Carotenogenesis and physico-chemical characteristics during maturation of red fleshed papaya fruit (Carica papaya L.)

Carotenoid development of red fleshed papaya fruit (Carica papaya L) was investigated in the course of a complete pre- and postharvest period using HPLC-DAD coupled to mass spectrometry. Esterified xanthophylls such as beta-cryptoxanthin laurate and caprate were the most abundant pigments during incipient carotenoid biosynthesis. Subsequent fruit maturation led to a gradual accumulation of carotenoids, whereas particularly beta-cryptoxanthin laurate and total lycopene contents disproportionately increased, reaching maximum contents of up to 775 and 3168 mu g/100 g of fresh weight (FW), respectively. Total carotenoid contents of fully ripe papaya ranged from 5414 to 6214 mu g/100 g of FW, while corresponding biosynthetic precursors like phytoene, phytofluene, and zeta-carotene were only detected in trace amounts. Due to high contents of vitamin A precursors like beta-carotene and beta-cryptoxanthins, edible parts of the ripe fruit contained 132-166 mu g retinol equivalents per 100 g of FW. Furthermore, the development of morphological and physico-chemical fruit traits was characterized revealing significant correlations to carotenoid accumulation. A ripening index derived from several parameters was developed to easily allow exact assignment of ripening stages in studies of carotenoid development during fruit ontogenesis. Additionally, on-tree ripened versus postharvest ripened fruits were compared revealing striking similarity of their physico-chemical parameters and contents of individual carotenoids. (C) 2011 Elsevier Ltd. All rights reserved.