Author : Nipa Kunsongkeit

Summary : 'Carabao' mango fruits stored under low oxygen atmospheres (2.7 % - 7.7%) for seven days or high carbon dioxide (CO2) combined with low O2 (18.5% CO2 + 2.5% O2) for 4-7 days at ambient temperatures (26-32 C) exhibited internal breakdown. Fruits stored in 18.5% CO2 + 2.5% O2 had more areas affected and with the severe type of disorder. High CO2 with abundant O2 (18.5% CO2 + 20% O2) failed to initiate this disorder. Low O2 was associated with the occurrence of internal breakdown, which was aggravated by high CO2 and prolonged exposure period. Anaerobic respiration appears to be the predominant process in the disposition of disorder as indicated by low oxygen uptake and high respiratory quotient during storage. This was further substantiated by the presence of fermented odor ripening. Low oxygen (2.7% - 7.7%) atmosphere maintained respiration and ethylene production of stored fruits at low rates during storage. There were indications among fruits at these levels of O2 for failure to show the typical climacteric respiratory behavior during and after storage for four and seven days. Low ethylene production was also observed during storage at low oxygen. However, the rate and pattern was not consistent particularly upon transfer to air. Anaerobic respiration which occurred during storage in those atmospheres further brought about low internal ethylene concentration, accumulation of organic acids, high pH, failure to starch hydrolysis, and slower carotenogenesis. These abnormal chemical changes might have elicited the following features of internal breakdown: delineated starchy areas with or without air pockets formation, low sugar content, pale yellow pulp color, and presence of fermented odor.