2.5. System performance coefficient (SPC)
The ohmic heating system performance coefficients (SPCs)
were defined by using the energies given to the system and taken
up by the juice samples. To simplify the calculation of
SPC, the following assumptions were made: (i) specific heat
capacity of the pomegranate juice is constant within the range
of temperatures considered; (ii) SPC is constant, (iii) Prior to
commencing ohmic heating it is assumed that the entire sample
is at a uniform temperature of 20 C.
The energy given to the system and the heat required to
heat the sample to a prescribed temperature were calculated
by using the current, voltage and temperature values recorded
during the heating experiments. The energy given to the system