Abstract: Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to determine three pesticide residues including carbendazim, diethofencarb and prochloraz in four different processed products of Agaricus bisporus. Meanwhile, the key process and parameters for reducing pesticide residues were analyzed. The results showed that the percentage removal of three pesticide residues by different processing methods were in the following decreasing order: canning > salting > quick freezing > freeze drying, and the residual levels of pesticides in these processed products were in the ranges of 3.4%–11.7%, 11.5%–22.3%, 61.5%–86.1% and 150.4%–152.3% respectively. Washing and heating were the key steps for reducing 3 pesticide residues in canned products. Soaking in Na2CO3 solution for 25 minutes was the most effective among these processing treatments, resulting in 37.2% removal of carbendazim. The percentage removal of three pesticides were increased by increasing precooking time, which were 22.0%, 15.9%, and 17.1%, respectively after precooking for 14 minutes.

Key words: Agaricus bisporus, processing, control, carbendazim, pesticide residue