Extraction of lutein from marigold flower with supercritical carbon dioxide

Abstract

The objective of the study was to extract lutein, an active component of marigold flower (Tagetes erecta) by means of supercritical carbon dioxide (sc-C02). Extractions on freeze-dried marigold petals were performed with a laboratory scale supercritical fluid extractor (LECO TFEIM2000) of highly advanced design and performance. Extracts were analysed for lutein by high-performance liquid chromatography (Agilent Technology 1100 Series HPLC System) using a calibration line constructed by virtue of solutions of a commercially available standard (Indofine Chemical Company, Inc.). The conditions at which a maximum yield of lutein is obtained (52°C, 400 bar, 60 min) were determined by performing runs according to a statistical design and processing the data by computer assisted surface response analysis. A mass balance proved effective recovery of the extracted material from the supercritical extractor. The density of sc-C02 was found to be the variable which controls the extraction as the fluid becomes capable to chemically dissolve lutein once its density (and thus solvent strength) takes on liquid-like values (between 0.8 and 1.0 g/mL). The large negative value of the volume of activation ∆*V relates to the decrease in volume associated with melting and solvation of lutein while it dissolves in the highly compressed supercritical fluid. A function combining several process variables into a dimensionless quantity was used successfully to mathematically describe the extraction process.