Prolonged fermentation of whole wheat sourdough reduces phytate level and increases soluble magnesium

This work was designed to compare the effects of different leavens (yeast, sourdough, and a mixture of both) on phytic acid (PA) degradation and to as sess the repercussions of PA breakdown on phosphorus and magnesium solubili ty during bread-making. Sourdough fermentation was more efficient than yeas t fermentation in reducing the phytate content in whole wheat bread (-62 an d -38%, respectively). Furthermore, lactic acid bacteria present in sourdou gh enhanced acidification, leading to increased magnesium and phosphorus so lubility. To intensify phytate breakdown, bran was incubated with microorga nisms (yeast or sourdough) before bread-making. Using this new method, the percentage of phytate breakdown was near 90%, whereas 40% of phytate remain ed in traditional French bread. In conclusion, a prolonged fermentation wit h sourdough still leads to improved Mg and P solubility by decreasing phyta te content and through acidification.