Elderly individuals experience age-related declines in digestive function, which can hinder the digestion of dietary proteins and thereby negatively impact overall health. This study provides a comprehensive understanding of the protein digestive fate of beef with Protease-DS supplementation by analyzing gastric emptying behavior and amino acid and peptide profiles during a simulated in vitro elderly digestion process. The adult model exhibited superior gastric emptying capacity, with relatively rapid and early expulsion of gastric digesta into the intestinal segment. Additionally, the underperforming elderly model showed notable improvement in the emptying process with Protease-DS supplementation, achieving a rate of 0.0110 min