Extraction yield, antioxidant activity andphenolics from grape, mango and peanut agro-industrial by-products/Rendimento de extracao, atividade antioxidante e compostos fenolicos dos subprodutos agro industriais de uva, manga e amendoim

• Published in: Ciência rural 2016-08, Vol.46 (8), p.1498
• Main Authors: Braga, Gilberto Costa, Melo, Priscilla Siqueira, Bergamaschi, Keityane Boone, Tiveron, Ana Paula, Massarioli, Adna Prado, de Alencar, Severino Matias
• Format: Article
• Language: English
• ISSN: 0103-8478
• DOI: 10.1590/0103-8478cr20150531

The objective of this study was to determine and correlate the extraction yields, antioxidant activity total phenolics and total flavonoids from grape, mango and peanut agro-industrial by-products. The [beta]-carotene/linoleic acid autoxidation system and scavenging capacity for DPPH and ABTSfree radicals assays were used. The results were expressed in terms of lyophilized sample or dry extract. Mango bagasse exhibited the highest extraction yield (37.07%) followed by peanut skin (15.17%) and grape marc (7.92%). In terms of lyophilized sample, total phenolic s did not vary significantly among the residues evaluated (average of 60.33mg EAG [g.sup.-1]); however, when they were expressed as dry extract grape marc exhibited the highest total phenolic (768.56 [+ or -] 116.35mg GAE [g.sup.-1]), followed by peanut skin (404.40 [+ or -] 13.22mg GAE [g.sup.-1]) and mango bagasse (160.25 [+ or -] 4.52mg GAE [g.sup.-1]), Peanut skin exhibited the highest content of total flavonoids (2.44mg QE [g.sup.-1]), while grape marc (1.76mg QE [g.sup.-1]) and mango bagasse (1.70 mg QE [g.sup.-1]) showed no significant differences. The extraction yield showed strong negative linear correlation with total phenolic and total flavonoid. This study showed that peanut skin was the sample with the highest antioxidant activity and it was strongly influenced by total flavonoids. All extracts of byproducts showed antioxidant activity comparable to [alpha]-tocopherol, and they can be a source of natural compounds with potential to replace synthetic antioxidants such as BHT. Key words: total phenolics, total flavonoids, ethanolic extraction. O objetivo deste estudo foi determinar e correlacionar os rendimentos de extracao, atividade antioxidante, compostos fenolicos totais e flavonoides de subprodutos agroindustriais de uva, manga e amendoim. A autoxidacao do sistema [beta]-caroteno/ acido linoleico e a capacidade de sequestro dos radicais DPPH e ABTS foram os ensaios antioxidantes utilizados. Os resultados foram expressos com base na amostra liofllizada ou no extrato seco. O bagaco de manga apresentou o maior rendimento de extracao (37,07%) seguido da pelicula de amendoim (15,17%) e bagaco de uva (7,92%). Em termos de amostra liofllizada, o teor de fenolicos totais nao variou significativamente entre os residuos avaliados (media de 60,33mg EAG [g.sup.-1]), entretanto, quando foi expresso com base no extrato seco, o bagaco de uva exibiu o maior teor de fenolicos totais (768,56 [+ or -] 116