Lessening polygalacturonase activity in a commercial enzyme preparation by exposure to pulsed electric fields

The effect of high-intensity pulsed electric field (HIPEF) treatments on polygalacturonase (PG) activity in an aqueous solution of a commercial enzyme preparation was evaluated. HIPEF treatments reduced PG activity notably. Exponentially decaying pulses of 40 and 160 μs generated by a laboratory scale device were applied in a batch processing and bipolar mode. Electric fields ranged from 5.18 to 19.39 kV/cm. The number of pulses ranged up to 400. Temperature was always below 25 °C. Maximum inactivation of PG activity (98%) required 32.4 ms HIPEF treatment at 10.28 kV/cm. PG activity depleted exponentially because of HIPEF treatments. The first order rate constants ranged from 32 to 590 μs-1 and increased exponentially with electric field intensity. PG activity decreased exponentially with input electric energy density.