摘要
在储存过程中大米发生代谢活动,加上脱支酶等引起的酶促反应,使其直链淀粉含量增加而支链淀粉含量减少,从而改变了直链淀粉/支链淀粉比例。在同一储存温度下随着储存时间的延长,大米回生性能增强,粳米与籼米由于具有较高的直链淀粉含量,因此回生速度明显快于糯米。在同一储存时间下随着储存温度的提高,结晶熔融时温度无明显变化,但熔融时热焓值亦出现逐步升高的现象。另外,糊化后样品随冷藏时间的延长回生度增强,而熔融时的初始温度、峰值温度及终止温度则表现出逐步下降的现象。由于支链淀粉的重结晶过程对温度具有依赖性,在4℃时成核速度较快,而25℃下成核速率较慢,因此,样品糊化后25℃存放时淀粉回生速度明显慢于4℃时情况。
In storage process owing to metabolic activities and enzymatic reactions etc. caused by de-branching enzyme in rice, content of amylose increases and of amylopectin decreases making variation of ratio of amylase/amylopectin. As storage time extension at the same storage temperature, resuscitation properties of rice are enhanced. Meanwhile, resuscitation rate for japonica rice and indica rice was obviously faster than that of glutinous rice owing to their higher content of amylose starch. At same storage time as storage temperature rises, there was no obvious change of melting temperature of crystallization, but melting enthalpy also gradually increased. In addition, with prolonging of storage time at 4℃ resuscitation degree of sample ＇after gelatinization increased while there was a phenomenon of gradual decline for the initial temperature （To） , vertex temperature （Tp） and final temperature （Te） of melting. Nucleation rate was rapider at 4℃ than at 25℃ because of dependence of re-crystallization of amytopectin on temperature, therefore, resuscitation rate of starch at 25℃ after gelatinization was significantly slower than that at 4℃.
出处
《粮油加工（电子版）》
2015年第8期33-39,共7页
Machinery for Cereals Oil and Food Processing Main Contents
基金
2014年杭州市农业科研攻关专项基金资助(20140432B107)
