Abstract

Moringa stenopetala is one of the indigenous agro-forestry tree species cultivated in multi-storey inter-cropping system in the southern dry land areas of Ethiopia. It is an economically important tree species in which most parts of the plant are used for different purposes. Leaves of the plant collected from age classes of the tree are edible after processing. Despite its wider usage in the southern parts of the country, little is known about the nutritional composition of the leaves at different age classes of the tree. We investigated the effect of tree age on nutritional, ant-nutritional and proximate composition of M. stenopetala leaves and determined the moisture content, ash content, crude fiber, crude protein, fat, tannin content, phytate content, iron, calcium, phosphorus and potassium in the leaves. Authentic representative M. stenopetala leave samples were collected from 3, 4, 5, 6 and 7 years old tree in Derashe area, southern part of Ethiopia. The collected leaf samples were dried and subjected to physico-chemical analysis following standard methods of analysis. The laboratory results were analyzed using SAS Statistical software. The analysis indicated a significant difference in the main effect of all nutrition and anti- nutritional parameters between the five classes at 1% significant level. However, there was no significant difference in the cationic composition of iron and zinc among age classes of the tree. This study suggests that plant age has an influence on nutrition, anti-nutritional composition and most of the proximate elements. M. stenopetala trees that grew up well and reached age of five had better nutritional, anti-nutritional and proximate composition implying that leaf collection should to be done on trees that are established and grown well and reached at least five years of age.

Key words:  Moringa stenopetala, nutritional, anti-nutritional, proximate composition.