African Journal of Biotechnology Vol. 2 (10), pp. 369-373, October 2003

ISSN 1684-5315  © 2003 Academic Journals

Full Length Research Paper

Mycology and spoilage of retail cashew nuts

L. O. Adebajo¹* and S. A. Diyaolu²

¹Department of Biological Sciences, Olabisi Onabanjo University, Ago- Iwoye, Nigeria. lawadebajo@yahoo.com

²Biology DepartmentTai Solarin College of Education, Ijebu Ode, Nigeria.

*Correspondence author; E-mail: lawadebajo@yahoo.com.

Accepted 18 September 2003  

Thirty-two samples of retail cashew nuts from Lagos, Nigeria were examined on two media. The pH values (5.1-6.3) of all the samples were conducive for fungal growth and mycotoxin production. Moisture content levels ranged between 4.1 and 6.8%. Fifteen samples had moisture contents up to or above 5.8%, the highest level estimated to be ‘safe’ for the storage of the nuts. Fourteen fungal species, mostly toxigenic and belonging to 5 genera were isolated. Seven species were from genus Aspergillus, 3 from Penicillium, 2 from Rhizopus and one each from Mucor and Syncephalastrum. The most predominant isolates were: A. niger, A. restrictus, A. flavus, A. fumigatus and Aspergillus sp. The mean and range of total fungal counts (CFU/g) in samples were: 3,368 (180 to 16, 300). At acceptable fungal levels of 10³ and 10⁴/g, only 14 and 28 samples, respectively, were deemed fit for human consumption. All the species recovered induced detectable loss in weights of the milled nuts, though to varying extents and would be expected to cause considerable spoilage of the nuts.

Key words: Cashew nut, Anacardium occidentale, fungal count, mycology, Aspergillus sp., Penicillium sp., spoilage.