Selection of phytate-degrading human bifidobacteria and application in whole wheat dough fermentation

Lately, whole wheat products are highly recommended from their healthy properties. However, the presence of phytic acid (InsP6) could partly limit their benefits because it decreases the mineral bioavailability due to its chelating properties. The objective of this work was to select strains with high phytate-degrading activity from human feces, and evaluate their suitability for the bread making process. Twenty-three different bifidobacterial strains (13 from infants and 10 from adults) were isolated, belonging to the species Bifidobacterium longum, Bifidobacterium breve and Bifidobacterium catenulatum. The phosphatase and phytase activities of these strains were evaluated as well as their ability to degrade InsP6 during growth. Then, the fermentative ability of the strain showing the highest phytate-degrading activity (B. longum. BIF307) was determined in whole wheat breadmaking. The use of the selected bifidobacterial strain as starter during whole wheat fermentation resulted in bread with similar technological quality than the control (in absence of bifidobacteria) and crumb with lower levels of inositol phosphates. Therefore, the used of the selected Bifidobacterium strain in whole wheat breadmaking process could provide potential nutritional benefits by decreasing the antinutrient content of the product.