The Impact of Pulsed Electric Field Treatment of Beetroots on the Physicochemical Properties of Juice, Dried Juice, and Dried Pomace

Abstract

The aim of this work was to determine the impact of pulsed electric field treatment of beetroots on select physicochemical properties of the obtained juice, spray-dried juice, and freeze-dried pomace. Pulsed electric field pretreatment of beetroots was conducted with a different number of pulses (3 or 44 pulses) at a constant electric field strength of E = 1.07 kV/cm, which resulted in the total energy levels of 0.5 and 4 kJ/kg. The juice was dehumidified and air spray-dried with NUTRIOSE® as a drying carrier at 90/60 °C, while pomace was freeze-dried at 0.63 Pa and a shelf temperature of 20 °C. Pulsed electric field (PEF) treatment caused an increase in pigment content in beetroots and the juice. In the case of powders, the following effects were noted: a decrease in drying efficiency, changed powder color, decreased powder particle diameter. Dried juice and pomace treated with a higher pulsed electric field (PEF) treatment were characterized by the highest hygroscopicity.