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RHEOLOGICAL CHARACTERIZATION OF STIRRED YOGHURT: VISCOMETRY
Author(s) -
SKRIVER A.,
ROEMER H.,
QVIST K.B.
Publication year - 1993
Publication title -
journal of texture studies
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.593
H-Index - 54
eISSN - 1745-4603
pISSN - 0022-4901
DOI - 10.1111/j.1745-4603.1993.tb00043.x
Subject(s) - shear thinning , rheology , viscometer , rheometer , shear rate , bingham plastic , materials science , apparent viscosity , viscosity , yield (engineering) , mathematics , composite material
Rheological characteristics of stirred yoghurt, varying in dry matter content, fermentation temperature and composition of bacteria cultures, were evaluated using a Bohlin VOR Rheometer. Flow curves, covering the shear rate range 29–920 s −1 , generally indicated the presence of a yield point and pseudoplastic behaviour, but also Bingham plastic behaviour was observed for some of the specimens. Systematic variations in the profile of the flow curves were observed as a result of the applied manufacturing conditions. Flow curves exhibiting pseudoplastic behaviour with a yield stress could not, over this broad shear rate interval, be described satisfactorily by the often applied Casson or Herschel‐Bulkley models, and consequently a new one, the QRS‐model was introduced. This model contains three parameters and gave a significantly better fit, with R 2 values generally above 0.99.