Proximate and mineral composition of the fruits of Ziziphus mauritiana Lam. (Rhamnaceae) and Hypaena thebaica L. (Arecaceae)

Abstract

The fruits of Ziziphus mauritiana and Hypaena thebaica are consumed by the people of Kano State, Nigeria for many centuries, however, the nutritional composition and medicinal values of the species growing in Kano State are not widely investigated. Thus, the present study was aimed at evaluating the proximate and mineral composition of their fruits using standard laboratory procedures. The results showed that the fruits of H. thebaica had the highest crude protein (9.03±0.21 %), moisture (7.28±0.01 %), crude lipid (0.62±0.01 %) and carbohydrate (72±0.06 %) contents, while the fruits of Z. mauritiana had the highest crude fibre (15.26±0.42 %) and ash (5.53±1.62 %) contents. Also, the mineral analysis showed that the fruits of H. thebaica had the highest potassium (350.52±0.50 mg/kg), magnesium (44.72±0.23 mg/kg), sodium (24.26±0.53 mg/kg), phosphorus (9.92±0.02 mg/kg), iron (12.65±0.51 mg/kg), selenium (9.81±0.29 mg/kg), copper (0.95±0.10 mg/kg), nickel (0.31±0.04 mg/kg), manganese (0.89±0.01 mg/kg) contents, while the fruits of Z. mauritiana had the highest calcium (190.95±0.15 mg/kg) content. The findings in this study showed that the fruits of H. thebaica and Z. mauritiana contain appreciable amounts of proximate, macro and microelements. Therefore, the fruits of these trees could be utilized as raw materials in food and pharmaceutical industries.