Mutagenicity Arising from Boiled Rice on Treatment with Nitrous Acid

Abstract
When an aqueous homogenate of boiled rice was treated with nitrous acid at pH 3, direct‐acting mutagens were formed. The presence of the mutagens was demonstrated by isolating the mutagenic fractions through blue‐rayon adsorption, a method used to extract polycyclic compounds, and subsequent high‐performance liquid chromatography (HPLC). The mutagens were active in Salmonella typhimurium TA100 and TA98 without metabolic activation. Several different mutagens were formed, as judged from the HPLC profile.