Journal Article

Comparative Nutritive Evaluation of Cyperus esculentus and Cyperus rotundus Nuts

Abstract

Tiger nut, locally known as ‘aya’, is a common delicacy in Nigeria, eaten raw or processed. Two species of tigernut; black (Cyperus rotundus) and yellow (Cyperus esculentus) were evaluated to determine their comparative nutritive composition. The nutritive evaluation was carried out by proximate analysis and mineral analysis. Calcium (Ca), Copper (Cu), Zinc (Zn) and Cobalt(Co), were evaluated using Atomic Absorption Spectrophotometric method and Phosphorus (P) was determined using spectrophotometer. For the Black tigernut variety, the moisture content, ash, lipid, crude protein, and carbohydrate content, were 9.20%, 3.81%, 24.59%, 3.95% and 58.45% respectively. For the Yellow variety of tigernut, the moisture content, ash, lipid, crude protein, and carbohydrate were 8.93%, 3.41%, 24.59%, 3.95% and 59.12 respectively. The mineral composition obtained from the analysis of Black Tiger nuts in parts per million (PPM) was; Cu= 0.065, Zn = 0.79, Ca = 0.02, Co below 0.03 and phosphorus was 0.52mg/100ml. The mineral composition of the yellow tigernut was of the same value to that of black tigernut, but with only difference in Phosphorus, which was 0.15mg/100ml. The result of this work shows that, although both species tigernut have reasonable amount of lipid, carbohydrate and ash content, they cannot in any way be used as a whole or complete diet, due to their low protein content. From this investigation, there is no comparative nutritive advantage of one of the two species of tigernut over the other.

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