Selected Lactic Acid Bacteria Synthesize Antioxidant Peptides during Sourdough Fermentation of Cereal Flours

Abstract

A pool of selected lactic acid bacteria was used for the sourdough fermentation of various cereal flours with the aim of synthesizing 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 reversephase 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. This study demonstrates the capacity of sourdough lactic acid bacteria to release peptides with antioxidant activity through the proteolysis of native cereal proteins.

A Multistrategic Approach in the Development of Sourdough Bread Targeted Towards Blood Pressure Reduction

“…Antioxidant peptides may delay oxidative processes in vivo through radical scavenging, chelation of metal ion, inhibition of lipid peroxidation, etc. [12]. To the best of our knowledge no literature data deal with the development of a functional wheat bread from an innovative multi-strategic approach consisting of partial replacement of salt by potassium citrate, protease addition and sourdough fermentation by Lactobacillus brevis CECT 8183 strain (isolated from Spanish cheese) with proven high GABAproducing ability [14].…”

“…Recent studies have shown that LAB metabolism may produce new nutritionally bioactive compounds with antihypertensive activity such as γ-aminobutyric acid (GABA), the main inhibitory neurotransmitter in the mammalian nervous system, that is well known for lowering BP and its diuretic and tranquilizer effects [8,9]. Angiotensin I converting enzyme (ACE)-inhibitory peptides and antioxidant peptides may be also synthesized by LAB during sourdough fermentation [10][11][12]. Inhibition of ACE hinders the formation of angiotensin II, a potent vasoconstrictor that results in BP decrease [13].…”

Long-Term Fungal Inhibition by Pisum sativum Flour Hydrolysate during Storage of Wheat Flour Bread

“…Overall, proteolysis may enhance food digestibility and decrease the effects of toxic, allergenic and antinutritional compounds (41). Although food proteins are sources of indispensable nutrients (42), it has been well established that they may release encrypted biologically active sequences due to enzyme degradation (43), thus assuming technological and functional significance (42).…”

Dynamic Stresses of Lactic Acid Bacteria Associated to Fermentation Processes

“…On the contrary the study of nonvolatile metabolites can be performed by normal chromatographic technique (HPLC), especially for amino acids and sugars [15], or by Fast Protein Liquid Chromatography (FPLC) separation for peptides, followed by a mass spectrometry identification [127]. An NMR approach to evaluate the effects on the growth of L. plantarum raising the medium molarity by high concentrations of KCl or NaCl and iso-osmotic concentrations of non-ionic compounds was performed [128].…”