Reference Number: 96
This study demonstrates the capacity of sourdough lactic acid bacteria to release peptides with antioxidant activity through the proteolysis of native cereal proteins.
A pool of selected lactic acid bacteria was used for the sourdough fermentation of various cereal flours with the aim of synthesising antioxidant peptides.
The radical-scavenging activity of water/salt-soluble extracts (WSE) from sourdoughs was significantly (P < 0.05) higher than that of chemically acidified doughs. The highest activity was found for whole wheat, spelt, rye, and kamut sourdoughs. Almost the same results were found for the inhibition of linoleic acid autoxidation. WSE were subjected to reverse- phase fast protein liquid chromatography. Thirty-seven fractions were collected and assayed in vitro. The most active fractions were resistant to further hydrolysis by digestive enzymes. Twenty-five peptides of 8 to 57 amino acid residues were identified by nano-liquid chromatography-electrospray ionization-tandem mass spectrometry. Almost all of the sequences shared compositional features which are typical of antioxidant peptides. All of the purified fractions showed ex vivo antioxidant activity on mouse fibroblasts artificially subjected to oxidative stress.
SIGNIFICANCE OF THIS STUDY
This study unravels the mechanism by which lactic acid bacteria produces antioxidant peptides from cereal flour during the fermentation process. Antioxidant peptides in general play an important role in the prevention of a range of diseases including cancer which then highlights the importance and functional benefits of lactic acid bacteria in sourdough fermentation.