Effects of different packaging systems on microbiological, sensory and peptide profile in fiordilatte cheese

- Effects of different packaging on peptide profile in fiordilatte are described.
- A bioinformatics approach coupled with nanoLC and electrospray ionization was used.
- Differences in proteolytic profile between samples were recorded.
- Correlations between quality decay of cheese and proteolytic trend were highlighted.

Effects of different packaging systems on water soluble oligopeptide fractions in fiordilatte cheese during its refrigerated storage are described. The degradation of the main protein fractions and the characterization of peptides arising from caseins were monitored by nanoliquid chromatography and electrospray ionization ion trap mass spectrometry (MS) coupled with a bioinformatics approach based on the scoring distribution and a post-database search validation. Microbiological and sensory properties of fiordilatte samples packaged under different conditions were also evaluated in order to find possible correlations between quality decay of cheese and peptide profile. The various packaging solutions differently responded to the degradation processes, thus allowing to identify the three systems that better preserved cheese quality: the two active coated samples packaged under MAP with and without brine and the sample in brine acidified at pH 5. As far as the peptide profile is concerned, a dynamic evolution of hydrophilic peptides was observed belonging almost exclusively to β-casein that could be regarded as the primary substrate of proteolysis in fiordilatte cheese. Characteristic trends with maximum and minimum values at different times were observed, throughout the refrigerated storage, leading to continuous changes in the peptide composition. A reduction in levels of β-casein peptides was observed in all the samples compared to the control, for which no specific packaging treatments were adopted.