Abstract: This study processed Jingxi rice 7233 into reasonably well milled (RWM, bran degree 2.8%, 4.9%) and well milled (WM, bran degree 1.4%) grades, and compared the processing characteristics, physicochemical properties, fatty acid composition, volatile composition and taste quality between the two grades. The results showed that the average rice yield and head rice yield of RWM were 1.3% and 1.8% higher than those of WM, respectively. The contents of total phenolic acids, water-soluble protein, unsaturated fatty acids, especially polyunsaturated fatty acids, in RWM rice were more than 1.5 times as high as those in RWM rice. The color difference between RWM and WM rice was greater than 2.0, which could be perceived with the naked eye. Totally 62 characteristic peaks were marked by gas chromatography-ion mobility spectrometry (GC-IMS), and 38 compounds were accurately identified. The contents of 58% of volatile components were significantly higher in RWM rice than in WM rice. The cooking time of RWM rice was significantly longer than that of WM rice, and the breakdown viscosity of starch and stickiness were significantly lower than those of WM rice. RWM rice has great advantages in paddy utilization rate, nutrition and health, but further research and optimization are needed in terms of appearance, smell and taste quality.

Key words: Jingxi rice; reasonably well milled; well milled; fatty acid composition; volatiles; taste quality