Bitter peptide from hemoglobin hydrolysate: isolation and characterization.

Two separation methods, ultrafiltration and 2-butanol extraction, have shown that a peptide is the major agent responsible for bitterness in peptic hemoglobin hydrolysates. It was easily purified from these complex mixtures by specific hydrophobic adsorption on Superose 12, a gel-filtration column, which could constitute an original and interesting method for bitterness detection. The bitter peptide which corresponded to VV-hemorphin 7, the fragment 32-40 of the beta chain of bovine hemoglobin, is first generated during proteolysis, then hydrolysed by pepsin. It exhibited a strong bitterness at 0.25 mM equivalent to 0.073 mM quinine sulfate or 21 mM caffeine.