湿热处理对玉米淀粉理化性质及消化性的影响

Effects of Heat-Moisture Treatment on Physicochemical Properties and Digestibility of Maize Starch

在不同的水分含量下对普通玉米淀粉进行了湿热处理,研究了湿热处理对玉米淀粉颗粒形貌、黏度、热力学性质、结晶性和消化性的影响.结果表明:湿热处理玉米淀粉的颗粒外形仍保持完整,但颗粒表面出现破损,偏光十字仍存在,高水分含量下处理时部分偏光十字消失;经湿热处理后,淀粉起糊温度提高,峰值黏度、终止黏度和崩解值下降,淀粉糊化过程吸热焓变减小;结晶度随湿热处理水分含量先增加后减小,在高水分含量下处理的淀粉中出现A+V型结晶峰,表明形成了淀粉脂质复合物;抗性和慢消化淀粉含量随湿热处理水分含量的提高而增加.

Heat-moisture treatment（ HMT） was performed for normal maize starch with different moisture contents,and the effects of HMT on the morphology,viscosity,thermodynamic properties,crystallinity and digestibility of the starch were investigated. The results show that（ 1） the integrity of starch granules with HMT keeps well but fragment appears on the granules surface;（ 2） the polarization cross still exists in the treated starch but it partially disappears at high moisture content;（ 3） after the HMT,the gelatinization temperature of starch increases,the peak viscosity,the terminal viscosity,the breakdown value and the gelatinization enthalpy decrease,while the crystallinity first increases and then decreases with the increase of moisture content;（ 4） A ＋ V crystal pattern appears in the starch treated at high moisture content,which indicates the formation of starch-lipid complex; and（ 5） the contents of resistant starch and slow digestible starch in the starch with HMT both increase with the increase of the moisture content.