Impact of Spontaneous Fermentation and Inoculum with Natural Whey Starter on Peptidomic Profile and Biological Activities of Cheese Whey: A Comparative Study

Fermentation is a promising solution to valorize cheese whey, the main by-product of dairy industry. In Parmigiano Reggiano production, natural whey starter (NWS), an undefined community thermophilic lactic acid bacteria, obtained from previous day residual through incubation at gradually decreasing temperature after curd cooking. The aim this study was investigate effect fermentation regime (spontaneous (S) and NWS-inoculated (I-NWS)) on biofunctionalities release bioactive peptides during fermentation. S I-NWS trials proteolysis reached peak 24 h, which corresponded drop out in pH maximum increase acid. Biological activities increased as function time. NWS inoculum positively affected antioxidant activity, whilst overcame angiotensin-converting enzyme (ACE) DPP-IV (dipeptidyl peptidase IV) inhibitory activities. Peptidomics revealed more than 400 peptides, mainly derived β-casein, κ-casein, α-lactalbumin. Among them, 49 were 21 ACE-inhibitors. Semi-quantitative analysis strongly correlated ACE-inhibitory activity with sum peptide abundance peptides. both samples, lactotripeptide isoleucine-proline-proline (IPP) higher valine-proline-proline (VPP), highest content h conclusion, we demonstrated ability endogenous microbiota extensively hydrolyze proteins, promoting improving protein digestibility.