Proteolysis by Sourdough Lactic Acid Bacteria: Effects on Wheat Flour Protein Fractions and Gliadin Peptides Involved in Human Cereal Intolerance

• DOI: 10.1128/aem.68.2.623-633.2002
• Publication Date: 2003-02-26T15:22:46Z
• Authors: Raffaella Di Cagno; Maria De Angelis; Paola Lavermicocca; Massimo De Vincenzi; Claudio Giovannini; Michele Faccia; Marco Gobbetti
• Keywords: Lactobacillus brevis; Gliadin; Proteolysis

ABSTRACT Sourdough lactic acid bacteria were preliminarily screened for proteolytic activity by using a digest of albumin and globulin polypeptides as substrate. Based on their hydrolysis profile patterns, Lactobacillus alimentarius 15M, brevis 14G, sanfranciscensis 7A, hilgardii 51B selected used in sourdough fermentation. A fractionated method protein extraction subsequent two-dimensional electrophoresis to estimate proteolysis sourdoughs. Compared chemically acidified (pH 4.4) dough, 37 42 polypeptides, distributed over wide range pIs molecular masses, hydrolyzed L. 7A. Albumin, globulin, gliadin fractions hydrolyzed, while glutenins not degraded. The concentrations free amino acids, especially proline glutamic aspartic also increased the lactobacilli positively influenced softening dough during fermentation, determined rheological analyses. Enzyme preparations which contained proteinase or peptidase enzymes showed 31-43 fragment A-gliadin, toxic peptide celiac patients. peptic-tryptic (PT) gliadins was vitro agglutination tests K 562 (S) subclone cells human myelagenous leukemia origin. lowest concentration PT that agglutinated 100% total 0.218 g/liter. Hydrolysis 15M 14G completely prevented at 0.875 Considerable inhibitory effects other strains higher found. mixture peptides produced enzyme decreased with respect whole A-gliadin.