Effect of the Olive Pruning Wood Extract on Lipid Oxidation in Sunflower Oil.

Abstract

P. Gonzalez-Fuentes, M. Zuniga, C. Olea-Azar, M. Loyola and C. Folch-Cano. 2017. Effect of the Olive Pruning Wood Extract on Lipid Oxidation in Sunflower Oil. Cien. Inv. Agr. The production of high quality natural antioxidants from olive pruning wood extracts and their application to prevent the oxidation of vegetable oils were evaluated. The extraction of antioxidants from olive pruning wood (OPW) using Soxhlet extraction and ethanol was optimized, evaluating the use of dry and fresh OPW, extraction initial mass of 1 and 3 g, and extraction time of 2, 4 and 8 h. For the antioxidant evaluation of the OPW extracts (OPWE) the DPPH radical bleaching and ORAC-FL assays were performed. Additionally, the phenolic profile of the OPWE by HPLC-DAD was obtained and total phenolic composition was quantified by the Folin-Ciocalteu assay. The OPWE obtained from dry OPW and using 1 g of initial mass showed the highest content of phenolic compounds and better antioxidant capacity compared to those obtained from fresh OPW. Both extracts showed the same profiles, but the OPWE obtained from dry OPW showed twice the concentrations of catechin (1.00 g /100 g OPWE) and oleorupein (12.59 g /100 g OPWE). Low concentrations of optimized OPWE showed activity against lipid oxidation of sunflower oil, measured by the peroxide value by microwave heating. Under high temperature conditions and concentrations, the results suggest that OPWE may present the opposite effect.