Fenólicos totais e capacidade antioxidante in vitro de resíduos de polpas de frutas tropicais Total phenolics and in vitro antioxidant capacity of tropical fruit pulp wastes

Abstract

O objetivo deste trabalho foi determinar a concentração dos compostos fenólicos dos resíduos de polpas de frutas tropicais acerola (Malpighia glabra L.), goiaba (Psidium Guayaba L.), abacaxi (Ananas comosus L.), cupuaçu (Theobroma grandiflorum), bacuri (Platonia insignis) e graviola (Annona muricata L.), bem como avaliar a sua capacidade antioxidante in vitro, pelos métodos de captura de radicais DPPH• e ABTS+. Os resultados encontrados demonstraram elevados teores de fenólicos totais para o resíduo da polpa de acerola, com 247,62 ± 2,08 mg.100 g-1 de fenólicos totais para o extrato aquoso e 279,99 ± 3,5 mg.100 g-1 para o extrato hidroalcoólico (p The objective of this study was to determine the phenolic compound contents and evaluate the in vitro antioxidant capacity of the following extracts from tropical fruit pulp wastes: acerola (Malpighia glabra L.), guava (Psidium Guayaba L.), pineapple (Ananas comosus L.), cupuaçu (Theobroma grandiflorum), bacury (Platonia insignis), and cherimoya (Annona muricata L.) using the DPPH and ABTS+ radical capture methodologies. The results showed high levels of phenolic compounds in the aqueous and hydroalcoholic extracts of the acerola pulp wastes, of 247.62 ± 2.08 mg.100 g-1 and 279.99 ± 3.5 mg.100 g-1, respectively (p < 0.05). The antioxidant activity, when measured by the DPPH method, showed that the hydroalcoholic extract of the guava wastes presented the highest values with an EC50 of 142.89 μg.mL-1, followed by the hydroalcoholic and aqueous extracts of the acerola wastes, with EC50 values of 308.07 and 386.46 μg.mL-1, respectively. When the antioxidant activity was evaluated by the ABTS method, the acerola pulp wastes showed the highest antioxidant capacity, with TEAC values of 0.518 ± 0.103 and 0.743 ± 0.127 mM.g-1 of residue for the aqueous and hydroalcoholic extracts, respectively (p < 0.05). Thus, the fruit pulp wastes studied in this work, especially acerola and guava, represented potential sources of phenolic compounds, apart from possessing significant in vitro antioxidant capacity, the levels varying according to the residue studied.

Keywords

• Atividade antioxidante
• DPPH
• ABTS
• fenólicos totais
• resíduos agroindustriais
• Antioxidant capacity
• DPPH
• ABTS
• Total phenolics
• Agro-industrial wastes