Effects of Storage Methods and Fungal Biodeterioration on Nutrient and Aflatoxin Compositions of ‘Abacha’ a Staple Food from Nigeria

Jonathan SG, Okoro CE, Adejoye

Abstract

This study was aimed to study the food value, associated spoilage fungi (Biodeterioration) and possible aflatoxin contents of ‘Abacha’ a cheap popular food locally prepared as shredded cassava in Nigeria. Fresh and stored samples (25) were collected from different markets and analysed for nutrient, fungal components and aflatoxin concentrations; these was compared laboratory prepared samples (control). The samples contained mainly carbohydrate (96.95-97.95%), moisture (10.6-12.21%), crude protein (1.57-1.63%), fat (0.44-0.49%) and fibre (0.48- 0.51%). Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, Aspergillus tamarii, Aspergillus ochraceus, Fusarium oxysporium, Penicillum chrysogenum, Penicillum oxalicum, Trichoderma sp. and Rhizopus stolonifer were isolated from the samples, these are commonly reported in many food deterioration and aflatoxin production. Aflatoxin contents were higher in market samples than the control, and increased with storage time. Aflatoxin G2 had highest concentration (0.0263-0.0388 μg/kg) followed by aflatoxin G1 (0.0150-0.0213 μg/kg), aflatoxin B2 (0.0048-0.0071 μg/kg) while aflatoxin B1 had the least concentration (0.0030- 0.0056 μg/kg). This study showed that fungal contamination and storage time have effect on the nutrient content and aflatoxin components of ‘Abacha’. The detected aflatoxin contents of abacha were found below the tolerance limit but increase with storage time. It is therefore necessary to avoid fungal contamination of this food before and during storage period to avoid being contaminated with aflatoxins and ensuring its nutritive quality.

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