The impact of processing on phytic acid, in vitro soluble zinc and Phy/Zn molar ratio of faba bean (Vicia faba L.)

Faba bean is a major source of micronutrients in many rural areas. Unfortunately the bioavailability of zinc from faba bean is low. Influence of soaking, germination and fermentation with expectation of increasing its bioavailability was investigated. Fermentation treatments were most effective in decreasing phytic acid (48-84%), followed by soaking at 10°C after preheating (36-51%). Steeping of faba beans for 24 h at 25°C had the least effect on phytic acid removal (9-24%). With increased germination time at 30°C, phytic acid progressively decreased from 9 to 69%. Most wet processing procedures, except soaking after wet preheating, caused losses of dry matter and zinc (8-22%). In vitro zinc solubility, as a percentage of total zinc in soaked faba bean after dry preheating, was significantly higher than in raw faba bean (P 0.05). Probably complex association between dietary fiber and zinc is the reason for the poor bioavailability of zinc in faba bean.