Study on improvement of the quality of brown rice by infrared pretreatment

The infrared (IR) pretreatment was used to investigate the quality of brown rice (BR) . Various factors, such as the initial moisture content of BR, IR irradiation distance and treatment time on quality of BR were examined. Meanwhile, surface morphologies of BR before and after treatment were observed by scanning electron microscope (SEM) . The results showed that the residual of lipase activity and catalase activity of treated BR was 69.8% and 70.8%, respectively, and the free fatty acid value was decreased 9.5mg KOH/ (100g BR) when the initial water content of BR, IR irradiation distance and treatment time was controlled at 15%, 20 cm, and 5min, respectively. In addition, the surface of treated BR formed many microspores, and the edges of starch granules disappeared. Therefore, these results revealed that IR pretreatment could not only stabilize the lipase enzyme activity of BR to ensure the safety storage, but also improve the cooking quality of BR.