Application of phytases from bifidobacteria in the development of cereal-based products with amaranth

The effects of the inclusion of purified phytases from Bifidobacterium longum spp. infantis ATCC15697 and Bifidobacterium pseudocatenulatum ATCC27919 on phytate (InsP ₆) levels were analyzed during breadmaking process. Two different levels of whole amaranth (Amaranthus cruentus) flour (25 and 50 %) were used in bread dough preparation, and they were compared to control doughs made with 100 % wheat flour and 100 % whole wheat flour. Bread samples made with 50 % of amaranth flour showed a significant decrease in technological quality parameters in comparison with control white breads. However, a 25 % of amaranth flour improved the nutritional value of the bread, with only a slight depreciation in the quality. Addition of bifidobacterial phytases resulted in higher InsP ₆ degradation compared with a commercial fungal phytase, without affecting the bread quality. InsP ₆ reduction was especially efficient in breads with 25 % amaranth, leading to InsP ₆ levels below the threshold of mineral bioavailability inhibition for Fe and Zn in human nutrition.