Journal Article

Nixtamalization of Maize to Reduce Mycotoxin Exposure: A Human Biomonitoring Intervention Study in Soweto, South Africa

Adelusi, Oluwasola A., Odukoya, Julianah O., Oyeyinka, Samson A., Akinmoladun, Oluwakamisi F., Croubels, Siska, De Boevre, Marthe, Njobeh, Patrick B., Ndlangamandla, Palesa, Pero-Gascon, Roger, De Saeger, Sarah, Maris, Elias, Fagbohun, Richard T., Sekhejane, Palesa

2025

Overview

Mycotoxin contamination is a global threat to food safety and human health, especially in regions facing food insecurity, such as Sub-Saharan Africa. This intervention study evaluates the effectiveness of nixtamalization, a traditional alkaline cooking method, in reducing mycotoxin levels in maize and corresponding urinary biomarkers of exposure. Forty adult healthy volunteers from an informal settlement in Kliptown, Soweto (South Africa), were randomly assigned to consume control maize or visibly moldy maize subjected to nixtamalization. Nixtamalization achieved a reduction in fumonisin B3 and deoxynivalenol (DON) to unquantifiable or undetectable levels in maize, while reducing fumonisin B1 (FB1), fumonisin B2, and zearalenone (ZEN) by 95%, 95%, and 89%, respectively. Aflatoxin B1 was unquantifiable before and eliminated after treatment. Biomarker analysis revealed that after consumption of either control or nixtamalized maize, urinary levels of FB1, ZEN, and its metabolites α- and β-zearalenol (α- and β-ZEL) did not show significant differences between groups (p > 0.05). DON and tenuazonic acid levels were not affected by the intervention (p > 0.05), with urinary detection frequencies remaining above 90%. These results demonstrate nixtamalization effectively lowers mycotoxin levels in maize, resulting in exposure levels comparable to control maize, and highlight human biomonitoring as a sensitive tool for evaluating food safety interventions.

• Publisher: MDPI AG,Multidisciplinary Digital Publishing Institute (MDPI)
• Subject: Adult / Aflatoxin B1 / Aflatoxins / Biological Monitoring / Biomarkers / Biomarkers - urine / Biomonitoring / Consumption / Cooking - methods / Corn / Crop diseases / Deoxynivalenol / Education / Exposure / Female / Food / Food contamination / Food contamination & poisoning / Food Contamination - analysis / Food Contamination - prevention & control / Food safety / Food security / Fumonisin B1 / Fumonisin B2 / Fumonisins - urine / Fungi / human biomonitoring / Humans / Infrastructure / maize / Male / Metabolites / Middle Aged / mycotoxin / Mycotoxins / Mycotoxins - analysis / Mycotoxins - urine / Nixtamalization / Population / Public health / Safety and security measures / Safety standards / Sensitivity analysis / South Africa / Sub-Saharan Africa / Tenuazonic acid / Toxicity / Young Adult / Zea mays - chemistry / Zea mays - microbiology / Zearalenone