不同鲜食玉米灌浆期籽粒主要营养成分的积累动态

通过理化方法对5种不同类型的14个鲜食玉米品种在不同灌浆期籽粒的营养成分进行分析,研究不同类型鲜食玉米籽粒主要营养成分的积累动态,以期筛选能够充分反映品种品质特性的客观理化指标,为鲜食玉米最佳采收期的确定以提高我国鲜食玉米的品质提供理论参考和试验依据。结果表明:鲜食玉米灌浆期籽粒的可溶性总糖、蔗糖、还原糖、蛋白质、支链淀粉、直链淀粉和含水量在不同品种间、不同灌浆期间差异极显著;随着籽粒的发育,不同类型鲜食玉米品种的可溶性总糖和蔗糖含量呈动态曲线变化,变化趋势都是先上升后下降;还原糖含量和含水量呈不断下降的趋势;直链淀粉和支链淀粉含量呈不断上升的趋势;蛋白质含量变化幅度很小,变化趋势不明显;这些成分的变化速率在不同类型的鲜食玉米之间存在差异;根据鲜食玉米营养成分与品质的关系,初步提出籽粒含水量结合可溶性糖含量、籽粒含水量结合粗淀粉含量可作为甜玉米和糯玉米最佳采收期的指标。 英文摘要: To study the accumulated dynamic of main nutrient composition in different fresh corn grains, the main nutrient composition in grains of 14 fresh corn varieties belonging to five different types were analyzed during its different filling stage using physical and chemical method, in the hope of screening some objective quality evaluation indices, which would provide theoretical reference and experimental basis for determining the optimum harvesting time and improving the quality of domestic fresh corn. The main results were as follows: there were significant differences in total soluble sugar content, sucrose content, reducing sugar content, protein content, amylopectin content, amylose content and moisture content in grains among different filling stage as well as different fresh corn varieties. Along with the development of grain, the dynamic changing curve of total soluble sugar content and sucrose content were similar, which both increased gradually first and then decreased gradually; reducing sugar content and moisture content gradually decreased, while amylopectin content and amylose content gradually increased; protein content didn’t show much variation and clear tendency; but the rate of change of those nutrient composition was different among different fresh corn types. According to the relation between nutrient composition and quality, moisture content with total soluble sugar content and moisture content with crude starch content in grain should be adopted as the optimum harvesting index for sweet corn and waxy corn. 查看全文
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