Whey-based sports supplements: Heat damage and protein breakdown after in vitro gastrointestinal digestion

This study was aimed to evaluate the effect of heat damage on the release of total amino acids (AA), essential AA (EAA), branched-chain AA (BCAA) and bioactive peptides following in vitro static simulated gastrointestinal digestion (SGID) of four commercial whey-protein based sports supplements. The extent of protein glycation and denaturation was evaluated through the determination of the content of furosine and soluble whey proteins. The strongest protein breakdown (41.3 %) and the highest release of AA, EAA and BCAA (36.20, 27.78, and 11.30 g/ 100 g protein, respectively) was observed in the sports supplement characterised by the lowest (52.5 %) level of soluble whey proteins; whereas the protein glycation had a negligible impact on the studied parameters. The SGID also led to the release of several peptides with various reported bioactivities that may be beneficial to sports activity.