不同鲜食玉米灌浆期子粒主要营养成分的积累动态

Dynamic of the Main Nutrient Ingredients Accumulated in Different Fresh Corn Grains During Filling Stage

摘要:

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子粒的营养成分进行分析，研究不同类型鲜食玉米子粒主要营养成分的积累动态，筛选能够指示不同类型鲜食玉米最佳采收期的客观理化指标。结果表明，鲜食玉米灌浆期子粒的可溶性总糖、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。随着子粒的发育，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。根据鲜食玉米营养成分与品质的关系，提出子粒含水量结合可溶性糖含量和粗淀粉含量可分别作为甜玉米和糯玉米最佳采收期的指标。

Abstract:

The main nutrient ingredients of grains in 14 fresh corn varieties were analyzed, and the accumulat-ed dynamic of these ingredients during filling stage were studied, aiming to screen the physicochemical index relat-ed with optimum harvesting time for fresh corn. The fresh corn was involved in five types, that is, sweet, enhancedsweet, super-sweet, waxy, and waxy+sweet. Many indexes of grain among filling stages and varieties showed signifi-cant difference, which included total soluble sugar content, sucrose content, reducing sugar content, protein content, amylopectin content, amylose content and moisture content. Along with grain developing, the dynamic curves of total soluble sugar content and sucrose content were similar, both increasing gradually and then decreasing gradually; the reducing sugar and moisture contents gradually decreased; the amylopectin and amylose contents gradually in-creased; protein content was relatively stable. According to the relationships between grain nutrient ingredients and grain quality, that moisture content together with total soluble sugar content and crude starch content in grain should be adopted as optimum harvesting index of sweet corn and waxy corn.