Arsenic concentrations in at home prepared cooked and fried rice

Abstract

Rice is the most widely consumed food for a large part of the world containing a variety of essential nutrients, but can also be contaminated with toxics like arsenic. This study analyzes the effect of cooking and frying, processed in the consumer’s kitchen, on arsenic concentrations Firstly, arsenic concentrations were measured in a number of rice species from Thailand and Turkey, available in supermarkets. The effect of cooking was studied in both white and brown rice with time of cooking and rice: water ratio as recommended by the producer. Part of the cooked rice was fried together with other ingredients for the preparation of the popular dish nasi goreng. Arsenic concentrations were measured with instrumental neutron activation analysis. Only one of the ten analyzed species contained an arsenic concentration beyond the European maximum limit of 0.3 mg/kg. Cooking of white rice resulted in a decrease of the arsenic concentration by 46%, while the concentration in brown rice was reduced by 27%. The preparation of the fried rice dish nasi goreng resulted in an additional reduction by 20% per weight unit, which should be attributed for the most part to a diluting effect by the addition of the other ingredients. Heating of rice without water reduced the arsenic concentration only by 10%. Cooking and frying of rice according to recommendations by the producer, result in a significant reduction of the arsenic concentration.