Particle Sizing in Milk by Combined Differential Dynamic Microscopy and Cryo-FIB-SEM Tomography

Milk is a suspension with a multimodal size distribution of fat droplets and protein micelles, which most sizing methods do not distinguish. We demonstrate the use of differential dynamic microscopy and cryo-FIB-SEM tomography to simultaneously size fat globules and casein micelles in homogenised milk without the need for prior physical separation. The two techniques are complimentary, with Cryo FIB-SEM tomography providing an in-depth picture of the constituents, which then allows for confident interpretation of the high-throughput DDM data with its associated improved statistics.