Effect of pulsed electric fields pretreatment on juice expression and quality of chicory

Abstract

This study investigates the effects of pulsed electric fields (PEF) and freeze thawing (FT) pretreatments on juice yield and quality from chicory by pressing (P). The four different modes (P, PEF-P, FT-P and P-PEF-P) were compared. The effects of pressing mode, PEF conditions, cossettes size on the juice yield, and total soluble matter (°Bx), conductivity, pH, turbidity in expressed juices were evaluated. The pressing kinetics for different modes were also investigated. For studied modes, the highest juice yield and kinetic rate were obtained for FT-P mode, the lowest was P mode. PEF-P and P-PEF-P modes resulted in the same juice yield, an increase of 9% higher than P mode. A 600 V/cm of intensity and 0.2 s duration were optimal PEF conditions with desired energy consumption. Moreover, cake mixing and relative small-sized cossettes allowed improving juice yield assisted by PEF-P mode. Quality analysis showed that expressed juice from smaller cossettes by PEF-P mode has lower turbidity and higher inulin content.