Abstract:Based on the simulation of gastrointestinal digestion in infants and young children, particle size distribution, zeta potential and laser confocal scanning electron microscopy were used to observe the differences in the physical properties of milk fat globules (MFG) from different milk sources (bovine, ovine and camel) at different stages of digestion, Gas chromatography-mass spectrometry coupled to a titration method was used to study the changes in free fatty acids and lipolysis rate at different stages of digestion to refine the changing law of lipid digestion. The results showed that the particle size of MFG from different milk sources tended to decrease with increasing digestion time, which was consistent with the observation after laser confocal microscopy staining. At the end of intestinal digestion, the mean particle size of camel milk MFG was (0.46±0.07) μm, which was significantly lower than that of cow milk MFG (P<0.05). The absolute values of potentials measured by dynamic light scattering potentiometry showed that all milk source MFGs had strong negative electrical properties after entering the gastrointestinal digestion, with the absolute values of potentials at the end of the intestinal digestion in the order of goat's milk > cow's milk > camel's milk from largest to smallest. There was no significant difference in the rate of lipolysis of MFG from different milk sources during intestinal digestion, whereas camel milk MFG had a significantly higher (P<0.05) content of palmitoleic acid (C16∶0) and a lower proportion of long chain fatty acids compared to the other two milk sources at different stages of digestion. The results of this study provide new ideas for the processing of camel milk products and the preparation of new formulas.