Production of free lutein by simultaneous extraction and de-esterification of marigold flowers in liquefied dimethyl ether (DME)–KOH–EtOH mixture

• Published in: Food and bioproducts processing Vol. 106; pp. 193 - 200
• Main Authors: Boonnoun, Panatpong, Tunyasitikun, Pemika, Clowutimon, Weerawat, Shotipruk, Artiwan
• Format: Journal Article
• Language: English
• Published: Rugby Elsevier B.V 01-11-2017; Elsevier Science Ltd
• Subjects: Bioavailability; Calendula; De-esterification; Dimethyl ether; Esterification; Extraction processes; Fatty acids; Flowers; Flowers & plants; Liquefied dimethyl ether; Lutein; Marigold flowers; Organic chemicals; Pigments; Simultaneous process; Solvent extraction; Xanthophylls; Lutein; Liquefied dimethyl ether; De-esterification; Solvent extraction; Marigold flowers; Simultaneous process
• ISSN: 0960-3085; 1744-3571
• DOI: 10.1016/j.fbp.2017.10.002

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•Dimethyl ether is a green solvent that can suitably be used for lutein extraction.•DME extraction allows the reduction of operating time and energy requirements.•Simultaneous enhanced the process efficiency for both wet and dried samples.•The higher free lutein yield was achieved with the simultaneous process.
Extraction of xanthophylls from marigold flowers using liquefied dimethyl ether (DME) was investigated. The most suitable DME extraction condition was found to be 33:0.5 (w/w) DME to dried marigold flowers ratio and at 35°C, giving 20.65mg of total xanthophylls/g of dried marigold flowers. Following extraction, the suitable de-esterification conditions to convert the extracted lutein fatty acid ester (the major compound in xanthophylls) to free lutein, a more bio-available form, were determined to be 2.5%w/v KOH–EtOH, at 35°C for 4h. While employing the most suitable conditions in each of the two steps gave favorable free lutein yield (16.65mg free lutein/g dried marigold flowers), a one-step process in which simultaneous extraction and de-esterification carried out at the most suitable condition: the DME to dried marigold flowers ratio 33:0.5 (w/w), EtOH to dried marigold flowers ratio 10:0.5, 5% KOH–EtOH concentration, at 35°C for 1h, could lead to about 20% improvement (20.71mg free lutein/g dried marigold flowers). Furthermore, the results from this study suggested that wet marigold samples could possibly be used both in the DME extraction for xanthophylls and in the simultaneous process to obtain free lutein.