P. Lopez et al., INACTIVATION OF PEROXIDASE, LIPOXYGENASE, AND POLYPHENOL OXIDASE BY MANOTHERMOSONICATION, Journal of agricultural and food chemistry, 42(2), 1994, pp. 252-256
The combined effects of heat and ultrasonic waves operating at absolut
e pressures between 1.5 and 7.2 kg/cm(2) on peroxidase, polyphenol oxi
dase, and lipoxygenase inactivation have been studied over a broad ran
ge of temperatures, static pressures, and ultrasound amplitudes. A syn
ergistic effect which can substantially reduce enzyme resistance and t
he heat treatment required for inactivation was observed in all cases.
The peroxidase z value, estimated at 26 degrees C, was not changed by
the combined treatment, but that of lipoxygenase increased from 4.2 d
egrees C (heat treatment) to 6.8 degrees C (combined treatment). The e
nzyme destruction efficiency of the combined process greatly increases
with ultrasonic wave amplitude; decimal reduction times at constant t
emperature decreased logarithmically with increasing amplitudes. Stati
c pressure does not seem to affect much the destructive effect of the
combined process. This combined treatment could help-to solve, in milk
, juices, and other drinks, problems caused by thermostable enzymes.