Macroalge are regarded as a helathy food due to their composition and nutritional properties [1]. In this work, nutritional composition of two green (Ulva rigida, Codium tomentosum) and two red (Palmaria palmata, Porphyra purpurea) edible seaweed species widely distributed in Atlantic shores were studied using a variety of analytical methods. Total lipids were measured gravimetrically as evaporated mass after petroleum-ether Soxhlet extraction of samples. In addition, fatty acid profile was determined by gas chromatography coupled to a flame ionization detector (GC-FID). Results showed that all studied species were accounted for very low levels of lipids (>1% DW), but levels of unsaturated fatty acids oleic, linoleic and linolenic acids were present at high concentrations, with P. palmata displaying the highest quantities (>200 mg C18:1 / g extract). In parallel, proteins were quantified following the macro-Kjedahl method in which the nitrogen content is converted to protein using a conversion factor of 6.25. In this analysis, red algae, specially P. purpurea showed signficant protein content up to 30% DW. Total organic acids were determined by ultra-filtration liquid-chromatography coupled to an amperometric detector (UFLC-PAD) after an acid extraction, being P. purpurea the algae with the higher organic acid content (10.61 % DW), half of which was determined as citrate. Minerals were idenfitied and quantified by inductively coupled plasma atomic emission spectroscopy (ICP-OES), suggesting that both algae groups are rich in K and Mg (>15 g / kg), but U. rigida also displayed a remarkable iron content (>1 g Fe / kg). Finally, hydrocarbons were determined as the difference of the rest of components, following AOAC guidelines. Altogether, results corroborate that these edible algae are a good source of nutrients in accordance with literature.
References.
- Martínez–Hernández, G.B.; Castillejo, N.; Carrión–Monteagudo, M. del M.; Artés, F.; Artés-Hernández, F. Nutritional and bioactive compounds of commercialized algae powders used as food supplements. Food Sci. Technol. Int. 2018, 24, 172–182, doi:10.1177/1082013217740000.
Acknowledgements
The research leading to these results was supported by MICINN supporting the Ramón y Cajal grant for M.A. Prieto (RYC-2017-22891) and the FPU grant for A. Carreira-Casais (FPU2016/06135); by Xunta de Galicia for supporting the program EXCELENCIA-ED431F 2020/12, the post-doctoral grant of M. Fraga-Corral (ED481B-2019/096), the program BENEFICIOS DO CONSUMO DAS ESPECIES TINTORERA- CO-0019-2021 that supports the work of F. Chamorro and the program Grupos de Referencia Competitiva that supports the work of J. Echave (GRUPO AA1-GRC 2018); by the Bio Based Industries Joint Undertaking (JU) under grant agreement No 888003 UP4HEALTH Project (H2020-BBI-JTI-2019) that supports the work of P. Otero, P. Garcia-Perez and C. Lourenço-Lopes; and by Ibero-American Program on Science and Technology (CYTED—AQUA-CIBUS, P317RT0003). The JU receives support from the European Union’s Horizon 2020 research and innovation program and the Bio Based Industries Consortium. The project SYSTEMIC Knowledge hub on Nutrition and Food Security, has received funding from national research funding parties in Belgium (FWO), France (INRA), Germany (BLE), Italy (MIPAAF), Latvia (IZM), Norway (RCN), Portugal (FCT), and Spain (AEI) in a joint action of JPI HDHL, JPI-OCEANS and FACCE-JPI launched in 2019 under the ERA-NET ERA-HDHL (n° 696295). The authors are grateful to AlgaMar enterprise (www.algamar.com) for the collaboration and algae material provision.
