Abstract: In this article , two main pigments lycopene andβ2carotene were identified in Red flesh navel orange by using Thin Layer Chromatography and PAD combined with HPLC , its red flesh was pigmented by lycopene which
made up to 55. 36 % - 58. 49 %of the total peak area (counted in peak area of solvent) , whereasβ2carotene held 18. 12 % - 19. 93 %. Using Reverse-phase HPLC , standard curves of authentic lycopene and β-carotene were obtained and then be applied to calculate concentration changes of pigments during fruit development and storage under room temperature. Results showed that concentration of carotenoids was the highest at ripening time (lycopene was up to 109. 67μg·g^-1 of dry mass , and β-carotene as much as 15. 52μg·g^-1) , after harvest , a tendency of decreasing in pigments was easy to be seen , but there was also a significant increase appeared in Jan. 16th. After 4 months of storage , concentration of carotenoids reached the lowest among all investigated periods.

Key words: Red flesh navel orange (Citrus sinensis L. ), Pigments, Thin layer chromatography, High performance liquid chromatography