Supercritical CO2 Extraction of Annatto (Bixa orellana) Pigments and Some Characteristics of the Color Extracts

Abstract
Supercritical CO2 (SC‐CO2) was used to extract natural food colors from Annatto (Bixa orellana) seeds with different pressures and temperatures. Results from the reverse thin‐layer chromatographic separation and GC/MS revealed that SC‐CO2 extracts were composed mainly of bixin, geranylgeraniol and norbixin. Differences in absolute values of solubility parameters (SPD) between these main compounds and SC‐CO2 indicated bixin was more easily extracted than norbixin under conditions used. A higher yield of total pigments was obtained at extraction pressure above 310 bar than at 210 bar and 50°C.