AbstractA method is presented for the determination of limonin, the bitter principle of oranges, based upon selective extraction and conversion to the dinitrophenylhydrazone, which is separated by thin‐layer chromatography for estimation by spectrophotometry. The method can be used as a routine procedure for the study of variations in the limonin content of oranges and processed juices. Some examples are given of its application to the study of the problem of bitterness in orange juice.