ANTIMUTAGENICITY OF HEAT-DENATURED OVALBUMIN, BEFORE AND AFTER DIGESTION, AS COMPARED TO CASEINATE, BSA, AND SOY PROTEIN

The antimutagenicity of ovalbumin was investigated and compared to tha t of sodium caseinate, bovine serum albumin and soy protein. Antimutag enicity was measured against N-methyl-N'-nitro-N-nitrosoguanidine (MNN G) in the E. coil DNA repair liquid suspension assay. Heat-denatured o valbumin showed a strong increase in antimutagenicity compared to unde natured ovalbumin. The antimutagenicity of heat-denatured ovalbumin wa s superior to the antimutagenicity found for the other proteins tested . After digestion of native and heat-denatured ovalbumin using the pH- stat method, antimutagenicity remained. Antimutagenicity measurements with samples taken from a gastro-intestinal simulator showed strong co mutagenic properties. This turned out to be due to comutagenicity agai nst MNNG caused by bile acids and lipase. It was concluded that food p roteins exhibit different antimutagenic properties toward MNNG and tha t the choice of a particular protein digestion model can influence res ults to a great extent.