Effects of putrescine postharvest dips and refrigerated storage temperature on quality attributes and shelf-life of ‘Solo’ papaya fruit

Purpose: Low temperature storage is commonly used to extend papaya (Carica papaya L.) fruit storability. The optimal recommended storage temperature is below 10 °C for export and distant markets. However, chilling injury (CI) disorder occurs at 10 °C or lower temperatures (5-8 °C) during prolonged cold storage. Chilling injury affects fruit quality and consumer preference. Therefore, the study investigated the potential of postharvest polyamine dips to improve the quality and shelf-life of ‘Solo’ papaya fruit. Research Method: Mature papaya fruit were treated with putrescine (PUT) dips (0, 1, 2 or 3 mM) and stored for 21 days at 7.5 °C plus 6 days at ambient temperature. Findings: The results showed that 2 and 3 mM PUT treatment significantly (P 0.05) reduced mass and firmness loss compared to 1 mM PUT dips and untreated fruit. The same trend was observed in peel colour change. Furthermore, the results showed that 2 mM PUT treatment retained lower titratable acid and total soluble solids values compared to control fruit. Research limitations: The study did not focus on Put mode of action including antioxidant system response. Originality/Value: The study demonstrated that 2 and 3 mM PUT postharvest dips reduce ‘Solo’ papaya pathological and physiological disorders during low temperature long storage. Therefore, 2 mM has the potential to improve postharvest quality by reducing the onset/development of pathological and physiological disorders under low temperature storage thereby benefitting exporters.