Biochemical and phytochemical analyses of avocado, cashew and soursop leaves

Abstract

Ethno-medicine has widespread in all field of medicine and gradually taking over the orthodox medicine with different range of products  The chemical composition of young and matured leaves of Avocado (<i>Persea americanna</i>), Cashew (<i>Anacardium occidentale</i>), and Soursop  (<i>Annona muricata</i>) was evaluated in the Central Research Laboratory unit of the Faculty of Agriculture, University of Benin,  Benin City, Nigeria. The proximate composition was investigated using the weende system, while the phytochemicals were determined by  gravimetric and spectrophotometric methods. Matured leaves of avocado had the highest amount of crude protein (25.76 %) which  was not significantly (P<0.05) different from that in matured leaves of soursop (23.92 %). The matured avocado leaf also contained the  highest amount of ash (15.85 %) and crude fiber (21.20 %) but with the lowest amount of oil (5.17 %). Matured soursop leaf had the highest amount of oil (19.70 %. The NFE (nitrogen free extract) values ranged from 17.25 % in matured soursop leaf to 48.8 % in young  cashew leaf. The matured leaves of soursop recorded the highest levels of calcium, magnesium, sodium, and phosphorus, while young  soursop contained the highest amount of potassium. The phytochemicals present in the leaves were alkaloid, tannin, flavonoid, phenol  and saponins of which matured soursop leaf recorded the highest concentrations (1.10, 7.57 and 3.15 respectively). Tannin levels ranged  from 0.18 in matured cashew leaf to 0.42 in young cashew leaf, with significant differences (p<0.05) between the leaf samples. The phytochemicals content of these plants' leaves make them medicinal potentials in therapeutic usage while the mineral and nutrition  contents enhance their usage as leafy vegetable for human and animal consumption.