Table 3.
Effect of alkaline cooking (nixtamalization) of maize kernels and of entire tortilla production on contents of mycotoxins other than aflatoxins and fumonisins.
| Study No. in Figure 2 | Nixtamalization | Tortilla Baking on Hot Plate | Myco- toxin(s) | Initial Level in Raw Maize (µg/kg) a | Corrected Change (%) b | Comment(s) | Reference | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Alkaline Solution | Additions on Orig. Maize Mass Basis | Cooking | Steeping | Washing of Nixtamal | |||||||
| 32 | 2% Ca(OH)2 solution | Not specified | 5 min (incl. stirring) | 12 h | Thorough rinse with distilled water | 110–120 °C, 7–8 min on each side | ZEN | 230|4,230 | Nejayote: n.d.|weak accum. Tortillas: −100|−59 |
- | [65] |
| DON | 3,280|12,260 | Nejayote: n.d.|n.d. Tortillas: −82|−72 |
|||||||||
| 15-acetyl-DON | 1,490|9,830 | Nejayote: n.d.|n.d. Tortillas: −100|−100 |
|||||||||
| ZEN | 750|3,620 (spiked) | Nejayote: n.d.|weak accum. Tortillas: −71|−74 |
Mycotoxins were injected into the maize embryos | ||||||||
| DON | 850|4460|8250 (spiked) | Nejayote: n.d.|n.d.|n.d. Tortillas: −82|−72|–74 |
|||||||||
| - | - | - | - | - | - | Baking in a tortilla oven at 260 °C, 20 s | ZEN | 4.5–8.7|19–24 | Tortilla chips: ‘as is’: +116 to −7 (mean: +32)|−35 to −64 (mean: −49) | Use of maize flour mixtures. Commercial processing. Tortilla chips were prepared by frying tortilla |
[49] |
| DON | 47–466 | Tortilla chips: ‘as is’: +28 to −76 (mean: −32) | |||||||||
| 33 | 0.25% lime solution | 400% water, 1% lime | 88 °C, 20 min | 16 h | Two rinses with 250% water (based on orig. maize mass) | Baking in a gas-fired oven at ca. 365 °C for ca. 3 min | MON | 1420 | Cooked maize: −97 c Nixtamal: −100 c Nejayote: n.d. Wash water: n.d. Masa: −100 c Tortillas: −100 c |
Pilot-scale process | [68] |
| 34 | 0.25% lime solution | 400% water, 1% lime | 88 °C, 20 min | 16 h | Two rinses with 125% water (based on orig. maize mass) | ca. 250 °C, 3 min on each side | MON | 17,640 (inoculated) | Cooked maize: −54 c Nixtamal (before washing): −64 c Nixtamal (washed): ~−69 c Nejayote: n.d. Wash water: n.d. Masa: ~−71 c Tortillas: ~−70 c |
Laboratory-scale | |
a: If not mentioned otherwise, maize was naturally contaminated. b: Unless indicated otherwise, the change in the mycotoxin concentration is corrected for change in moisture content. Changes on a product ‘as is’ (wet weight) basis are indicated. Negative values: reduction; positive values: increase. c: Here, it is not clear if the change in the mycotoxin concentration is corrected for change in moisture. |: Here, data of different batches are separated by this symbol. ~: Approximate values that were calculated for this overview by using the data provided in the cited literature. DON: deoxynivalenol, MON: moniliformin; ZEN: zearalenone. accum.: accumulation; n.d.: not detected; orig.: original.