Extraction of astaxanthin from Haematococcus pluvialis with hydrophobic deep eutectic solvents based on oleic acid. (15th June 2022)

• Record Type: Journal Article
• Authors: Pitacco, Walter; Samorì, Chiara; Pezzolesi, Laura; Gori, Virginia; Grillo, Antonio; Tiecco, Matteo; Vagnoni, Martina; Galletti, Paola
• Is Part Of: Food chemistry. Volume 379(2022)
• Publication Date: 2022-06-15
• Subjects: Astaxanthin -- Haematococcus pluvialis -- Algal culture -- Deep eutectic solvents -- Terpenes -- Antioxidant potential; TAO thymol:oleic acid mixture 3:1 -- MAO DL-menthol:oleic acid mixture 2:1 -- GAO geraniol:oleic acid mixture 13/1; Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; 664
• DOI: 10.1016/j.foodchem.2022.132156
• Languages: English
• ISSNs: 0308-8146

Abstract

Highlights: Oleic acid and terpenes are used to prepare DESs composed of safe and edible ingredients. DESs recover about 60% of the astaxanthin produced by H. pluvialis. DESs extract astaxanthin directly from H. pluvialis culture, by-passing dewatering. Thymol confers excellent light stability to astaxanthin formulations. Thymol and astaxanthin contribute to creating powerful antioxidant formulations. Abstract: Three novel hydrophobic deep eutectic solvents (DESs) based on oleic acid and terpenes (thymol, dl -menthol, and geraniol) were prepared, characterized, and used to extract astaxanthin from the microalga Haematococcus pluvialis without any pre-treatment of the cells. The three DES were composed of Generally Recognized As Safe (GRAS) and edible ingredients. All the tested DESs gave astaxanthin recovery values of about 60 and 30% in 6 h if applied on freeze-dried biomass or directly on algae culture, respectively. The carotenoid profile was qualitatively identical to what was obtained by using traditional organic solvents, regardless of the DES used; the monoesters of astaxanthin with C18-fatty acids were the main compounds found in all the carotenoid extracts. The thymol:oleic acid DES (TAO) could preserve astaxanthin content after prolonged oxidative stress (40% of the astaxanthin initially extracted was still present after 13.5 h of light exposure), thanks to the superior antioxidant properties of thymol. The capacity of improving astaxanthin stability combined with the intrinsic safety and edibility of the DES components makes the formulation astaxanthin-TAO appealing for the food ingredients/additives industry.