Rheology of chocolate

VIGNETTE IV RHEOLOGY IN MANUFACTURING AND QUALITY CONTROL Rheology of Chocolate... 

Kleinert, J. 1976. Rheology of chocolate. In Rheology and texture in food quality, ed. J.M deMan et al. Westport, CT AVI Publishing Co. 

Chevalley, J. 1991. An adaptation of the Casson equation for the rheology of chocolate.. 7 Texture Stud. 22 219-229. 

Simple empirical viscometers of the orifice and falling ball types, and the controlled shear rate McMichael coaxial cylinder viscometer, have been used traditionally in the chocolate industry. Sophisticated rheometers are now being used increasingly because the economic pressure to reduce the cocoa butter content of chocolate has generated a need for a greater understanding of chocolate rheology (Minifie, 1999). 

Quemada et al. (1985) model (Equation 2.11) was used to analyze data on cocoa dispersions (Fang et al., 1996) and the role of cocoa butter replacers (Fang et al., 1997). Selected values of rheological properties of chocolate are given in Table 5-G. In addition, the data of Fang et al. (1996) (Table 5-H) before and after degasification as a function of temperature are note worthy. 

Luengo Get aM 997 Thin film rheology and tribology of chocolate J. Food Sol. 62 767-72... 

The Casson equation (equation 5.1) is often used to describe the rheology of liquid chocolates and couvertures. The relation between the shear stress (a) and the shear rate (y) depends on two parameters the yield stress, Oy, i.e. the shear stress required to initiate flow, and the plastic viscosity, i.e. the viscosity after yield. 

Afoakwa, E.O., Paterson, A., Eowler, M., 2007. Eactors influencing rheological and textural ojuali-ties of chocolate — a review. Trends Eoxxl Sci. Technol. 18, 290-298. 

Schantz, B., Rohm, H., 2005. Influence of lecithin-PGPR blends on the rheological properties of chocolate. Lebensm. Wiss. Technol. 38, 41-45. 

Lipases are used to hydrolyse milk fat for a variety of uses in the confectionary, sweet, chocolate, sauce and snack food industries and there is interest in using immobilized lipases to modify fat flavours for such applications (Kilara, 1985). Enzymatic interesterification of milk lipids to modify rheological properties is also feasible. 

In order to use these powders for chocolate seeding, a characterisation of their mechanical and rheological properties is needed and this will be done in future work. 

Steiner, E. H. 1958. A new rheological relationship to express the flow properties of melted chocolate. Rev. Internationale de la Chocolatiere. 13 290-295. 

Fats provide fundamental structural and textural attributes to a wide range of consumer products, including lipstick, chocolate, and everyday products such as butter and margarine (1, 2). Within these fat-based products, certain textural properties are required to meet desirable sensory attributes to gain consumer acceptance (3). This has led to an increase in research efforts on the physical properties of fats, particularly their rheology. 

Pastry, Cake, and Biscuit Products. In general, fats play several essential nutritional, technological, functional, and organoleptic roles in most all-bakery applications. As a result of its physical properties, fat plays a major part in the production of the majority of items in the pastry, cake, biscuit, and chocolate confectionery sector for example, in the preparation of pastry cream and in the desired appearance and texture of the end product. These physical properties include, above all, the rheological properties (consistency, plasticity, texture, etc.), and the properties of fusion and crystallization depend on the type of fat, the temperature, and the working conditions of the product. 

Chapters 18—25 are related in that they discuss aspects of crude oil-based emulsions. The topic of environmental emulsions is covered by Fingas, Fieldhouse, and MuIIin. They analyze in depth the emulsification and stabilization processes in oil spills. These processes are crucial because they complicate the removal and treatment of these so-called mousses or chocolate mousses. Natural forces in the form of wind and waves are important mechanisms for the formation of the oil-spill emulsions. Most likely, the stabilization of the formed dispersions is due to naturally occurring components such as asphaltenes and resins. The authors give a comprehensive analysis of different kinds of oil spills with regard to stability and rheological properties. 

Chocolate tion of starch retrogradation (bread staling) Improvement of rheological... 

---