Plasma amino acid response after ingestion of different whey protein fractions.
Farnfield MM, Trenerry C, Carey KA, Cameron-Smith D.
School of Exercise and Nutrition Sciences, Deakin University, Burwood, Victoria, Australia.
Background and objectives The digestion rate of proteins and subsequent absorption of amino acids can independently modulate protein metabolism. The objective of the present study was to examine the blood amino acid response to whey protein isolate (WPI), beta-lactoglobulin-enriched WPI, hydrolysed WPI and a flavour-identical control. Methods Eight healthy adults (four female, four male) were recruited (mean+/-standard error of the mean: age, 27.0+/-0.76 years; body mass index, 23.2+/-0.8 kg/cm(2)) and after an overnight fast consumed 500 ml of each drink, each containing 25g protein, in a cross-over design. Blood was taken at rest and then every 15 min for 2 h post ingestion. Results Ingesting the beta-lactoglobulin-enriched WPI drink resulted in significantly greater plasma leucine concen