Antioxidant capacity and chemical composition of passion fruit peel (Passiflora edulis)

The aim of the study was to evaluate the chemical composition of flour obtained from the peel of passion fruit and their antioxidant activity in vitro. The fruits were cleaned, the peels were separated from pulp, dried in an oven with circulating air and ground to obtain the flow: The centesimal composition was determined and the polyphenols present in the peel were extracted by three methodologies. Total phenolic content and antioxidant activity were determined using three different methods (scavenging of 2,2-diphenyl-1-picrylhydrazyl - DPPH free radical, Ferric Reducing Antioxidant Power - FRAP e Oxigen Radical Absorbance Capacity - ORAC). The results show that the flour has high fiber content (65.22 +/- 0.27%) and 74% of which correspond to insoluble fraction. Although the results of total polyphenol indicate that there is a predominance of compounds with hydrophilic characteristics in the peel, the evaluation of the antioxidant activity of the extracts showed that the antioxidant power of lipophilic compounds present in the methanol / acetone extract was superior to the compounds present in the aqueous and ethanol extracts. The results of this study demonstrate that the passion fruit peel could be used as a source of fiber and antioxidants, however, its incorporation into food formulations must address their physical, chemical and sensory, to ensure their best use and acceptance among consumers.