Determination of Mineral Composition of Common Legumes Sold in Jos Market, Plateau State

Legumes constitute a primary dietary protein and mineral source in the food culture of Plateau State, where meat consumption is often limited among low-income households, making their mineral composition a nutritionally important subject of investigation. This study determines the mineral composition of five commonly consumed legumes including soybeans, cowpea, groundnut, Bambara groundnut, and pigeon pea purchased from Jos main market in Plateau State. Samples were collected in triplicate, oven-dried, ground to fine powder, and subjected to dry ashing followed by acid dissolution for mineral analysis. Calcium, phosphorus, magnesium, potassium, iron, zinc, copper, manganese, and selenium concentrations were determined by atomic absorption spectrophotometry, with phosphorus quantified by the vanadomolybdate colorimetric method. Results show that soybeans contained the highest protein-associated minerals, with calcium at 176 milligrams per 100 grams, iron at 8.9 milligrams per 100 grams, and zinc at 3.8 milligrams per 100 grams. Groundnut contributed the highest selenium content at 0.34 micrograms per gram. Bambara groundnut showed a notably high calcium content relative to its protein contribution. Iron content across all legumes was nutritionally significant, though bioavailability concerns related to phytate content must be considered. Comparative analysis against Recommended Daily Allowance values suggests that these legumes can meaningfully contribute to daily mineral requirements, particularly for women of reproductive age. Regular consumption of a varied legume combination is recommended to cover micronutrient needs. Keywords: mineral composition, legumes, atomic absorption, Jos market, Plateau State.