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

Abstract

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