Effect of post-ripening nitrogen atmosphere storage on banana shelf life, visual appearance and aroma

Abstract

Bananas (Musa acuminata Colla, Cavendish cv. ‘Williams’) were stored in nitrogen at 22 °C for 6, 12 and 24 h at a more green than yellow (stage 3) or more yellow than green (stage 4) ripening stage. Shelf life in nitrogen at 22 °C, that is the time taken from a more yellow than green colour stage 4 to yellow with slight brown flecking stage 7, was not extended when compared to air-stored bananas. However, areas of brown discolouration appeared on bananas placed in nitrogen-storage. The aroma of ripe bananas was assessed with a mass spectrometry-based chemical nose. Bananas stored in nitrogen generally had a riper aroma profile compared with air-storage. An ion with a mass to charge ratio of 61 was strongly associated with nitrogen-treated bananas; this ion is a decomposition product of a known banana aroma compound, ethyl acetate that produces an over-ripe banana note. An ion with a mass to charge ratio of 55 was associated with air-stored bananas; this ion is a decomposition product of ripe bananas (3-methylbutyl ester and 1-butanol). Post-climacteric nitrogen storage is not a suitable method for increasing shelf life, as it causes skin browning.