Significant differences for PPO activity were observed among cultivars and FDSs (Table 1). At the IFDS, ‘Fuji’ and ‘Elstar’ presented the highest values followed by ‘Mellow’ and ‘Aori27’, the last showing a significantly lower value than ‘Fuji’ and ‘Elstar’. At the MFDS, ‘Fuji’ and ‘Elstar’ presented the highest mean values for PPO activity followed by ‘Mellow’, which presented similar values to those observed for ‘Elstar’ but different from those recorded for ‘Fuji’. ‘Aori27’ presented the lowest mean value among all cultivars at the MFDS. At the commercial harvest time (FFDS), ‘Aori27’ showed the lowest PPO activity among all cultivars, and no statistical differences were observed among ‘Elstar’, ‘Fuji’, and ‘Mellow’ (Table 1). ‘Elstar’, ‘Fuji’, and ‘Mellow’ did not show significant differences for PPO activity during fruit development, whereas ‘Aori27’ showed a significant decrease along fruit maturation with the values recorded at the FFDS showing lower mean than the values recorded at the IFDS (Table 1).