Effect of Packaging with Polyethylene Bags on Shelf Life and Volatiles Production of Ripening-initiated Bananas

Abstract

'Cavendish' banana (Musa sapientum L) fruits were treated with ethylene for 1 day and held for 2days at 20°C. These greenish yellow banana fruits were packaged hermetically in polyethylene bags (0.03mm thick.) with or without ethylene absorbents and stored at 12°C and 20°C. The shelf life and the change of volatiles production of the fruits were investigated. During the storage at 20°C, the fruits packaged in perforated polyethylene bags became full yellow in 3days, and lost salability in 6days due to occurrence of brown flecks developing to entire browning. Polyethylene packaging completely inhibited the occurence of brown flecks regardless of ethylene absorbents and prolonged the shelf life. Water-soaked injury, however, happened in sealed bags 10days after packaging, though ethylene absorbents delayed this injury 5 more days. O₂ concentrations were 1-2% and CO₂ concentrations were about 10% in the bags with or without ethylene absorbents at 20°C. The production of isoamyl acetate and iso-butyl acetate, characteristic banana flavor volatiles, increased quickly in the fruits in perforated bags at 20°C. In the fruits packaged in sealed bags, the production of these compounds increased slowly at early periods, but marked increase followed at later periods especially in the packaging with ethylene absorbents. Productions of ethyl alcohol, acetaldehyde and ethyl acetate increased quickly in the sealed bags with or without ethylene absorbents, in spite of limited increase of these volatiles in perforated bags at 20°C. They, howewer, decreased gradually at later periods in the packaging with ethylene absorbents. At 12°C, disappearance of green in peel were insufficient throughout the storage period and water-soaked injury occurred after 15days in both hermetically sealed and perforated bags. Volatiles production was markedly lower than that at 20°C with an exeption of butyl acetate.