Strains of lactic acid bacteria isolated from sour doughs degrade phytic acid and improve calcium and magnesium solubility from whole wheat flour

Five strains of lactic bacteria have been isolated from sour doughs and exa mined for their ability to degrade phytic acid. In white flour medium in wh ich phytic acid was the only source of phosphorus, the disappearance of phy tate and an elevation of inorganic phosphate were observed after only 2 h o f incubation in all strains tested (-30 and +60%, respectively). Both pheno mena correspond to phytate breakdown. No difference was observed in the lev els of phytic acid hydrolysis among strains, suggesting that phytase enzyme s are similar among these bacteria. Using whole wheat flour medium naturall y rich in phytic acid in the presence of Leuconostoc mesenteroides strain 3 8, a 9 h fermentation established that the degradation of PA and the produc tion of lactic acid lead to greater Ca and Mg solubility than in control me dium.