Antioxidant activity of agroindustrial residues from tropical fruits.
Infante J., Selani M. M., Toledo N. M. V. de, Silveira-Diniz M. F., Alencar S. M. de, Spoto M. H. F.
Author Affiliation: Programa de Pós-Graduação em Ciência e Tecnologia de Alimentos, Mestrado em Ciências, Escola Superior de Agricultura Luiz de Queiroz - ESALQ, Universidade de São Paulo - USP, 13418-900 - Piracicaba, SP, Brazil.
Alimentos e Nutrição 24 : 87-91
Abstract : Brazil is a country with high agricultural activity, and because of it, is one of the largest producers of agroindustrial residues. In the search for alternatives to the application of these products, the objective of this study was to determinate the content of phenolic compounds and antioxidant activity of residues from pineapple (peel and pomace pulp), passion fruit (peel and seed), cashew (pomace pulp) and mango (pomace pulp), from tropical fruits used for industrial purposes. The material was frozen, freeze-dried and stored at -18°C. The content of phenolic compounds was analyzed by Folin-Ciocalteau method; antioxidant activity was assessed using the DPPH free radical scavenging method, ?-carotene/linoleic acid system autoxidation and FRAP (Ferric Reducing Antioxidant Power). Regarding the phenolic compounds, it was observed that the extract of cashew presented the highest content, followed by extracts of mango, passion fruit and pineapple. Among the analysis of antioxidant activity, the DPPH free radical scavenging method showed the highest positive correlation with phenolic content (r=0.97). Both in the DPPH assay, as in FRAP, the residue of cashew presented the best results. For the method of ?-carotene/linoleic acid system autoxidation, all residues, except the cashew, showed significant activities, inhibiting the carotenoids oxidation in approximately 50% when compared to the control. The study showed that the residues have antioxidant activity, with potential to be used as source of natural antioxidants.