Isolation and Characterization of Individual Peptides from Wine

Two peptide fractions with molecular weight higher and lower than 700 Da were obtained from a sparkling wine aged with yeast over 15 months. The amino acid composition of each fraction and their hydrophobicity were determined. Asp and/or Asn, Glu and/or Gln, Ser, Thr, and α-Ala were found to be the major amino acids that form both fractions. The peptide fraction <700 Da showed an hydrophobicity value higher than the fraction >700 Da. Four main peptides from the fraction >700 Da and six peptides from the fraction <700 Da were isolated by reversed-phase HPLC. The isolated peptides from the fraction >700 Da were found to contain between 13 and 25 amino acid residues, whereas the ones from the fraction <700 Da corresponded to peptides with a number of residues between 6 and 10. Hydrophobicities of the isolated peptides ranged from 0 to 1128.9 cal/amino acid residue. Keywords: Peptides; wine; amino acids; hydrophobicity