Use of specific polyclonal antibodies to detect heat treatment of ovalbumin in mushrooms

Using ovalbumin as a model protein in pure solution it was found that affinity chromatography of antisera against either native ovalbumin (NOA) or heat‐denatured ovalbumin (HDOA) gave four different antibody populations AC1 4 from each antiserum, with different binding properties to the related or unrelated antigen. Direct ELISA was shown to be useless for differentiating NOA from HDOA. Immunoprecipitation in solution is time consuming and, moreover, whereas NAC1 was shown to be specific for NOA compared with HDOA, DAC1, NAC2 and DAC2 were shown not to be fully specific for HDOA. In contrast, by using as capture antibodies either NAC3 or DAC4, a sandwich ELISA can be designed which is fully specific for NOA or HDOA, respectively. An approach to the identification of the temperature at which ovalbumin has been heated is described. This test will show whether ovalbumin has been heated to lower than 65°C or higher than 85°C. The test was applied to juices from canned mushrooms containing 2% ovalbumin.