Angiotensin I converting enzyme-inhibitory peptides in Asiago d'Allevo cheese.

Asiago d’Allevo (AA) is an Italian PDO cheese produced with raw skimmed milk and ripened from 6 to 18 months. This study aimed at evaluating the Angiotensin-I-converting enzyme (ACE)-inhibitory activity (IA) of water-soluble extracts (WSEs) from AA cheeses. The samples analysed were obtained from milk produced by cows fed with a total mixed ration or alpine pasture plus concentrate and ripened for 6, 12 or 18 months. WSEs were ultrafiltrated onto 10000 Da cut-off membrane and subsequently onto 3000 Da cut-off to obtain small peptides which probably make a considerable contribution to ACE-IA. This bioactivity was determined with a rapid in vitro enzymatic test. Values of ACE-inhibition were submitted to ANOVA considering also the peptide concentration tested as covariate. Preliminary results showed no differences among ripening groups while the concentration of peptides resulted statistically significant (P<0.05). In addition, the interaction between ripening and feeding system was also statistically significant. This finding suggests that alpine grazing condition influences microbial enzymes activity and the derived biopeptides. Furthermore gastro-intestinal digestion will be simulated in order to evaluate whether digestive enzymes generate peptides with high ACE-IA