高粱粉对面团特性及面包品质的影响

将高粱粉加入到面团与面包中,利用布拉班德粉质仪测定面团的粉质特性,并测定含高粱粉面包的保水性与老化度。结果表明,高粱粉添加量为10%时,面包面团的粉质特性下降不明显,获得的面包感官品质较好,保水性性高,老化度低。     

木糖添加量对面团流变学特性与面包品质的影响

添加木糖代替面包配方中的蔗糖,采用直接发酵法制作木糖面包。采用粉质仪法、拉伸仪法测定添加木糖前后面团的流变学特性,研究木糖添加量对面团流变学特性和面包品质的影响。结果表明:木糖添加量越高,面团的粉质指数越低,稳定和断裂时间越短,软化度和公差指数越高;添加木糖可使面团的吸水量减少,对形成时间无影响。随木糖添加量的增加,面团的拉伸能量、拉伸阻力和拉伸比降低,而延伸度增加;但是随醒发时间的增加,木糖添加量与拉伸特性各指标间相关系数降低,木糖对面团拉伸特性的影响效果减弱。配方中添加1.5%的蔗糖即可满足面包酵母生长需求。添加木糖对面包的规则度影响较小,但可使面包的体积和比容变小,感官品质变差;木糖添加量3.0%时面包硬度最小,超过3.0%时面包体积、比容和感官得分明显降低。添加木糖可提高面包的水分保持能力和抗氧化能力,对酸度和酸价无影响。     

葡萄糖氧化酶制剂对面包粉品质的影响研究

主要研究葡萄糖氧化酶对国产面包粉的改良效果。在面包粉中分别添加10、20、30、40、50 ppm葡萄糖氧化酶,分别测定面包粉的粉质特性、拉伸特性和制作成的面包感官品质,结果表面,添加葡萄糖氧化酶后,粉质特性中面团的吸水率、稳定时间增加,弱化度减小;拉伸特性中的拉伸面积、拉伸阻力、拉伸比增加,延伸度减小;制作的面包体积、质地和纹理结构都有提高。当葡萄糖氧化酶添加量为40 ppm时,品质改善效果最佳。说明在面包粉中适当添加葡萄糖氧化酶,有利于改善面粉的加工特性,在提高筋力、延缓面包老化、提高面包柔韧性方面表现突出。     

菊糖对面团流变学特性及面包品质的影响

添加不同比例的菊糖于面包粉中,对面包面团特性及面包品质变化进行研究。结果表明,添加菊糖能够明显影响面包粉的粉质和拉伸等流变特性。随着菊糖添加量的增加,面团吸水率显著下降,面团形成时间和面团稳定时间延长,弱化度减小;添加菊糖可增加面团的延伸度、拉伸面积和拉伸阻力;面粉的峰值黏度、最终黏度、衰减值和回生值也显著降低,其淀粉老化速度得到延缓;弹性模量和黏性模量显著增加,面团的网络结构得到改善;但面团发酵体积显著减小,使得面包的比容减少,面包初始硬度显著性增加,在面包贮藏过程中,添加2.5%、5%、7.5%的菊糖面包硬度明显低于未添加菊糖的面包硬度,说明适宜添加量的菊糖能够改善面包内部结构,降低其贮藏过程中的硬度和老化速率,延长面包货架期。     

菊粉添加量对面团流变学特性和面包品质的影响

采用粉质仪、拉伸仪、质构分析仪(TA)研究不同添加量菊粉(2%~10%)对面粉粉质特性、拉伸特性和面包焙烤品质的影响。实验结果表明,随着菊粉的添加,面团的吸水率几乎不变,形成时间和稳定时间延长,弱化度降低,评价值增加;面团延伸度指标呈现一定的增大趋势,但拉伸曲线面积、拉伸阻力、最大拉伸阻力和拉伸比呈现先增加后减少的趋势。面包的硬度、弹性、咀嚼性和回复性因添加菊粉而下降。综合感官评定可知,当菊粉添加量为6%时,面包综合品质达到最佳状态。     

海藻酸钠对面团特性及面包品质的影响

考察了海藻酸钠添加量对混合粉粉质特性、拉伸特性、糊化特性,以及对面包比容、含水量、硬度、弹性、感官品质的影响。结果表明,添加海藻酸钠可有效改善小麦粉面团的粉质特性、拉伸特性及糊化特性,提高面包的含水量,适量添加可有效提高面包比容、面包弹性及面包感官品质,降低面包硬度。综合分析添加海藻酸钠对混合粉粉质、拉伸和糊化特性以及对面包焙烤品质的影响,确定海藻酸钠最佳添加量为0.6%,为其在焙烤食品中的应用提供了理论依据。     

川秋葵超微粉对面团、吐司质构特性及烘焙品质的影响

川秋葵超微粉的添加显著影响了面团和吐司的质构特性,4%~12%川秋葵超微粉的添加可降低面团硬度及咀嚼性,10%添加量可极显著降低吐司咀嚼性、硬度、黏胶性,显著提高吐司弹性。秋葵超微粉添加量在4%~10%时,随着秋葵超微粉添加量增加,面团发酵体积以及吐司比容呈增大趋势,10%添加量时,面团发酵体积及吐司比容最大;12%添加量时,面团发酵体积及吐司比容下降。综上,在100 g面粉中,秋葵超微粉添加量不高于10 g为宜。以10%添加量作为试验组研究秋葵超微粉对面团粉质特性、吐司烘焙品质以及贮藏中吐司品质劣变的影响,研究结果显示,10%添加量对面团的粉质特性影响较大,面团稳定时间显著下降了51.2%,粉质质量指数下降了32.9%,面团形成时间增加了0.2 min,弱化度显著增加了130 FU,吸水率由58.3%上升到65.7%;秋葵超微粉面团在焙烤后,其烘焙品质较好,质构改善,比容增加,秋葵超微粉吐司贮藏过程中的品质劣变减缓。     

脱毒亚麻粕籽粉对面团流变学及面包特性的影响研究

采用粉质仪、拉伸仪、质构仪等分析手段探讨脱毒处理后的亚麻籽粕粉添加到小麦粉中对面团流变学特性(粉质特性、拉伸特性)、面包烘焙特性的影响。结果表明,挤压处理使有毒成分生氰糖苷含量显著降低(从257.85 mg/kg降到18.58 mg/kg);随着脱毒亚麻籽粕粉添加量的增加,面团吸水率、弱化度增加;面团形成时间、稳定时间和粉质评价值降低;面团的R5阻力、最大拉伸阻力、拉伸长度、拉伸能量降低;复合小麦粉所制面包比容下降,感官评分及硬度、弹性等物性指标均无较大的变化。当添加量增大(超过5%时),需同时配合使用小麦粉改良剂。     

海藻酸丙二醇酯对面团流变学和面包烘焙特性的影响

采用粉质仪、拉伸仪和质构分析仪研究添加不同比例(0.1%、0.2%、0.3%和0.4%)的海藻酸丙二醇酯(PGA)对面团流变学特性和面包烘焙特性的影响。结果表明,添加PGA能改善面团的粉质和拉伸特性,能显著提高面团的吸水率,延长面团的稳定时间,提高粉质评价指数,增大面团的延展性、拉伸阻力和拉伸比值。添加PGA能增大面包比容,显著提高面包的弹性,降低面包硬度,改善面包的口感,提高面包的感官评分。PGA添加量在0.2%~0.3%时,对面团和面包的改善效果最为显著,面包品质最好。     

苦荞超微粉对苦荞小麦混合粉及其挂面品质的影响

将普通苦荞粉,苦荞超微粉A和B按照5%~30%的比例添加到小麦粉中,对苦荞小麦混合粉的面团粉质特性及其挂面的感官品质、蒸煮品质及质构特性进行了研究,结果表明:与普通粉相比,添加苦荞超微粉的混合粉面团的吸水率增加,面团形成时间和稳定时间缩短,弱化度值升高,粉质指数降低;添加苦荞超微粉提高了挂面的感官品质;添加量在15%以下时,添加苦荞普通粉制作的面条煮熟增重率较高,添加量在15%~30%时,添加苦荞超微粉A制作的面条煮熟增重率较高,而添加量在5%~30%时,添加苦荞超微粉A制作的面条煮熟的干物质损失率最低;苦荞粉超微处理增加了苦荞挂面的坚实度和剪切功,面条咀嚼性和韧性增强。小麦粉中添加20%苦荞超微粉A时制作的挂面韧性,口感良好。     

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.     

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     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press