Enhanced recovery of phycobiliproteins from Arthrospira platensis by combined glass bead vortexing and ultrasonication

Phycobiliproteins (PBPs) derived from Arthrospira platensis are high-value natural pigments with increasing applications in food, nutraceutical, and pharmaceutical fields. Efficient recovery of these pigments remains challenging due to the structural resistance of the cyanobacterial cell envelope, which limits pigment release and may reduce purity during intensive disruption procedures. In the present study, six extraction approaches were comparatively evaluated, including glass bead-assisted vortexing (GB), ultrasonication (US), freeze–thaw cycles (FT), enzymatic lysis (EL), chemical maceration (CM), and a combined mechanical protocol integrating bead-mediated vortexing with pulsed ultrasonication (GB–US). All extractions were performed under controlled low-temperature conditions (4 °C) to minimize pigment degradation. Among the tested methods, the combined GB–US treatment produced the highest total phycobiliprotein yield (27.01 mg g⁻¹ DW), corresponding to a 33% increase compared with ultrasonication alone, and showed the highest phycocyanin purity index (A620/A280 = 0.84), indicating improved selectivity with reduced co-extraction of non-target proteins. Spectral scanning (280–700 nm) confirmed the presence of characteristic absorption peaks at 562, 620, and 652 nm, suggesting preservation of pigment structure after extraction. In contrast, chemical and passive treatments resulted in lower recovery efficiency and reduced purity. The improved efficiency of the combined mechanical protocol may be related to the sequential application of different mechanical forces, in which bead-assisted vortexing is followed by ultrasonication, facilitating pigment release without excessive protein contamination. These results indicate that the GB–US method represents an effective and reproducible approach for phycobiliprotein extraction and may provide a useful basis for further optimization of downstream processing in microalgal biotechnology.