Blood amino acid dynamics after ingestion of chicken-derived peptides in healthy subjects

Background: The rate of protein digestion and amino acid (AA) absorption determines the postprandial rise in circulating AA and modulates postprandial muscle protein synthesis (MPS) rates. Furthermore, it is necessary to consider the timing of protein ingestion, along with its quantity and quality, to regulate the blood AA concentration. Chicken breasts are a popular food among athletes as they are a good source of animal protein, containing sufficient essential amino acids (EAAs) and branched-chain amino acids (BCAAs). Low-molecular-weight chicken peptides (Cpep), a novel protein supplement, were isolated from chicken breasts. Blood AA dynamics, which have a significant influence on MPS rates, were observed and compared with commercially available whey- and soy-derived protein supplements.Objectives: We evaluated blood AA dynamics after Cpep intake compared with whey protein (WP), and soy protein (SP).Methods: Three groups of six healthy adult men volunteers (age 39 ± 10 years) ingested 0.3 g/kg (protein/body weight) of Cpep, WP, and SP. The concentrations of AA in the plasma were measured before and after the ingestion period and their kinetics were compared.Results: Cpep comprises free amino acids or peptides, and their average molecular weights are lower than those of WP and SP. The absorption dynamics of AA in the plasma were evaluated. After Cpep intake, EAA and BCAA concentrations peaked at 30 min and levels of EAA and BCAA were higher than those after WP and SP ingestion at 15 and 30 min, respectively. Conversely, the levels of total AA, EAA, and BCAA decreased 45 min after Cpep intake compared with WP and SP intakes. In contrast, WP and SP showed similar blood AA dynamics with a peak at 60 min.Conclusions: Cpep is absorbed significantly faster than WP and SP, making it a useful option for efficient protein intake to maintain and increase muscle mass.Keywords: chicken-derived peptides, blood amino acid dynamics, branched-chain amino acid, muscle protein synthesis