【摘要】 通过控制酶解时间和加酶量对淀粉颗粒进行水解,制备了水解率相近的微孔淀粉,并通过扫描电子显微镜分析、差式扫描量热分析、小角X射线散射分析等方法研究了酶解时间和加酶量对淀粉颗粒聚集态结构的影响.结果表明:水解率相近的前提下,加酶量多、酶解时间短的微孔淀粉破碎程度高于加酶量少、酶解时间长的样品,但后者淀粉颗粒内部及无定形区被大量水解,颗粒内部出现大的空腔;随着水解率的增大,淀粉的焓值减小,在较高酶解程度下,酶解时间长的微孔淀粉焓值下降更明显;在酶解过程中,淀粉颗粒的聚集态结构发生变化,无定形区及半结晶区结构均受到影响,提高加酶量主要影响半结晶区的水解,而延长酶解时间主要影响无定形区的水解.更多还原

【Abstract】 A series of porous starches with similar hydrolysis rates were prepared by controlling the hydrolysis time and the enzyme dosage. The influences of the hydrolysis time and the enzyme dosage on the aggregation structure of starch granules were investigated by means of SEM,DSC and the small angle X- ray scattering( SAXS). Experimental results indicate that( 1) at similar hydrolysis rates,starch granules with a shorter hydrolysis time and a higher enzyme dosage are broken more significantly than those with a longer hydrolysis time and a lower enzyme dosage,but the amorphous region and the inner part of the latter were hydrolyzed more seriously with a bigger cavity inside the granules;( 2) the enthalpy of the starches decreases with the increase of the hydrolysis rate,and it decreases more obviously with the extension of the hydrolysis time at a higher hydrolysis rate; and( 3) during the hydrolysis,the aggregation structures of starch granules change in the amorphous region and the semi- crystalline region; specifically,the hydrolysis time and the enzyme dosage mainly affects the semi- crystalline region and the amorphous region,respectively.更多还原