Detection of Aflatoxigenic Molds and Aflatoxin Levels in Groundnuts Marketed in Zaria Kaduna State Nigeria

Globally, studies on identification and detection of Aflatoxins have gained massive attention, especially in recent times. Consequently, the present work aimed to detect aflatoxigenic molds and aflatoxin levels in groundnuts marketed in Zaria metropolis, Kaduna state, Nigeria. A sum of 72 groundnut specimens comprising 24 specimens each from the three selected markets; Samaru, Sabon-Gari, and City market Zaria, were collected and analyzed in the study. The proximate compositions of the groundnuts were determined according to standard procedure of AOAC. Freshly prepared potato dextrose agar (PDA) was used to isolates molds, which were further identified microscopically (X 40) using wet preparation. All Aspergilli isolates were then screened for the ability to produce aflatoxin on desiccated coconut agar (DCA) supplemented with phenol red as indicator. The fungal cultures, aged 72 hours, were examined under ultraviolet (UV) light at a wavelength of 365 nm to assess fluorescence on DCA plates. Although the observed differences were not statistically significant, the compositional analysis indicated that groundnut samples from Samaru market exhibited the highest moisture content (4.92 ± 0.38%) and crude fat (53.87 ± 0.58%). The study also revealed the presence of Aspergillus flavus (19.44%), Aspergillus parasiticus (6.94%), Aspergillus niger (34.73%), Rhizopus sp. (29.17%), and Trichoderma sp. (9.72%) fungal isolates from samples collected from the selected markets. Furthermore, groundnut samples sourced from the Samaru market recorded the highest average aflatoxin concentration at 248.01 µg/kg and lowest concentration was found in samples from Sabon Gari, which measured 203.72 µg/kg.