Bioaccessible Iron and Zinc in Native and Fortified Enzyme Hydrolyzed Casein and Soya Protein Matrices.

Casein and soybean are superior quality proteins; however, these
are known to inhibit mineral absorption. These investigations
were aimed at enzymatic modification of these proteins and to
study their effect on mineral bioaccessibility. Casein and soybean
proteins were hydrolyzed with alcalase and trypsin individually
under optimum conditions. The protein hydrolysates, prepared
with different degrees of hydrolysis, were freeze dried, fortified
with either iron or zinc and analyzed for bioaccessible minerals in
vitro. Proteolytic hydrolysis enhanced the bioaccessibility of iron
and zinc in proportion to the degree of hydrolysis. Tryptic hydrolysis
enhanced the bioaccessible iron from 1–4% in casein and
from1.3–3.3% in soybean. Alcalase hydrolysis showed a comparatively
higher enhancement with both the proteins. Tryptic hydrolysis
enhanced zinc bioaccessibity by 3-fold in casein and alcalase
hydrolysis enhanced by 2- to 2.5-fold. In soybean, dephytinization
showed a synergistic effect. In conclusion, enzymatic hydrolysis of
proteins looks promising for enhancing bioaccessibility of minerals
in protein matrices.