籼米淀粉的流变性及其提取纯化的研究     

纪良宽  周裔彬  任琪 《农产品加工．学刊》2006,(11):7-10,69

对籼米淀粉微观结构进行分析。结果表明,随着温度的升高,淀粉颗粒的粒径增大,在温度为80℃时,淀粉囊开始破裂,从而导致直链淀粉游离出来。与此同时对籼米淀粉流变性进行研究实验,结果表明,随着温度的升高,其黏度上升,随着剪切速率的上升,黏度反而下降,从而得知籼米淀粉为典型假塑性流体。  相似文献   

Development of near-isogenic lines of wheat carrying different null Wx alleles and their starch properties   总被引：3，自引：0，他引：3  

H. Miura  M.H.A. Wickramasinghe  R.M. Subasinghe  E. Araki  K. Komae 《Euphytica》2002,123(3):353-359

The granule-bound starch synthase (GBSS I) encoded by the Wxgenes, is involved in amylose synthesis. For analyses of mechanisms of amylose synthesis and associated starch properties in hexaploid wheat, eight possible genotypes having different combinations of the three null alleles at the Wx loci with a common genetic background are a prerequisite. A near-isogenic population of doubled haploid (DH) lines was produced from Chinese Spring × waxy Chinese Spring F₁ plants using the wheat × maize method. The Wx protein phenotypes of the DH progeny were examined by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and found that the null alleles at each of the three Wx loci segregated in a Mendelian fashion. A field trial demonstrated no differences between the eight types for ear emergence time, plant height and grain yield traits. Amylose content in the endosperm starch was highest in the wild type while lowest in the waxy type having no Wx proteins. Comparison between single null types and double null types indicated that the amylose synthesis capacity of Wx-A1a allele is the lowest. Pasting properties of starch are the highest in the waxy type, followed by the double null types. Consequently, both peak viscosity and breakdown were negatively correlated with amylose content. The chain-length distribution analysis of amylopectin structure revealed no clear difference among the eight types,suggesting that the reduced GBSS I activity due to introgression of the null Wx alleles does not affect either the chain length or the degree of branching of amylopectin. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

土壤质地对冬小麦淀粉组分积累动态及直支比的影响     

闫凌云  赵喜茹  郭天财  王应君  韩巧霞 《河南农业科学》2006,(10):16-19

研究了3个小麦品种在3种质地土壤上直链淀粉和支链淀粉的积累动态,结果表明:在不同质地土壤上,直链淀粉的积累动态均呈线性增长趋势;支链淀粉的积累动态均呈抛物线增长。直链淀粉积累动态在粘土和壤土上均达显著水平,砂土上达极显著水平。支链淀粉的积累动态在壤土上达显著水平,在砂土和粘土上则差异不显著。不同质地间直支比的动态变化差异不显著。  相似文献   

小麦胚乳Wx蛋白缺失对籽粒淀粉含量的影响   总被引：2，自引：0，他引：2       下载免费PDF全文

师凤华  徐杰  李保云  刘广田 《中国农业大学学报》2006,11(6):41-44

旨在通过比较不同的小麦胚乳Wx蛋白亚基缺失类型材料籽粒的Wx蛋白总量支直链淀粉含量及总淀粉含量,明确胚乳Wx蛋白对支直链淀粉合成的作用。利用SDS-PAGE方法鉴定了13个品种Wx蛋白亚基组成,并测定了这些品种的Wx蛋白总量、直、支链淀粉含量及直/支比。结果表明,任何Wx基因缺失都会造成Wx蛋白合成数量的明显著减少,随着Wx基因不表达的数量增多,Wx蛋白合成的减少量增多;糯麦的直链淀粉含量最少。Wx蛋白含量与直链淀粉含量和直/支链淀粉含量之间存在极显著和显著的正相关,r=0.860 0,r=0.810 8;Wx蛋白含量与支链淀粉含量之间呈中度相关,r=0.402 7,这说明Wx蛋白总含量对直链淀粉含量的大小起到决定性作用,而对支链淀粉和总淀粉含量只有一定影响;通过操纵Wx基因可以改变籽粒胚乳中的直链淀粉含量和淀粉的直/支比,进而达到改进淀粉理化特性和加工特性的作用。  相似文献   

Amylopectin Fine Structure and Rice Starch Paste Breakdown   总被引：1，自引：0，他引：1  

Xian-Zhong Han  Bruce R. Hamaker 《Journal of Cereal Science》2001,34(3):279

Ten rice starches with a fairly narrow range of amylose content, but wide variation in RVA pasting curves, were selected to study a possible relationship between amylopectin fine structure and RVA paste viscosity parameters. Amylopectin fine structure was found to significantly correlate with paste breakdown. Proportion of long chains of amylopectin (FrI) was negatively correlated (r=0·84, p<0·01) and proportion of short chains of amylopectin (FrIII) was positive correlated (r=0·89, p<0·001) with paste breakdown. The findings imply that amylopectin fine structure relates to the extent of breakdown of swollen granules and the viscosity after gelatinised starch granule structure is disrupted. The results suggest the possibility that lines can be selected with high proportion of amylopectin long chains for reduced paste breakdown.  相似文献