title: The effects of alpha-lactabumin and whey protein concentrate on dry matter recovery, TCA soluble protein levels, and peptide distribution in the rat gastrointestinal tract.
abstract: The effects of two dietary proteins on dry matter recovery, trichloroacetic acid (TCA) soluble protein concentration, and peptide distribution in gastrointestinal contents were investigated in rats trained to consume, in a single 2-hour daily meal, diets containing alpha-lactalbumin (alpha-LA) or whey protein concentrate (WPC) for two weeks. Compared with the WPC diet, the alpha-LA diet emptied faster from the stomach. Dry matter recovery was higher in the stomach contents of rats fed the WPC diet than in those given the alpha-LA diet, but dry matter content in the small intestine was comparable. TCA soluble protein levels in the stomach and the small intestinal contents were also significantly (P < 0.001) higher in rats fed the WPC diet. The concentration of peptides having molecular weights (MW) ranging from 12,500-30,000 daltons (Da) was higher in the stomach contents of rats fed the WPC diet. Conversely, the level of peptides ranging from 5000-12,500 Da was higher in the stomach contents of rats fed the alpha-LA diet. For both diets, the small intestinal contents were characterized by high levels of amino acids and small peptides. These results suggest that the hydrolysis and absorption of alpha-LA is faster than that of WPC.
authors.affiliation: Department of Food and Nutrition Sciences, Faculty of Food and Agriculture Sciences, Dairy Research Center, Laval University, Sainte-Foy, QC, Canada. Odile.Pantako@aln.ulaval.ca
authors.forename: O T
authors.initials: OT
authors.lastname: Pantako
authors.forename: L
authors.initials: L
authors.lastname: Lemieux
authors.forename: J
authors.initials: J
authors.lastname: Amiot
mesh_terms: D000818:Animals; D004044:Dietary Proteins / Q000493:pharmacokinetics*; D004063:Digestion / Q000502:physiology*; D004064:Digestive System / Q000378:metabolism*; D005746:Gastric Emptying / Q000502:physiology; D007408:Intestinal Absorption / Q000502:physiology; D007421:Intestine, Small / Q000378:metabolism; D007768:Lactalbumin / Q000493:pharmacokinetics*; D008297:Male; D008894:Milk Proteins / Q000493:pharmacokinetics*; D008970:Molecular Weight; D010455:Peptides / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014238:Trichloroacetic Acid / Q000378:metabolism*; D000067816:Whey Proteins
chemical_list: D004044:Dietary Proteins; D008894:Milk Proteins; D010455:Peptides; D000067816:Whey Proteins; D014238:Trichloroacetic Acid; D007768:Lactalbumin