Nutritional and Mineral Compositions of Tiger Nut (Cyperus esculentus) Tubers from Different Ecotypes in Niger

Abstract

Nutritional characterization is an essential component for a better knowledge of the different ecotypes of Niger tiger nut. To do this, 20 samples of tiger nut tubers were taken for nutritional investigation, including 5 ecotypes representative of the Niger tiger nut and 15 others randomly selected from the ecotypes collected in the producing villages in the Maradi and Dosso regions. The content of mineral elements was analyzed by atomic absorption spectrophotometer and the content of macronutrients determined by different types of assay. The results showed that the tiger nut ecotypes are rich in lipids (12,00% to 25.20%), carbohydrates (24.50% to 47.70%), fiber (21.90% to 39.40%), protein (2.90% to 11.90%), and mineral elements such as calcium (14.100± 5.44a to 65.380± 19.940), iron (0.881± 0.017 to 15.809± 6.524), potassium (102.800± 2.970 to 308.410± 8.900), magnesium (366.800 ±1.942 to 471.830± 8.927). The fat content is much higher in small tigernut ecotypes with an average of 21.60% than in large tigernut ecotypes with an average of 14.90%. The Copper (Cu), Sodium (Na), Calcium (Ca) and Magnesium (Mg) contents are significantly identical for all the ecotypes studied. On the other hand, the Zinc (Zn), Iron (Fe), Potassium(K) contents of ecotypes E1(Big tigernut), E2(Small tiger nut), E3(Small tiger nut), E4(Small black tiger nut), E5(Small wild tiger nut), E7(Small wild tiger nut), E8(Small tiger nut), E9(Small tiger nut), E11(Small tiger nut), E12(Small tiger nut), et E15(Big tigernut) are significantly higher compared to the other ecotypes. The study showed that the tiger nut tubers are rich in iron and that the iron composition of the wild ecotype is much higher. Compared to other foods, the tigernut tubers of certain ecotypes studied(E1, E2, E3, E4, E5, E7,E8, E9, E11, E12 and E15) are richer in iron than the leaves of Moriga oleifera (3.810 ± 0.120mg/100g), the pods of Vigna unguiculata (7.800± 0.150mg /100g) and leaves of Hubicus sabdariffa (8.270 ± 1.010 mg/100 g).