Effect of thermal processing on the concentration and bioaccessibility of rare earth elements in seaweed and oyster

An in vitro digestion method was used to investigate the effect of thermal processing on rare earth elements (REEs) content and bioaccessibility in seaweed and oyster. For raw and thermal processed seaweed, the REEs content was determined to be 2.60 to 2.67 mg kg−1 dry weight by ICP-MS, respectively. For oyster, the REEs concentration ranged from 2.61 to 3.17 mg kg−1, in increasing order, fried < raw < steamed. No significant difference in the concentration of REEs was found between raw and thermal processed samples. Regarding seaweed, the thermal treatment had a significant effect in increasing the REEs bioaccessibility, from 33.33 to 77.68%. On the contrary, the thermal processing had an apparent reduction effect on the REEs bioaccessibility on oyster. Comparing the raw and thermal processed samples, the results indicated that thermal processing had a considerable effect on the bioaccessibility. These data provide additional reference information to properly assess dietary risks of REEs in aquatic products. Practical applications Rare earth elements (REEs) have been widely used in many fields, especially in agricultural activities in China over the last two decades. With the wide-scale application, there is the potential to create an accumulation of REEs in the food chain and a number of environmental risks to human health. This work was to provide information on the content and in vitro bioaccessibility of REEs in seaweed and oyster before and after thermal processing. These data could truly estimate the health risk and provide a basis for developing standards of REEs in seafood.