Impact of thermal cooking processes on organochlorine pesticide residues (OCPs) in the edible green seaweed, Ulva lactuca, and associated human health risk assessment

Seaweeds are emerging natural food items in different countries. However, they are known to be potentially contaminated by chemical residues. This study examined the impact of domestic cooking methods such as boiling, steaming, and microwave cooking on reduction of organochlorine pesticide (OCP) level in edible green seaweed Ulva lactuca. Thermal cooking processes significantly influences the OCP residues in U. lactuca. The OCP residue concentration decreased after boiling, steaming, and microwave cooking compared to raw seaweed. The total OCP residue concentration in raw seaweed was 0.707 mg/kg, which reduced to 0.168, 0.178, and 0.241 mg/kg after boiling, microwaving, and steam cooking, respectively. Aldrin, endrin, DDT, and endosulfan were predominant OCPs in raw and processed seaweeds. Health risk due to OCP residues was evaluated using food consumption data, acceptable daily intake, and safety indices such as hazard quotient (HQ) and hazard index (HI). The HQ and HI values did not exceed the unit value (HQ, HI < 1), indicating that the level of OCP residues in U. lactuca does not pose any appreciable risk to the consumers. Therefore, the research finding establishes that different thermal cooking processes reduce the OCP residue concentration in U. lactuca.