ABSTRACT

This study evaluated and compared the mineral status of cowpea and soybean hull ashes and their blends. Wholesome cowpea and soybean seeds were procured and processed. The hulls were sun dried and incinerated separately to obtain their raw ash. The ashes were subjected to muffle furnace ashing to obtain the dry ash separately. Percentage(%) blends were formulated at the ratio of 20% cowpea hull: 80% soybean hulls, 80% cowpea hull: 20% soybean hull and 50 % cowpea hull: 50% soybean hull. While I 00% cowpea hull and 100% soybean hull respectively served as controls. The dry ash were analyzed for their percentage raw ash yield, percentage dry ash yield, macro and micro mineral composition, heavy metal composition, physical properties and antioxidant properties using standard methods. The statistical analysis was carried out using oneway ANOVA at 95% confidence level. The percentage raw ash yield ranged from 60.09 to 68.70%. The percentage dry ash yield ranged from 40.80 to 95.74 % The result of the macro mineral composition ranged from 15.13 to 15.27 mg/lOOg, 64.53 to 86.50 mg/lOOg, 102.22 to 104.17 mg/100g, 30.55 to 46.70 mg/I OOg, 1.64 to 2.35 mg/100g and 110.35 to 110.68 mg/I OOg for sodium, calcium, phosphorus, magnesium, manganese and potassium respectively. The result of the micro mineral ranged from 6.81 to 10.28 mg/lOOg, 3.47 to 5.05 mg/l00g, and 1.34 to 1.55 mg/I OOg for iron, zinc and copper respectively. The result of the heavy metal composition ranged from 0.22 to 0.37 mg/lOOg, 0.03 to 0.07 mg/lOOg and O.IO to 0.32 mg/lOOg for lead, argon and nickel respectively. The result of the physical properties ranged from 7 .02 to 7 .51, 250.1 0 to 250.5 1 mpa.s, 36.23 to 61.15 % and 5.02 to 6.0 I for pH, viscosity, emulsion capacity and colour respectively. The result of the antioxidant properties ranged from 42.59 to 55.77 %, 157.32 to 320.49 MFe2+/g and 42.77 to 55.03 % for DPPH, FRAP and ABTS respectively. The outcome of this study showed that the ashes obtained from the cowpea and soybean hulls were of food grade and good source of macro and micro minerals, high antioxidant properties and low in heavy metal composition. Therefore, suitable for application in food enrichment.