Fig. 2. Changes in polyphenol oxidase (PPO) and peroxidase (POD) activity of
banana peels treated with different packaging methods during storage for 9 days at
20 C. j, normal packaging; d, CO2 gas exchange packaging; N, normal packaging
with an ethylene generator. Means ± SD (n = 3) with different letters are significantly
different at 5% level.