Extraction of Arthrospira platensis (Spirulina) proteins via Osborne sequential procedure: Structural and functional characterizations

• Published in: Journal of food composition and analysis 2023-01, Vol.115, p.104984, Article 104984
• Main Authors: Benelhadj, Sonda, Douiri, Sabrine, Ghouilli, Afef, Hassen, Rached Ben, Keshk, Sherif M.A.S., El-kott, Attalla, Attia, Hamadi, Ghorbel, Dorra
• Format: Article
• Language: English
• Subjects: Albumin; Extraction; Functional properties; Globulin; Hydrophobicity; Prolamin; Protein; Secondary structure; Spirulina; Surface
• ISSN: 0889-1575; 1096-0481
• DOI: 10.1016/j.jfca.2022.104984

The Osborne sequential extraction procedure was performed to extract proteins from Arthrospira platensis (A. platensis). The physicochemical description of the extracted proteins yielded three fractions (albumins (Alb, 51.5 %), globulins (Glb, 2.4 %), and prolamins (Pro, 46.1 %)). No glutelin-like proteins (Glu) were found in this microalga. FTIR spectra displayed the β-turn, the β-sheet, and the α-helix as the principal structures in the Alb, Glb, and Pro fractions, respectively; the random coil was absent in the Pro fraction. The zeta-potential measurements indicated isoelectric points closer to 3.0 and 4.5 for the Alb and Glb protein fractions, respectively. In contrast, the Pro protein fraction displayed a negative charge for pH values from 2 to 10. The Alb and Glb fractions exhibited the highest surface hydrophobicity. The best water-holding capacity was attributed to the Alb and Glb fractions, whereas the highest oil-holding capacity and foam stability were assigned to the Pro fraction. The surface hydrophobicity was positively correlated to the emulsion generation. The Osborne method is a promising procedure to obtain green (Alb), blue (Glb), and orangish-red (Pro) extracts from A. platensis through an environment-friendly process. [Display omitted] •A. platensis proteins were fractionated into Alb, Glb and Pro fractions.•The β-turn was the predominant structure in the Alb protein fraction.•The β-sheet was the predominant structure in the Glb protein fraction.•The α-helix was the predominant structure in the Pro protein fraction.