INACTIVATION OF TOMATO PECTIC ENZYMES BY MANOTHERMOSONICATION

The resistance of tomato pectic enzymes to manothermosonication (MTS), a combined treatment of heat and ultrasound under moderate pressure, was studied. Pectinmethylesterase (PMF) and polygalacturonases (PG)I a nd II were inactivated much more efficiently by MTS than by simple hea ting. In MTS inactivation of these enzymes, the effect of heat and ult rasonic waves was synergistic. D values [the time required for the (or iginal) enzyme activity to decrease by 90%] for PME heat inactivation at 62.5 degrees C were reduced 52.9-fold by MTS and those for PG I at 86 degrees C and PG II at 52.5 degrees C, 85.8-fold and 26.3-fold, res pectively.