July 1-6, 2007
The science underlying the removal of dairy fouling layers, and particularly the dissolution of proteinaceous deposits in alkaline solution, is relatively poorly understood even though this is a critical feature of many cleaning-in-place operations. We report key results from a series of investigations on heat-induced gels of β- lactoglobulin, the primary whey protein component in milk and whey foulant. These model systems were used to elucidate the reaction behaviour of gels and aggregates whereby the proteinaceous material is converted to a softer, swollen form that can then be removed by fluid shear or diffusion. We show that several features, such as the occurrence of an optimal pH for cleaning, can be related by analogy to the behaviour of synthetic polyelectrolyte polymers. The structure and history of the foulant, pH, ionic strength and salt concentration in the cleaning solution are all shown to be important factors in the chemistry of inter- and intra-molecular interactions explaining why it has been difficult to generalise about the mechanisms involved and to write simple models of their kinetics.
R. Mercadé-Prieto,; W.R. Paterson; and D.I. Wilson, "THE SCIENCE OF CLEANING OF DAIRY FOULING LAYERS" in "Heat Exchanger Fouling and Cleaning VII", Hans Müller-Steinhagen, Institute of Technical Thermodynamics, German Aerospace Centre (DLR) and Institute for Thermodynamics and Thermal Engineering, University of Stuttgart, Germany; M. Reza Malayeri, University of Stuttgart, Germany; A. Paul Watkinson, The University of British Columbia, Canada Eds, ECI Symposium Series, (2007). http://dc.engconfintl.org/heatexchanger2007/17