Effect of temperature on the AC impedance of protein and carbohydrate biopolymers

The influence of temperature on the electrical behaviour of protein biopolymer papain and carbohydrate biopolymers like gum acacia, gum tragacanth and guar gum has been investigated using AC impedance technique. The observed semi-circles represent the material’s bulk electrical property that indicate the single relaxation process in the biopolymers. An increase in bulk electrical conductivity in the biopolymers with temperature is due to the hopping of charge carriers between the trapped sites. The depression parameter reveals the electrical equivalent circuit for the biopolymers. The AC electrical conductivity in the biopolymers follows the universal power law. From this, it is observed that the AC conductivity is frequency dependent and the biopolymer papain obeys large polaron tunnelling model, gum acacia and gum guar obey ion or electron tunnelling model, and gum tragacanth obeys the correlated barrier hopping model of conduction mechanisms.