Effect of Drying Method, Extraction Temperature and Solvent Type on the Total Phenolic and Flavonoids Contents of the Leaves of Moringa oleifera

Moringa oleifera, Lam., a perennial deciduous tropical plant belonging to the Moringaceae family, is a plant rich in many bioactive compounds. M. oleifera, is a plant known for its high nutritional and medicinal value. Preservation of the bioactive metabolites is dependent on the sample preparation and drying methods as well as extraction solvents used. Thus, the present study was carried out to investigate the effect of different drying methods and extraction temperatures and solvent types on the total phenolics and flavonoid contents of M. oleifera leaves. The leaves of M. oleifera were dried using different drying methods and extracted using ethanol, and aqueous solvents at different concentrations. The results showed that the yield of M. oleifera leaf extracts ranged from 11.05% – 36.50%. The aqueous extract had a higher yield than that of ethanol and ethanol is a better solvent for extracting flavonoids thus the higher average yield. Air drying and concentrating at 50℃ proved to be the best method of extracting flavonoids irrespective of the solvent used. The present findings suggest that variability in drying methods and solvents for extraction plays a crucial role in enhancing the efficiency of extraction of the total phenolic and flavonoid contents of the leaves of M. oleifera.