Performance of natural chelates in the enhancement of iodine biofortification in cassava (<I>Manihot esculenta</I> Crantz)

Abstract

The study investigated the ability of some organic chelates to enhance iodine availability, uptake and deposition in the edible root of cassava. The chelates used were EDTA as standard chelate, Bontera as commercial organic chelate and periwinkle effluents and Smoke solution as local organic chelates. The cultivars used were TME419 and TMS3168/UMUCASS/36 also known as YELLOW ROOT (YR). One hundred (100ml) of 100μg of iodine obtained from potassium iodide was added to 5000ml each of deionized water, 1ml/L Bontera, 1ml/L EDTA , Periwinkle effluents and Smoke solution. The treatments were applied through foliar application at 3 months after planting. The iodine content distribution ranged from 350μg/g (TME419 Root peel; control) to 23440μg/g (YR Stem; SS +KI). In the edible root, the bioavailable iodine ranged from 790μg/g (YR; PE +KI) to 7710μg/g (TME419; PE +KI). After processing to garri and fufu, the content ranged from 100μg/g (YR; control and PE +KI) to 1030μg/g (TME419; PE +KI) in fufu and 410μg/g (YR, PE +KI) to 4010μg/g(TME419; PE +KI) in garri. The study revealed that all the chelates had good potentials to enhance iodine biofortification. However, among the chelates used Bontera proved to be best because, it was stable when used individually and in combination with KI and was also stable in both cultivars used. Among the cultivars used YR proved to be better because, it has the ability to retain iodine for a longer period of time. The use of organic chelates should be encouraged to fast track micronutrients biofortification and availability.

Key words: Iodine, Biofortification, Cassava, Organic chelates, Bioavailability