Bioactive Peptides in Ovine and Caprine Cheeselike Systems Prepared with Proteases from Cynara cardunculus

Abstract 

The potential angiotensin-converting enzyme (ACE)–inhibitory and antioxidant activities of peptides in water-soluble extracts, obtained from raw and sterilized ovine and caprine cheeselike systems coagulated with enzymes from the plant Cynara cardunculus, were assessed. Prior to the assay, the 3,000-Da permeate from 45-d-old cheeselike systems was fractionated by tandem chromatographic techniques. Several peaks were obtained in each chromatogram, but only some were associated with ACE-inhibitory or antioxidant activity or both. Peptides Tyr-Gln-Glu-Pro, Val-Pro-Lys-Val-Lys, and Tyr-Gln-Glu-Pro-Val-Leu-Gly-Pro-* from β-casein, as well as Arg-Pro-Lys and Arg-Pro-Lys-His-Pro-Ile-Lys-His-* from α_s1-casein exhibited ACE-inhibitory activity. Peptides released upon cleavage of the peptide bond Leu190-Tyr191 (either in ovine or caprine β-casein), and corresponding to the β-casein sequence Tyr-Gln-Glu-Pro-*, possessed antioxidant activity.

Key words: plant protease, ovine cheese, caprine cheese, angiotensin-converting enzyme inhibition