Cracking the Cocoa Code: Particle Characterization with Laser Diffraction & Dynamic Imaging

Cocoa powder is a key ingredient in chocolate manufacturing, valued for its distinctive flavor, color, and functionality. Produced from fermented, roasted, and ground cocoa beans, cocoa powder contains finely milled cocoa solids and residual cocoa butter. Its microstructure – comprising irregular, fat-coated particles with a broad size distribution plays a decisive role in determining chocolate’s texture, gloss, and sensory properties [2][4].
The particle size and shape of cocoa components directly influence both processing and consumer perception. Finer, more spherical particles enhance smoothness and gloss but increase viscosity due to higher surface area, while larger or irregular particles reduce flow resistance yet may impart a gritty mouthfeel [6][3]. Recent studies confirm that variations in particle morphology significantly affect rheological and tribological behavior, linking particle size distribution (PSD) to mouthfeel and flow stability in modern chocolate formulations [7].
During industrial production, refining and conching processes are used to control particle size and texture. Inadequate dispersion or agglomeration can cause uneven viscosity, reduced gloss, or fat bloom [5][1]. Reliable measurement of PSD and morphology is therefore critical but challenging, as cocoa systems contain non-spherical, hydrophobic particles that tend to agglomerate. Modern analytical techniques such as laser diffraction provide high-resolution PSD data, but their accuracy depends heavily on the dispersion method employed [5][8].
The Liquid Flow Imaging (LFI) Dispersion Unit offers a robust solution to this challenge. It can measure dispersions while ensuring homogeneous particle distribution without altering particle integrity. This enables accurate differentiation of PSD variations arising from shape differences and prevents agglomeration artifacts. Combined with the Litesizer DIF 500, the LFI Dispersion Unit provides quick, reproducible, shape-sensitive measurements that enhance understanding of chocolate’s microstructural and rheological behavior. Besides that, it can also act as a tool for screening and detecting outlier contaminants in the sample with its filtering feature in Kalliope software. These measurements are simultaneously measured in one measurement, results combined automatically and displayed on the same page in the Kalliope software. Ultimately, this approach supports improved quality control and formulation optimization in chocolate manufacturing.