A study on the extraction of lutein from selected locally grown vegetation

Abstract

A study on the extraction of lutein from selected locally grown vegetation was carried out as the first step in developing the most suitable method of producing the lutein. Lutein is an antioxidant, important for preventing age related macular degeneration (ARMD) from occumng especially for person approaching the age of 60 years. The first part of the study was focused on screening some potential raw materials to determine the most suitable source of lutein which offers the highest yield and easily assessable. Two main extraction methods, namely the conventional method and the Soxhlet method, were investigated using the chosen raw material. In evaluating the extraction methods, some important factors affecting the extraction process were investigated. These include the standing or exposure time, solids to solvent ratio, and variation in diffei-ent types of solvents. The effect of these parameters on the concentration of the extracted lutein, and the rate of extraction were examined. In this study, it was found that in both the conventional and soxhlet method of extractions, acetone yielded the highest amount of lutein compared to other solvents used in the study. In general, the amount of lutein extracted was proportional to the standing time and the raw materials to solvent ratio. In all the operating conditions, maximum achievable lutein concentration was present, after which a plateau condition was observed. The maximum achievable lutein concentration was dependent on the operating conditions. As expected, the rate of mass transfer was higher in soxhlet extraction in comparison to the conventional method, with a magnitude of approximately 5 folds. Recognizing the emerging of ultrasound technology in enhancing many unit operations, a feasibility study was also conducted to gauge its capability in improving the extraction of lutein. It was found that the ultrasound extraction method offers a much improved technique with mass transfer rate equivalent to 4000 folds that of the conventional method, and 40 folds that of the soxhlet extraction method, and with much increased product yield.