Efeito da digestão simulada in vitro na atividade antioxidante e nos compostos bioativos fenólicos da casca da graviola (Annona muricata L.)

Abstract

The soursop (Annoma muricata L.), a fruit from the Annonaceae family, has been highlighted for its potential biological effects related to the prevention and/or reduction of the risk of nontransmissible chronic diseases. However, few studies have evaluated the impact of the gastrointestinal digestion process on the compounds related to these biological effects. Therefore, this work aimed to understand the effect of simulated in vitro digestion on the antioxidant activity and phenolic bioactive compounds of soursop peel. For characterization and comparison, the soursop pulp and peel were analyzed for proximate composition, ascorbic acid content, total phenolic compounds by the Folin-ciocalteau method and in vitro antioxidant activity by DPPH, ABTS and FRAP methods. The accessibility of phenolic compounds and antioxidant capacity was assessed by simulated in vitro digestion in gastric, enteric I and enteric II stages. The soursop peel stood out for its expressive content of fiber, especially insoluble fiber. In both parts analyzed, low levels of protein, lipids and ash were found. The soursop pulp and peel presented expressive levels of ascorbic acid, with the pulp having 30% higher levels than the peel. The soursop peel showed high levels of total phenolic compounds and antioxidant capacity, regardless of the method used. After in vitro digestion simulation, the total phenolic compounds present in the bark showed stability during gastric, enteric I and enteric II stages. After simulating the in vitro digestion, the peel showed stability in the DPPH antioxidant capacity analysis. In the antioxidant capacity analyses ABTS and FRAP, both obtained higher accessibility in enteric step II (40% and 29%), with respect to enteric step I, respectively. The results of this work can promote the valorization of the fruit peel, which is currently discarded as waste and could be reused.