THE IMPACT OF ASSOCIATED FUNGI ON POST-HARVEST DETERIORATION OF SHEA KERNELS IN NIGERIA

Abstract

Shea kernels constitute a major source of income and nutritional components for a vast majority of the population in many African countries including Nigeria, particularly the rural areas and Nigeria has been reported to be the largest producer of shea but the recurring problem of mouldiness of Shea nuts/kernels and high free fatty acid and impurities in Shea butter due to the lack of established Hazard Analysis and Critical control points (HACCP) in the Nigerian Shea nut/butter production chain unfortunately is a major threat to food security. Three Shea- producing states in Nigeria (Kwara, Oyo and Niger) were investigated for fungi impact on shea kernels and samples were analysed for fungi contamination and its identification. The study examined the types of storage houses and materials used for shea products (kernels and butter) storage and the associated pathogens of Vitellaria paradoxa (Gaertn.). Results from this study revealed the presence of fungi-mould on kernels which was most prevalent. Eight fungal species from the genera Aspergillus, Trichoderma and Penicillium were encountered from the samples collected in the selected ecological zones covered in the survey. Samples from Kwara state had the highest frequency rate of microbial contamination at 95% followed by Niger State which had a moderate frequency rate of microbial contamination at 50% and Oyo State having the least frequency rate of microbial infection at 25%. The characteristic rapid deterioration of shea products coupled with the total absence of effective storage management system, have already put the Shea industry in Nigeria in a serious menace. It is expedient to urgently develop a long-term storage approach for shea and its products in order to generally sustain shea industry worldwide.