米糠对糙米重组米糊化特性及回生动力学的影响

Effect of rice bran on gelatinization and retrogradation properties of restructuring brown rice

以糙米粉为营养重组米原料,采用差示扫描量热法(DSC),对比了普通糙米重组米和添加了米糠制备的糙米重组米糊化特性的差异,糊化测试扫描温度由20℃逐渐升至100℃,再由100℃逐渐降至20℃,扫描速率为10℃/min,测定时以空坩埚作为对照,载气为氮气,氮气的流速为20ml/min;通过DSC和Avrami方程研究营养重组米的回生特性,将两种重组米蒸煮至彻底糊化,回生条件为4℃,回生时间为1、3、5、7、14和21d。试验结果表明,在相同的生产工艺条件下,添加了钝化米糠的糙米重组米糊化温度升高,糊化焓值降低,热稳定增强;与普通糙米重组米相比,添加了钝化米糠的糙米重组米结晶速率常数k较低,指数n较大,表明添加了钝化米糠的糙米重组米在储存期具有更低的回生速率,即钝化米糠对糙米重组米的回生具有抑制作用。

With rice flour as raw materials for the nutritional restructuring rice,the effect of rice bran on gelatinization and retrogradation properties of restructuring brown rice was researched.The different gelatinization characteristics of the restructuring brown rice and that added rice bran were compared by the differential scanning calorimetry（DSC）.The scanning temperature rose from 20℃ to100℃ and dropped on the contrary.The scanning rate was 10℃ per minute and a 20 milliliter per minute nitrogen was used as the carrier gas.The DSC and Avrami equation were used to research the two kinds of restructuring brown rice.The thoroughly steamed two kinds of restructuring brown rice＇s retrogradation periods were 1,3,5,7,14 and 21d.The result showed that the gelatinization temperature of restructuring brown rice added rice bran of deactivation rose and its gelatinization enthalpy reduced,thermal stability enhanced.Compared with the general one,the retrogradation rate constant kof restructuring brown rice added rice bran of deactivation reduced,while the index of nincreased.Therefore the addition of the rice bran of deactivation had lower retrogradation rate in the storage period,which meant that the rice bran of deactivation could weakened the retrogradation.