Effect of pulsed electric field on the rheological and colour properties of soy milk.

摘要

Effects of pulsed electric field (PEF) treatments (electric field intensities of 18, 20 and 22 kV/cm at 25, 50, 75 and 100 pulses) on rheological and colour properties of soymilk were evaluated. Flow behaviour, viscosity and rheological parameters of PEF-treated soymilk were monitored using a controlled stress rheometer. Shear rates of 0-200 s--1 were used for rheological property measurements of soymilk. The rheological behaviour of control and PEF-treated soymilk were described using a power law model. The PEF treatments affected the rheological properties of soymilk. Apparent viscosity of soymilk increased from 6.62 to 7.46 (10--3 Pa s) with an increase in electric field intensity from 18 to 22 kV/cm and increase in the number of pulses from 0 to 100. The consistency index (K) of soy milk also changed with PEF treatments. Lightness (L*), red/greenness (a*) and yellowness/blueness (b*) of soymilk were affected by PEF treatments.