Effect of modified atmosphere on internal browning of 'Smooth Cayenne' pineapples

'Smooth Cayenne' pineapples (Ananas comosus L. Merril) at green-matured stage (total soluble solids (TSS) = 11.70; titratable acidity = 107.5 meg/l; texture = 90 N), were harvested and submitted to the following treatments: (1) control, (2) dipped in wax; (3) wrapped with 0.020 mm thick PVC foil; (4) wrapped with 0.030 mm thick PVC foil; (5) dipped in wax and wrapped with 0.020 mm thick PVC foil; (6) dipped in wax and wrapped with 0.030 mm thick PVC foil. Fruits were stored at 8.5 degrees C and 90% R.H. for 30 days. After storage, fruits were held at 20 degrees C for 8 days. Analyses of texture, TSS, phenolic compounds, polyphenoloxidase (PPO) and peroxidase (POD) activity and internal browning were made at 2-day intervals. All the treatments, compared with the control, presented lower levels of POD and PPO activity and higher textural values. Internal browning was observed only from the fourth day in all the treatments.