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United States Department of Agriculture

Agricultural Research Service

Title: Fumonisin B1 and Hydrolyzed Fumonisin B1 Levels in Nixtamalized Maize (Zea Mays L.) and Tortillas from Two Different Geographical Locations in Guatemala

Authors
item Meredith, Filmore
item Torres, Olga - INST NUTRICION,GUATEMALA
item Merrill, Jr, Alfred - BIOCHEM,EMORY, ATLANTA
item Riley, Ronald

Submitted to: Journal of Food Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 22, 1999
Publication Date: N/A

Interpretive Summary: A fungus, Fusarium moniliforme, produces toxic substances called fumonisins. These toxins are produced on maize (corn and maize (corn) products, and are health risks for animals and humans. This study reports on the concentration of fumonisin found in processed corn and in tortillas made from the processed corn from two different Guatemalan communities. The process is called nixtamalization. In the nixtamalization process, maize is heated for about an hour in a solution of water and calcium carbonate and allowed to stand in the alkali solution for 12 to 14 hours. The alkali solution is removed and the cooked maize, which is called nixtamal, is washed several times with water and then ground. The nixtamal is patted out into flat cakes and cooked on a ceramic griddle to make tortillas. The tortillas are the main staple food of the people. Fifty samples of nixtamal and 50 samples of tortillas were collected from households of each community for fumonisin determination. Fumonisin was found in the nixtamal from both communities. Another toxic fumonisin called hydrolyzed fumonisin was not found. The fumonisin in the presence of alkali is converted to the hydrolyzed fumonisin. Analysis of the tortillas showed that fumonisin and hydrolyzed fumonisin were present. The cooking of the tortillas produced the hydrolyzed fumonisin while the nixtamalization process did not. The study showed that people from the two communities in Guatemala are eating large amounts of toxic fumonisins in maize that is used as food.

Technical Abstract: To study the effect of nixtamalization and cooking conditions used in Guatemalan communities on fumonisin concentration and the formation of hydrolyzed fumonisin, nixtamalized maize (nixtamal) and home made tortillas were collected from two different locations (Santa Marie de Jesus, Sacatepequez and Patzicia, Chimaltenango) of the central highlands of Guatemala, (n=50 samples per location) and analyzed by HPLC for fumonisin B1 (FB1) and hydrolyzed B1 (HFB1). Nixtamal from both locations contained only FB1, with Santa Marie de Jesus having the high concentration (77.2 ug/g dry wt). Tortillas contained both FB1 and HFB1, with Santa Marie de Jesus having the highest level of HFB1 (185 ug/g dry wt). The estimated daily intake of FB1 from tortillas for Santa Marie de Jesus and for Patzicia was 0.010 and 0.040 mg/kg/day while the daily intake of HFB1 was 0.195 and 0.044 mg/kg/day. The estimated daily intake of FB1 from both communities was less than reported for moldy corn (0.44 mg/kg) from Transkei, South Africa, but higher than reported for good corn (0.014 mg/kg). The important observation of this study was that HFB1 was not produced during the nixtamalization process, HFB1 was formed during the cooking of the tortillas; and the population of the two communities are ingesting daily substantial quantities of FB1 and HFB1.

Last Modified: 10/22/2014
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