resumo
Chlorella vulgaris is a green microalga approved for human consumption with high biological value due to its high protein content and polyunsaturated fatty acids composition. Moreover, this microalga is rich in starch and structural polysaccharides that could have potential to be valued as food ingredients. To fulfill this hypothesis, starch digestibility was evaluated in raw and boiled biomass, showing 43% and 71% of glucose released, respectively. The low extraction yield of starch obtained with water (13%) allowed to infer protein hindrance. This was overcome by 1 M and 4 M KOH aqueous solutions that allowed to obtain an additional 51% of starch. The final residue left showed that only 16% of total starch remained unextracted. KOH solutions allowed also to obtain galactans composed by 1,3-, 1,6- and 1,3,6-linked galactose residues. These linkages were also observed in the polysaccharides recovered from the growth medium, showing similarity between the exopolysaccharides and those present in the cell wall. The extracellular polymeric material revealed immunostimulatory effect on B lymphocytes. This opens the possibility of the use of both starch and exopolysaccharides of C. vulgaris as food ingredients.
palavras-chave
CELL-WALL; CO2 CONCENTRATION; STARCH; L.; GLYCOPROTEIN; INGREDIENTS; MICROALGAE; EXTRACT; QUALITY; GROWTH
categoria
Biotechnology & Applied Microbiology
autores
Ferreira, AS; Ferreira, SS; Correia, A; Vilanova, M; Silva, TH; Coimbra, MA; Nunes, C
nossos autores
Cláudia Nunes
Investigador Auxiliaragradecimentos
Thanks are due to the University of Aveiro and FCT/MCT for the financial support for the QOPNA research unit (FCT UID/QUI/00062/2019) and CICECO-Aveiro Institute of Materials (FCT UID/CTM/50011/2019) through national funds and, where applicable, co-financed by the FEDER, within the PT2020 Partnership Agreement. Andreia S. Ferreira and Sonia S. Ferreira thanks FCT for the individual grant (SFRH/BD/102471/2014 SFRH/BD/103003/2014, respectively). AC was supported by FCT through Stimulus of Scientific Employment Individual Support 2017 (CEECIND/01514/2017). This work was also funded by national funds (OE), through FCT, I.P., within the scope of the framework contract foreseen in the numbers 4, 5 and 6 of the article 23, of the Decree-Law 57/2016, of August 29, changed by Law 57/2017, of July 19. We are grateful to Allmicroalgae for providing of C. vulgaris biomass and growth medium.