Fermented dairy products have traditionally been used in many cultures for their health promoting effects. Commercially available products such as kefirs, and fermented yoghurt and cheeses are now widely available, although the characterization of the bioactive peptides contained in these products is still relatively understudied. Moreover, the process of fermentation is dynamic and highly influence by the many variables involved, which include time, temperature, starter microorganisms or strains, ongoing proteolysis, and available substrates, among other things. The ability to study the by-products of fermentation in real-time, for example by time course discovery proteomics or peptidomics, offers a window into the fermentation process and may provide information on optimizing the health-promoting substances in these dairy products. In a recent study by Nielsen and others, researchers compare chemically acidified, live and heat-inactivated fermented dairy yoghurt and analyzed the peptides in these products by LC-MS/MS. The PEAKS identified peptides were compared to know bioactive peptides, examined for antimicrobial activity by CAMPR3 and ACE-inhibition using AHTpin, and in silico digested to determine potential stability in the digestive tract.
How was PEAKS used
Fermented dairy products have traditionally been used in many cultures for their health promoting effects. Commercially available products such as kefirs, and fermented yoghurt and cheeses are now widely available, although the characterization of the bioactive peptides contained in these products is still relatively understudied. Moreover, the process of fermentation is dynamic and highly influence by the many variables involved, which include time, temperature, starter microorganisms or strains, ongoing proteolysis, and available substrates, among other things. The ability to study the by-products of fermentation in real-time, for example by time course discovery proteomics or peptidomics, offers a window into the fermentation process and may provide information on optimizing the health-promoting substances in these dairy products. In a recent study by Nielsen and others, researchers compare chemically acidified, live and heat-inactivated fermented dairy yoghurt and analyzed the peptides in these products by LC-MS/MS. The PEAKS identified peptides were compared to know bioactive peptides, examined for antimicrobial activity by CAMPR3 and ACE-inhibition using AHTpin, and in silico digested to determine potential stability in the digestive tract.
Nielsen SD, Jakobsen LMA, Geiker NRW, Bertram HC. Chemically acidified, live and heat-inactivated fermented dairy yoghurt show distinct bioactive peptides, free amino acids and small compounds profiles. Food Chem. 2021 Dec 23;376:131919. doi:10.1016/j.foodchem.2021.131919. Epub ahead of print. PMID: 34968909.
Abstract
Previous studies found variations in the health-promoting effects of consuming different dairy products. This study aims at investigating the chemical composition of microbial fermented yogurt, chemically acidified yogurt and whole milk to understand the differences in the effects these products exert on human health. For this purpose, peptides and small compounds present in the products were examined using a combination of liquid chromatography mass spectrometry and nuclear magnetic resonance spectroscopic techniques. Results revealed that each product had its own characteristic peptide, free amino acid and small compound profile, and database search for bioactivity disclosed that fermented yogurt manufactured using a starter culture is associated with a higher bioactivity potential than chemically acidified yogurt or whole milk. Additional cold storage (14 days) further enhances the bioactivity potential of fermented yogurt while heat-inactivation, ensuring long shelf-life, modulates the proteins available for proteolysis and thereby the peptide profile generated.