Prolonged storage of ‘Karuthacolomban’ mango by modified atmosphere packaging at low temperature

Mature ‘Karuthacolomban’ mangoes were sealed in low-density polyethylene (LDPE) bags to create modified atmosphere (MA) conditions and stored at 13°C and 94% r.h. The effect of potassium permanganate impregnated bricks as ethylene scavengers and activated granular charcoal as carbon dioxide scavengers on extending the storage life of mango was examined. The in-package concentrations of oxygen, carbon dioxide and ethylene, and changes in physico-chemical properties during storage were determined. Storage was terminated at different intervals, and the fruits were allowed to ripen naturally under ambient conditions. The optimum storage period was determined based on the visual quality rating (VQR) and disease index (DI) of the ripened fruits. The physico-chemical and sensory properties of the ripened fruits subjected to MA storage were determined and compared with the fruits packaged in perforated LDPE bags. In-package oxygen, carbon dioxide and ethylene concentrations were 2.3%, 6.2% and 0.24 mg kg–¹, respectively, in packages containing the scavengers on day 21 in storage. These corresponding concentrations in the packages were 7.5%, 11.7% and 0.8 mg kg–¹, respectively, in the absence of scavengers on day 21 in storage. The fruits packaged with scavengers had lower percent weight loss and minimum changes in physico-chemical properties compared with the fruits packaged without scavengers. The modified atmosphere created in LDPE was effective in delaying ripening of ‘Karuthacolomban’ mangoes up to 16 d; ripening was further delayed up to 21 d in the presence of scavengers. Physico-chemical and sensory properties, VQR and DI of MA stored mango after ripening were similar to those packaged in perforated LDPE bags. Therefore, packaging of ‘Karuthacolomban’ mango in 0.05 mm LDPE bags of 1:1 surface area to weight ratio (cm²g–¹) with 50 ml of saturated potassium permanganate absorbed onto suitable porous matrices and 2 g of activated granular charcoal could be recommended to increase storage life at 13°C.