Chikezie, PC. “Extraction and Activity of Polyphenol Oxidase from Kolanuts (<i>Cola nitida</i> and <i>Cola acuminata</i>) and Cocoa (<i>Theobroma cacao</I>)”. Journal of Agriculture and Food Sciences 4, no. 2 (May 27, 2008): 115–124. Accessed September 25, 2026. https://www.ajol.info/index.php/jafs/article/view/41598.