Abstract
The shear flow behaviour of stirred yoghurt in the cone-and-plate and cylindrical Couette geometries was studied using diffusing wave spectroscopy (DWS) and nuclear magnetic resonance (NMR) velocimetry. Differences between the transmission and backscattering DWS correlations suggest the formation of a high shear rate band near the surface of a moving cone of a cone-and-plate geometry at low shear rates. At higher shear rates, homogeneous shear flow is indicated. NMR velocimetry unambiguously demonstrated that a high shear rate band forms at the moving inner wall of a cylindrical Couette geometry at low shear rates. At intermediate shear rate, a high shear rate band is formed at the stationary outer wall and plug-like flow is observed mid-gap. At higher shear rates, homogeneous shear flow is observed. Slip is seen at both walls. The three flow regimes appear to correlate loosely with transitions in the pseudo-steady-state flow curve and may reflect a break-up of the protein aggregates observed with confocal microscopy.
Similar content being viewed by others
References
Basak S, Ramaswamy HSA (1994) Simultaneous evaluation of shear rate and time dependency of stirred yogurt rheology as influenced by added pectin and strawberry concentrate. J Food Eng 21:385–393
Benezech T, Maingonnat JFA (1994) Characterization of the rheological properties of yoghurt. J Food Eng 21:447–472
Bicout D, Maret G (1994) Multiple light scattering in Taylor-Couette flow. Physica A 210:87–112
Bicout D, Maynard R (1993) Diffusing wave spectroscopy in inhomogeneous flows. Physica A 199:387–411
Britton MM, Callaghan PT (1997) NMR Microscopy and the non-linear rheology of food materials. Magn Reson Chem 35:S37–S46
Callaghan PT (1991) Principles of nuclear magnetic resonance microscopy. Oxford University Press, Oxford
Callaghan PT (2008) Rheo-NMR and shear banding. Rheol Acta 47:243–255
de Kruif CG, Zhulina EB (1996) Kappa-casein as a polyelectrolyte brush on the surface of casein micelles. Colloids Surf A: Physicochem Eng Asp 117:151–159
Gibaud T, Barentin C, Manneville S (2008) Influence of boundary conditions on yielding in a soft glassy materials. Phys Rev Lett 101:258302
Gibaud T, Barentin C, Taberlet N, Manneville S (2009) Shear induced fragmentation of laponite suspensions. Soft Matter 5:3026–3037
Henningsson M, Ostergren K, Dejmek P (2006) Plug flow of yoghurt in piping as determined by cross-correlated dual-plane electrical resistance tomography. J Food Eng 76:163–168
Horne DS (1998) Casein interactions: casting light on the black boxes, the structure in dairy products. Int Dairy J 8:171–177
Hoult DI, Richards RE (1975) Critical factors in the design of sensitive high resolution nuclear magnetic resonance spectrometers. Proc R Soc Lond A344:311–340
Lucey JA, Singh H (1998) Formation and physical properties of acid milk gels: a review. Food Res Int 30(7):529–542
Moller PCF, Rodts S, Michels MAJ, Bonn D (2008) Shear banding and yield stress in soft glassy materials. Phys Rev E 77:041507
Olmsted PD (2008) Perspectives on shear banding in complex fluids. Rheol Acta 47:283–300
Raudsepp A, Callaghan PT, Hemar Y (2008) A study of the nonlinear rheology of complex fluids using diffusing wave spectroscopy. J Rheol 52:1113–1129
Rogers SA, Vlassopoulos D, Callaghan PT (2008) Aging, yielding and shear banding in soft colloidal glasses. Phys Rev Lett 100:128304
Salmon J-B, Collin A, Manneville S (2003) Velocity profiles in shear-banding wormlike micelles. Phys Rev Lett 90:228303
Suwonsichon T, Peleg M (1999) Rheological characterization of almost intact and stirred yogurt by imperfect squeezing flow viscometry. J Sci Food Agric 79:911–921
Weitz DA, Pine D (1992) Diffusing-wave spectroscopy. In: Brown W (ed) Dynamic light scattering. Oxford University Press, Oxford
Yoon WB, McCarthy KL (2002) Rheology of yogurt during pipe flow as characterized by magnetic resonance imaging. J Texture Stud 33:431–444
Acknowledgements
The authors thank Aurélie Cucheval, Institute of Fundamental Sciences, Massey University, New Zealand for the confocal microscopy measurements. The NMR velocity measurements were performed in the Rheo-NMR Facility operated by Prof. Paul Callaghan at Victoria University of Wellington, New Zealand. Allan Raudsepp thanks the Royal Society of New Zealand for funding and Kirk Feindel thanks the Natural Sciences and Engineering Research Council of Canada for a post-doctoral fellowship.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Raudsepp, A., Feindel, K.W. & Hemar, Y. Shear localisation in stirred yoghurt. Rheol Acta 49, 371–379 (2010). https://doi.org/10.1007/s00397-010-0438-9
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00397-010-0438-9