Mycological, toxigenic and nutritional characteristics of some vended groundnut and groundnut products from three Northern Nigerian ecological zones

Abstract

Groundnut (Arachis hypogaea L.) and groundnut products are important, street-vended, energy-rich sources of protein and oils useful in human and animal diets although fraught with microbial contaminations. Fungi associated with vended samples of roasted groundnut, Kulikuli, Donkwa, peanut butter and Yaji obtained from Kano, Kaduna, Minna and Ibadan were isolated using pour-plate method. These were qualitatively screened for presence of mycotoxin on palm kernel agar medium and the concentrations of aflatoxin and deoxynivalenol content in the samples quantified through immunoassay. The fungal load of the samples was highest between 1.3X103 and 1.6X104 TFU/g while the frequency of occurrence of Aspergillus, Fusarium, Rhizopus and Penicillium species in the samples were 36%, 33%, 20% and 11%, respectively. Qualitatively, the highest aflatoxin intensity producers were two strains of Aspergillus flavus from a Yaji and Kulikuli sample. The highest aflatoxin concentration (115ppb) was recorded in the Kaduna Yaji sample and 65% of the samples had aflatoxin concentration above the FDA-prescribed 20ppb. The highest deoxynivalenol concentration (0.7ppm) was recorded in Kaduna Donkwa sample which was still lower than the 1.0ppb prescribed recommendation. Kano Yaji and Kaduna Kulilkuli had the highest protein content (60% and 44% respectively) while all samples were high in calcium and potassium (725.16-1292.75 and 325-1280mg/100g) respectively. There was fungal contamination of vended groundnut product samples and the detection of mycotoxins in all the samples. Regulatory bodies, especially in developing countries, need to set quality standards and ensure compliance of the same in street vended food products for product and consumer safety.

Keywords: Groundnut products, Mycotoxigenic properties, Deoxynivalenol, Aflatoxin, Nutritional composition

Afr. J. Biomed. Res. Vol. 22 (January, 2019); 65- 71