Apocarotenoids contribute to fruit color and aroma, which are critical quality marketability attributes. Previously, we reported that the red peels of citrus fruits, characterized by higher expression levels a carotenoid cleavage dioxygenase 4b (CitCCD4b) gene, accumulate ?-citraurin ?-citraurinene than yellow peels. Here, identified quantified 12 apocarotenoids, either volatile or nonvolatile,...