PHYSICOCHEMICAL AND UV-VISIBLE SCREENING OF AQUEOUS WOOD-ASH EXTRACTS OF LOCUST BEAN, SHEA BUTTER, MANGO AND CASHEW TREES

Abstract

Aqueous extract of wood ash is used by some ethnic groups in Nigeria especially Nupes and Gbagyis to prepare food for preservation and other purposes. In the recent past the use of chemical additives has gained ground. The recent call for green revolution and natural products intervention necessitates reverse actions. This study, therefore, aimed at determining the physico-chemical properties of the ashes obtained from four different plants and at investigating the beneficial and/or detrimental effects on the consumers. The extracts were screened for the presence of bioactive constituents, mineral elements and for UV-visible absorption. The alkalinity of the extracts was found at pH 13.00, 12.66, 11.07 and 10.51 in the order of Parkia biglobosa, Vitalleria paradoxa, Mangifera indica and Anacardium occidentale. Saponin was the only phytochemical found in all ashes. A strong UV absorption was observed at 225-325 nm which is attributable to the only phytochemical found. A. occidentale which produced highest aqueous extract to ash recovery (i.e. y/x ratio 76.32 %) ratio was also found to have highest composition of sodium, potassium, magnesium and phosphorous (Na=21250, Mg=618, Mn=620 and P=620 mg/L), highest UV absorbing components and mildest pH 10.51. We hereby recommend that attention should be directed towards ash obtained from A. occidentale (Cashew tree) for both medicinal and industrial uses. Conclusively, the physicochemical properties of the extract are beneficial to the health of the consumers in question and this study supports the use of wood ash extract as practiced by Nupes and Gbagyis.