Effect of physical properties of mango juice on the effectiveness of pulsed electric field treatment

Abstract

Pulsed electric field technology is emerging as one of the effective non-thermal processing methods for liquid foods. The effectiveness of the PEF treatment was found to be dependent on the physical properties such as pH, electrical conductivity (EC), density and viscosity of food materials. The properties of the liquid food were measured at various temperatures ranging from 4 to 40 ˚C. From the measured values, the change in temperature (△T), the total energy delivered (P) and the Reynolds numbers (NRe) were modeled. The results revealed that increase in temperature decreased the pH values from 5.25±0.03 to 4.52±0.02, density from 1050±13.25 to 1006.34±3.77 kg/m3 and viscosity from 0.01295±0.000071 to 0.00719±0.00127 Pa.s. However, the rise in temperature increased the values of EC from 0.079±0.0064 to 0.1866±0.0052 S/m, change in temperature from 7.68 to 19.03 ˚C, total energy delivered from 32.92 to 79.14 J/ml and Reynolds number from 1698.51 to 2929.84. The observation showed that at 30 and 40˚C the temperature change, total energy delivered was found to be high, the flow was found to be turbulent and pH was lower. Processing the liquid food under these conditions can increase the effectiveness of the PEF treatment.