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ARS Home » Southeast Area » Stoneville, Mississippi » Biological Control of Pests Research » Research » Publications at this Location » Publication #427961
Research Project: Management of Aflatoxin and Other Mycotoxins in Row Crops such as Maize, Peanut, and Soybean

Location: Biological Control of Pests Research

Title: Local nixtamalization processes shift metabolome and reduce aflatoxin B1 concentration in naturally contaminated maize

Author
item GLESENER, HANNAH - Arizona State University
item ROBERTS, DREW - University Of Connecticut
item TANVEER, HAADIA - Arizona State University
item KRAJMALNIK-BROWN, ROSA - Arizona State University
item ABDOLLAHZADEH, DARYA - Arizona State University
item SEEGMILLER, EMELINE - Arizona State University
item MUSE, CHRISTOPHER - Arizona State University
item Weaver, Mark
item AKSENOV, ALEX - University Of Connecticut
item KRAJMALNIK-BROWN, ROSA - Arizona State University
item VOTH-GAEDDERT, LEE - Arizona State University

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/9/2026
Publication Date: 4/23/2026
Citation: Glesener, H., Roberts, D., Tanveer, H., Krajmalnik-Brown, R., Abdollahzadeh, D., Seegmiller, E., Muse, C., Weaver, M.A., Aksenov, A., Krajmalnik-Brown, R., Voth-Gaeddert, L. 2026. Local nixtamalization processes shift metabolome and reduce aflatoxin B1 concentration in naturally contaminated maize. Journal of Agricultural and Food Chemistry. https://doi.org/10.1021/acs.jafc.5c13174.
DOI: https://doi.org/10.1021/acs.jafc.5c13174

Interpretive Summary: Nixtamalization, the cooking of maize in an alkaline solution, is the traditional practice throughout Mesoamerica.  This process results in numerous changes to the composition of the masa and the tortillas and can also improve food safety by reducing the content of aflatoxin B1, a mycotoxin, in the tortillas.  These benefits from nixtamalization have been reported previously, but questions remain about the effect of varying local practices.  We conducted controlled laboratory experiments to observe the effect of calcium hydroxide concentration, steeping duration, repeated washing of the cooked maize and cooking temperature of the tortillas on nutritional content and the reduction of aflatoxin B1.  Nutrient composition and the metabalome for maize samples were recorded for samples from the USA and Guatemala and from samples collected at various points in the nixtamalization process.  A standard, representative, traditional process resulted in 81% reduction of aflatoxin B1while an extended steeping step and additional washes of the cooked maize resulted in further reductions and less variability, respectively.  Calcium and iron concentrations were increased by over 800% and 30%, respectively while smaller changes were noted for copper, magnesium, phosphorus, protein, potassium, phytic acid and manganese.  Metabolomic analysis revealed that the most significant chemical changes in the maize processing took place in the cooking and steeping steps, with fewer unique metabolic features identified during the later processing and baking steps. 

Technical Abstract: We conducted a controlled lab study using maize, naturally contaminated with an aflatoxigenic Aspergillus flavus strain, to evaluate the effect of rural-Guatemalan cooking practices on how variations in nixtamalization parameters affect aflatoxin B1 (AFB1) reduction and nutritional quality. The study included 9 total conditions, evaluating both early parameters such as Ca(OH)2 concentration and steeping as well as later parameters such as washing cooked maize and tortilla cooking temperature. Across all conditions, AFB1 concentrations decreased from raw grain to final tortillas, with extended steeping and adequate Ca(OH)2 levels enhancing toxin reduction. Additional maize washes after steeping improved reproducibility, while cooking temperature had minimal impact. Nutritional analysis showed increased calcium and modest shifts in protein and several micronutrients. Untargeted metabolomics revealed that early processing steps drive major biochemical changes, with distinct profiles across maize source countries and biofortification status. These findings highlight the food safety and nutritional implications of nixtamalization and provide a framework for evaluating traditional food preparation methods as culturally relevant interventions to reduce toxin exposure and improve dietary quality.