微波法萃取橘皮中果胶的研究

以橘皮为原料在微波条件下提取果胶进行了研究，探讨盐析pH值、微波加热时间、硫酸铝用量、液料比、盐析温度、盐析时间等因素对果胶产率的影响，结果表明：微波法提取果胶的最佳工艺条件为盐析pH5．0，微波力加热时间5min，硫酸铝用量2．5g，液料比16mL／g，盐析温度60％，盐析时间60min，果胶平均得率25％。     

冬瓜皮果胶的提取工艺研究

摘要：用单因素试验和正交试验研究了冬瓜皮果胶的提取工艺条件。结果表明：从冬瓜皮中提取果胶的最佳工艺条件为：pH值2．0、提取温度90℃、料液比1：6、提取时间1．5h,在此条件下冬瓜皮果胶的提取率达8．61％;四因素对冬瓜皮果胶提取率的影响程度大小依次为：pH值〉提取时间〉提取温度〉料液比。     

酸提取大豆种皮果胶的工艺优化

本文采用酸提取方法对大豆种皮果胶的提取工艺条件进行研究，考察了温度、pH、料液比、提取时间等因素对果胶收率的影响。确定了酸提取大豆种皮果胶的最佳工艺条件：pHl．5、提取温度为85℃、提取时间30min、料液比为1：8。     

微波辅助提取苹果渣中高酯果胶的研究

以苹果渣为原料。对用微波辅助提取、提取液脱色、乙醇沉析获得果胶的关键提取条件进行了研究。通过L9（3^4）正交试验,得到了在微波辐射功率为250w时果胶提取的最佳工艺条件：料液比1：40,提取时间35min,pH=1．3,提取温度65℃,此时,果胶的提取率可以达到10．61％。效果很佳。     

烟梗中果胶的酶法降解

烟梗中的果胶对卷烟感官质量有不利影响。为减少果胶含量,从4种酸性果胶酶中筛选出1种适用于降解烟梗中的果胶,并采用单因素实验方法分别考察了加酶量、料液比、pH、处理时间和温度5个因素对烟梗中果胶降解效果的影响。采用正交试验分析方法,对该果胶酶的作用条件进行了优化。结果表明:最优作用条件为:加酶量100 U/g,料液比1∶20,初始pH 3.0,处理时间8 h,温度45℃,此条件下烟梗中果胶的降解率可达42.38%。     

豆腐柴中有效成分复合分离提取研究

试验以豆腐柴叶为原料，采用复合分离提取工艺，提取叶中的蛋白质和果胶产品。首先通过不同溶剂提取蛋白质，得到碱溶性蛋白质〉水溶性蛋白质〉醇溶性蛋白质〉盐溶性蛋白质的结论；并对提取蛋白质后的上清液和滤渣进行了提取果胶的最佳条件和参数的确立，进行了萃取果胶时的萃取液种类、pH和盐析果胶时的盐的用量的单因素实验，又以萃取时的温度、pH、时间和料液比四个因素四个水平进行了正交试验，得到如下结论：从豆腐柴叶中复合提取分离蛋白质和果胶的最佳提取工岂条件：以盐溶液作为复合提取剂较为理想，果胶提取分离的最佳条件为萃取温度90℃、溶液pH值4、萃取时间95min、料液比l：45，在此条件下豆腐柴叶果胶的产量为22％，同时可得到0．15％的蛋白质。     

β-葡聚糖提取过程中果胶类物质分解

在碱法提取β-葡聚糖过程中,酒精沉淀β-葡聚糖工艺中有大量果胶一同沉淀下来,降低β-葡聚糖纯度。该实验采用添加果胶酶方法除去果胶,实验以西藏青稞和燕麦为原料,经过碱法粗提β-葡聚糖,然后调节pH,加入果胶酶溶液,在一定温度下反应一段时间,反应液浓缩后经酒精沉淀,沉淀物即为较纯β-葡聚糖。实验中研究不同pH、温度、酶加量及反应时间对酶解β-葡聚糖中果胶影响,确定酶解果胶最佳条件为：pH=3;温度为50℃;酶加量为120 U/g;反应时间为5 h;添加果胶酶使燕麦和青稞中β-葡聚糖提取率分别从0．1%和0．2%提高到1．9%和2．2%;利用粘度法测得青稞中提取β-葡聚糖分子量为1．8×10~4,燕麦中提取β-葡聚糖分子量为2．1×10~4。     

向日葵盘中低甲氧基果胶提取工艺的研究

本试验以新疆的向日葵为原料,研究了在普通酸法提取的基础上添加螯合剂六偏磷酸钠提取果胶的工艺条件。试验采用正交设计,利用方差分析对提取温度、提取时间和提取液的pH值对果胶得率的影响进行了探讨,得出酸解工艺的最优化条件为：提取温度75℃、提取时间65min、料液比1：25、提取液pH值为3．0,此条件下向日葵盘中果胶类物质的提取率为10．06％。     

向日葵盘中低甲氧基果胶提取工艺的研究

本试验以新疆的向日葵为原料,研究了在普通酸法提取的基础上添加螯合剂六偏磷酸钠提取果胶的工艺条件。试验采用正交设计,利用方差分析对提取温度、提取时间和提取液的pH值对果胶得率的影响进行了探讨,得出酸解工艺的最优化条件为：提取温度75℃、提取时间65min、料液比1：25、提取液pH值为3．0,此条件下向日葵盘中果胶类物质的提取率为10．06％。     

从苹果渣中提取食用纤维和果胶的研究

探讨了以苹果渣为原料采用化学方法制备食用纤维和果胶的工艺条件,通过对提取的料液比、pH值、碱液浓度、反应时间及反应温度等影响因素的研究,分别得到了提取食用纤维和果胶的最佳工艺条件。     

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