Pulsed electric field pretreatment for energy efficient processing of industrial peach cultivars

Abstract

Extraction of peach juice is commonly performed with centrifugal paddle mesh extractors, scraping peaches against meshes after destoning to separate peels and residual stone pieces from pulp. Late season peaches are notorious for their hard texture, complicating comminution processes and leading to low juice yields. To avoid this, thermal treatments are employed, resulting in juice quality deterioration and increased energy consumption. Pulsed Electric Fields (PEF) rely on electroporation of plant tissues to soften them and increase extraction yields. This research explores the effect of PEF (0.5–2.0 kV/cm, specific energy 0–12 kJ/kg) on peach fruit texture, juice yield and quality, compared to thermal treatments. Peach juice yield was non-monotonically dependent on treatment intensity. Maximum juice yield of 70 % was achieved with 0.6 kJ/kg specific energy, compared to untreated peaches exhibiting a juice yield of 65 %. The specific energy input required for PEF treatment was equal to 0.31 % of the corresponding value for a thermal blanching (195 kJ/kg). The juice obtained from blanched peaches exhibited significant discoloration. Conclusively, PEF pretreatment provides substantial energy savings by rendering the juicing process of problematic crops such as peaches highly efficient and sustainable.