Improving the eating quality of brown rice by defatting combined with hydrothermal treatment

Abstract

Aiming at consumer acceptability of brown rice such as cooking difficulty and coarse taste, the effects of defatting and hydrothermal treatment alone or in combination on the texture and sensory score of cooked brown rice were studied, and the improvement mechanism was explored through cooking quality and microscopic morphology. The results showed that defatting combined with hydrothermal treatment could significantly improve the quality of brown rice, the hardness and chewiness of treated cooked brown rice decreased respectively from 20.385 N and 10.221 N to 14.494 N and 6.886 N, and the sensory score increased from 68.90 to 83.50. The room temperature water absorption rate of the treated brown rice increased from 10.72 % to 29.71 %, which was much higher than that of polished rice. The cooking quality of the treated brown rice was obviously improved, the optimal cooking time decreased from 30.33 min to 22.67 min, and the heating water absorption, volume expansion rate and solid loss increased from 147.32 %, 255.20 % and 13.35 mg/g to 219.15 %, 400.39 % and 22.49 mg/g, respectively. Scanning electron microscope showed that defatting combined with hydrothermal treatment significantly increased cracks and micropores of brown rice grains, which may be the intrinsic reason for the improvement in room temperature water absorption rate and cooking quality of brown rice and thus eating quality of cooked brown rice. The results are of great significance for promoting the staple consumption of whole-grain brown rice with broad application prospects.