Quantification of the phytic acid in Ugandan raw and cooked maize

Abstract

Micronutrient deficiency is high in Uganda and is exacerbated by consumption of foods rich in antinutritional factors such as oxalate, trypsin inhibitors and Phytic acid. Phytic acid which is the inositol combined with six phosphate groups is present abundantly in plant foods and it poses a threat to the bioavailability of Zinc and Iron. Iron and Zinc are some of the important micronutrients required for human growth and development. Cereal grains like maize, are among the foods with the highest content of Phytic acid. This study was carried out to determine the effect of cooking and cooking time on the phytic acid content in maize. The phytic acid content was determined using complexometric titration of residual Iron (III) after phytic acid precipitation. Raw maize contained 8.4±0.47mg/g of Phytic acid while in the cooked maize it ranged from 5.7±0.57mg/g to 0.93±0.38mg/g. There was generally reduction of phytic acid with cooking time. Therefore, cooking treatment was effective in decreasing phytic acid content. However due to long cooking time in this study, it is recommended that cooking maize can be combined with soaking to reduce on the cooking time as well as the expenses in terms of fuel.