Release of Biologically Active Peptides from Grape Juice by Oenococcus oeni Isolated from Argentine Wine

Abstract

The increase in biologically active peptides after proteolytic activity of Oenococcus oeni X 2 L was studied in grape juice medium (GJM) and in GJM fermented with Saccharomyces cerevisiae mc2. Sequential inoculation of O. oeni X 2 L with proteolytic activity in GJM before ("I" medium) and after ("F" medium) yeast fermentation allowed peptide release. In the "I" medium, bacterial proteolytic activity (0.083 mM) released 3.88 mg nitrogen (N) of peptides per liter and produced an increase of 203.39 µmol/L in the ferric reducing antioxidant power (FRAP) and 16.49% in the angiotensin I-converting enzyme inhibitory (ACE-I) activity after 48 hrs of incubation. In the "F" medium, a higher proteolytic activity was evidenced after 48 hrs of incubation (0.179 mM), releasing 0.87 mg N of peptides/L. The released peptides in the "F" medium produced an increase in ACE-I activity (22.15%). Calculation of the specific activity (activity expressed per mg N of peptide released) of FRAP, 1, 1-diphenyl-2-picrylhydrazyl scavenging, and ACE-I after 48 hrs of incubation revealed a higher activity in the "F" than in the "I" medium. This finding indicates a higher efficiency of the proteolytic system of O. oeni X 2 L on grape juice proteins in the release of bioactive peptides after yeast growth.

Peptides in Brewed Wines: Formation, Structure, and Function

“…oeni resulted in a significant increase compared to grape juice fermented only by O. oeni . The authors demonstrated that the proteolytic system of O.…”

“…76 Yeast autolysis further increased the peptide concentration and enhanced the ACEI activity 15,77 and antioxidant effects. 77 However, some studies reported that O. oeni can also use proteins in grape juice 78 and wine medium 79,80 78 The authors demonstrated that the proteolytic system of O. oeni contributed to release bioactive peptides after yeast fermentation. The impact of O. oeni on peptides in wine has two aspects: using peptides as the nitrogen source and releasing peptides by its own proteolytic system.…”

“…However, some studies reported that O. oeni can also use proteins in grape juice and wine medium , as its substrate and, thus, lead to the release of ACEI and antioxidant peptides. Fermentation of grape juice by O.…”