Table 1.
Rate constants (k) and activation energies (E _a) of PPO and POD in citrus juice

Thermal treatment	k	R2	Ea
PPO 70°C	0.0041	0.8663	237.92 J/mol
PPO 80°C	0.0066	0.7869
PPO 90 °C	0.0056	0.5854
	k	R2	Ea	k'	R2	Ea'
POD 70 °C	0.0428	0.9620	883.69 J/mol	0.0070	0.8492	1093.94 J/mol
POD 80°C	0.0764	0.9623		0.0100	0.9556
POD 90 °C	0.1394	0.8244		0.0304	0.3880