Nutrient variation in colored varieties of Ipomea batatas grown in Vihiga County, Western Kenya

Nutrient deficiencies are a major global health problem affecting more than 2 billion people (children included) in low income countries. Deficiencies are reported for both organic nutrients such as vitamin C, beta-carotene (BC)-the vitamin A (VA) precursor and for mineral nutrients; calcium (Ca), iron (Fe) and potassium (K). In Kenya, potential nutrient-rich foods such as Ipomea batatas (sweet potato) are locally available but their nutrient content needs to be quantified. Vihiga County, Kenya grows white, yellow, purple and orange colored flesh sweet potato varieties. This study aimed at quantifying vitamin VA and C in raw and boiled varieties of sweet potato from Vihiga County. In addition, raw samples of sweet potato as well as soils growing them were quantified for Ca, Fe, K and copper (Cu). Liquid chromatography, iodometric titration and atomic absorption spectroscopy were employed. The orange fleshed varieties had significantly higher level of Fe, K, Cu and vitamins. Vitamins though reduced significantly with boiling. The level of Ca, Fe, K and Cu in soils was positively correlated (r=0.07) with those found in the sweet potato. This study indicates that the orange fleshed sweet potato contain higher levels of Fe, Cu, K, VA and vitamin C making it a very rich source for both organic and mineral dietary nutrient. While production of other sweet potato varieties is encouraged, the study findings promote the consumption of orange fleshed sweet potato to address nutrient deficiencies.