Extraction of Lutein Fatty Acid Esters from Marigold Flower using Liquefied Dimethyl Ether (DME) as extractant

Abstract

This study will focus on the investigation of extraction of lutein fatty acid esters from marigold flowers using liquefied dimethyl ether (DME) which is nontoxic solvent as extractant. Since it is gaseous at normal temperature and pressure, DME can be easily removed from the final product by pressurizing. In this study, was divided into 3 parts. Part I involves the determination of suitable DME extraction. Effect of extraction conditions including solvent to sample ratio (w/w) and extraction temperature at 400 rpm for 30 min on extracted yield of lutein esters were investigated. The highest amount of lutein esters was found to be 20.65 mg/g dried marigold at the condition of 33:0.5 solvent to sample ratio and 35oC. The results were compared with solvent extractions using hexane as solvent and supercritical carbon dioxide extraction. Then, compared with DME extraction using wet sample with 80% and 70% moisture content. Part II deals with the determination of suitable saponification condition in order to convert the lutein esters to free lutein that was ratio of ethanol to oleoresin 20:1, 2.5% KOH concentration, 35 °C for 4 h. at such conditions, approximately 150 mg free lutein /g oleoresin was obtained. In part III, the evaluation of simultaneous DME extraction and saponification was carried out. The suitable condition for simultaneous DME extraction and saponification of lutein esters to free lutein was ratio of ethanol to dried marigold 10:0.5, 5% KOH concentration, 35 °C for 1 h. at such conditions, approximately 20.71 mg free lutein /g dried marigold was obtained. Then compared with those obtained with sequential DME extraction followed by saponification for free lutein that is 16.65 mg free lutein /g dried marigold. And also compared with simultaneous DME extraction and saponification using wet sample, at this study the amount of free lutein was 19.22 mg free lutein /g dried marigold.