ing index at 55 C and decreased with increasing drying temperatures.
Decrease in browning index may be explained by inactivation
of PPO. Elevated temperatures have been reported to
deactivate PPO (Akyildiz & Ocal, 2006). Moreover, the browning index
of PF and UF highly correlated with the phenolic content compared
with that of PSF and USF (data not shown). Browning
appears to be a complex process involving several factors including
substrate levels, enzymatic activity, presence of ascorbic acid, and
other inhibitors or promoters influencing the browning reaction, in
addition to tissue damage