溶涨值和透光率在面筋强度测定中的应用

面筋在乳酸溶液中的溶涨值和透光率同小麦粉的蛋白质含量和湿面筋含量等相关不显著;而溶涨值、透光率同和面时间、Pelshenke值呈极显著正相关。依据湿面筋的含量和面筋强度的高低,在参试小麦粉类型的划分上,溶涨值、透光率同和面时间、Pelshenke值的结果是一致的。因此,溶涨值或透光率可以方便地运用于面筋强度的测定上。     

优质强筋小麦粉乳酸保持能力的影响因素分析

以14个优质强筋小麦品种(品系)为材料,系统研究了小麦粉的蛋白质含量、湿面筋含量、GMP含量、SDS沉淀值、流变学特性、谷蛋白溶涨指数及其与微量乳酸SRC值间的关系。通过微量乳酸SRC值与蛋白质品质评价指标的相关分析得出,微量小麦粉乳酸SRC值与SDS沉淀值、拉伸能量和SIG20呈极显著正相关;与蛋白质含量、湿面筋含量、GMP含量、稳定时间、SIG0和SIG5呈显著正相关;与弱化度呈极显著负相关。通过二次旋转回归正交组合设计分析了微量SRC法中离心力、溶剂量、溶涨温度和溶涨时间等因素对乳酸SRC值的影响,得到了乳酸SRC值的模型。     

小麦谷蛋白溶涨指数与蛋白质组分关系的研究

谷蛋白溶涨指数是一种蛋白质品质测定方法，是一定量面粉在SDS乳酸溶液中溶涨、离心后的面粉重量与面粉原始重量的比值。为了研究小麦谷蛋白溶涨指数与蛋白质组分的关系，采用两种蛋白质组分分离方法提取测定了21个小麦品种(品系)的蛋白组分含量，并采用C．Wang的方法测定了不同溶涨时间(0min、5min、20min)的谷蛋白溶涨指数。简单相关分析结果表明：溶涨时间为5min、20min时的谷蛋白溶涨指数与球蛋白含量呈显著负相关，与总蛋白、醇溶蛋白、可溶性谷蛋白、不溶性谷蛋白含量呈极显著正相关；各蛋白质组分含量对SIG的通径分析结果为：谷蛋白含量对SIG值的影响最大，其中不溶性谷蛋白含量起主导作用。因此，谷蛋白溶涨指数法能间接预测不溶性谷蛋白的含量。     

谷蛋白溶涨指数与面制食品质量控制

选用27个中国小麦样品，研究了谷蛋白溶涨指数对于评价中国白盐面条品质评价的适用性。谷蛋白溶涨指数与面带长度呈极显著负相关，与面带厚度呈极显著正相关。谷蛋白溶涨指数各时间(0min，5min，20min)与面条最佳煮面时间、鲜面条最大拉伸阻力、拉伸能量、拉伸长度均呈极显著正相关(除SIGO与最佳煮面时间呈显著正相关)；谷蛋白溶涨指数与可溶性谷蛋白、不溶性谷蛋白含量、面筋指数及蛋白质含量呈极显著正相关；谷蛋白溶涨指数与煮后面条表面韧性呈显著或极显著负相关，与剪切韧性呈显著正相关。谷蛋白溶涨指数可以作为一种品质指标控制面制食品的质量。     

影响谷蛋白溶涨指数测定因素研究

谷蛋白溶涨指数(简称SIC)是一定量小麦粉在SDS乳酸溶液中溶涨、离心后的面粉重量与小麦粉原始重量的比值。该方法适宜应用于小麦不溶性谷蛋白含量的评价，进而评价小麦的焙烤特性、面条和通心粉的蒸煮特性。研究表明，SDS溶液仅对蛋白质起作用，能将蛋白质大分子分解成小分子，而淀粉在SDS溶液中不分解，淀粉对测定结果无影响。随着温度升高，谷蛋白溶涨指数呈增高趋势。对测定的样品用量、试剂用量进行调整，可用百分之一天平得到较为准确的实验结果。     

氧化淀粉对小麦面团品质变化影响研究

通过对面筋强度、巯基和二硫键含量测定、面筋蛋白电泳观察分析及面团流变学特性变化,研究氧化淀粉对小麦面团品质特性影响。结果表明,氧化淀粉能增加面筋乳酸溶涨值和透光率,提高面筋强度;对面筋蛋白具有氧化作用,增加大分子麦谷蛋白亚基含量,对面团粉质特性影响不显著;但能改善面团拉伸性能,其中以羧基含量为0.27%至0.40%氧化度氧化淀粉对面团品质变化影响最为显著。     

面筋聚集参数及其与小麦其它品质性状的关系

本文研究了小麦蛋白质品质检测指标面筋聚集试验与其它品质性状的关系 ,对其在指导谷物化学研究方面进行了讨论。结果发现 :面筋聚集试验中聚集时间与谷蛋白溶涨指数和湿面筋含量分别呈显著、极显著负相关 (r=- 0 .92 1,- 0 .878;p <0 .0 5 ,0 .0 1) ,聚集能量、平均能量输入、最大能量输入和面包烘焙潜能与蛋白质含量、Zeleny沉降值、谷蛋白溶涨指数、湿面筋含量均呈显著正相关 (r =0 .84 7～ 0 .990 ;p <0 .0 5 ,0 .0 1)。蛋白质组分中清蛋白和醇溶蛋白与面筋聚集参数、谷蛋白溶涨指数无关系 ;球蛋白与聚集能量、面包烘焙潜能、谷蛋白溶涨指数呈极显著负相关 (r =- 0 .881～ - 0 .96 9;p <0 .0 5 ,0 .0 1) ;谷蛋白与聚集能量、能量输入、面包烘焙潜能、谷蛋白溶涨指数呈显著正相关 (r=0 .890～ 0 .990 ;p <0 .0 5 ,0 .0 1) ;面筋聚集实验中聚集时间与百克面包重呈显著正相关 ,平均能量输入 ,最大能量输入和面包烘焙潜能与面包百克重呈显著负相关 (r =- 0 .86 0～ - 0 .94 0 ;p <0 .0 5 ,0 .0 1)。面筋聚集试验对面包产品品质有很好的预测能力 ,可以作为谷物化学研究、食品企业质量控制的测定指标之一。     

不同发芽状况对小麦主要加工品质性状影响研究

以强面筋,中强筋和弱面筋的５个小麦品种为材料,研究发芽程度差异对小麦加工品质性状的影响,结果表明,随发芽时间延长,小麦的蛋白质含量,ＳＤＳ沉淀值和溶涨值降低;面粉粉质曲线的吸水率减少,形成时间,稳定时间缩短,软化度上升,评价值降低。     

文献导读

小麦谷蛋白溶涨指数与蛋白质组分关系的研究谷蛋白溶涨指数是一定量面粉在SDS乳酸溶液中溶涨、离心后的面粉重量与面粉原始重量的比值。为了研究小麦谷蛋白溶涨指数与蛋白质组分的关系,采用两种蛋白质组分分离方法提取测定了21个品种的小麦的蛋白组分含量,并采用C!W ang的方法测定了不同溶涨时间的谷蛋白溶涨指数。简单相关分析结果表明:溶涨时间为5m in、20m in时谷蛋白溶涨指数与球蛋白含量呈极显著正相关;各蛋白质组分含量对SIG的通径分析结果表明:谷蛋白对SIG值的影响最大,其中不溶性谷蛋白含量起主导作用。因此,谷蛋白溶涨指数法…     

一种评价面包小麦面筋强度快速简便的新方法

面筋—乳酸溶液透光率是测定小麦面筋强度的一个快速有效的新方法,该方法的原理是测定面筋在弱酸中的不溶性,方法的优点是快速、简便、不受面筋含量的影响。本文报道了该方法的建立过程并予以验证。     

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