  Electrical Impedance Spectroscopy (EIS) technique is found to be an excellent
candidate for bio-sensing and food quality monitoring applications due to its
rapid, robust, cost-effective and point-of-care approach. The present research
work investigates the implementation of EIS technique supported by several
optical spectroscopic techniques such as Ultraviolet-Visible (UV-Vis) and
Fourier Transform Mid Infrared (FT-MIR) to detect and quantify several toxic
adulterants in foods and bio-consumables. A comprehensive understanding on the
background theory related to the study has been developed to analyze the
overall polarization of the system and the effect of frequency on complex
permittivity of such system have been observed. In the current work, the
technique is applied to adulterated saccharides, honey and turmeric samples
through a prototype sensing device. All the corresponding measurements have
been performed by dipping a custom-made parallel plate conductivity cell with
unity cell constant inside the solution under test. EIS study exhibited a
steady variation of electrical parameters such as impedance, capacitance,
conductance and current values with increasing adulterant percentage in the
solution. Variation in such properties due to adulteration provides a
systematic sensor plot through which one can determine their percentage of
adulteration in unknown adulterated samples. Co-efficient of sensitivity has
been extracted from the EIS data for adulteration study in terms of one of the
measured parameters. The results of UV-Vis and FT-MIR studies have been used
for comparative analyses which corroborate with the EIS results, wherever
applicable.
