Jorge F. B. PEREIRA1, Cassamo U. MUSSAGY5, Valéria C. SANTOS-EBINUMA2, João A. P. COUTINHO3, Adalberto PESSOA JR4
1University of Coimbra, CIEPQPF, Department of Chemical Engineering, Coimbra, Portugal
2Department of Engineering of Bioprocesses and Biotechnology, School of Pharmaceutical Sciences, São Paulo State University (UNESP), Araraquara, Brazil
3CICECO?Aveiro Institute of Materials, Department of Chemistry, University of Aveiro, Aveiro, Portugal
4Department of Pharmaceutical-Biochemical Technology, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
5Pontificia Universidad Católica de Valparaíso, Facultad de Ciencias Agronómicas y de los Alimentos, Quillota, Chile
Carotenoids are natural pigments synthesized by plants and microorganisms, being the last the most promising sustainable sources. Among the large amount of carotenoids applied in food, cosmetic, and pharmaceutical formulations, a particular interest is given to astaxanthin (AXT). Astaxanthin is an outstanding antioxidant natural pigment that can be produced by Phaffia rhodozyma yeast cells. Since this naturally antioxidant pigment is synthesized intracellularly, the development of sustainable, efficient and eco-friendly downstream processing platforms is a critical challenge for their recovery at commercial purity requirements. Over the last decades, several studies have been proposing the use of ILs and ES as “ideal solvents” or the extraction of compounds from natural matrices, mainly due to their high solvation characteristics, particularly of interest when used ILs and ES constituded by fully (or partially) derived from low-cost and eco-friendly renewable sources. Despite advances in using these classes of greener solvents, there is still no clear information of which are the “best” extractants. In this sense, the recovery of intracellular carotenoids from P. rhodozyma biomass using biocompatible ionic liquids (ILs) and Eutectic Solvents (ES) was herein evaluated. this work provides a comprehensive study regarding the extraction abilities of cholinium-based ILs and equivalent ES counterparts for the selective recovery of AXT and β-carotene from P. rhodozyma biomass.
First,it was evaluated the extraction performance of ILs and ES synthesized with the same precursors (choline chloride/choline bicarbonate, lactic and butyric acid), comparing respective recovery yields with that of DMSO as a control and those of the precursors. Considering the highest recovery yield of ES composed of cholinium chloride:butyric acid ([Ch]Cl:But), subsequently, the extraction performance was maximized as a function of the HBA : HBD molar ratio, water content and solid–liquid ratio (i.e., solvent-to-biomass ratio or wet cells concentration). Finally, carotenoids-rich ES extracts were used as plasticizer agents for the formulation of cornstarch-based biodegradable films, demonstrating the industrial potential of using ES for creating new functionalized bio-based materials.