A　tripeptide　peptide　with　strong　calcium-binding　capacity　was　isolated　and　purified　from　whey　protein　hydrolysates　using　diethylaminoethyl　cellulose　anion-exchange　chromatography,　Sephadex　G-25　gel　filtration,　semi-preparative　reversed-phase　(RP)　high-performance　liquid　chromatography　(HPLC)　and　analytical　HPLC.　It　was　identified　using　liquid　chromatography-electrospray　ionisation　mass　spectrometry　and　shown　to　have　a　molecular　mass　of　396.98　Da　with　the　confirmed　amino　acid　sequence　Tyr-Asp-Thr.　The　calcium-binding　capacity　of　Tyr-Asp-Thr　reached　79.5　mu　g　mg(-1),　an　increase　of　134%　compared　with　the　unpurified　hydrolysate　complex.　The　characteristics　of　the　Tyr-Asp-Thr-Ca　chelate　were　investigated,　indicating　that　the　major　binding　sites　included　oxygen　atom　of　the　carbonyl　group　and　nitrogen　of　amino　group　or　imino　group;　structural　modifications　of　the　peptide　arose　with　the　addition　of　calcium　ion.　The　findings　suggest　the　potential　of　peptide-calcium　chelates　as　dietary　supplements.　(C)　2014　Elsevier　Ltd.　All　rights　reserved.