NÍVEIS DE ACTIVIDADE FÍSICA AO LONGO DA GRAVIDEZ E A SUA INFLUÊNCIA NO ESTADO FÍSICO E PSICOLÓGICO DA MULHER, BEM COMO NOS PARÂMETROS MORFO-FUNCIONAIS DA CRIANÇA NO PRIMEIRO ANO DE VIDA

Financiador

Organização

Publicações

Biorefinery of Microalgae: production and characterization of protein fractions

Publication . Oliveira, Rebeca Vargues de; Matos, Cristina; Brazinha, Carla

Conventional protein sources are estimated to be insufficient for world food demand, by 2050. Microalgae are currently one of the most promising sources of proteins, providing good techno-functional properties and health benefits. The A4F microalgae proteins' extraction process was optimized to maximize the recovery yield of soluble proteins. Proteins characterization through the BCA method and SDS-PAGE were essential for the monitorization of proteins behavior in each operational step, in terms of concentration and molecular weight (MW) profile facilitating process optimization. Three species of microalgae were studied, which were Arthrospira platensis, Chlorella vulgaris and Nannochloropsis sp. SDS-PAGE was proposed as a technique to monitor the fractionation process efficiency of soluble proteins from microalgae. In a first approach, through SDS-PAGE analysis, each microalga protein's MW profile was characterized. Then, different proteins' stabilization strategies were studied, both at laboratory and pilot scale. Thus, it was determined that applying a 50 ºC thermal treatment, for 1 minute, to the biomass is important for bacterial growth inhibition. Diluting the biomass with deionized water, in the proportion of 5:1 (biomass:water), contributes to proteins' recovery maximization. For long-term storage at -25 ºC of proteins extracts in the liquid form, the best stabilization strategy includes the initial 50 ºC thermal treatment with no addition of solvents and, prior to storage, adding the supernatant 20 (w/w) % of an osmolyte (glycerol or sorbitol). This procedure minimizes proteins' degradation, improving the MW profile maintenance. Membrane filtration tests were also performed to evaluate protein recovery as a bulk soluble protein. It was confirmed that the SDS-PAGE results allowed the optimization of the membrane filtration operation parameters, including the best MWCO of the membranes.

2022-11-28Dissertação de mestrado

Acesso aberto

Ver mais

Entidade financiadora

Fundação para a Ciência e a Tecnologia

Número da atribuição

SFRH/BD/45375/2008