High pressure assisted extraction for cadmium decontamination of long rice grain

Cadmium (Cd) ranks seventh in the World Health Organization (WHO) priority list of hazardous toxic substances. In this study, a high-pressure extraction (HPE) method was explored for Cd decontamination in rice, and the process was compared with the traditional washing method. Optimal extraction conditions were achieved with experimental constraints. For washing, the Cd removal efficiency was 66% for intact rice grain and almost 100% for rice flour but only after washing for 20 h at pH 3.0; For HPE, a 600 MPa-10 min treatment at pH 5.5 yielded an extraction efficiency of 43% for rice grain and 82% for rice flour. No major changes in rice quality were observed after the HPE decontamination process. The Cd removal efficiency was further enhanced by multiple HPE cycles, almost reaching the 100% level. The HPE method has several attributes, including efficiency, preservation of rice quality and capability to remove Cd from rice grain and rice flour. This is the first study on HPE decontamination of Cd from rice. •.●High pressure extraction (HPE) is far superior for removing cadmium (Cd) from rice.•.●HPE (pH, pressure, duration, particle size) are significant factors for Cd removal.•.●HPE of 600 MPa/10 min at pH 5.5 yielded an extraction efficiency of 82% for rice flour.