辐照改良水稻淀粉特性的研究

以相似AAC的不同类型水稻 (籼稻、粳稻和杂交稻 )和不同AAC早籼稻品种为材料 ,研究了辐照对淀粉粘滞性、理化品质和淀粉颗粒的影响。研究表明 ,最高粘度 (PKV)、热浆粘度 (HPV)、冷胶粘度 (CPV)、消减值 (SBV)和回复值 (CSV)等 5个RVA谱特征参数随剂量增加均显著下降。辐照明显降低了低AAC品种、糯稻和中等AAC品种的AAC ,但对高AAC品种的AAC影响不显著。辐照对碱消值 (ASV)无影响 ,但最高粘度时间 (PKT)随剂量增加而下降。胶稠度尤其是高AAC的胶稠度 (GC)随剂量增加明显提高。胚乳内淀粉颗粒经辐照处理也有所变形。结果表明 ,辐照可提高稻米食用和蒸煮品质。

IMPROVEMENT OF RICE STARCH BY GAMMA IRRADIATION

Three types of rice cultivars,Indica,Japonica and hybrid rice,with similar intermediate apparent amylose content (AAC) as well as early Indica rice cultivars with different amounts of AAC were selected for studing the effects of gamma irradiation on starch viscosity,physico|chemical properties and starch granule structure.Four major parameters of RVA profile,peak viscosity (PKV),hot paste viscosity (HPV),cool paste viscosity (CPV),setback viscosity (SBV) and consistence viscosity (CSV) were considerably decreased with increasing dose levels.Gamma irradiation reduced the amylose contents in the cultivars with low AAC,intermediate AAC,and glutinous rice,but had no effects on the high AAC cultivar.No visible changes in alkali spreading value (ASV) were detected after irradiation,but the peak time (PKT) were reduced with the dose level.Gel consistency (GC) were significantly increased in the tested cultivars,especially in the high AAC Indica rice, suggesting that it is promising to use gamma irradiation to improve eating and cooking quality of rice.