Phenolic and carotenoid profiles of papaya fruit (Carica papaya L.) and their contents under low temperature storage.

Background: Tropical fruits are rich in phenolic and carotenoid compounds, and these are associated with cultivar, pre- and postharvest handling factors. The aim of this work was to identify major phenolics and carotenoids in 'Maradol' papaya fruit and to investigate their response to storage temperature.

Results: Ferulic acid, caffeic acid and rutin were identified in 'Maradol' papaya fruit exocarp as the most abundant phenolic compounds, and lycopene, β-cryptoxanthin and β-carotene were identified in mesocarp as the major carotenoids. Ranges of contents of ferulic acid (1.33-1.62 g kg(-1) dry weight), caffeic acid (0.46-0.68 g kg(-1) dw) and rutin (0.10-0.16 g kg(-1) dw) were found in papaya fruit, which tend to decrease during ripening at 25 °C. Lycopene (0.0015 to 0.012 g kg(-1) fresh weight) and β-cryptoxanthin (0.0031 to 0.0080 g kg(-1) fw) were found in fruits stored at 25 °C, which tend to increase during ripening. No significant differences in β-carotene or rutin contents were observed in relation to storage temperature.

Conclusion: Phenolics and carotenoids of 'Maradol' papaya were influenced by postharvest storage temperature with exception of β-carotene and rutin. Ripe papaya stored at 25 °C had more carotenoids than those stored at 1 °C. Low (chilling) temperature (1 °C) negatively affected the content of major carotenoids, except β-carotene, but preserved or increased ferulic and caffeic acids levels, as compared to high (safe) temperature (25 °C).