RHEOLOGICAL PROPERTIES OF MILK FAT COMPARED TO OTHER FATS: 2- THE.USE OF THE CHANGES IN MILK FAT RHEOLOGICAL PROPERTIES FOR DETECTING ITS ADUL TERATtON

Metwally, A. M. M.

doi:10.21608/jfds.2004.240109

RHEOLOGICAL PROPERTIES OF MILK FAT COMPARED TO OTHER FATS: 2- THE.USE OF THE CHANGES IN MILK FAT RHEOLOGICAL PROPERTIES FOR DETECTING ITS ADUL TERATtON

Document Type : Original Article

Author

A. M. M. Metwally

Dai'ry Science & Technology Department, Faculty of Agriculture, Cairo Unlverslty, Giza, Egypt

10.21608/jfds.2004.240109

Abstract

A method used the changes in now characteristics of buffaloes' and cows'
milk fat for detecting their adulleralion 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). vlscoslty, plastic viscosity and to-rpm
viscosity. The chanqes in the flow characteristlcs at buffaloes' and cows' milk fal by
their mixing with 10, 25 and 50% at each oil over a shear rate range from 73 10 196 S'
I and !empcraiure range of 35 • 65°C were determined. However. the measurements
at 196 S' shear rate and 40~C were recommended since at these condilions U1e
changes on mixing were the largest. The changes 01 the above parameters on mixing
10% or more were ~lgi1ificant at P < 0.00 1, were particular for each oil and fat and
could b(l used for their idenlification. There was linear. inverse or direct relationship
with R2 values 'of > 0.98 between .Ina adulterauon percent and the changes they
made. Equallons for calculallnq adulleration percent for any shear stress obtained on
mixing were calculated.

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