<i>In vitro</i> Extractability of Calcium, Iron, and Zinc in Finger Millet and Kidney Beans During Processing

Abstract

ABSTRACT: Finger millet ( Eleusine coracana ) and kidney beans ( Phaseolus vulgaris ) were processed by soaking, germination, autoclaving, and fermentation for incorporation into a complementary food for children. Extract‐ability of calcium, iron, and zinc were determined by in vitro HCl‐Pepsin and Pepsin‐Pancreatin methods after each processing step. Germination significantly increased the in vitro extractability of these minerals, while soaking, autoclaving and fermentation showed a smaller or insignificant effect. Iron extractability was low in germinated, autoclaved and fermented millet, as determined by the pepsin‐pancreatin method, but increased 6.8 times with addition of vitamin C. Phytic acid was reduced by 85 and 66% in finger millet and kidney beans, respectively, during the overall processing. These results show that various processing methods, especially germination, increase mineral extractability. Addition of vitamin C and mango could be used to enhance mineral extractabilities, thereby helping to alleviate micronutrient deficiencies in populations subsisting on these foods.