Aspergillus species and aflatoxin contamination in pepper (Capsicum annuum L.) in West Gojjam, Ethiopia

Abstract

Pepper (Capsicum annuum L.) is an important spice and source of income for smallholder producers in Ethiopia. Since the larger proportion is for the market, it takes a significant share of the national income from export commodity. However, often the product was rejected by some of the European Union markets due to the maximum aflatoxin level accumulations beyond their acceptable limits. So, the present study was carried out to highlight the importance of Aspergillus species invasion in pepper, and levels of aflatoxin contamination at maturity in the field (pod form), farmers' storage and local market (powder form)in West Gojjam, Ethiopia. A total of 135 pepper samples were collected from three districts of West Gojjam(Burie, Jabitehnan, and Fnoteselam), Ethiopia for fungal and aflatoxin analysis.The producers used a pre-validated structured questionnaire to obtain information on pepper production practices. Aspergillus species isolates were recovered using potato dextrose agar (PDA) medium and counting was through dilution method (cfu g-1). The pepper pods were ground to a fine powder for aflatoxin analysis using Enzyme-Linked Immunosorbent Assay(ELISA). The prevalence of infected samples revealed that, pre-harvest samples(51%) were less infected by Aspergillus species, compared to local markets (65 %) and storage (79 %).Aspergillus flavus species were recovered in pre-harvest samples, whilst A.niger were found in local market samples. Aflatoxin contamination at pre-harvest, storage, and local market were 10, 47, and 42 % with levels which ranged from non-detected to 10.6, 0.3 -17.1 and 3.1 -19.2 ppb, respectively.The mean aflatoxin concentration detected from storage samples (10.6 ppb)and local market (12.6 ppb)were found to be above the tolerable limits set byEU (5 ppb) in pepper products.From the findings in this study, proper drying, physical separation of molded pods and use of clean storage structures should be implemented along the production chain in order to reduce aflatoxin contamination in pepper in Ethiopia.