Isomerization and bioaccessibility of cypermethrin and fenpropathrin in Pacific oyster during simulated digestion as influenced by domestic cooking methods

Abstract

Pyrethroids can be ingested by humans through eating contaminated oysters, which is potentially harmful to health. This study aimed to investigate the effects of raw, steaming, and roasting on cypermethrin (CP) and fenpropathrin (FP) in oysters during simulated digestion. Results showed that the amount of released CP and FP was different from raw (CP: 0.617 µg·g−1, FP: 0.266 µg·g−1), steaming (CP: 0.498 µg·g−1, FP: 0.660 µg·g−1), and roasting (CP: 1.186 µg·g−1, FP: 0.588 µg·g−1) at the end of simulated digestion. The share of cis-CP and low-efficiency CP increased significantly (p < 0.05), and the share of high-efficiency trans-CP did not maintain a high level for a long time during simulated digestion. The fluorimetric titration and isothermal titration calorimetry confirmed that CP and FP could spontaneously interact with oyster actin, and CP could bind with oyster actin more tightly than FP. This study reveals that cooking methods affect the binding capacity of CP and FP to oyster tissues and influence the changes of CP and FP in oysters during digestion. Furthermore, the current study provides a reference for assessing the potential harm of pyrethroids in oysters to consumers.

Keywords

• cypermethrin
• fenpropathrin
• pyrethroids
• cooking methods
• simulated digestion
• isomers
• bioaccessibility
• fluorimetric titration
• isothermal titration calorimetry