过热蒸汽改性典型晶型淀粉的理化性质研究

Studies on Physicochemical Properties of Typical Crystalline Starches by Superheated Steam Treatment

以玉米淀粉(A型)、马铃薯淀粉(B型)和豌豆淀粉(C型)等3种典型晶型淀粉为对象,分析比较过热蒸汽短时间处理改性淀粉的颗粒形貌、粒径、热焓特性、糊化特性及结晶特性。结果表明,通过改性处理,3种晶型淀粉相对结晶度均极显著降低(P<0.01),玉米淀粉晶型由A型转变为A+V型,马铃薯淀粉、豌豆淀粉的晶型分别由B型、C型转变为A型;改性的玉米、马铃薯、豌豆淀粉颗粒发生膨胀,粒径极显著增大(P<0.01),糊化温度升高,糊化焓极显著减小(P<0.01),淀粉糊化的稳定性和抗剪切性能明显增强。3种改性淀粉的理化性质存在较大差异。相对结晶度和晶型是导致改性淀粉性质差异的主要原因。

In order to investigate the modification effects of superheated steam on the physicochemical properties of starch, three starches including corn, potato, and pea with typical crystal type A, B and C, respectively, were used. The changes of granule morphology, particle size, gelatinization enthalpy, pasting properties and crystalline properties of the starches were compared and analyzed. The results showed that the relative crystalline were significantly reduced （P〈 0.01）. Crystal structure of corn starch turned into （A＋V） type, while crystal structure of both potato starch and pea starch turned into A type. Modified starch granule expanded and particle size increased significantly （P〈0.01）. Gelatiniza- tion temperature increased and gelatinization enthalpy decreased （P〈0.01）, and gelatinization stability and shear resistance increased obviously. However, it was discovered that the main reason of the different physicochemical properties of three modified starches were, the differences of relative crystallinitiy and variations of crystal structure.