Molecular Identification of Mycotoxin-Producing Fungi Contaminating Dried Chilli Pepper (Capsicum annuum) in Kaduna and Kano Markets

Dried chilli pepper (Capsicum annuum) is a widely consumed condiment in Northern Nigeria, commonly traded through informal open market networks where storage and handling conditions favor mycotoxigenic fungal growth. Contamination of spices with aflatoxins and ochratoxin A poses significant food safety and health risks. This study molecularly identified mycotoxin-producing fungi in dried chilli pepper samples from five markets each in Kaduna and Kano States, Northwest Nigeria. Fifty samples were collected and subjected to direct plating on Dichloran Rose Bengal Chloramphenicol (DRBC) agar. Morphological identification was supplemented by PCR amplification and sequencing of the beta-tubulin gene for Aspergillus isolates and calmodulin gene for Penicillium isolates. Aflatoxin and ochratoxin A production capacity was verified by ELISA. Aspergillus flavus (40%), A. niger (28%), and Penicillium verrucosum (17%) were the most frequently isolated fungal taxa. Ochratoxin A was detected in 52% of samples, and aflatoxin B1 in 38%, with levels exceeding regulatory thresholds in several instances. Contamination rates were higher in Kano than Kaduna, likely reflecting differences in market storage practices. The findings support the need for regulatory monitoring of mycotoxin levels in dried spices in Northwest Nigeria. Keywords: mycotoxin, Aspergillus, chilli pepper, ochratoxin A, Kano State.