Effect of different soaking conditions on inhibitory factors and bioaccessibility of iron and zinc in pearl millet.

Pearl millet was decorticated to obtain a bran rich and endosperm rich fraction. The two fractions were
soaked in solutions with varying pH. Pearl millet grains were germinated and steamed followed by
decortication to obtain two fractions. It was observed that bran rich fractions contained high concentrations
of iron, zinc, polyphenols, phytic acid, fibre and flavonoids. Soaking for short duration of 3 h did
not result in major mineral losses but decreased the inhibitory factors which depended on the pH.
Alkaline soaking decreased flavonoid content by 62.7% in the endosperm rich fraction, while acidic
soaking decreased phytic acid content to the maximum in the bran rich fraction. Combination of
treatments like germination and heat decreased the phytate content to the maximum in the endosperm
rich fraction. Acidic conditions improved zinc bioaccessibility in the bran rich fraction (35%) and iron
bioaccessibility (2.5%) in the endosperm rich fraction. Bran rich fraction from germinated grain also had
enhanced bioaccessibility of both the minerals but comparatively lesser when compared to soaking
under acidic conditions. Soaking the grain components under slightly less than neutral conditions also
decreased some of the inhibitory factors and improved the zinc bioaccessibility to some extent in the
bran rich fraction.