Selenium accumulation in different brown rice cultivars and its distribution in fractions

The goal of this paper was to study the accumulation of selenium (Se) in different cultivars of brown rice and its distribution in fractions. The results of the study showed that Se content in brown rice increased significantly (P < 0.01) as the external selenite or selenate concentrations increased from 10 to 180 micromol/L. In contrast, no significant influence (P > 0.05) on germination percentage and growth of sprouts was observed when the supplied Se was lower than 60 micromol/L. Moreover, selenite was easily transformed into selenoproteins to selenate. Based on this, ten brown rice cultivars were compared for Se accumulation. Likewise, significant difference (P < 0.01) was found among cultivars with respect to the capacity for Se accumulation. To understand the distribution of Se in selenized brown rice and its loss during milling, two cultivars with relatively higher ability to accumulate Se, namely, Zhendao 8 (Z8) and Xieyou 57 (X57), were selected for further study. The results showed that Se content was highest in the sprouts and decreased remarkably (P < 0.01) from the bran layers to the endosperm. In terms of Se loss during the milling procedure, 39.02% and 48.46% of Se were lost in Z8 and X57, respectively.