Modelling the recovery of biocompounds from peach waste assisted by pulsed electric fields or thermal treatment

Abstract

The recovery of non-purified bioactive extracts (70% ethanol) from peach pomace (PP) was assisted by conventional thermal treatment (CTT, 50 °C up to 90 min) or pulsed electric fields (PEF, specific energy input, EV, of 0.0014–2.88 kJ/kg). The maximum concentration of biocompounds and antioxidant activity, assessed with spectrophotometric and HPLC methods, was obtained upon 40 min by CTT and 0.0014 kJ/kg by PEF, which took 16 μs. A two-step mechanism was proposed when CTT was applied, considering a first step (zero-order kinetic) in which the PP biocompounds were released into the extraction media and a second degradation stage (first-order). A significant relationship was found between EV and PP biocompound degradation during PEF extraction, and a two-term degradation model was proposed to explain obtained data. The CTT or PEF-assisted recovery of biocompounds from PP was adequately explained by the proposed mechanistic and empirical kinetic models, which are feasible tools to understand the involved phenomena in the extraction procedures.