Pulse electric field treatment effects on rheological properties and color of soy milk

摘要

This paper dealt with the effects of pulse electric field (PEF) treatments on rheological and color properties of soy milk. The flow behavior, viscosity and rheological parameters of PEF-treated soy milk were studied using a controlled stress rheometer. The treatment parameters of PFE were electric field intensity ranging from 18, 20 and 22 kV cm~(-1), the number of pulse ranging from 0 to 100 and pulse frequency 0.5 Hz. Rheological properties at shear rates between 0 to 200 s~(-1) were measured forcontrol sample and PEF-treated samples. The rheological behavior of control and PEF-treated soy milk were described with the power law model (R= 0.84-0.99). The rheological properties of soy milk were affected by PEF treatment. The apparent viscosity ofsoy milk increased from 6.62 to 7.46 (mPa.s) by increasing the intensity of electric field from 18 to 22 kV cm~(-1) and number of pulses from 0 to 100. The consistency index (K) of soy milk also changed with PEF treatment. The color changes of soy milk with PEF treatments were measured by colorimeter. Lightness (L*), red/greenness (a*), and yellowness/blueness (b*) of soy milk were affected by PEF treatments.