Comparison of rheological models for determining dark chocolate viscosity
Parameters in chocolate rheology, namely shear viscosity and yield stress, are important in manufacture and directly inﬂuenced by product particle size distribution (PSD) and composition. The Casson model was the standard confectionery industry strategy to quantify rheological properties of molten chocolate until in 2000, the International Confectionery Association recommended the use of interpolation data to describe viscosity. The two strategies are compared and correlated in deﬁning rheological properties of molten dark chocolates prepared using diﬀerent PSD, fat and lecithin content. Rheological parameters were determined using a shear rate-controlled rheometer and data examined using correlation, regression and principal component analyses to establish their inter-relationships. Correlation and regression analyses showed high correlation ( r = 0.89–1.00) and regression coeﬃcients (R2= 0.84–1.00). The newer International Confectionery Association technique gave higher correlation and regression coeﬃcients than the Casson model, but multivariate principal component analysis showed that the two models were highly related and either could eﬀectively quantify dark chocolate viscosity parameters.
Emmanuel Ohene Afoakwa, Alistair Paterson, Mark Fowler, and Joselio Vieira. "Comparison of rheological models for determining dark chocolate viscosity" International Journal of Food Science and Technology 2009.44 (2009): 162-167.
Available at: http://works.bepress.com/emmanueloheneafoakwa/97