2.3.1. Particle Size Analysis

Particle size and distribution of emulsions were measured in the fresh samples after UHPH or CH treatments using a Mastersizer laser diffraction 2000 analyzer (Malvern Instruments Ltd., Worcestershire, UK). Emulsion were added directly to the recirculating measuring cell containing distilled water or 0.5% SDS solution until 5–9% obscuration was achieved. The optical model based on the Mie theory of light scattering by spherical particles was used. The optical model used were a refractive index of 1.460 for BM, a refractive index of 1.332 for water, and absorption of 0.01. Results were expressed as the volume-weighted mean diameter (d_4.3, μm) and Span index. Measurements were made separately for water and SDS as dispersing media. Span is a parameter which indicates the homogeneity of the particle size distribution and was calculated using Equation (1).

where d_x (μm) is the size point below which x% of the particles is contained.