Rheological properties of milk fat compared to other fats [electronic resource]: 2-The use of the changes in milk fat rheological properties for detecting its adulteration.

Includes references.

A method used the changes in flow characteristics of buffaloes’ and cows’ milk fat for detecting their adulteration with each of the lard fat, palm, palm kernel and coconut oils was developed. The flow characteristics measured were the shear rate – shear stress relationship, consistency index (k), viscosity, plastic viscosity and 10-rpm viscosity. The changes in the flow characteristics of buffaloes’ and cows’ milk fat by their mixing with 10, 25 and 50% of each oil over a shear rate range from 73 to 196 S-1 and temperature range of 35 - 65?C were determined. However, the measurements at 196 S-1 shear rate and 40?C were recommended since at these conditions the changes on mixing were the largest. The changes of the above parameters on mixing 10% or more were significant at P < 0.001, were particular for each oil and fat and could be used for their identification. There was linear, inverse or direct relationship with R2 values of > 0.98 between the adulteration percent and the changes they made. Equations for calculating adulteration percent for any shear stress obtained on mixing were calculated.

Summary in Arabic.

1