DEVELOPMENT OF OPTICAL DEVICE FOR SEDIMENTATION ANALYSIS OF WHOLE MILK FAT

Methods of sedimentation analysis are used to determine the degree of homogenization and milk emulsion composition, and to calculate the dispersed phase particle sizes. At present, such studies are conducted using instrumental electronic optical analyzers operating in the infrared spectrum range. The aim of this research is to develop optical turbidimetry system for monitoring fat settling in whole and homogenized milk and identification of opportunities to use this device as a butyrometer. The objects of this study were whole and homogenized milk samples with different fat content. A method for the analysis of fat setting through periodic vertical scanning of the sample with an infrared sensor is proposed. To implement this method optical-mechanical device named «kremograph» has been developed. During 90 minutes milk samples with different fat content were exposed to periodically repeating scanning with the frequency of about 0.2 min-1 with a synchronously moving infrared radiation source and receiver. In this case, there was a clear relationship between the intensity of radiation passing through the whole milk sample and fat globule concentrationin milk allowing the thickness of the cream plug to be uniquely determined. The study results are presented in the form of graphs - kremograms. The data obtained have promoted the calculation of fat content of whole milk samples, and the radii of fat particles have been determined. Estimated value of the particle sedimentation rate is 0.11 mm/min. The average size of particles settled in a cream layer is 3.8 microns. The thickness of cream plug on whole milk settling with fat content of 4% is 10 mm. The feasibility of using kremographs for sedimentation analysis and the establishment of the dispersion degree of milk fat particles as well as the determination of the mass fraction of fat in milk after mechanical processing is demonstrated.