直链淀粉含量不同的稻米淀粉结构、糊化特性研究

选用直链淀粉含量不同的4个水稻品种，研究其淀粉体结构和糊化特性。发现不同品种的淀粉体结构、糊化特性随直链淀粉含量的不同呈现一定的变化规律。直链淀粉含量从3.43%至21.65%，其晶体类型为A型，相对结晶度呈下降趋势，消减值表现为升高趋势，相对结晶度和消减值与直链淀粉含量分别呈显著负相关和极显著正相关(r=－0.964*, r=0.997**)，消减值与结晶度呈显著负相关（r=－0.960*）。米粒的背部和腹部间淀粉体大小和排列有所不同，糯性或低直链淀粉含量与非糯性或高直链淀粉稻米的胚乳结构存在差异，淀粉体排列以糯稻较紧，粳稻次之，籼稻最松。淀粉的相对结晶度可能与胚乳中淀粉体的形状和紧密程度有关。

Starch Structure and Paste Property of Rice with Different Amylose Content

Four rice cultivars with different amylose content were used to investigate the starch structure and RVA pasting properties in this study. The results showed that differences existed between rice cultivars. Relative crystallinity decreased and setback viscosity increased with increasing amylose content, and there were significant negative and positive correlations between relative crystallinity and amylose content, amylose content and setback viscosity, respectively(r=-0.964, r=0.997). Correspondingly, the significant negative correlation of setback viscosity with relative crystallinity was discovered (r=-0.960). The crystallinity patterns of four rice starch cultivars showed as typical A type with amylose content ranged from 3.43% to 21.65%. Endosperm structure was different between glutinous or low-amylose and non-glutinous or high-amylose rice, and the arrangement and shape were different between the dorsum and abdomen of amyloplast in rice endosperm. The results implied that the shapes and arrangements of starch granule in endosperm might influence the relative crystallinity of rice starch.