Comparison of Different Sources and Degrees of Hydrolysis of Dietary Protein: Effect on Plasma Amino Acids, Dipeptides, and Insulin Responses in Human Subjects

• Published in: Journal of agricultural and food chemistry Vol. 58; no. 15; pp. 8788 - 8797
• Main Authors: Morifuji, Masashi, Ishizaka, Mihoko, Baba, Seigo, Fukuda, Kumiko, Matsumoto, Hitoshi, Koga, Jinichiro, Kanegae, Minoru, Higuchi, Mitsuru
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 11.08.2010
• Subjects: Adult; amino acids; Amino Acids - blood; analysis; Biological and medical sciences; blood; blood plasma; chemistry; dietary protein; Dietary Proteins; Dietary Proteins - analysis; Dietary Proteins - metabolism; dipeptides; Dipeptides - blood; Female; Food Chemistry/Biochemistry; Food industries; Fundamental and applied biological sciences. Psychology; Humans; Hydrolysis; Insulin; Insulin - blood; insulin secretion; Male; metabolism; Milk and cheese industries. Ice creams; nutrition physiology; nutritional intervention; Plant Proteins; Plant Proteins - chemistry; Plant Proteins - metabolism; protein hydrolysates; protein sources; Whey protein hydrolysates; plasma amino acids; insulin response; plasma peptides; Hydrolysis; Milk protein; Acids; Hydrolysate; Peptides; Insulin human; Dipeptides; Whey protein
• ISSN: 0021-8561; 1520-5118; 1520-5118
• DOI: 10.1021/jf101912n

The effect of protein fractionation on the bioavailability of amino acids and peptides and insulin response and whether the protein source influences these effects in humans are poorly understood. This study compared the effects of different sources and degrees of hydrolysis of dietary protein, independent of carbohydrate, on plasma amino acid and dipeptide levels and insulin responses in humans. Ten subjects were enrolled in the study, with five subjects participating in trials on either soy or whey protein and their hydrolysates. Protein hydrolysates were absorbed more rapidly as plasma amino acids compared to nonhydrolyzed protein. Whey protein also caused more rapid increases in indispensable amino acid and branched-chain amino acid concentrations than soy protein. In addition, protein hydrolysates caused significant increases in Val-Leu and Ile-Leu concentrations compared to nonhydrolyzed protein. Whey protein hydrolysates also induced significantly greater stimulation of insulin release than the other proteins. Taken together, these results demonstrate whey protein hydrolysates cause significantly greater increases in the plasma concentrations of amino acids, dipeptides, and insulin.