TY - JOUR
T1 - Antioxidant activity of yoghurt peptides
T2 - part 2 - characterisation of peptide fractions
AU - Farvin, Sabeena
AU - Baron, Caroline
AU - Nielsen, Nina Skall
AU - Otte, Jeanette Anita Held
AU - Jacobsen, Winnie Charlotte
PY - 2010/12
Y1 - 2010/12
N2 - The aim of the present study was to elucidate previous findings showing that peptide fractions isolated from yoghurt had antioxidant effects. Therefore, peptides and free amino acids released during fermentation of milk were characterised. Yoghurt samples were stripped from sugars and lactic acid and subsequently fractionated by ultra filtration using membranes with cut off sizes of 30, 10 and 3kDa. The peptides in these fractions were identified by LC-MS/MS. The identified peptides comprised a few N-terminal fragments of αs1-, αs2-, and κ-casein, and several fragments from β-casein. Almost all the peptides identified contained at least one proline residue. Some of the identified peptides included the hydrophobic amino acid residues Val or Leu at the N-terminus and Pro, His or Tyr in the amino acid sequence, which is characteristic of antioxidant peptides. In addition, the yoghurt contained a considerable amount of free amino acids such as His, Tyr, Thr and Lys, which have been reported to have antioxidant properties. Thus, our findings confirm that the antioxidant effects of the peptide fractions from yoghurt are due to the presence of certain peptides and free amino acids with recognised antioxidant activity in these fractions.
AB - The aim of the present study was to elucidate previous findings showing that peptide fractions isolated from yoghurt had antioxidant effects. Therefore, peptides and free amino acids released during fermentation of milk were characterised. Yoghurt samples were stripped from sugars and lactic acid and subsequently fractionated by ultra filtration using membranes with cut off sizes of 30, 10 and 3kDa. The peptides in these fractions were identified by LC-MS/MS. The identified peptides comprised a few N-terminal fragments of αs1-, αs2-, and κ-casein, and several fragments from β-casein. Almost all the peptides identified contained at least one proline residue. Some of the identified peptides included the hydrophobic amino acid residues Val or Leu at the N-terminus and Pro, His or Tyr in the amino acid sequence, which is characteristic of antioxidant peptides. In addition, the yoghurt contained a considerable amount of free amino acids such as His, Tyr, Thr and Lys, which have been reported to have antioxidant properties. Thus, our findings confirm that the antioxidant effects of the peptide fractions from yoghurt are due to the presence of certain peptides and free amino acids with recognised antioxidant activity in these fractions.
U2 - 10.1016/j.foodchem.2010.05.029
DO - 10.1016/j.foodchem.2010.05.029
M3 - Journal article
SN - 0308-8146
VL - 123
SP - 1090
EP - 1097
JO - Food Chemistry
JF - Food Chemistry
IS - 4
ER -