Background

C-phycocyanin (C-PC), a blue-colored natural pigment, is Spirulina's most crucial photosynthetic protein, and it is associated with this cyanobacteria's bioactivity. Many recent studies aimed at optimizing C-PC extraction from Spirulina using different protocols; however, the correlation between the extraction method (both lab scale experimental methods and industrial methods) and the antioxidant activity of the extract has not been explored yet.

Scope and approach

This review aimed to gather information regarding the most used C-PC extraction techniques from Spirulina in the last decade (2010–2020) and compare these biomolecules' antioxidant capacity with the extraction methodology applied. A density map was created by searching keywords related to C-PC extraction on Scopus, which guided the discussion on the C-PC extraction methods used and their impact on its bioactivity.

Key findings and conclusions

The density map showed that the lowest density words represented factors that can influence, describe, or determine the success of C-PC extraction. In contrast, the most cited expressions were related to the methods. The compilation of literature on the influence of C-PC extraction on its antioxidant activity showed that ultrasound-assisted extraction (UAE) and solvent extraction using water or buffer were the most used methods to extract C-PC from Spirulina in the last decade. However, the UAE does not seem to protect C-PC's bioactivity. Additionally, most studies of the previous ten years used a single method to determine C-PC's antioxidant activity. We concluded that C-PC's antioxidant activity needs to be appraised by more than one method using assays of different mechanisms to evaluate the extraction influence in its bioactivity in a panoramic way.