The present work aimed to determine the influence of modified atmosphere packaging on the quality maintenance of minimally processed 'Pera' oranges stored under refrigeration. Peeled oranges were placed on packaging materials and were submitted to the following treatments: (1) control - oranges placed in expanded polystyrene trays covered with PVC film; (2) passive - oranges wrapped in 32 µm-polypropylene film under passive modified atmosphere; (3) active - oranges wrapped in 32 µm-polypropylene film under active modified atmosphere (5% O2 + 10% CO2; balance N2). Minimally processed fruits were then stored at 6±1 ºC and 12±1 ºC. Chemical, sensorial and microbiological analyses were carried out periodically. Ethanol and acetaldehyde levels, as well as the peroxidase activity were determined. Chemical variables were not affected by treatments. However, it was observed an effect of storage time on the soluble solids content, which reduced throughout the storage period by 10%. Microbiological contamination levels were low and not affected by treatments. There was an accumulation of acetaldehyde and ethanol due to the modified atmosphere. However, it did not affect fruit flavor, which remained acceptable until the end of the storage period, as well as the appearance. Peroxidase activity was low and not influenced by treatments. PVC film was as effective as the polypropylene one under passive or active modified atmosphere within the period evaluated, with oranges stored at 6 ºC and 12 ºC showing shelf life of 12 and nine days, respectively.
Citrus sinensis; modified atmosphere; refrigeration; storage temperature; minimal processing; conservation
