Increase in antioxidant and antihypertensive activity by Oenococcus oeni in a yeast autolysis wine model

Accelerated autolysis of Saccharomyces cerevisiae mc2 in synthetic wine medium enabled the release of 3.7 mg peptide nitrogen/l, concomitantly with an increase in antioxidant properties (243 mu mol FeSO4/l in the case of ferric reducing antioxidant power and 0.5% in 2,2-diphenyl-1-picrylhydrazyl radical scavenging) and antihypertensive activity (22% in angiotensin I-converting enzyme inhibitory activity). Sequential inoculation of a proteolytic Oenococcus oeni strain in the synthetic medium after yeast autolysis produced an increase in peptide nitrogen concentration of 1.5 mg/l after 48 h of growth. After this incubation time an improvement in antihypertensive and antioxidant activities was detected. Oenococcus oeni X2L could give additional value to wine because of the bioactive peptides with multifunctional beneficial activity released as consequence of its proteolytic activity.