The effect of native and modified konjac on the physical attributes of pasteurized and UHT-treated skim milk

The aim of the current study was to examine the influence of addition of mechanically modified konjac glucomannan, on the physical properties of pasteurized and ultra-high-temperature (UHT) treated skim milk. The effect of adding modified konjac (0-0.12%, w/w) on the viscosity and stability of skim milk, following pasteurization or UHT treatment, was investigated. It was possible to add modified konjac at levels up to 0.12% (w/w) without phase separation, as compared to <0.03% (w/w) native konjac. Addition of modified konjac increased the viscosity of pasteurized and UHT skim from ∼2.0 to 3.6 mPa s, with UHT samples having increased stability to sedimentation during simulated storage. The addition of modified konjac had little effect on particle size or colour of the skim milk post heating. Addition of modified konjac could provide a mechanism to enhance the physical properties of both pasteurized and UHT-treated skim milk.