Eco-Integrated Production and Formulation of Arthrospira platensis Dietary Supplements

The increasing demand for sustainable and high-nutritional food sources has directed considerable attention toward microalgae, particularly Arthrospira platensis (Spirulina), due to its notable protein content and bioactive compounds. However, the high production costs associated with Spirulina cultivation remain a major limitation to its industrial expansion. This study proposes an integrated and eco-innovative strategy aimed at developing a Spirulina-based dietary supplement by optimizing cultivation efficiency, enhancing extraction yields of bioactive compounds, and improving bioavailability. Spirulina was cultivated in vertical tubular photobioreactors utilizing mine water supplemented with Zarrouk medium, achieving biomass yields and pigment concentrations comparable to conventional systems while significantly reducing dependence on freshwater resources. Notably, cultivation in mine water resulted in a higher protein content (52.64 ± 2.51 g·100 g⁻¹ DW) and improved protein-to-carbohydrate and protein-to-lipid ratios. To maximize the recovery of functional compounds, a green extraction protocol combining phosphate-buffered saline (PBS) maceration with ultrasound-assisted extraction (UAE) was developed. This method led to significant increases in the yields of total fatty acids (+60.48%), polyphenols (+65.99%), carotenoids (+30.84%), and overall antioxidant activity (+42.95%), although a partial reduction in protein and carbohydrate recovery was observed. To further enhance bioavailability and stability, Spirulina extracts were encapsulated into liposomes (Lps), bilosomes (Bls), and gelatin-enriched bilosomes (G-Bls). These nanocarriers exhibited favorable physicochemical characteristics, including small particle sizes (101.77–129.73 nm), high encapsulation efficiencies (>80%), and stable negative surface charges. Among the formulations, G-Bls demonstrated superior performance, offering gastric resistance, controlled intestinal release, high biocompatibility, and effective mitigation of H₂O₂-induced oxidative stress in Caco-2 cells. Overall, this work presents a sustainable and scalable platform for the valorisation of Spirulina biomass, reinforcing circular economy principles and supporting its application in dietary supplements designed to promote sports performance, manage oxidative stress, and improve metabolic health.