Temperature Dependent Electrical Conductivity of Soymilk during Ohmic Heating
Loading...
Date
2016
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Punjab Agricultural University, Ludhiana
Abstract
Ohmic heating, also known as „resistive heating‟ or „Joule heating‟ is a process when electrical
current is passed through a conducting substance and due to its internal resistance heat is generated
within that conducting substance. The present study aimed to design, built ohmic heating
system and ohmic heating behavior was studied in soymilk. Study was conducted on five
different voltage gradients (14, 12, 10, 8 and 6V/cm) and concentrations (100, 90, 80, 70,
60%) in the temperature range 30 to 70 ˚C. Ohmic heating behavior of any sample is affected
by different parameters like electrical conductivity, viscosity, pH, soluble solids etc. Results
indicated that there was a significant effect of voltage gradients and concentrations on the
heating rate and heating rate showed a linear behavior. Also, plots between temperature and
electrical conductivity depicted a linear trend. Other parameters- viscosity, pH and total
soluble solids (TSS) were measured before and after ohmic heating. Statistical analysis was
done on all of these parameters and it was concluded that ohmic heating had no effect on
viscosity and TSS of sample, but there was a significant effect of this treatment on pH at 14
and 6V/cm and non-significant effect on rest of the voltage gradients. System performance
coefficient (SPC) was calculated for all voltage gradients and all concentrations. It was
observed that SPC was higher for 14V/cm for all concentrations and its value decreased as we
decrease the voltage gradient.