OPERABILITY OF THE OHMIC HEATING PROCESS - ELECTRICAL-CONDUCTIVITY EFFECTS

Ohmic heating is a novel commercial process in which an electric current is applied to a flowing food stream. The passage of current generates heat, which is used to sterilise the food; it is thus possible to sterilise particles as fast as liquids. The controlling parameter is the electrical conductivity of the solid and liquid phases. The range of conductivities which are acceptable to the ohmic process have been examined by finite element simulation. The variation of electrical conductivity in the components of a feed mix on the operability of the process is considered, together with the ohmic heating patterns of composite materials. Providing the conductivities of the two phases do not differ significantly even heating will result. Other process conditions are also briefly discussed.