Kinetic Studies on the Heat Inactivation of Peroxidase in Sweet Corn a

SUMMARY A kinetic procedure employing D values was used instead of the usual end‐point method to study heat inactivation of peroxidase in whole‐kernel sweet corn. Results at 150–200°F indicated that a heat‐labile fraction and a heat‐stable fraction were being inactivated. The resistant fraction represented 5% of total enzyme activity, and was concentrated in the pericarp. Increasing the blanch time at 200°F from 2 to 5 min decreased residual enzyme activity from 3.3% to 1.7%. Inactivation of the heat‐resistant fraction at 210–290°F also followed a first‐order reaction. The phantom inactivation‐time curve showed that an HTST process based on microbial destruction could leave residual enzyme activity.