Effect of Different Processing Methods on Phytochemicals and Proximate Composition of Leaves of Pterocarpus mildbraedii, Adansonia digitata and Jatropha tanjorensis

Abstract

Leaves contain a range of phytochemicals minerals and vitamins, but they are easily perishable if not properly handled. Processing transforms perishable leaves into stable foods, improve their shelf life and makes them fit for ingestion. The purpose of this study is to determine how different processing methods affect the phytochemical and proximate constituents of the leaves of Pterocarpus mildbraedii, Adansonia digitata and Jatropha tanjorensis. Standard analytical methods were used to determine the phytochemical contents of the leaves while the official methods of AOAC were used to analyze the leaves for proximate constituents. The results of the phytochemical screening of the leaves of P. mildbraedii, A. digitata, J. tanjorensis indicated the presence of alkaloids, tannins, saponins, phenols and flavonoids. Proximate analysis showed a high crude protein of 24.16 ± 0.60 % and 22.31 ± 0.26 % in the blanched and boiled P. mildbraedii respectively. Ash content was found to be high in sun-dried J. tanjorensis. Mineral analysis revealed that Ca, Mg and Fe were significantly high in air-dried and boiled A. digitata. Vitamin C content was found to be highest amongst other vitamins analyzed in air-dried A. digitata. The air-dried and boiled samples of A. digitata were found to be the two most effective samples in terms of their phytochemical constituents, therefore, air drying and boiling are good processing methods in preserving the nutritional content as well as their phytochemical constituents.