College
College of Science
Faculty Mentor
Silvana Martini
Abstract
This research studies how the viscoelastic properties of chocolate change through the 72-hour grinding process of chocolate manufacturing. Utah State University's Aggie Chocolate Factory produces chocolate from single-origin sources, each of which has a unique flavor, and thus a unique chemistry. This research explores the effects of grinding time on the viscoelasticity of each of these origins' chocolate types, including dark, sweet dark chocolate, and milk chocolate. Chocolate is a non-Newtonian fluid and therefore the Casson model (eq. 1) was used to obtain values for viscosity and yield stress, τ^(1/2)=τ_0^(1/2)+(η_PL y' )^(1/2) (1) Where τ is the shear stress measured as a function of shear rate (y'), τ_0 is the yield stress and η_PL is the Casson plastic viscosity. The yield stress and the Casson plastic viscosity was obtained using rheometer by measuring the shear stress as a function of shear rate for chocolates collected during 5-7 time points throughout the grinding process and fitting the data to the Casson model. Results from this research showed that the yield stress increased, and the viscosity decreased with grinding time, which is consistent with prior research. It was also found that the dark chocolates had the highest viscosity, followed by the sweet dark chocolate, and then the milk sweet.
Document Type
Poster
Publication Date
1-25-2023
Recommended Citation
Cooney, Joseph, "Grinding Cocoa Changes Chocolate Properties" (2023). Research on Capitol Hill. Paper 131.
https://digitalcommons.usu.edu/roch/131