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Spirulina (Artrhospira platensis) protein extract: techno-functional properties and potential application as a natural emulsifier

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Resumo:Microalgae are valuable sources of proteins (20-70%) and have emerged as great alternatives to animal-based proteins (e.g., whey protein, egg yolk)1. This work aimed to obtain a microalga protein extract (SpE) from Artrhospira platensis (Spirulina) and evaluate its techno-functional properties and emulsion formation capability. The SpE was obtained by ultrasound and conventional mechanical stirring under an alkaline medium (pH 9.0) followed by acid precipitation (pH 3.0)2. In addition, the SpE techno-functional (protein solubility; oil and water absorption capacities) and structural properties (FTIR analysis) were investigated. Moreover, an emulsion (oil/water ratio (30/70); pH 7.0; SpE concentration (3.5%)) was prepared according to two sequential steps: i) high-shear homogenization (UltraTurrax; 11,000 rpm; 3 min) and ii) high-pressure homogenization (100MPa; 6 cycles)3. Then, it was analysed by optical microscopy, zeta potential and particle size. The SpE (66.6%±0.31 protein) presented the lowest solubility at pH 3.0 and the highest at pH 8.0. The protein extract showed higher absorption capacity in oil (21.7±0.10 g oil/ g SPE) than in water (10.3±0.50 g water/ g SPE). From the FTIR analysis (Figure 1a), the SpE showed two peaks at 1635 cm-1 and 1535 cm-1 (red circle in Figure 1a) attributed to the presence of characteristic protein groups, amide I and amide II, respectively. The oil-in-water emulsion (ESp) presented a light blue-green colour due to the presence of SpE (Figure 1a) and remained stable for 30 days (Figure 1b). The SpE presented a zeta potential of -47.20 mV and a particle size of 330 nm (D50, volume distribution) on the 30th storage day. Small and spherical droplets were observed, evidencing the particle size and stability over the storage time (Figure 1c). Thus, the SpE showed the ability to form emulsions with stability for up to 30 days, being a great alternative to replace animal-based and synthetic emulsifiers.
Autores principais:Silva, Samara Cristina
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.
Assunto:Spirulina Artrhospira platensis
Ano:2021
País:Portugal
Tipo de documento:documento de conferência
Tipo de acesso:acesso aberto
Instituição associada:Instituto Politécnico de Bragança
Idioma:inglês
Origem:Biblioteca Digital do IPB

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