Effect of precooking with sodium chloride and citric acid on residual amounts of lead and cadmium in rice

Rice contamination with heavy metals has always been one of the main concerns of food health. The purpose of this research is to investigate the rice effect of the precooking process with sodium chloride and citric acid on the amounts of residual lead (Pb) and cadmium (Cd). In the current study, eight brands of high-consumption rice were used in the Arak-Iran market and their amounts of Pb and Cd were measured using graphite furnace atomic absorption spectrometry. Two rice brands, Pakistani Moeid and Indian 21, which contained the highest amounts of Pb and Cd, were selected and treated with soak (for 4h) and boiling (for 60 min) in 1% sodium chloride and 0.6% citric acid. The results showed that precooking Pakistani Moeid and Indian 21 rice samples with 1% NaCl reduced the amount of Pb by 15.7% and 16.2%, respectively. Furthermore, the amount of Cd was reduced by 10.5% and 10.8% for Pakistani Moeid and Indian 21, respectively. Furthermore, the results for precooking of Pakistani Moeid and Indian 21rice samples with 0.6 % citric acid showed a reduction in the amount of Pb by 9.3% and the amount of 8.9% and Cd by 11% and 9.6%, respectively. These numbers were in comparison with precooking rice with pure water. According to the results of this research, precooking rice samples with NaCl reduces the amount of Pb more effectively than that of Cd. Furthermore, precooking rice with citric acid reduces the amount of Pb and Cd by almost the same amount. In general, precooking rice with NaCl is more effective in reducing heavy metal contamination compared to citric acid.