Rheological aspects of chocolate with an improved health profile
Posted: 28 August 2013 | Isabella Van Damme, Material Science Program Manager R&D, Mars Chocolate | No comments yet
Chocolate is adored by people around the world for its unique flavour and smooth, luxurious texture. It provides an indulgent pleasure with the added benefit that cocoa flavanols promote a range of health benefits. Is it possible to improve the nutritional profile of chocolate while still maintaining the quality aspects the consumer expects of good quality chocolate? The challenge to achieve this lies in being able to control the rheological properties of the new chocolate formulations.
Chocolate rheology describes and quantifies the flow and deformation properties of liquid chocolate. Viscosity, which is a measure of the resistance to flow, is the main rheological parameter used to describe chocolate and is an important quality control parameter. Although chocolate is eaten in the solid state, chocolate melts in the mouth as the body temperature is similar to the melting point of the fat in chocolate. It is the molten chocolate that covers the oral cavity and produces the smooth, luxurious mouth sensation and enables the release of flavours. The rheological properties of the liquid chocolate therefore play a role in the eating experience of chocolate, although several other aspects also impact on the complex processes that contribute to the eating experience. The design of new products must take into account that any major changes to the chocolate viscosity will impact the chocolate perception. It is, however, in the manufacturing process that rheological properties play a critical role to enable the production of high quality products. The chocolate must be sufficiently fluid to be pumped and adopt the required form of the product achieved through a range of enrobing, moulding or spraying techniques. On the other hand, the chocolate must be retained on the product and maintain its required shape and decorations without showing defects.