2.3. Determination of carotenoid content
2.3.1. Extraction of carotenoids
The carotenoid content in the samples were extracted using the method of Olives Barba, Cámara Hurtado, Sánchez Mata, Fernández Ruiz, and López Sáenz de Tejada (2006). A sample (2 g) was placed in a vessel, protected from light, and mixed with 100 ml of extraction solvent (hexane/acetone/ethanol: 50:25:25 v/v/v). The mixture was magnetically stirred during 30 min; then 15 ml of water were added. The upper layer was placed in a round-bottomed flask, and an aliquot of 10 ml of the extract was evaporated to dryness. The residue was dissolved to a final volume of 4 ml. The final solution was filtered through 0.45 lm membrane filters and 20 ll were injected for HPLC analysis.