Continuous ohmic heating unit under whey protein fouling

An evaluation of a continuous ohmic heating apparatus performance was carried out, using a whey protein solution. It was thereby shown that, as with conventional heat exchangers, ohmic processing of dairy product generates fouling on electrode surfaces. The presence of this motionless deposit causes an increase in electricity consumption and leads to an increase in the temperature of the electrode surfaces. During the observation of 4- and 6-h processes, three stages were noted: (i) at first, the deposit thickness was not significant for a short period and ohmic process was observed to operate satisfactorily (balance power, electrode temperature), (ii) then the deposit thickness was observed to gradually increase with processing time, provoking a corresponding simultaneous increase in both electricity comsuption and electrode temperature, (iii) finally, the electrode temperature reached boiling point, as did the deposit, leading to deposit adhesion and removal changes. © 2004 Elsevier Ltd. All rights reserved.