Preliminary Study of Mineral Constituents in Selected Cultivars of Root and Tuber Crops in Sri Lanka

A study was done to determine the levels of minerals (Calcium, Magnesium, Iron, Potassium and Zinc) in three different cultivars of yams (D. alata and D. esculenta), Xanthosoma sp and four different cultivars of sweet potatoes (Ipomea batatas Lam) from different regions in Sri Lanka. Yams (Rajala, Hingurala and Kukulala), Xanthosoma sp (Kiriala) and sweet potatoes (Swp3, Swp4, Swp5 and Swp7) were prepared for analysis 2 – 3 days after harvesting. Flour samples were subjected to ashing using AOAC (1980) method and mineral constituents were analysed using Atomic Absorption Spectrophotometer (AAS). Variation in mineral constituents on dry weight basis were analysed using ANOVA, Tukey‟s HSD test (p< 0.05) Minitab. All three cultivars of yams had significant levels (p< 0.05) of Calcium and Iron and high level of Magnesium was observed in Kiriala (45.27± 0.31 mg 100g-1). A significantly high level of Iron and Potassium (p<0.05) was observed in Rajala and Sweet potatoes respectively. Swp5 cultivar contained a comparatively high amount of Calcium and Magnesium while Swp3 and Swp7 contained a high level of iron (p<0.05). Comparatively high level of Zinc was present in Hingurala, Swp3 and Swp7 cultivars. Key words: Dioscorea , Ipomea batatas, minerals, Xanthosoma sp