Effect of ripening and in vitro digestion on the evolution and fate of bioactive peptides in Parmigiano-Reggiano cheese

The influence of ripening and in vitro digestion on the peptidomic profile of Parmigiano-Reggiano (PR) cheeses was investigated. Ripening and in vitro digestion thoroughly modified the peptidomic profile of the three cheeses. Twenty-six bioactive peptides were identified in undigested PR. Some peptides were degraded and others released during ripening. After digestion, 52 bioactive peptides were identified. Semi-quantitative data suggested that bioactive peptides released after digestion can be clustered in 5 groups according to the ripening time. VPP and IPP peptide levels in undigested samples were in the range of 4.52–11.34 and 0.66–4.24 mg kg−1, with the highest amounts found in 18-month ripened PR. YPFPGPI peptide was absent in undigested PRs but was released after digestion, especially in the 12-month-old sample (20.18 mg kg−1). The present study suggests possible differences in bioactive peptide levels after digestion as a function of the duration of ripening of PR cheese.