The removal of cadmium from rice optimized by response surface methodology

Abstract

ObjectiveTo reduce the content of cadmium in rice， the method of cadmium removal from rice was established and the extraction conditions were optimized by response surface methodology.MethodsThe cadmium extraction rate was used as the index to screen the cadmium removal methods. Commercially available cadmium positive rice was chosen as the test sample and four kinds of food grade organic weak acids were chosen as extractants. The concentration of acid solution， extraction time， solid-liquid ratio and rice powder particle size were used as independent variables to carry out the single factor extraction. And the optimal conditions for removing cadmium from rice was obtained by response surface design.ResultsThe optimal conditions for removing cadmium from rice were 4.2% acetic acid solution， 11 min extraction， liquid-to-material ratio 13：1 （mL/g）， and at least 50 mesh for rice flour. Under these conditions， the average removal rate of cadmium in rice was 98.67%.ConclusionThe experimental model is reasonable and the optimized extraction method is feasible. The removal or reduction of cadmium in raw rice is realized with optimal cadmium extraction conditions， which provides a scientific method for the research on cadmium removal from cadmium-contaminated rice.

Keywords

• organic acid
• rice
• cadmium
• response surface methodology