【摘要】 二甲亚砜(dimethyl sulfoxide,DMSO)是淀粉精细结构分析中溶解淀粉的关键试剂。以普通玉米淀粉为原料,研究其在DMSO/水体系中的溶解性与精细结构变化。结果表明,当溶解时间达到12h后,普通玉米淀粉在90%DMSO溶液中溶解性达到最大值97.15%;随着溶解时间的延长,溶解性无显著变化。扫描电镜(SEM)结果表明,90%的DMSO对淀粉颗粒结构破环最大,证明90%DMSO是淀粉的最佳溶剂。然而进一步通过高效液相体积排阻色谱联用系统(HPSEC)、阴离子色谱(HPAEC)等技术研究发现,淀粉溶于90%DMSO后,随着溶解时间的延长,其分子量和回旋半径逐渐下降,在溶解过程中淀粉分子发生了降解,主要降解部分为支链淀粉的B2、B3链,而B1链相对稳定。更多还原

【Abstract】 Dimethyl sulfoxide(DMSO)is the key reagent to dissolve starch in the starch structural analysis.In this paper,solubility and structural changes of corn starch in DMSO/water system were studied.Corn starch achieved maximum solubility of 97.15% in 90%DMSO solution when the dissolution time reaches 12 h.With the excessive dissolution,no significant change in solubility was detected.Scanning electron microscopy(SEM)analysis showed that starch granules structure were the largest damaged in 90% DMSO,which confirmed that 90% DMSO was the best solvent for starch.High performance size exclusion chromatography(HPSEC)and high performance anion-exchange chromatography(HPAEC)found that the molecular weight and radius of gyration of starch dissolved in 90%DMSO gradually decreased with the extension of the dissolution time,which indicated that starch molecules were degraded.Furthermore,theB2 and B3chains of amylopectin were more easily to degrade,and the B1 chains were relatively stable.更多还原