Extraction of Fatty Acids and Phenolics from Mastocarpus stellatus Using Pressurized Green Solvents

Abstract

Polyunsaturated fatty acids are well known for their protective properties in relation to different skin diseases. Although seaweeds possess a low lipid fraction, they could act as an alternative renewable source of polyunsaturated fatty acids whenever other valuable seaweed components are also valorized. In this study, a biorefinery process using Mastocarpus stellatus as a model seaweed was proposed. The process started with the supercritical carbon dioxide extraction of the lipid and phenolic fractions. The influence of pressure during extraction with pure supercritical CO2 was studied while operating at a selected temperature and solvent flow rate. Kinetic data obtained during the ethanol-modified supercritical CO2 extraction were fitted to the spline model. Sequential processing was proposed with (i) pure CO2 to obtain a product with 30% PUFA content and ω-3:ω-6 ratio 1:1, (ii) ethanol-modified CO2 to extract phenolics, and (iii) microwave-assisted subcritical water extraction operating under previously optimized conditions for the extraction of phenolics, carrageenan and protein fractions. The composition of the supercritical extracts showed potential for use in both dietary and topical applications in skin care products. The remaining solids are suitable for the extraction of other valuable fractions.

Microwave-Assisted Extraction of Carrageenan from Sarcopeltis skottsbergii

“…Different intensification technologies have been applied for the reduction in chemicals, including pressurized hot water extraction [ 10 , 11 ] and microwave heating pretreatment before [ 12 ], or during, pressurized hot water extraction [ 13 ]. This technology could be incorporated after extraction of the lipidic and phenolic fractions with supercritical CO 2 [ 14 ]. These strategies were applied to Mastocarpus stellatus and allowed reduced operation time and energy consumption compared to the conventional extraction or lower alkali concentration during pretreatment [ 12 ].…”