A combined technique of temperature preconditioning and modified atmosphere packaging to prolong the storage life of papaya

Abstract

Papaya is a popular tropical fruit for human consumption over the world. However, it has a relatively short shelf life due to rapid ripening and anthracnose infection after harvest. Generally, papaya is stored at the optimum temperature of 12°C and can last only two weeks. After this period, the fruit will begin to ripen and spoil. Theoretically, fruit stored at lower temperatures will have a longer shelf life. However, papaya is prone to chilling injuries characterised by pitting and inability to ripen if stored at sub-optimum temperature, which may also cause secondary postharvest disease attacks if held for a longer period. The study aimed to evaluate the effectiveness of a combination of temperature preconditioning treatment and modified atmospheric packaging (MAP) in prolonging the storage life of papaya under sub-optimum temperature. In terms of visual appearance, no chilling injury symptoms were observed in samples stored at a suboptimum temperature of 7°C throughout the storage period. No significant differences were recorded in the parameters of total soluble solids (TSS), total titratable acidity (TTA) and TSS: TTA ratio. Relatively lower ascorbic acid content and higher firmness value were recorded in fruits subjected to the combined technique of temperature conditioning and MAP, which could be associated with delayed ripening. A combination of temperature preconditioning and MAP techniques maintains the papaya quality under storage at sub-optimum temperatures as low as 7°C without chilling injury problems, with a longer shelf life (4 weeks) than only 2 weeks for conventional handling techniques. The fruits can be ripened by being exposed to ethylene when they are ready to be marketed. The technology is helpful for the industry, farmers, wholesalers, and exporters, particularly for the delivery of more extended distribution and periods.