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

Abstract

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

Emerging Trends in Bioavailability and Pharma-Nutraceutical Potential of Whey Bioactives

“…GMP-containing commercial medications for hunger management and weight management have been made available to the public in recent years. GMP, on the other hand, has been shown to enhance the proliferation of bifidobacterium, indicating that it might be involved in the regulation of the gut microbiota [ 29 ]. When opposed to proteins that are digested more slowly, such as casein, whey protein's rapid digestion and absorption cause a quick rise in the levels of the hormones insulin, glucagon-like peptide-1, cholecystokinin, and plasma amino acids.…”

The Microbial Community of Natural Whey Starter: Why Is It a Driver for the Production of the Most Famous Italian Long-Ripened Cheeses?

“…The most influential parameters are the temperature of curd cooking, the management of the gradient temperature during whey fermentation, and the increase in acidity. Changing one or more of these parameters can lead to the selection of a characteristic microbiota mainly consisting of thermophilic, aciduric, and moderately heat-resistant LAB [24,36,40].…”