Red seaweeds Grateloupia turuturu and Porphyra umbilicalis as nutraceuticals and functional food: nutritional/chemical composition and immunostimulatory activity

1st Natural Products Application: health, cosmetic and food - International online conference, 4-5 February 2021The number of nutraceuticals and functional foodsfrom marine origin is increasing in the worldwide market. Specifically, the red seaweeds Grareloupia turuturu and Porphyra umbilicalis have shown their potential considering relevant bioactive compounds and nutritional value [1,2]. Nevertheless, it is pertinent to explore knowledge gaps regarding their nutritional/chemical composition and bioactivities. Hence firstly G. turuturu and P. umbilicalis proximate composition and lipid classes were determined; secondly, after preparing hydroethanolic and aqueous infusion and decoction) seaweed extracts, mycosporine-like ami no acids (MAAs) and carbohydrates were quantified. and the immunomodulatory potential was assessed using RAW 264.7 cell line. Results show that dietary fibre was the most abundant nutritional parameter for both seaweed species, followed by relevant ash and protein contents. Free fatty acids were the main lipid class in both seaweed species, whereas tocopherols exhibited residual contentsby RP-HPLC-FLD. For hydroethanolic and aqueous extracts, several MAAs were quantified by RP-HPLC-DAD and LC-DAD ESI-MS. P. umbilicalis extracts demonstrated greater MAAs content than G. turuturu, and porphyra-334 was the main MAA. The aqueous extracts of both seaweeds showed higher carbohydrate contents than the hydroethanolic, with P. umbilicalis decoction exhibiting the highest level. Concerning the immunomodulatory activity, for 0.02 mg/mL, the exposure to P. umbilicalis aqueous extracts resulted in the most accentuated 'NO production by RAW 264.7 cells, showing immunostimulatory potential. MAAs and carbohydrates are believed to be responsible for the immunostimulatory activity [3,4]. G. turuturu and P. umbilicalis potential as functional food and nutraceuticals, relying on their relevance as sources of bioactive compounds to the food, pharmaceutical and cosmetic industries, is thus reinforcedThis work was financed by European Funds FEDER/COMPETE/POCI under project POCI-01-0145-FEDER-006958 (CITAB), and by FCT to CECAV (UIDB/CVT/00772/2020), CITAB (UlDB/04033/2020) and CESAM (UIDP/5001712020+UIDB/50017/2020). FCT is also acknowledged for a doctoral grant to Joao Ferreira (SFRH/BD/144882/2019)N