Supercritical CO2 extraction of carotenoids from pitanga fruits (Eugenia uniflora L.)

Supercritical carbon dioxide (SC-CO2) extraction was employed to extract carotenoids from the freeze-dried pulp of pitanga fruits (Eugenia uniflora L.), an exotic fruit, rich in carotenoids and still little explored commercially. The SC-CO2 extraction was carried out at two temperatures, 40 and 60 °C, and seven pressures, 100, 150, 200, 250, 300, 350 and 400 bar. The carotenoids were determined by high-performance liquid chromatography connected to photodiode array and mass spectrometry detectors. Lycopene, rubixanthin and β-cryptoxanthin were the main carotenoids present in the freeze-dried pitanga pulp, whereas β-cryptoxanthin concentration was negligible in the SC-CO2 extracts, for all the investigated state conditions. The maximum recovery of carotenoids was obtained at 60 °C and 250 bar, extracting 55% of the total carotenoid content, 74% of the rubixanthin and 78% of the lycopene from the pulp. Under these state conditions, the total carotenoid concentration in the extract was 5474 μg/g, represented by 66% lycopene and 32% rubixanthin. The experimental state conditions produced different SC-CO2 extracts with respect to the extraction yield and concentration of different carotenoids, indicating that the supercritical carbon dioxide was selective in the extraction of the pitanga carotenoids as a function of temperature and pressure.