resumo
An increasing demand of consumers for natural bioactive compounds has boosted the interest of the scientific community for vegetables and fruits, with many efforts being made to identify new bioactive compounds and to develop sustainable extraction methods that preserve the compounds bioactivity. Such is thicase of pressurized liquid extraction and supercritical fluid extraction using green solvents as supercritical CO2, ethanol, and ethyl acetate. The accurate design of these processes requires the knowledge of transport properties, namely, diffusion coefficients, D-12. Astaxanthin and squalene are two bioactive compounds whose D-12 values were measured in compressed liquid ethyl acetate using a chromatographic technique. For astaxanthin the D-12 values were in the range 0.817 x 10(-5) - 1.223 x 10(-5) cm(2) s(-1) (at 303.15-333.15 K and 1-100 bar) and for squalene they were in the range 1.052 x 10(-5) - 1.822 x 10(-5) cm(2) s(-1) (at 303.15-333.15 K and 1-150 bar). The influence of tem- perature, pressure and Stokes-Einstein coordinate was studied for both systems and explained with the most relevant theories of the literature.
palavras-chave
BINARY DIFFUSION-COEFFICIENTS; SUPERCRITICAL-FLUID EXTRACTION; CARBON-DIOXIDE EXTRACTION; BIOACTIVE COMPOUNDS; SOLVENT SELECTION; INFINITE DILUTION; LENNARD-JONES; DENSE FLUIDS; HARD-SPHERE; WIDE RANGES
categoria
Engineering
autores
Bruno Zêzere, José M. Silva, Inês Portugal, José R. B. Gomes, Carlos M. Silva
nossos autores
Bruno Miguel Martins Zêzere
Estudante de doutoramento
Carlos Manuel Silva
Professor associado
Inês Portugal
Professor Auxiliar
José Miguel Cardoso da Silva
Estudante de doutoramento
José R. B. Gomes
Investigador PrincipalGrupos
G4 - Materiais Renováveis e Economia Circular
G6 - Materiais Virtuais e Inteligência Artificial
agradecimentos
This work was developed in the scope of the project CICECO-Aveiro Institute of Materials (Ref. FCT UID/CTM/50011/2019), financed by National Funds through the FCT/MEC and when applicable co-financed by FEDER under the PT2020 Partnership Agreement. Bruno Mere thanks FCT for PhD grant SFRH/BD/137751/2018.