Reduction of potentially toxic elements content of dried laver Pyropia spp. using ultrasonic treatment

The study sought to remove potentially toxic elements (PTEs), such as cadmium (Cd), lead (Pb), arsenic (As), and iodine (I), from raw laver Pyropia spp. using ultrasonic treatment and to determine the impact of such reduction on raw laver quality. Notably, the treatment had no effect on dried laver color. The following optimal conditions were used for response surface methodology: ultrasound intensity, 75 % at 449.8 W; raw laver amount, 150 g/L; and treatment time, 10 min. Heat generation was reduced to tolerable levels during ultrasonic treatment. By applying the optimal conditions, the levels of Cd, Pb, and As were reduced by 80.8-83.0 %, while that of I was reduced by 90.1 %. The energy released by the bubbles generated during ultrasonic treatment collapsed due to shock waves, enabling PTEs removal. The study highlighted the effectiveness of ultrasonic treatment in ensuring the safety of raw and dried lavers for consumption.