In recent years, valuable progress has been
made in understanding polyphenoloxidase
and phenolics of apple and apple products.
Many studies have been restricted to model
systems with enzyme acting on a single
phenolic substrate. However, these studies
would provide a better understanding of the
relationship between the extent of browning
and the phenolic composition of fruit.
Fresh-cut apples cause an increase in PPO
activity during storage for 7 days at 4oC. This
increase has been found to be highly
correlated with L value and the browning
index. Changes in color parameters of apple
cubes during storage were found to correlate
quite well with PPO activity (R2 between 0.79