WATER VERSUS LACTOSE SOLUTION AS A DISPERSION MEDIUM FOR PARTICLE ANALYSIS IN SWEETENED CONDENSED MILK BY LASER DIFFRACTION

Sweetened condensed milk contains various dispersed particles, such as proteins, fats, and lactose, all of which make it highly viscous. During sweetened condensed milk production, microcrystalline lactose is added in order to control the product crystallization. The purpose of this study was to characterize the behavior of commercially sold sweetened condensed milks submitted to laser particle size analysis using two different dispersion media: water and a lactose solution. The lactose solution dispersion medium extended the length of time the sweeten condensed milk samples’ original characteristics were present during the laser diffraction particle sizing measurements that were carried out. Significant difference was observed (p < 0.05) between analysis times when water was used as a dispersing medium versus when a lactose solution was used (p > 0.05). Using a lactose solution as a dispersion medium when determining particle size in sweetened condensed milk prolongs the original characteristics of the sample substance during laser diffraction particle analysis.