Innovative technologies for antioxidants extraction from food and food byproducts

Abstract

In this work, the efficiency of innovative technologies such as ultrasounds (US), pulsed electric fields (PEF), high-voltage electrical discharges (HVED) and accelerated solvent extraction (ASE) in terms of polyphenol extraction from grapes, vine shoots and grape pomace was studied. PEF pre-treatment (48 kJ/kg) of grapes enhances the subsequent polyphenols (98% anthocyanin) extraction during the winemaking process. US, PEF or HVED were used as pretreatments prior to the alkaline extraction of polyphenols from vine shoots. US (3428 kJ/kg), PEF (762 kJ/kg) and HVED (254 kJ/kg) provoked cellular damage to vine shoots cells up to 25, 40 and 75 % respectively. Therefore and compared to solid-liquid extraction (1.15 g GAE/100 g DM), US (3428 kJ/kg), PEF (762 kJ/kg) and HVED (254 kJ/kg) enhanced polyphenol recovery to 1.5, 2.2 and 3.5 g GAE/100 g DM, respectively. HVED extracted the highest concentration of resveratrol (0.4 mg/g) and epicatechin (2.459 mg/g) with the lowest energy consumption amongst innovative technologies. On the other hand, ASE was used to enhance polyphenol recovery from grape pomace. ASE ameliorated polyphenol extraction from 5.5 (solid-liquid) to 16.2 g GAE/100 g DM and the radical scavenging capacity from 67 % to 76.5 %.