Centrifugal osmotic dehydration and rehydration of carrot tissue pre-treated by pulsed electric field

Abstract

This paper studies the centrifugal osmotic dehydration (OD), rehydration and texture of carrot tissue treated by pulsed electric field (PEF). The influence of centrifugal acceleration (0–5430 g), salt addition (NaCl/sucrose solutions 0/65, 7/44 and 15/50% w/w), and temperature (20–40 °C) on the OD kinetics was investigated in the presence and absence of PEF ( E=0.60 kV/cm, treatment duration t PEF=0.05 s). The centrifugal OD of samples untreated and treated by PEF was compared with OD under stirring (250 tr/min). Centrifugal force, PEF and salt addition increase the amount of water removed during OD. However, the centrifugal force decreases the intake of solids by the product. The application of PEF enhances both water loss (WL) and solid gain (SG) during OD (under stirring or centrifugation), increases the rehydration capacity of carrot tissue, but somewhat decreases the firmness of rehydrated product. The combination of centrifugal field with PEF and salt addition can be advantageous for reducing the OD duration. The textural study shows that the product obtained with OD is less affected by thermal treatment than the directly dried product.