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Measurement of milk clotting activity by rotational viscometry

Published online by Cambridge University Press:  17 March 2011

Mandy Jacob ,
Martin Schmidt ,
Doris Jaros  and
Harald Rohm
Mandy Jacob
Affiliation:
Institute of Food Technology and Bioprocess Engineering, Technische Universität Dresden, 01069 Dresden, Germany
Martin Schmidt
Affiliation:
Institute of Food Technology and Bioprocess Engineering, Technische Universität Dresden, 01069 Dresden, Germany
Doris Jaros
Affiliation:
Institute of Food Technology and Bioprocess Engineering, Technische Universität Dresden, 01069 Dresden, Germany
Harald Rohm*
Affiliation:
Institute of Food Technology and Bioprocess Engineering, Technische Universität Dresden, 01069 Dresden, Germany
*
*For correspondence; e-mail: harald.rohm@tu-dresden.de
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Abstract

Standard method for the determination of the activity of milk coagulants is the rotating bottle method, where clotting time is defined as the time when visually observable flocculation starts. Aim of this study was to verify whether it is possible to determine milk clotting time by rotational viscometry. Using three different coagulants and reconstituted milk of different pH and temperature, flocculation time and viscosity in steady shear was determined, and milk gelation was monitored by small amplitude oscillating shear rheometry. The results show that, independent of pH and temperature, milk clotting time is related to an apparent viscosity of 7·24±0·45 mPa.s, indicating that rotational viscometry can be used for the screening of flocculation time with an accuracy of approximately 6%.

Keywords

Milkclottingviscositycasein micelles
Type
Research Article
Information
Journal of Dairy Research , Volume 78 , Issue 2 , May 2011 , pp. 191 - 195
Copyright
Copyright © Proprietors of Journal of Dairy Research 2011

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