Spirulina (Arthrospira platensis) protein-rich extract as a natural emulsifier for oil-in-water emulsions: optimization through a sequential experimental design strategy

• Autor(a) principal: Silva, Samara Cristina
• Data de Publicação: 2018
• Outros Autores: Almeida, Thayná Domingues, Colucci, Giovana, Santamaria-Echart, Arantzazu, Manrique, Yaidelin A., Dias, Madalena M., Barros, Lillian, Fernandes, Ângela, Colla, Eliane, Barreiro, M.F.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10198/23349
• topic: Microalgal proteins; Protein-rich extract; Oil-in-water emulsions; Protein-stabilized emulsions; Experimental design

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.