Crystallization and rheological properties of soya milk chocolate produced in a ball mill

The aim of this paper is to define the optimal conditions for the pre-crystallization of chocolate produced in a ball mill, that contains 20% soya milk. Chocolate mass and soya milk are refined in a ball mill employing three refining times (30, 60 and 90 min) and pre-crystallization temperatures (26, 28 and 30 degrees C). Increasing the refining time leads to organized chocolate systems with soya milk. The nucleation time of the system refined for 90 min and pre-crystallized at 30 degrees C is three times longer compared to that pre-crystallized at 26 degrees C. By prolonging the refining time, the system becomes dominantly viscous due to the refining and homogenization (tan delta > 1). Taking into consideration all three parameters, i.e., viscosity, yield stress and the area of the thixotropic loop, a refining time of 90 min at the pre-crystallization temperature of 30 degrees C seems optimal. (C) 2012 Elsevier Ltd. All rights reserved.