Advisor(s)
Abstract(s)
Spirulina (Arthrospira platensis) proteins have been proven to present emulsifying properties. In this work, a
Spirulina protein-rich extract obtained by ultrasound extraction (SpE) was tested to stabilize oil-in-water (O/W)
emulsions. For this purpose, a sequential experimental design strategy (Fractional Factorial Design (FFD) 24–1
followed by a Central Composite Rotatable Design (CCRD) 22)) was applied. The effect of four variables, SpE
concentration, O/W weight ratio, pH and storage time, on emulsions’ zeta potential and number-mean droplet
diameter was considered for the FFD 24–1, indicating SpE concentration and storage time as the relevant variables
for the CCRD 22. According to zeta potential and number-mean droplet diameter evaluation, for the studied SpE
concentration range (2–5 wt%), quite stable emulsions were obtained along the tested 30-days period. Even so,
for 5%, visual inspection revealed extract segregation after 20-days. The optimal solution comprised 4 wt% of
SpE, for an O/W weight ratio of 30/70 and a pH of 7.0 (number-mean droplet diameter of 55.66 nm and zeta
potential of -43.83 mV). Overall, SpE has proven to be an excellent emulsifier, offering the potential to substitute animal-based proteins and synthetic emulsifiers. In addition, no signs of contamination by microorganisms
were observed, suggesting that the SpE may also act as an antimicrobial agent.
Description
Keywords
Microalgal proteins Protein-rich extract Oil-in-water emulsions Protein-stabilized emulsions Experimental design
Pedagogical Context
Citation
González-Arias, Judith; Sánchez, Marta Elena; Martínez, Elia Judith; Covalski, Camila; Alonso-Simón, Ana; González, Rubén; Cara-Jiménez, Jorge (2020). Hydrothermal carbonization of olive tree pruning as a sustainableway for improving biomass energy potential: Effect of reaction parameters on fuel properties. Processes. ISSN . 8:10, p.
Publisher
Elsevier