The present work was carried out to evaluate the application of delayed ripening (employing controlled atmosphere (CA) storage) to minimize or alleviate the development of the ripening disorder known as internal bruising. Tomato (Lycopersicon esculentum Mill) fruits, cv. Solimar, were harvested at the mature-green stage and gassed with 100 mL.L-1 of ethylene at 20°C to screen out immature-harvested fruits. Breaker stage tomatoes were either dropped from a 40 cm height to induce internal bruising or not dropped. Half of the two treatments was stored in CA (3% O2; 4% CO2; balance N2) for 8 days at 20°C and 85-95% relative humidity, then transferred to air until completely ripe. The other tomatoes were stored continuously in air at the same temperature and RH. At the ripe stage, dropped tomatoes from CA or continuous air treatments developed visible symptoms of internal bruising in locule tissues. The ripening treatments did not have significant differences in vitamin C, or total carotenoids for bruised locule or pericarp tissues. However, bruised locule tissue from CA storage had titratable acidity 15% higher (about 162 meq citric acid. kg-1) than air storage (about 140 meq citric acid kg-1), and was similar to air-stored, unbruised locule tissue (about 174 meq citric acid kg-1). Pericarp tissue from the impacted region had similar PG activity for CA or air treatments. Electrolyte leakage of bruised, pericarp tissue was similar for CA and air storage (about 50%) and about 40% for unbruised tissues from either storage treatment. Controlled atmospehere storage was not an effective way of delaying or alleviating changes in quality observed in bruised tomato fruits.
Lycopersicon esculentum; electrolyte leakage; mechanical injury; polygalacturonase; postharvest; quality; storage
