Picture of a sphere with binary code

Making Strathclyde research discoverable to the world...

The Strathprints institutional repository is a digital archive of University of Strathclyde research outputs. It exposes Strathclyde's world leading Open Access research to many of the world's leading resource discovery tools, and from there onto the screens of researchers around the world.

Explore Strathclyde Open Access research content

Influence of tempering and fat crystallization behaviours on microstructural and melting properties in dark chocolate systems

Afoakwa, Emmanuel Ohene and Paterson, A. and Fowler, Mark and Vieira, Joselio (2009) Influence of tempering and fat crystallization behaviours on microstructural and melting properties in dark chocolate systems. Food Research International, 42 (1). pp. 200-209. ISSN 0963-9969

Full text not available in this repository. (Request a copy from the Strathclyde author)

Abstract

Particle size distribution (PSD) and temper influences on dark chocolate fat crystallization were studied using differential scanning calorimetry (DSC) and microscopy to establish relationships with their melting properties and microstructure. Variations in PSD had no influence on crystallinity of products at all temper regimes. Particle size (PS) increases had limited effects on Tonset, Tpeak, and -Hmelt independent of temper regime but significant decreases in Tend and Tindex were noted. Contrary, varying temper regime influenced the crystallinity and melting properties (Tend, Tindex and -Hmelt) of products. Under-tempered chocolate showed widened crystal size distribution (CSD) with significant changes in Tend, Tindex and -Hmelt of products. Over-tempering caused moderate increases in CSD and melting properties, with significant effect on Tend, Tindex and -Hmelt but no changes were noted in Tonset, Tpeak of products. Fat-sugar melting profiles showed similar levels in all products independent of temper regime, suggesting fat and sugar components are present in similar amounts in under-, over- and optimally-tempered products. Micrographs revealed clear crystalline network structure and well defined inter-crystal networks among tempered and over-tempered samples. Under-tempered products showed re-arrangement and re-crystallization of unstable fat crystals to smaller numbers of larger agglomerates with formation of solid bridges between the crystalline network structures. Attainment of optimal temper regime during pre-crystallization of dark chocolate is necessary for the achievement of premium quality products and avoidance of defects in structure and melting character.