title: Aflatoxin contamination of groundnut and maize in Zambia: observed and potential concentrations.
abstract: OBJECTIVE
  The aims of the study were to quantify aflatoxins, the potent carcinogens associated with stunting and immune suppression, in maize and groundnut across Zambia's three agroecologies and to determine the vulnerability to aflatoxin increases after purchase.
  
  
  RESULTS
  Aflatoxin concentrations were determined for 334 maize and groundnut samples from 27 districts using lateral-flow immunochromatography. Seventeen per cent of crops from markets contained aflatoxin concentrations above allowable levels in Zambia (10 μg kg-1). Proportions of crops unsafe for human consumption differed significantly (P < 0·001) among agroecologies with more contamination (38%) in the warmest (Agroecology I) and the least (8%) in cool, wet Agroecology III. Aflatoxin in groundnut (39 μg kg-1) and maize (16 μg kg-1) differed (P = 0·032). Poor storage (31°C, 100% RH, 1 week) increased aflatoxin in safe crops by over 1000-fold in both maize and groundnut. The L morphotype of Aspergillus flavus was negatively correlated with postharvest increases in groundnut.
  
  
  CONCLUSIONS
  Aflatoxins are common in Zambia's food staples with proportions of unsafe crops dependent on agroecology. Fungal community structure influences contamination suggesting Zambia would benefit from biocontrol with atoxigenic A. flavus.
  
  
  CONCLUSIONS
  Aflatoxin contamination across the three agroecologies of Zambia is detailed and the case for aflatoxin management with atoxigenic biocontrol agents provided. The first method for evaluating the potential for aflatoxin increase after purchase is presented.
authors.affiliation: School of Plant Sciences, University of Arizona, Tucson, AZ, USA.|School of Agricultural Sciences, University of Zambia, Lusaka, Zambia.
authors.forename: P W
authors.initials: PW
authors.lastname: Kachapulula
authors.affiliation: International Institute of Tropical Agriculture, Lusaka, Zambia.
authors.forename: J
authors.initials: J
authors.lastname: Akello
authors.affiliation: International Institute of Tropical Agriculture, Ibadan, Nigeria.
authors.forename: R
authors.identifier: http://orcid.org/0000-0003-2422-4298
authors.initials: R
authors.lastname: Bandyopadhyay
authors.affiliation: School of Plant Sciences, University of Arizona, Tucson, AZ, USA.|Agricultural Research Service, United States Department of Agriculture, School of Plant Sciences, University of Arizona, Tucson, AZ, USA.
authors.forename: P J
authors.initials: PJ
authors.lastname: Cotty
mesh_terms: D000348:Aflatoxins / Q000032:analysis*; D010367:Arachis / Q000737:chemistry* / Q000382:microbiology; D001231:Aspergillus flavus / Q000737:chemistry; D018556:Crops, Agricultural / Q000737:chemistry* / Q000382:microbiology; D004784:Environmental Monitoring; D005506:Food Contamination / Q000032:analysis*; D006801:Humans; D015024:Zambia; D003313:Zea mays / Q000737:chemistry* / Q000382:microbiology
chemical_list: D000348:Aflatoxins
keywords: Aspergillus section Flavi; Zambia; aflatoxin; agroecologies; groundnut; maize