Investigation of selenium content in rice in Nanning Area

Objective To investigate the situation of selenium enrichment in rice in Nanning City,provide a basis for scientific selenium supplementation and the development of selenium enrichment industry. Methods GB 5009.93-2017 National Standards for Food safety:Determination of Selenium in Food and GB/T 22499-2008 Evaluation Standard of Selenium-rich were used as the test and evaluation criteria,to detect and analyze the selenium content of 865 rice samples from five counties and seven urban areas of Nanning City from 2018-2019. Results From 2018-2019,the selenium enrichment rate of rice in Nanning City was49.25%,and the average selenium content was 0.053 3 mg/kg. The selenium enrichment rate was the highest in Jiangnan District(70.27%) and the lowest in Longan County(26.67%). The selenium enrichment rate of six regions was higher than that of rice from outside Nanning City,and the difference was statistically significant(all P<0.05). The selenium content was related to the the position and variety of rice,while the selenium content of whole grain was higher than that polished rice,and Simiao rice and Zayou rice were higher than Youzhan rice and Qiuyou rice. The selenium content of rice was positively correlated with arsenic,cadmium and mercury,but not with lead. Conclusion The average selenium content of rice in Nanning City is 0.049 1 mg/kg,and the daily intake of selenium is 38.7 μg,which is far lower than the daily recommended intake in China. Scientific supplementation of selenium and prevention of disease are still necessary measures to carry out healthy Nanning.