Comparison of Trace Element Contents between Brown Rice and Polished Rice.

The National Agricultural Products Quality Management Service (NAQS) analyzes agricultural products from potentially contaminated land with trace elements to prevent contaminated agricultural products from distribution before their distribution. Base on the results of the analysis, NAQS can order owner of the land which has been used for contaminated agricultural products to fallow or to use the land for non-food crop production. Rice has been collected from potentially contaminated land and analyzed for trace elements as part of general survey of trace element content in agricultural products each year. The huge number of rice samples concentrated at harvest time makes fast analysis difficult. Analysis of polished rice is the standard method of analysis for rice in Korea. It would be of great help if brown rice can be used for rice analysis considering the length of time required for rice polishing process. This study was carried out to find out potential use of brown rice for rice analysis by comparing trace element contents in brown rice and polished rice. For that, 1992 sets of processed rice samples were analyzed for Cd, Pb, As and Hg after processing for brown rice and polished rice. Results showed that Cd contents in polished rice and brown rice were in the range of 0~1.56mg/kg and 0~1.64mg/kg, respectively; Pb contents 0~0.21mg/kg and 0~0.25mg/kg; Cu contents 0.07~8.41mg/kg and 0.12~8.15mg/kg; As contents 0~0.92mg/kg and 0~1.09mg/kg; and Hg contents 0~0.05mg/kg and 0~0.05mg/kg, respectively. Results of the pared T-test showed that the significance probability of 95% confidence level was 0.021 for Cd and 0 for Pb, Cu, As and Hg indicating a potential of analyzing brown rice for standard method of rice analysis.