Implementation of Pulsed Electric Field in Virgin Olive Oil Production: Impact on Oil Yield, Quality and Volatile Profile

This study investigates the effects of pulsed electric field (PEF) pretreatment—applied prior to malaxation using electric field strengths ranging from 2 to 7 kV/cm for 30 to 90 seconds—on oil yield, quality parameters, and volatile profiles of virgin olive oils (VOO) from four Croatian autochthonous varieties: Istarska bjelica and Rosulja (Istria), and Levantinka and Oblica (Dalmatia). The mild PEF conditions resulted in a significant improvement in oil yield (between 2.5 % and 36 %) for all varieties, with the effects being most pronounced for varieties with lower initial oil yields. While the PEF treatment had a negligible effect on the basic quality parameters, it significantly altered the volatile organic compound (VOC) profiles of the oils. In particular, all treated oils showed an increased content of VOCs originating from the lipoxygenase (LOX) pathway, especially at lower field strengths. In addition, PEF treatment had a significant effect on the composition of VOCs from the LOX path, indicating a change in the activity of the enzymes involved in their biosynthesis. We investigated the effects of PEF treatment on LOX activity and found that it varied by cultivar, indicating a variety-dependent response. In addition, PEF generally had a positive effect on minor VOCs associated with oxidation and microbial activity. These results emphasize the potential of PEF as a non-thermal, environmentally friendly technology to increase the efficiency of oil extraction and improve the aroma profile of VOO.