Effect of enzymatic treatment on phytate content and mineral bioacessability in soy drink.

The objective of this study was to evaluate in vitro bioaccessibility of calcium (Ca), iron (Fe) and zinc (Zn) in soy drink after phytase treatment and correlate it with the content of myo-inositol phosphates. Samples of commercial soy drink products and one sample produced in the laboratory by maceration were evaluated. Phytase was applied using 300 U per liter in 60 min considering the phosphate release. The content of myo-inositol tris-, tetrakis-, pentakis and hexakisphosphate was not observed after phytase treatment. The solubility assay showed an increase from 2.0% to 20.8% for Ca, 2.2% to 37.1% for Fe and 38.8% to 67.4% for Zn after phytase treatment with significant differences (p ≤ 0.05) for most samples. Dialysis assay demonstrated 1.0% to 9.5% for Ca after phytase treatment (p ≤ 0.05) except for one commercial sample. The phytase treatment is a valuable alternative process for improving mineral natural availability in soy drink and decreased the use of salts in the fortification.