Practical Food Rheology

Preface. Contributors. 1 Introduction - Why the Interpretive Approach? (Niall W. G. Young). 1.1 Rheology - What is in it for me? 1.1.1 Case study. 2 Viscosity and Oscillatory Rheology (Taghi Miri). 2.1 Introduction. 2.2 Food rheology. 2.3 Directions of rheological research. 2.3.1 Phenomenological rheology or macrorheology. 2.3.2 Structural rheology or microrheology. 2.3.3 Rheometry. 2.3.4 Applied rheology. 2.4 Steady-state shear flow behaviour: viscosity. 2.4.1 Rheological models for shear flow. 2.4.2 Wall slip. 2.5 Viscoelasticity and oscillation. 2.5.1 Oscillatory testing. 2.6 Process, rheology and microstructural interactions. 2.7 Rheology of soft solids. 2.7.1 Capillary rheometer. 2.7.2 Squeeze flow rheometer. 2.8 Measuring instruments - practical aspects. 2.8.1 Choosing the right measuring system. 3 Doppler Ultrasound-Based Rheology (Beat Birkhofer). 3.1 Introduction. 3.1.1 Overview. 3.1.2 History of ultrasonic velocimetry. 3.1.3 Existing literature on UVP-based rheometry. 3.2 Ultrasound transducers. 3.3 Flow adapter. 3.3.1 Doppler angle. 3.4 Acoustic properties. 3.4.1 Propagation. 3.4.2 Attenuation. 3.4.3 Sound velocity. 3.4.4 Scattering. 3.4.5 Backscattering. 3.5 Electronics, signal processing and software. 3.5.1 Electronics. 3.5.2 Signal processing and profile estimation. 3.5.3 Software. 3.6 Pipe flow and fluid models. 3.6.1 Gradient method or point-wise rheological characterisation. 3.6.2 Power law fluid model. 3.6.3 Herschel-Bulkley fluid model. 3.6.4 Other models. 3.7 Rheometry. 3.7.1 Averaging effects at the pipe wall. 3.7.2 Fitting. 3.7.3 Gradient method. 3.8 Examples. 3.8.1 Carbopol solution. 3.8.2 Suspension of polyamide in rapeseed oil. 3.9 Summary. 4 Hydrocolloid Gums - Their Role and Interactions in Foods (Tim Foster and Bettina Wolf). 4.1 Introduction. 4.2 Behaviour of hydrocolloid gums in solution. 4.3 Hydrocolloid gelation and gel rheology. 4.4 Hydrocolloid-hydrocolloid interactions. 4.5 Hydrocolloids in foods - role and interactions. 5 Xanthan Gum - Functionality and Application (Graham Sworn). 5.1 Introduction. 5.2 Xanthan molecular structure and its influence on functionality. 5.3 The conformational states of xanthan gum. 5.4 Food ingredients and their effects on xanthan gum functionality. 5.4.1 Salts. 5.4.2 Acids (pH). 5.4.3 Xanthan and proteins. 5.4.4 Xanthan and starch. 5.5 Food processing and its impact on xanthan gum functionality. 5.5.1 Thermal treatment. 5.5.2 Homogenisation. 5.5.3 Freezing. 5.6 Food structures. 5.6.1 Emulsions. 5.6.2 Gels. 5.7 Applications. 5.8 Future trends. 6 Alginates in Foods (Alan M. Smith and Taghi Miri). 6.1 Alginate source and molecular structure. 6.2 Alginate hydrogels. 6.3 Alginic acid. 6.4 Alginate solutions. 6.5 Enzymatically tailored alginate. 6.6 Alginates as food additive. 6.6.1 Gelling agent. 6.6.2 Thickening agent. 6.6.3 Film-forming agent. 6.6.4 Encapsulation and immobilisation. 6.6.5 Texturisation of vegetative materials. 6.6.6 Stabiliser. 6.6.7 Appetite control. 6.6.8 Summary. 7 Dairy Systems (E. Allen Foegeding, Bongkosh Vardhanabhuti and Xin Yang). 7.1 Introduction. 7.2 Fluid milk. 7.2.1 Rheological properties of milk. 7.2.2 Measurements of the rheological properties of milk. 7.2.3 Factors influencing milk rheological properties. 7.2.4 Correlating rheological properties of milk to sensory perceptions. 7.2.5 Process engineering calculation. 7.3 Solid cheese. 7.3.1 Small amplitude oscillatory tests. 7.3.2 Large strain rheological analysis. 7.3.3 Creep and stress relaxation. 7.4 Rheological properties of semi-solid dairy foods. 7.4.1 Flow properties. 7.4.2 Yield stress. 7.4.3 Viscoelastic properties of semi-solid dairy products. 7.5 Effect of oral processing on interpretation of rheological measurement. 8 Relationship between Food Rheology and Perception (John R. Mitchell and Bettina Wolf). 8.1 Introduction. 8.2 Rheology and thickness perception. 8.3 Rheology and flavour perception. 8.4 Mixing, microstructure, gels and mouthfeel. 8.4.1 Mixing. 8.4.2 Microstructure. 8.4.3 Mouthfeel. 8.4.4 Gels. 8.5 Beyond shear rheology. 8.6 Conclusions. 9 Protein-Stabilised Emulsions and Rheological Aspects of Structure and Mouthfeel (Fotios Spyropoulos, Ernest Alexander K. Heuer, Tom B. Mills and Serafim Bakalis). 9.1 Introduction. 9.2 Processing and stability of emulsions. 9.2.1 Instabilities in emulsions. 9.2.2 Protein functionality at liquid interfaces. 9.2.3 Protein-stabilised oil-in-water emulsions - Effect of aqueous phase composition. 9.2.4 Effect of processing. 9.3 Oral processes. 9.3.1 Different stages and phenomena during oral processing. 9.3.2 Fluid dynamics during oral processing. 9.3.3 Interactions with saliva. 9.3.4 Interaction with oral surfaces. 9.4 In vitro measurements of sensory perception. 9.5 Future perspectives. 10 Rheological Control and Understanding Necessary to Formulate Healthy Everyday Foods (Ian T. Norton, Abigail B. Norton, Fotios Spyropoulos, Benjamin J. D. Le Reverend and Philip Cox). 10.1 Introduction. 10.2 Design and control of material properties of foods inside people. 10.2.1 Oral perception of foods. 10.2.2 Food in the stomach. 10.2.3 Food in the intestine. 10.3 Reconstructing foods to be healthy and control dietary intake. 10.3.1 Use of emulsions as partial fat replacement. 10.3.2 Duplex emulsions. 10.3.3 Fat replacement with air-filled emulsion. 10.3.4 Sheared gels (fluid gels). 10.3.5 Water-in-water emulsions. 10.3.6 Self-structuring systems. 10.4 Conclusions. References. Index.