Carotenoids were extracted from gac fruit according to methods previously described (18). Individual carotenoids were identified and quantified with the use of reversed-phase HPLC. The system consisted of 2 Absorbosphere HS octadecylsilane columns (150-mm long × 4.6-mm internal diameter, 3-μm particle size; Alltech, Deerfield, IL) connected in series. The liquid chromatograph was a Hewlett-Packard (Palo Alto, CA) 1100 equipped with diode-array detection. The mobile phase conditions were as follows: 0–5 min, 100% acetonitrile:methanol:ammonium acetate (85:15:0.01, vol:vol:wt); 5–20 min, linear gradient to 30% 2-propanol at a flow rate of 0.9 mL/min. The absorbance at 450 nm was monitored. Compounds were identified by comparing their retention times and ultraviolet-visible absorbance spectra with those of authentic standards.