Optimization of chemical extraction of phenolic compounds from fruits and vegetable residue by UPLC-MSE

Abstract

Phenolic compounds (PC) extraction can be affected by many intrinsic characteristics of food matrix, as well as the analytical method employed to separate and identify these compounds. In this study, 30 conditions were analyzed considering as variables: time, temperature, and ethanol:water proportions as solvent. All extracts were analyzed into a UPLC ESI-Q-TOF-MS/MS in negative ion mode. All data were processed by QI Progenesis software by using a customized database based on phenolic compounds. The antioxidant activity (AA) was assessed by DPPH method. Globally, 43 PC were tentatively identified, and flavonoids were the most abundant. The increase in temperature was the main interfering with the extraction process. However, the temperature of 40°C for 24 h with ethanol:water ratio (75:25; v/v) promoted the most abundant extraction of hesperidin, and the highest AA (28.23 ± 0.01 µmol Trolox.g−1). All extraction conditions lead to extracts with similar qualitative profiles, but different AA.