Laser light scattering by milk particles

Introduction. The main objective of this article is the theoretical and experimental study of laser light scattering by milk particles and the analysis of the character of size distribution of milk particles depending on the concentration and the heating of the samples during the technological processes. Materials and methods. Theory of light scattering and the dependence of the coefficient of scattering on the wavelength of light and parameters of milk particles are discussed. The experimental investigation of light scattering by milk particles was done with the photon correlation spectrometer System 4700c. Results and discussion. Different types of scattering such as Rayleigh Scattering, Rayleigh-Gans Scattering, Anomalous Diffraction, and corresponding coefficients of scattering are discussed. Histograms of size distribution of the diluted (C <= 10(-3) %) milk (temperature 25 degrees C) and samples of milk with different fat concentration (4.2%; 5.2%; 7.4% at temperature 20 degrees C and 7.4% at temperature 50 degrees C), just as the dependence of the intensity of scattered light on the angle of observation were studied. The method of light scattering can be used for analysis of the effect of milk content and technological processes which are related to heating (pasteurization, sterilization, homogenization) on the size distribution of milk particles. Conclusions. Laser light scattering is an advanced technique that can be used to determine the size distribution profile of milk particles. It is characterised with high accuracy, non-destructive action and does not require calibration standards.