谷朊粉与其改良面粉流变学特性的相关性研究

为研究不同谷朊粉对小麦粉品质的改良作用,选用10种市售谷朊粉为试材,分析其主要品质及改良面粉面团的流变学特性,通过相关性分析及逐步回归分析研究谷朊粉与改良面粉品质之间的相关关系。结果表明:谷朊粉的灰分、粗蛋白、水分、巯基含量、溶解性、持水力、吸水性及泡沫稳定性与改良面粉的吸水率、形成时间、稳定时间、弱化度、延伸性、最大拉伸阻力及能量呈显著相关(p0.05)或者极显著相关(p0.01)。谷朊粉的泡沫稳定性、水分、粗蛋白、灰分、粗脂肪、持水力、持油力及巯基含量等指标对改良面粉的品质影响较大,其中谷朊粉中粗蛋白含量对改良面粉的综合品质影响最大。     

谷朊粉与其改良面粉流变学特性的相关性研究

为研究不同谷朊粉对小麦粉品质的改良作用,选用10种市售谷朊粉为试材,分析其主要品质及改良面粉面团的流变学特性,通过相关性分析及逐步回归分析研究谷朊粉与改良面粉品质之间的相关关系。结果表明:谷朊粉的灰分、粗蛋白、水分、巯基含量、溶解性、持水力、吸水性及泡沫稳定性与改良面粉的吸水率、形成时间、稳定时间、弱化度、延伸性、最大拉伸阻力及能量呈显著相关(p<0.05)或者极显著相关(p<0.01)。谷朊粉的泡沫稳定性、水分、粗蛋白、灰分、粗脂肪、持水力、持油力及巯基含量等指标对改良面粉的品质影响较大,其中谷朊粉中粗蛋白含量对改良面粉的综合品质影响最大。      

基于主成分分析法评价谷朊粉品质

以10种市售谷朊粉为试材,在分析谷朊粉的水分、灰分、粗脂肪、粗蛋白等理化指标及吸水率、溶解性、持水力、起泡性及泡沫稳定性等功能性的基础上,利用主成分分析法对谷朊粉的品质进行了的评价。结果表明:不同企业生产的谷朊粉品质不同,通过主成分分析,提取3个主成分累计方差贡献率为83.824%,其中第1、第2和第3主成分方差贡献率分别为54.443%、18.039%和11.341%。确定泡沫稳定性、溶解性、吸水率、起泡性、水分及粗蛋白含量是影响谷朊粉品质的重要指标,建立了综合评价谷朊粉品质的方法,对谷朊粉品质进行综合评分并排序。谷朊粉综合得分越高,谷朊粉的品质越好,10种谷朊粉中排在前三位的依次是8号、5号和7号谷朊粉。      

不同种类谷朊粉对新鲜面条品质的影响

选用4种自制谷朊粉及6种市售谷朊粉,测定其理化及功能特性后按照1.5%的比例添加到面粉中制备新鲜面条并进行品质分析。结果表明:不同种类谷朊粉间理化和功能特性差异显著,自制谷朊粉水分及灰分含量低,蛋白含量、持水性及吸水率高于市售谷朊粉。谷朊粉能降低面条亮度、延长煮制时间、提高面条吸水率,并改善面条质构及感官特性。相关性分析得出:谷朊粉持水性与水分及灰分含量呈显著负相关,与粗蛋白含量呈极显著正相关;面条最佳煮制时间与谷朊粉持水性呈显著性正相关;而谷朊粉持水性与面条拉伸强度呈显著性正相关。     

麦谷蛋白和麦醇溶蛋白配比对高水分组织蛋白品质的影响

为了探究麦谷蛋白和麦醇溶蛋白不同配比对高水分组织蛋白品质的影响，研究将谷朊粉中的麦谷蛋白和麦醇溶蛋白进行提取后按比例重组，替代挤压配方中的谷朊粉，分析麦谷蛋白和麦醇溶蛋白不同配比下挤压混料的流变学特性及高水分组织蛋白品质的变化规律。结果表明：随着谷醇比的减小，挤出过程中物料的流动性增强；挤压产品的色泽变亮，持水性、硬度和咀嚼性降低，横向剪切力、拉伸距离和组织化度显著升高(P<0.05)。当提取出的麦谷蛋白和麦醇溶蛋白配比为20∶80时，产品的品质最优。麦谷蛋白对产品结构的支撑具有重要作用，麦醇溶蛋白有利于产品纤维结构的形成。     

谷朊粉、麦醇溶蛋白与麦谷蛋白基本性质研究

以溶解度、乳化性及乳化稳定性、起泡性及起泡稳定性为考察指标,系统研究不同pH 值条件下,谷朊粉、麦醇溶蛋白、麦谷蛋白的功能特性及其相互间关系。结果表明：pH 值3～11 范围内,谷朊粉的溶解度、乳化性及乳化稳定性、起泡性在pH7 时最小。在同一pH 值条件下,麦醇溶蛋白溶解度、乳化性及乳化稳定性、起泡性及起泡稳定性大于麦谷蛋白,且在乳化性及乳化稳定性方面,麦醇溶蛋白远大于麦谷蛋白。麦醇溶蛋白是提高谷朊粉功能特性的主要成分。     

多糖类物质对谷朊粉蛋白膜性能的影响

研究了多糖类物质对谷朊粉蛋白膜及其脂类复合膜性能的影响。结论表明,添加多糖类物质能提高谷朊粉蛋白膜的透光率、阻水性、机械性和阻氧性,多糖物质的适宜添加量为0.03 g/g WG～0.05g/g WG。果胶和壳聚糖对谷朊粉蛋白膜性能的影响较大。添加果胶可使膜的水蒸气透过率下降12.75%,阻氧性、抗拉强度和断裂伸长率分别提高18.54%,20.31%和30.63%;卡拉胶与谷朊粉交联程度相对较小,膜的性能提高不显著。添加多糖类物质对谷朊粉—脂类复合膜的改性与其对谷朊粉蛋白膜具有相似的变化趋势,添加果胶改善了WG-脂类复合膜的机械性能和阻氧性,阻水性虽比WG-脂类复合膜有所提高,但也远低于谷朊粉单基膜。谷朊粉—多糖复合膜的红外光谱分析结果表明果胶与谷朊粉分子结合良好,分子间的氢键作用加强,复合膜的性能得到提高。     

大豆蛋白/谷朊粉复合材料的结构和性能

通过模压成型方法制备了一系列大豆蛋白(SP)/谷朊粉(WGP)复合材料,并研究了复合材料的动态力学性能、热稳定性、力学性能、吸水性能、微观结构和形态。结果表明:红外光谱显示复合材料中大豆蛋白与谷朊粉之间发生氢键作用;扫描电镜和动态力学分析证实,当谷朊粉含量低于28%时,大豆蛋白/谷朊粉复合材料的组织结构均匀,未出现新的损耗峰,表明谷朊粉与大豆蛋白发生共塑化、形成均相体系,且相容性良好;当谷朊粉含量为3.5%时,复合材料的热稳定性提高,并且材料的拉伸强度、断裂伸长率和断裂能分别比非复合材料增大0.33 MPa、31.21%和0.37 kJ/m2,表明复合材料的强度、延伸性、韧性改善;复合材料的2 h吸水率和24 h吸水率均减小,表明谷朊粉的加入显著提高了该材料的抗水性。     

谷朊粉、乳化剂对全麦面条品质的影响

按照小麦籽粒各组分的固有比例复配全麦粉,研究谷朊粉、硬脂酰乳酸钠(SSL)、单甘脂(GMS)对100%全麦面条品质的影响。研究结果表明:谷朊粉应用于全麦的面条中能够有效改善全麦面条品质,随着谷朊粉添加量的增加(1%~3%),全麦面条溶出率和吸水率逐渐降低,但当谷朊粉的添加量达到3%后,全麦面条的品质趋于稳定。谷朊粉继续增加,面条溶出率和吸水率略有增加。然而乳化剂对全麦面条的溶出率和吸水率影响不显著,并不能明显改善面条的品质。     

谷朊粉及其主要组分对果糖吸湿的抑制作用

为改善果糖因其强吸湿性而导致的结块和潮解现象,通过绘制吸湿曲线,吸湿等温线,宏观形态分析,接触角测定以及低场核磁等表征手段,考察谷朊粉（Wheat Gluten,WG）添加量对果糖冻干品吸湿特性的影响,并比较了谷朊粉中两种主要成分：麦醇溶蛋白和麦谷蛋白的作用差异。结果表明,谷朊粉显著降低了冻干果糖样品的平衡吸湿率（Equilibrium Moisture Content,EMC）,在25 ℃、75%相对湿度下果糖与谷朊粉比例为10:0、3:7、2:8的EMC分别为36.33%、16.00%、14.61%;随着谷朊粉比例的增加,样品的结块程度减弱,接触角由11.3 °增大到94.8 °。Peleg模型可以准确描述果糖-蛋白体系的水分吸附过程;相较于麦醇溶蛋白,添加麦谷蛋白的样品EMC更低,结块量更小,且麦谷蛋白的接触角（88.2 °）大于麦醇溶蛋白（64.6 °）;低场核磁结果显示,与麦醇溶蛋白相比,麦谷蛋白对降低水分自由度产生了更有效的影响。以上结果表明,谷朊粉及其主要组分对果糖的吸湿有显著的抑制作用,相较于麦醇溶蛋白,麦谷蛋白抑湿效果更突出。     

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