Process of microbic biotechnology for completely degrading gluten in flours

A process for preparation of a liquid sourdough in which gluten is completely degraded and which is suitable for use in production of leavened gluten-free products, comprising:

• a) culture propagating of Lactobacillus sanfranciscensis DSM22063 and Lactobacillus plantarum DSM 22064 lactic acid bacteria;
• wherein the lactic acid bacteria of step a) each have an x-prolyl dipeptidyl aminopeptidase activity of between 17.5 U and 22 U, U being defined as the enzyme amount necessary to release 1 μmol/min of amino acid;
• b) mixing flour, water and the culture of step a),
• wherein the flour is about 20-50 wt % of the resulting mixture of step b), the water is about 50-80 wt % of the resulting mixture of step b) and the culture of step a) has a cellular density of about 108 cfu/g;
• and
• wherein the flour is at least one gluten-containing flour selected from the group consisting of bread wheat, durum wheat, tender wheat, barley, rye and oat flours;
• c) adding at least one fungal protease into the resulting mixture of step b), wherein at least one of the protease has a final concentration of about 200-500 ppm;
• and
• d) incubating the resulting mixture of step c) for 8-20 h, at 30-37° C. to obtain the liquid sourdough.