不同类型小麦品种大、小淀粉粒的分离和特性

为给小麦品质育种提供依据,以3个不同类型的小麦品种(济南17号、扬麦12号和扬麦9号)为材料,分离了大、小淀粉粒,并对它们的特性(形状、大小、膨胀势、晶体特性、糊化特性等)进行了测定和分析.结果表明,大、小淀粉粒形状为椭球形或球形,品种间无差别,但其大小和含量在品种间存在很大差异;大淀粉粒的膨胀势大于小淀粉粒.大、小淀粉粒都为A型淀粉晶体,大淀粉粒的相对结晶度差别不大,但小淀粉粒的相对结晶度差别较大,表现为济南17号＜扬麦12号＜扬麦9号.品种内大淀粉粒的起始温度To、峰值温度Tp值和吸收热焓△H高于小淀粉粒,终止温度Tc值却比小淀粉粒低.

Isolation and Properties of Large and Small Starch Grains of Different Types of Wheat Cultivars

Large and small starch grains were isolated from three different types of wheat cultivars(Jinan 17,Yangmai 12 and Yangmai 9),and their properties(morphology,size,swelling power,crystalline properties,thermal properties) were investigated in this paper.Results indicated that large and small starch grains were oval to round in shape.There were no detectable differences in the granule morphology,but the average diameters and proportion(wt %) of large and small starch grains were different among varieties.Swelling power values for large starch grains were higher than that for small starch grains.The X-ray diffraction patterns of the starch grains exhibited the character of an A-type crystal.The relative crystallinity of large starch grains exhibited a smaller range,while the relative crystallinity of small starch grains exhibited a greater range with Jinan 17 as the lowest and Yangmai 9 as the highest.The transition temperature and enthalpy values of large starch grains were higher than those of the small starch grains except the conclusion temperature of small starch grains which was higher than that of large starch grains.