Changes in cadmium concentration in rice during cooking

Abstract

We have studied changes in cadmium concentration during the cooking of rice (Oryza sativa japonica) to estimate actual intake. Samples included highly contaminated rice. Cooking involved washing and soaking rice, then cooking it in an electric ricecooker. Cadmium concentration was determined using ICP-MS. Inorganic element concentrations of P, K, Mg, Ca, Mn, Zn, Fe, and Cu were mainly decreased by washing step. Cadmium concentration was only slightly decreased by cooking and less so than other inorganic elements. In cooking of polished rice, cadmium concentration in cooked rice was about 95% of that in raw rice on a dry basis.