Three different chocolate types: dark, milk and white were characterized and compared for the microstructural
and rheological (fundamental and empirical) characteristics. A light microscope coupled to an
image analysis system was employed in order to evaluate the particle size, the network structure and the
distance between particles of each matrix. Rheological parameters (yield stress, viscosity, thixotropy)
were evaluated by using a stressestrain rheometer, while mechanical properties (consistency and
cohesiveness) were analysed using a texture analyzer. The Power law, Casson and Windhab rheological
models were used in order to better explain the rheological behaviour of chocolate samples.
Results showed that white chocolate, with the highest amount of fat in formulation, had the smallest
sized particles, the less aggregate structure and the lowest yield stress, viscosity and thixotropic values.
Dark chocolate samples instead presented the highest aggregate structure, with less void spaces between
particles that involved the highest rheological parameter values. Milk chocolate matrix exhibited intermediate
microstructural and rheological characteristics compared to dark and white chocolate ones.