Alcohol oxidase- and formaldehyde dehydrogenase-based enzymatic methods for formaldehyde assay in fish food products

► Two enzymatic methods for assay of formaldehyde have been developed. ► An applicability of both methods for formaldehyde assay in fish was demonstrated. ► Oxidase-peroxidase-based method is the most sensitive for formaldehyde analysis. ► Hake and cod contain high formaldehyde concentrations (up to 100 mg/kg wet weight).