白果直链/支链淀粉的分离及性能研究

摘要

以白果为原料,对其淀粉进行提取分离,对直/支链淀粉进行纯化,分别对其性能进行分析测定,测定结果如下:400～800 nm范围内全波长扫描,淀粉-碘络合物最大吸收波长不同,原淀粉与碘络合后在600 nm处,直连淀粉与碘络合后在620 nm处,支链淀粉与碘络合后在560 nm处;白果原淀粉、直链淀粉、支链淀粉在真空条件下干燥后,颗粒大小均在20 μm以下,且扫描电镜(SEM)显示白果原淀粉颗粒为椭圆状,提取后的白果直链淀粉及支链淀粉均无固定形状;DSC分析后发现含水量50％的白果直链/支链淀粉乳液峰值温度(Tp)为 138.23 ℃/76.6 ℃,均为糊化温度,含水量小于5％白果直链/支链淀粉Tp为117.56 ℃/94.83 ℃,均为脱残留水分的吸热峰.由凝胶色谱结果分析得到,白果直链淀粉由两种直链淀粉组成,分子质量分别为10.31和2.32 ku;白果支链淀粉分子质量为1 189.05 ku.%Starch was extracted and separated from Ginkgo biloba Linn.Its amylase and amylopectin were purified and their performances,e.g.maximum absorption wavelength,DSC,SEM,were analyzed.The results indicated that maximum absorption wavelength on starch,amylase and amylopectin of G.biloba was 600,620,and 560 nm separately by wavelength scanning from 400 nm to 800 nm.Their particles were less than 20 μm.The SEM images showed that the starch feature was ellipsoid and the amylase and amylopectin particles were not steady feature.The maximum endothermic peak of amylase and amylopectin with 50％water was 138.23 ℃ and 76.6 ℃.They were gelatinized.The maximum endothermic peak of amylase and amylopectin with less than 5％water were 117.56 ℃ and 94.83 ℃.They were dehydration peaks.The gel permeation chromatographic analysis(GPC)showed that the molecular weights of two amylases were 10.31 ku and 2.32 ku and the molecular weight of amylopectin was1 189.05 ku.