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Kinetic studies of in vivo digestion of bovine unheated skim-milk proteins in the rat stomach

Published online by Cambridge University Press:  01 June 2009

Guy Miranda
Affiliation:
Laboratoire de Biochimie et Technologie Laitières, Institut National de la Recherche Agronomique, CNRZ 78350, Jouy-en-Josas, France
Jean-Pierre Pelissier
Affiliation:
Laboratoire de Biochimie et Technologie Laitières, Institut National de la Recherche Agronomique, CNRZ 78350, Jouy-en-Josas, France

Summary

The in vivo action of gastric proteinases on bovine milk proteins was studied in rats fed with skim-milk, by analysing gastric contents after 30, 60 and 240 min of digestion. Gastric proteolysis was already marked after 30 min of digestion and liberated a large number of peptides with different molecular weights. αs1-Casein and β-casein were still the main components of the stomach contents together with α-lactalbumin and β-lactoglobulin, which were little degraded, even after 240 min of digestion. A statistical analysis (multivariate method), made on several parameters (such as pH, N, and NPN) showed changes in the stomach contents during the digestion. The amino acid composition of the protein fraction was close to that of the diet, whilst that of the non-protein fraction was very different, being between the amino acid composition of the endogenous proteins and that of the diet.

Type
Original Articles
Copyright
Copyright © Proprietors of Journal of Dairy Research 1983

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