Effect of Arthrospira (Spirulina) Biomass Quality on Phycocyanin Extraction and Antioxidant Activity

Phycocyanin (PC), a natural blue pigment derived from Arthrospira (Spirulina), exhibits strong antioxidant, anti-inflammatory and neuroprotective properties. It reduces oxidative stress, enhances immunity, prevents chronic diseases, making it a valuable natural ingredient for healthpromoting applications. This study aimed to evaluate the antioxidant potential of PC extracted from two Arthrospira sources with different PC contents: GF (7.97 %PC) and NT (14.30 %PC) PC was extracted from algal biomass using a 10 mM phosphate buffer, followed by a two-step membrane filtration process—microfiltration (MF) and ultrafiltration (UF)—to obtain crude and partially purified PC. The partially purified PC from NT biomass showed the highest purity ratio (A620/A280 = 1.24), PC content (43.13% of extract weight), and total phenolic content (41.86 mg GAE/g extract). The high quality of this extract resulted in stronger antioxidant activities. The partially purified PC from NT biomass exhibited a high FRAP value (38.36 mg Fe2⁺/g extract) and strong activities in ABTS, DPPH, FIC, NOS and LPO assays, with IC50 values of 0.23, 0.84, 5.36, 0.66 and 19.21 mg/mL, respectively. These findings demonstrate that algal biomass with a high PC content can provide a high-quality PC extract with strong antioxidant activity, supporting its potential for health-promoting applications.

Keywords: Phycocyanin, Arthrospira, Extraction, Antioxidant