Impact of different sugar and cocoa powder particle sizes on crystallization of fat used for the production of confectionery products: Particle size distribution influences fat crystallization

Abstract

© 2018 Wiley Periodicals, Inc. The effect of solid particle size distribution (PSD) on the crystallization and microstructure of fat blends was evaluated. Samples were prepared as suspensions of sugar and cocoa particles of different sizes in a palm oil fraction and textural and rheological characteristics were determined. Solid fat content (SFC) was measured using pulsed nuclear magnetic resonance and confocal laser scanning microscopy was used to study the microstructure. Particle size reduction accelerated the crystallization process and resulted in final hardness increase. These systems also had the highest values of G′ and crystallization onset at the highest temperature during cooling. PSD did not affect the final SFC. SFC results showed significant difference only in samples with sugar particles. Results from this study highlight that the nucleation ability of solid particles is important for fat crystallization and strength of the underlying fat crystal network. Microstructure analysis showed that the amount of liquid oil decreased as particle size decreased. Practical applications: Chocolate and other confectionery products are suspensions of solid particles, sugar and cocoa, in fat matrix. Understanding the effect of different particle sizes on physical characteristics of these products and defining a desirable particle size gives an opportunity to producers to adjust properties of a product. Namely, many undesirable occurrences may be prevented (fat blooming, loss of flavor, changed appearance, etc.) during the production process, and adequate final product texture could be achieved.