Inactivation rates (kref) at the indicated reference temperatures (Tref), as well
as activation energies for inactivation (Ea), were determined from the regression
lines fitted to the data in the Arrhenius plots (Figures 2, 5, and 7) b DTref and z
values were calculated from the kref and Ea values, respectively, using the equations
given in Materials and Methods.
The plot of the inactivation data for
a second tomato variety, BOS 3155, was very similar. There
was, therefore, no difference in the inactivation kinetics between
the typical hot-break and cold-break cultivars. The activation
energies as well as other inactivation parameters for PME in
these two tomato cultivars are listed in Table 1