The carotenoid pigments in the juice and flavedo of a mandarin hybrid (Citrus reticulata) cv michal during ripening

Abstract

Abstract The carotenoid pigments ofthe mandarin hybrid ( Citrus reticulata ) cv Michal, in the juice and flavedo were characterized at three ripening stages, before, during and after colour break. During ripening the characteristic mandarin pattern was formed in the juice, which contained cryptoxanthin as the principal pigment. In the flavedo the chloroplast carotenoid pattern of the green fruit changed into the characteristic pattern of C. reticulata with a high level of citraurin which, together with cryptoxanthin, imparts an intensive reddish tint to the hybrid. The flavedo contained an unusual C 30 apocarotenoid, β-citraurinene (8′-apo-β-caroten-3-ol). The flavedo carotenoids of this accidental hybrid were compared with the carotenoids of the presumed parents Dancy tangerine and Clementine. The hybrid resembles more the second parent, from which it inherited the ability to biosynthesize a higher amount of citraurin as well as citraurinene. Citraurinene, considered a Citrus hybrid-specific pigment, was found for the first time in a Citrus variety. A possible biosynthetic pathway of the Citrus C 30 -apocarotenoids is proposed.