Correlation and influence of antioxidant compounds of peels and pulps of different species of cacti from Brazilian Caatinga biome using principal component analysis
Érica de Andrade Vieira, Julineide Gadelha Silvestre Côelho, Cristiani Viegas Brandão Grisi, Bianca Silva dos Santos, Jayme César da Silva Júnior, Maristela Alves Alcântara, Bruno Raniere Lins de Albuquerque Meireles, Nataly Albuquerque dos Santos, Ângela Maria Tribuzy de Magalhães Cordeiro
Abstract
This study investigated the influence of the plant part (peel and pulp) on the phenolic compounds, antioxidant activities, and principal component analysis (PCA) of five cactus fruits from the Caatinga, an exclusively Brazilian biome. All species evaluated presented a high total phenolic content (TPC), mainly in their peels. The antioxidant potentials were measured using in vitro assays (2–2-diphenyl-1-picrylhydrazil radical (DPPH·), ferric reducing antioxidant power (FRAP), and β-carotene-linoleic acid assay). The results showed significant differences among the species and among the fruit parts. Pilosocereus gounellei species peel showed the best antioxidant activity both for DPPH and FRAP. However, moderate inhibiting action was found for β-carotene-linoleic acid assay. The species were characterized by the predominance of benzoic acid derivatives bearing a phenol group (salicylic, hydroxybenzoic, and protocatechuic acids), as well as flavonoids (catechin, myricetin and quercetin). Using PCA, it was possible to group the extracts of the cactus peels and pulps to evaluate the relationships between the samples. In most of the cases, the peel represented the main source of phenolic compounds and antioxidant activity. Therefore, the peel of the cacti can be an important by-product for the extraction of antioxidants for industrial purposes.