The Bitter Constituents of Navel and Valencia Oranges

Orange juice quality with an emphasis on flavor components

“…For example, navel oranges are extremely bitter and are not used extensively for orange juice because of their high content of the bitter triterpene derivative, limonin. 14 As seen in Figure 2, the different parts of the orange fruit are called the flavedo, albedo, carpels, and seeds. The flavedo is the outer colored layer of the orange peel containing the chromoplasts and the oil sacs.…”

BITTER FLAVOE IN CARROTS. III. THE ISOLATION OF A COMPOUND WITH SPECTRAL CHARACTERISTICS SIMILAR TO HYDROCARBON EXTRACTS OF BITTER CARROTS.a

“…The taste characteristics of Compound A are not unique since Higby (6) has shown that limonin, a bitter constituent of navel oranges, does not taste bitter as a solid, but exhibits a proiiounced bitter taste when it is dissolved in dilute alcohol.…”

Limonin Bitterness in Citrus Juices

“…The precursor theory on the mechanism of the delayed bitterness was put forth by Higby (1938) who first isolated limonin from navel orange juice, and proposed that the fruit tissue contains a nonbitter, water soluble substance which converts to the bitter limonin in extracted juice (1941). Over the years evidence to support the precursor theory has accumulated.…”