S23 - Session P11 - Phytochemical screening of cocoa (Theobroma cacao L.) leaves

Authors: Patrick Kumah *, Samuel Ampofo, Irene A. Idun

Cocoa, a perennial tree crop widely grown in West Africa and South America with so many industrial uses is also reported to contain polyphenols with high antioxidant and antimicrobial properties. The main aim of the study was thus to test for the phytochemical properties of cocoa leaves extracts as a basis for its use as an alternative to synthetic fungicide in treating fungal rots in white yam. Fresh cocoa leaves (CL) were plucked from cocoa plants at Juaso Cocoa Research Station, steam-blanched, dried, powdered and qualitatively analyzed. Crude aqueous CL extract was also prepared by cold maceration for 7 days. Polyphenolic compounds (total phenol content and total antioxidant capacity) were assessed using standard methods. Preliminary phytochemical analysis revealed the presence of Saponins, Tannins, Glycosides, Triterpenoids, Sterols, Coumarins, Flavonoids, and Alkaloids. The various assessments showed that Ethylacetate purified CL extract yielded highest in both total phenol content and total antioxidant capacity whereas the crude aqueous CL Extract was the least active. In the resulting weights of yields (w/w) of extracts, the Ethylacetate purified CL produced highest yield (57%), followed by Acetone purified CL (10%) and the lowest by crude aqueous CL (6.7%). Total phenolics varied from 22.07mg/g˂70.60mg/g˂274.90mg/g for crude aqueous CL, Acetone purified CL and Ethylacetate purified CL, respectively. Ethylacetate purified CL was the most potent in antioxidants (2034.72mg/g) followed by Acetone purified CL (671.77mg/g) and crude aqueous CL (349.91mg/g). The CL exhibited high total phenol content and antioxidant capacity with the Ethylacetate purified extraction method, with least polarity, yielding highest polyphenols. We, therefore, conclude that Ethylacetate purified CL extract could be a potential natural alternative to synthetic antimicrobial chemicals for controlling rot-causing pathogens on export grade white yam.