Storage temperature during the early stage of ripening determines whether or not the peel of banana (Musaspp. AAA, Cavendish subgroup) degreens

Abstract

Introduction . The peel of bananas that ripen at ≥ 24 ℃ does not turn fully yellow, but retains a green colour, reducing the commercial value of the fruit. Historically, in experimental studies of this problem, fruit are ripened at constant temperatures; for example, either 20 ℃ or 30 ℃. In our experiments, we systematically varied the temperature of banana storage during ripening to investigate early events in ripening that may determine whether or not the peel remained green. Materials and methods . Fruits were exposed to temperatures of 20 ℃ or 30 ℃ for short periods before then storing at 30 ℃ or 20 ℃ to complete ripening. The L* a* b* colour system was used to measure change in green colour in the banana peel. Results . If the temperature of the fruit stored was 20 ℃ for the first few hours (≥ 14 h), then the peel became fully yellow, even in fruit subsequently ripened at 30 ℃. Conversely, if the temperature of the bananas stored was 30 ℃ for the first few hours of ripening, then full yellow colour was not obtained even if fruits were subsequently ripened at 20 ℃. Conclusion. The temperature of the first few hours of banana ripening determines whether or not the peel reaches full yellow colour.