevag和木瓜蛋白酶联用三种方法分别对粗菊糖进行脱蛋白纯化,选择最佳的脱蛋白方法。结果表明：木瓜蛋白酶与Sevag 联用脱蛋白效果最好,蛋白去除率达90.83%。     

啤酒酵母多糖脱蛋白方法的应用研究

以提取的粗酵母多糖为原料,采用Sevag法及Sevag法与酶法结合对其进行脱蛋白.结果表明,Sevag法脱蛋白3次,Sevag试剂中的氯仿:正丁醇=5:1,糖液:Sevag=5:1脱蛋白效果最好,此时蛋白质残留量为6.392mg/mL,多糖损失率为24.62%.Sevag法与酶法结合脱蛋白,蛋白质水解的最佳工艺条件为:水解温度60℃,pH7.0,样液:酶液=3:1,时间为2h,此时蛋白质残留量为6.86mg/mL,多糖损失率仅19.74%.     

米糠多糖脱蛋白工艺的研究

米糠多糖存在于稻谷颖果皮层中,在提取过程中,常混有一定量的蛋白质,影响多糖的纯度。本文比较了Sevag法、三氯乙酸法、酶法、酶-Sevag法及酶-TCA法对米糠多糖脱蛋白的效果。在单因素试验基础上,通过蛋白质脱除率和多糖损失率的比较得出酶-Sevag法效果优于其它方法。选取酶的添加量、pH值、Sevag试剂添加量、脱蛋白次数为四因素,各取三个水平,以蛋白质脱除率和多糖损失率为指标,做L9(34)正交实验确定酶-Sevag法的最佳脱蛋白工艺。结果显示:最佳工艺为酶的添加量为2.0%,pH为6.0,Sevag试剂用量为1/6糖液体积,脱蛋白次数为1次,在此条件下蛋白质脱除率可达76.89%,多糖损失率仅为13.45%。因此,酶-Sevag法是一种有效的米糠多糖脱蛋白方法,本文可为米糠多糖的开发提供参考。     

发酵液中水溶性热凝胶提取工艺的优化

为提取纯化发酵液中水溶性热凝胶,首先采用单因素结合响应面分析方法优化Sevag法去除发酵液中的蛋白,在单因素优化基础上,根据中心组合实验设计(Central Composite Design)实验原理,设计3因素5水平的响应面分析实验,最终得到最优去蛋白工艺:氯仿与正丁醇体积比为3.5的Sevag试剂,按发酵上清液与Sevag试剂体积比3.75的比例加入上述试剂,振荡混匀后静置33 min,重复上述操作5次;此条件下蛋白去除率为85.73%,水溶性热凝胶回收率为90.29%。对去蛋白后的处理液进行有机溶剂法的最佳提取工艺优化,优化得到乙醇为最佳提取试剂,加入乙醇至终浓度为90%,混匀后静置4 h,最后得到水溶性热凝胶的提取率为40.12%,纯度为89.10%。     

富贵菜功能成份多糖提取纯化工艺优化

目的：研究富贵菜多糖提取纯化工艺,为有效开发利用功能性食品--富贵菜提供方法学基础。方法：通过正交试验,优化提取方案;采用Sevag 法脱蛋白,双氧水和活性碳脱色,蒽酮- 硫酸法测定多糖含量。结果：在温度100℃,固液比1:7(富贵菜:水,g/mL),提取时间3.5h,提取次数2 次的条件下,所得多糖含量最高。以氯仿:正丁醇的体积比4:1 为脱蛋白剂,加入0.15g/mL 的活性炭溶液,80℃脱色45min,脱色2 次或加入多糖供试液体积70% 的双氧水试液于60℃脱色120min 效果最佳。结论：该工艺条件简单可行,多糖提取率高,稳定性好,可作为富贵菜多糖的提取纯化工艺。     

碱提菜籽多糖脱蛋白方法的研究

采用5种方法对碱提菜籽多糖进行脱蛋白处理,结果表明:酶法-Sevag法联用的方法可以有效的脱除游离蛋白并使多糖损失较小,其最佳的条件,酶用量为0.12%,反应温度为60℃,反应时间为45min,Sevag法脱蛋白的次数为3次。经过最佳条件脱蛋白,蛋白的脱除率为74.8%,多糖损失率为21.6%。     

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