Emulsifiers in chocolate: New findings and their relevance for the industry

verfasst von

Knut Franke, Ute Bindrich

Abstract

From the physicochemical point of view, chocolate mass represents a concentrated lipophilic suspension where different solids are distributed in a continuous fat phase. Due to the high solid volume fraction of 60% and more, the behavior of the suspension is mainly determined by the properties of these solids, e.g. particle size distribution and especially surface properties. With respect to the surface properties, it can be differentiated between particles with hydrophilic surfaces (sugar particles), lipophilic surfaces (fat crystals) and particles with both hydrophilic and lipophilic regions (milk powder, cocoa particles). Furthermore, the mechanical grinding of solids in the suspension by roller refining leads to an activation of particle surfaces which also impacts suspension properties. Emulsifiers are added for adjustment of flow behavior and texture of chocolate masses. These substances significantly influence the interactions of the refined solids among each other and with the continuous lipophilic phase.However, so far the principles of emulsifier action in interaction with the particle surfaces and the continuous phase are not know in detail. Therefore, up to now the suitable type and amount of addition of these substances are chosen empirically. Additionally, with respect to GMO aspects of soy lecithin alternative emulsifiers, e.g. citric esters, are discussed or already tested for application in chocolate. So far, these tests are also on empirical basis and often carried out in direct comparison to soy lecithin. In the frame of current research activities at the German Institute of Food Technologies the mechanisms of emulsifier action in chocolate mass are evaluated by a more sophisticated characterization of their interactions with the different solids in a lipophilic environment. Both traditional and alternative emulsifiers are included in these investigations. The new approach bases on a stepwise design of model suspensions with increasing complexity to generate fundamental and generalizable knowledge about the adsorption behavior of emulsifiers at different solid surfaces. Based on such data scientific reliable know how can be established regarding optimum dosage of suitable emulsifiers depending on chocolate mass properties, e.g. formulation and degree of grinding. On the other hand, new findings for the design of optimized emulsifier systems can be expected, for example HLB-values required for different chocolates.In the presentation, the procedure for these investigations, the methods used and the first available results will be presented and discussed.

Organisationseinheit(en)

Institut für Lebensmittelwissenschaft und Humanernährung
Arbeitsbereich Lebensmitteltechnologie

Typ

Paper

Publikationsdatum

2008

Publikationsstatus

Veröffentlicht