Effects of Ethylene and Temperature on Carotenoid Pigmentation of Citrus Peel

Carotenoids in the peel of harvested citrus in creased following treatment with ethylene. Im proved color resulted primarily from an increase in the amount of an orange-red pigment, cryptoxanthin, and a red pigment, jg-citraurin. Tempera ture influenced pigment accumulation. At 65 °F and 75 °F, rapid accumulation of both cryptoxanthin and jg-citraurin resulted in highly colored fruit. At 85 °F, however, accumulation of /3-citraurin was inhibited which resulted in fruit having a lighter shade of orange color. This temperature sensitivity may explain the lack of substantial carotenoid formation during commercial degreening and the generally poor color of fruit grown in the tropics.