Cooking methods effectively alter perfluoroalkyl substances and nutrients in cultured and wild bullfrogs

Abstract

The ubiquitous distribution of perfluoroalkyl substances (PFASs) poses a threat to the health of aquatic organisms and humans. Bullfrogs are considered a popular aquatic food product in South China, providing high protein and tasty cuisine; however bullfrogs have been shown to contain significant concentrations of PFASs. However, the risk-benefit ratios of PFASs and nutrient contents in cooked bullfrogs are not well understood. PFASs and nutrients were investigated in raw and cooked specimens of cultured and wild bullfrogs in this study. Novel PFASs showed higher detection levels and accumulation in wild bullfrogs than in cultured bullfrogs. Potential factors such as fat and fatty acid ratio affected PFASs accumulation in different tissues and by different cooking methods of bullfrogs. All cooking methods can reduce PFASs in edible tissues while significantly enhancing the nutritive value index (NVI) compared to raw bullfrogs. Steaming was the most effective way to reduce PFASs (rate of reduction was over 66%) and resulted in a lower risk of contributing to arteriosclerosis than other cooking methods assessed by atherogenicity index (AI) values. Cultured bullfrogs instead of wild bullfrogs were recommended for human consumption, and steaming was regarded as a better cooking method in terms of risk-benefit concerns. Overall, this work provides quantitative analysis of cooking methods that alter PFASs and nutrients in bullfrogs.