冷冻处理对糙米水分迁移以及微观结构的影响

以糙米为原料,采用低场核磁和扫描电镜研究冷冻处理对糙米水分迁移和微观结构的影响。低场核磁结果表明,冷冻处理后,糙米结合水横向弛豫时间和质子密度达到稳定时的时间为未冷冻处理糙米的1/3;扫描电镜实验结果证实冷冻后糙米表面有裂痕产生且糙米内部淀粉颗粒之间缝隙增大,说明冷冻处理增加了糙米的吸水速率。

The effect of freezing treatment on moisture migration and microstructure in brown rice

The effect of freezing treatment on moisture migration in brown rice was studied using low-field nuclear magnetic resonance (LF-NMR) and the microstructure was also observed under a scanning electron microscope (SEM). After freezing, cracks appeared on the surface of brown rice with the increasing space of the starch granule. In addition, it took one-third of the time to reach the stable stage of proton density for frozen brown rice compared to the regular brown rice. Correspondingly, transverse relaxation time of bound water (T₂₁) was in the same ratio of the regular brown rice. The result indicated freezing treatment could increase the water absorption rate of brown rice.