Carotenoids and volatile profiles of yellow- and red-fleshed papaya fruit in relation to the expression of carotenoid cleavage dioxygenase genes

Fruit of two different papaya cultivars ('Sui huang', yellow flesh, and 'Sui hong', red flesh) were characterized in terms of carotenoid and volatile profiles throughout storage at 25 degrees C. The results showed that 'Sui huang' cultivar exhibited significantly lower carotenoid contents than 'Sui hong', which accounted for the different color characteristic. The analyses of HPLC coupled to mass spectrometry showed that zeaxanthin, beta-cryptoxanthin and and beta-carotene were identified as the most abundant carotenoids in 'Sui huang' fruit while the most abundant carotenoids were lycopene, followed by beta-carotene, zeaxanthin and beta-cryptoxant hin in 'Sui hong' fruit. The high expression of carotenoid cleavage dioxygenase gene (CpCCD1) in 'Sui hong' papaya fruit might stimulate the degradation of beta-carotene and lycopene and then form the specific volatiles of 6-methyl-5-hepten-2-one and beta-ionone. (C) 2015 Published by Elsevier B.V.