水分含量对鲜湿米粉品质影响

研究不同水分含量对鲜湿米粉成品感官品质,蒸煮特性方面影响;并研究水分含量对鲜湿米粉储藏期内感官品质、微生物指标、蒸煮特性(蒸煮损失率和熟断条率)和酸度影响。结果表明,水分含量为65%鲜湿米粉成品感官评分最高;在储藏期内,随水分含量增加,鲜湿米粉感官品质变劣速度、微生物指标超标、蒸煮损失率和熟断条率及酸度增加也越快。经综合考虑,选鲜湿米粉最宜水分含量为65%。     

鲜湿米粉品质改良研究

鲜湿米粉是我国南方的传统米制主食,属于高含水量产品,在实际加工过程中,品质较难保证。选择以马铃薯变性淀粉、焦磷酸钠、卵磷脂、海藻酸钠作为鲜湿米粉加工中的品质改良剂,以鲜湿米粉蒸煮损失率及感官评价为指标,比较上述4种品质改良剂不同添加量对鲜湿米粉的品质影响。以此为基础设计正交实验,发现在添加马铃薯变性淀粉5%(干物质质量分数,下同)、焦磷酸钠0.4%、卵磷脂0.4%、海藻酸钠0.3%时,鲜湿米粉蒸煮损失率为1.3%,感官评分为91.4分,在同等条件下达到最佳。然后,以断条率、蒸煮损失率、透色比、糊化度为指标,未添加品质改良剂的鲜湿米粉为对比样,以单因素实验中最适添加量添加品质改良剂制作鲜湿米粉、正交实验中最佳复合添加量添加品质改良剂制作鲜湿米粉,进行对比实验。以最佳添加量添加复合品质改良剂制作的鲜湿米粉断条率降低到1.7%,蒸煮损失率降低到1.3%,透射比提高到0.836,糊化度提升到92.1%,在对比实验中品质改良效果最佳。     

微晶纤维素对鲜湿米粉性质的影响

通过测试鲜湿米粉的蒸煮特性和感官品质,研究微晶纤维素添加量对鲜湿米粉食用品质的影响。结果表明:棉绒微晶纤维素添加量为1%、秸秆微晶纤维素添加量为2%时,米粉的吐浆值达到最低值。随着棉绒微晶纤维素和秸秆微晶纤维素添加量增加,鲜湿米粉的断条率呈先下降后上升趋势,鲜湿米粉的透射比呈下降趋势。与对照组相比,添加微晶纤维素的鲜湿米粉的断条率低。当棉绒微晶纤维素添加量≤3%、秸秆微晶纤维素添加量≤4%时,鲜湿米粉具有良好的食用品质。     

大米蛋白对大米淀粉糊化特性及鲜湿米粉品质影响的研究

以蛋白质含量不同的5种大米:银晶软黏、金丝苗、珍桂、秋优1025和越南504作为研究对象,通过测定5种大米脱蛋白前后糊化特性以及制作的鲜湿米粉的断条率、蒸煮损失和碘蓝值,研究大米蛋白对大米糊化特性及鲜湿米粉品质的影响。结果表明,脱蛋白处理明显降低大米淀粉糊化的起始糊化温度,使大米淀粉更易于糊化,但糊化温度降低的程度并不和蛋白质含量成正比;脱蛋白后大米淀粉的特性黏度以及回生值、消减值降低,而崩解值显著升高,脱蛋白处理使大米淀粉的热稳定性降低,延缓大米淀粉的老化。脱蛋白大米制作的鲜湿米粉的断条率的差异性随大米品种和大米中蛋白质含量而异,大米蛋白含量越高则脱蛋白制作的鲜湿米粉的断条率越高;而脱蛋白组制作的鲜湿米粉蒸煮损失率要高于未脱蛋白组鲜湿米粉。通过比较不同蛋白质梯度配比鲜湿米粉的碘蓝值,当蛋白质含量超过3%以后,米粉的碘蓝值较小,蒸煮品质较好。     

不同品种籼米生产的鲜湿米粉理化特性与感官品质

采用湖南省各地区广泛种植的50种籼米原料来生产鲜湿米粉,对鲜湿米粉的理化特性及其感官品质进行研究.通过二者相关性和回归分析,为生产鲜湿米粉的品质评价和专用稻种的选择提供理论依据.研究结果发现,理化性质中的透射比、熟断条率、碘蓝值、吐浆值与鲜湿米粉的组织形态、口感、色泽等重要感官品质呈极显著或显著相关,当碘蓝值中等(0.1～0.3)、透射比高(＞0.85)、熟断条率低(＜10%)以及吐浆值低(＜5%)时,鲜湿米粉的感官评分相对最高.碘蓝值、透射比、熟断条率和吐浆值这些理化特性指标能够较好地反映出鲜湿米粉的感官特性,可以用来评价鲜湿米粉的品质.同时,稻米品种对鲜湿米粉的品质有极显著影响,其中T优167、早熟213和中嘉早17品种的籼米制作的鲜湿米粉的品质最好.     

慈姑淀粉添加量对鲜面条品质的影响

目的:探究慈姑淀粉对鲜面条品质的影响,将不同比例的慈姑淀粉添加入麦芯粉中制得鲜面条。方法:对所制鲜面条蒸煮特性、色泽、感官品质、质构特性及挥发性风味成分等进行测定。结果:随着慈姑淀粉添加量增多,鲜面条的吸水率、断条率、蒸煮损失率整体呈上升趋势,风味物质、硬度和弹性增大,但咀嚼性、胶黏性、感官品质降低;慈姑淀粉添加量为5%时鲜面条感官品质最佳,其最佳蒸煮时间为4.5 min,面条断条率为0%,蒸煮损失率为5.28%,吸水率为70.09%,色差△E^*为2.31,GC-MS检测表明慈姑淀粉鲜面条中富含烃类、醇类等风味物质。结论:添加适量的慈姑淀粉可以改善鲜面条品质。     

米糠膳食纤维对鲜湿米粉食用品质的影响

通过测试鲜湿米粉的蒸煮特性、质构特性和感官品质,研究米糠膳食纤维添加量对鲜湿米粉食用品质的影响。结果表明,米糠膳食纤维添加量≤2%可使鲜湿米粉具有较好的蒸煮特性,添加量≤3%可使鲜湿米粉具有良好的质构特性,添加量≤6%对鲜湿米粉感官品质没有显著性影响。因此,米糠膳食纤维添加量≤2%时,鲜湿米粉具有良好的食用品质。     

四川地方大米品种特性对方便米粉品质的影响

以四川省农业科学研究院试验区筛选出的7种优质杂交水稻为研究对象,米粉工业常用大米作对照,通过测定原料基本成分、米粉感官品质、蒸煮品质和质构特性等指标,研究不同品种四川地方大米原料对方便米粉品质的影响,通过相关分析建立大米原料品种指标与米粉品质间的相关性。结果表明:原料米品种对方便米粉感官品质、蒸煮品质、质构特性的均有显著影响。米粉的劲道、爽滑、风味等感官指标及其综合评分,质构特性与大米直链淀粉含量均呈显著的正相关性。米粉的断条率、复水时间与大米的直链淀粉含量、蛋白质含量呈显著的负相关性,与大米的支链淀粉含量、粗脂肪含量呈显著的正相关性(P0.05或P0.01)。当大米直链淀粉含量在21.40%～25.61%时,米粉感官品质、硬度、拉伸长度和断条率均最优。采用本实验方法制作米粉时,4#、5#、6#这3种大米加工的米粉品质较好,为进一步确定四川方便米粉原料标准化提供了参考依据。     

不同淀粉添加和老化时间对干米粉品质的影响

为研究不同淀粉添加和老化时间对干米粉品质的影响,以干米粉复水率、断条率、质构特性、感官特性品质为考察指标,研究干米粉加工过程中不同比例玉米淀粉、木薯淀粉和不同老化时间处理对其品质的影响。结果表明,添加适量淀粉可明显改善干米粉的复水率和断条率;随着老化时间的延长,米粉的硬度、弹性逐渐增大,黏性降低,淀粉链的结构呈现有序化的趋势。因此,添加20%玉米淀粉或40%木薯淀粉老化6 h,干米粉品质较好。     

鲜湿米粉原料适应性改良研究

通过对大米糊化特性和淀粉组成进行分析,选择一种鲜湿米粉加工适应性差的早籼米作为改良试验原料。试验以辅料不同添加比例为单因素,米粉蒸煮损失和感官评分作为评价指标,进行正交设计的优化试验。确定的最佳辅料配方为玉米淀粉15%、小麦淀粉10%、米粉头子6%,在此条件下,鲜湿米粉蒸煮损失率为10.7%,感官评分为80分,接近优质原料生产米粉。     

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