Procedure. Crude bean ethanolic extracts were prepared as described by Bolling and Parkin [22] . Briefly, 1 litre of ethanol was used to extract 100 g of shade-dried T. esculentum bean at 78 • C using a Soxhlet apparatus (Carl Roth WHLG2/ER-Serie, Karlsruhe, Germany) for extraction. The evaporation procedure ensured the exclusion of ethanol from the extracts; the resultant extract was a thick paste; these extracts were labelled MSCE (seed coat ethanolic extract) and MCE (cotyledon ethanolic extract) and stored at −20 • C until use. Ethanolic extracts are known to contain mainly lipids and other ethanol soluble contents such as isoflavones [22] [23] [24] . The following extracts from T. esculentum beans and tuber were obtained: cotyledon ethanolic extract (MCE) and seed coat ethanolic extract (MSCE) ( Table 1) .