Design and Development of Direct Resistance Heating Device for Liquid Food Processing and its Monitoring

An experimental batch ohmic heating unit was designed and fabricated for thermal processing of liquid foods. The unit was supported by a data acquisition system for sensing the liquid temperature distribution, voltage and current with time. The data acquisition system performed well and could record temperatures, voltage and current at intervals of one second. The performance of the ohmic heating unit was evaluated based on experiments. Tests with 2, 4 and 6 w/v% aqueous sodium chloride solutions showed the ohmic heating to be fast. Results indicated that fabricated ohmic system can heat the samples faster than traditional heating system and also increasing of applied voltage will increase heating rate in ohmic system.