Abstract

Dried mature red variety nuts of Cola nitida and Cola acuminata were purchased from three major markets noted for their wholesales with a view to ascertaining the quality of the nuts and generating a baseline data towards elaborating standards for the nuts. Dirt’s and other extraneous materials were removed from the sampled nuts and oven dried at 80°C for 16 h. The nuts were physically characterised and pulverised to powder. The proximate, chemical and mineral composition of the nuts was determined in addition to the microbal load and aflatoxin content. The shape of the two species of kola nut varied from flat to oval to spherical. In addition C. nitida had two big cotyledons while C. acuminata had on the average, 3 to 6 cotyledons. The mean length, breadth and thickness of C. nitida were 3.0, 2.0 and 1.8 cm, while that of C. acuminata were 3.4, 2.73 and 2.31cm respectively . The colour of the two species of kola nuts was found to vary between white, red and pink while the proximate, chemical and mineral contents of C. nitida were higher than C. acuminata thus justifying its description as the true kola of commerce. The study further showed that kola nuts contain some active principles found in coffee and cocoa that have important pharmacological properties. The microbial load of the nuts were also within the permissible limit specified by the International Commission on Microbiological Specifications for foods and only two moulds species; Aspergillus flavus and Rhizopus arrhizus were isolated from the kola nuts while the aflatoxin content was found to be less than 2 μg/kg.

Key words: Kola nut, physical characterization, proximate, chemical and mineral composition, microbial load.