Changes in lamb soup's colloidal nanoparticles for in vitro dynamic digestion: Nutrition, colloidal properties and lipidomics

Soup is an integral component of the daily diet, however, its digestive characteristics remain unclear. In this study, the dynamic human stomach-intestine system (DHSS) was used to simulate the digestion of colloidal nanoparticles (CNPs) isolated from lamb soup through oral, gastric, and intestinal stages. The colloidal properties, morphology, and structural characteristics of CNPs were assessed using dynamic light scattering (DLS), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and Fluorescence spectroscopy (FL). The results demonstrated a progressive decline in triglyceride (TG) concentration throughout the digestion process. Aggregation and significant enlargement of CNPs were observed during the oral and gastric phases, while a notable reduction in particle size (P < 0.05) occurred during the intestinal phase, without clear boundaries. Additionally, spectroscopic analysis revealed that the CNPs’ structure underwent unfolding during digestion, exposing their clusters. Lipidomics analysis indicated variations primarily in TG and diglyceride (DG) concentrations across the oral, gastric, and intestinal digestion stages of CNPs. Furthermore, it was discovered that the main significantly different lipid molecules in the digested CNPs were up-regulated by the oral digestion simulation and down-regulated by the gastrointestinal digestion simulation (VIP >1, P < 0.05). • CNPs size decreased in intestinal digestion with no clear boundaries. • CNPs structure unfolded and the clusters were exposed along with digestion. • Lipids were up-regulated by oral and down-regulated by gastrointestinal digestion.