Quality improvement of fresh-cut tomato under active and passive modified atmosphere packaging
E. Aguayo, V.H. Escalona, F. Artés
ISHS Acta Horticulturae 628:351-356
2003
บทคัดย่อ
Long-life 'Calibra' tomatoes were selected based on color (65-78º hue angle) and freedom from defects. They were minimally fresh-processed into slices in a clean room at 5 °C. Before slicing, tomatoes were washed in chlorinated (100 ppm) water and air-drained at ambient temperature. Fruit were then cut into slices of about 0.8 cm thickness. Slices were packaged in polypropylene (PP) trays heat-sealed with a 35 *m PP film. As control a macro-perforated (9 holes of 0.7 mm diameter on 210 cm2) PP film was used. Packages were stored up to 14 days at 5 °C under passive and two active (3 kPa O2 + 0 kPa CO2 or 3 kPa O2 + 4 kPa CO2, with N2 as the balance gas) modified atmosphere packaging (MAP) treatments. Changes in microbial counts and sensorial and chemical quality attributes of fresh-cut tomato were evaluated at harvest and after 14 days of storage. At the end of storage, gas composition was 10 kPa O2 + 12 kPa CO2 in passive MAP, while atmospheres of 9 kPa O2 + 8 kPa CO2 and 6 kPa O2 + 9 kPa CO2 were reached in the two active MAP treatments. The levels of C2H4 accumulating under passive MAP (12 ppm) were double the levels reached under both active MAP treatments. Compared with control, MAP reduced total microbial counts. After 14 days all treatments were safe, showing levels lower than 105 CFU/g for total plate counts, than 103 CFU/g for yeasts and than 102 CFU/g for molds. Based on the sensorial quality evaluation, control tomato slices were unsuitable for consumption. Meanwhile slices under all MAP treatments kept a good visual appearance, overall quality and texture, and although only a fair flavour rating was found, they were acceptable for commercial purposes.