Toxic Tortillas?

[cornivore]

On the bright side, I was reading several studies about how mycotoxins can be greatly reduced by pressure cooking, if you'd rather make a tamale. It isn't totally foolproof, but is probably a safer way to cook this kind of stuff. Well, they say that electric pressure cookers aren't as reliable for food safety, because they don't necessarily stay as hot as the traditional pressure cookers. This could be one reason there are mixed results using those for cooking the mycotoxin-contaminated food, in the studies (they didn't always say what kind of pressure cooker it was, or the altitude involved). Not that it made things any worse than cooking to a lesser extent, I just wouldn't be so confident as for eating a lot of one ingredient, whether or not it's said to be prone to that kind of contamination (it gets into just about everything to some extent). Anyway, it was also interesting to read about tamales: "For nearly two thousand years the main use of nixtamal was the preparation of tamale. Tortillas were a much later development that occurred at ~900 a. C. and became the principal form of nixtamal consumption and the center of the Mesoamerican diet"...

Tamales weren't found to be inherently safer in the Guatemalan diet though, I'm just thinking that since they are prepared by steaming corn flour, then pressure cooking at higher temperatures could be most appropriate for that kind of recipe, instead of tortillas and chips (although they say that frying reduces mycotoxins to some extent in tortilla chips).

[brimstoneSalad]

Interesting to hear, I didn't know cooking significantly reduced them even at relatively high temperatures.

[cornivore]

It looks like it usually would with pressure cooking, here's the info I checked out. A couple of the studies did not find reductions for some mycotoxins in either wheat or corn, and a couple did, along with rice, and beans. So, over all it appears to work more often than not (and also for endospores, like the botulinum toxin, which may survive for several hours at the boiling point). "Inside a pressure cooker, once the water (liquid) is boiling and the steam is trapped, the pressure from the steam increases and pushes on the liquid, which increases its boiling temperature"...

Effect of pressure cooking on aflatoxin B1 in rice:

"The aflatoxin loss (78-88%) was notable after pressure cooking."

https://www.ncbi.nlm.nih.gov/pubmed/16536630


Fate of ochratoxin a during cooking of naturally contaminated polished rice

"OTA concentration, as determined by HPLC analysis, in the cooked rice by both types of cookers was significantly lower than (59 to 75%) in the raw polished rice and water-washed rice. The cytotoxicity of the OTA that remained in the pressure-cooked rice from three lots was markedly decreased (approximately 20%, P < 0.05) when compared with other samples in respective lots".

https://www.ncbi.nlm.nih.gov/pubmed/16245714


The effect of cooking on ochratoxin A content of beans, variety 'Carioca'

"samples were taken, analysed for their OA content, and then cooked under pressure, with and without previous soaking. It was observed that cooking caused a substantial reduction in the levels of OA (up to 84%)"

https://www.ncbi.nlm.nih.gov/pubmed/8647310

Deoxynivalenol and Fumonisins during the Production of Wheat Bread and Cornflakes

"Cornflakes can be produced from grits by conventional pressure cooking as well as by extrusion cooking of maize flour; both processes have a high potential to reduce fumonisin contaminations to below 50%"

Poster: https://www.mytoolbox.eu/sites/mytoolbo ... Poster.pdf

Abstract for the poster: https://www.ncbi.nlm.nih.gov/pmc/articl ... 00276title

The Fate of Mycotoxins During the Processing of Wheat

"High‐pressure cooking of wheat grain at 100 °C for 40 min in the presence of sugar, malt, salt, and vitamins appeared to have, on average, no reducing effect on the DON concentration (Scudamore & Patel, 2008). Here, no liquid was removed after cooking. In contrast, steam cooking at atmospheric pressure (at 100 °C for around 30 min) and subsequent discarding of the aqueous effluent lowered the DON concentration in this study, on average, by 57%."

https://onlinelibrary.wiley.com/doi/ful ... 4337.12338


Effect of industrial processing on the distribution of fumonisin B1 in dry milling corn fractions

"The cooking of polenta in a domestic pressure cooker did not affect fumonisin contamination because the mycotoxin concentrations were similar to those of the starting flour"

https://www.ncbi.nlm.nih.gov/pubmed/15222562/

Endospore

"A highly resistant, dormant inclusion body formed within certain bacteria. To kill spores, temperatures above boiling are usually needed. For this, pressure cookers and autoclaves are required".

http://www.uomisan.edu.iq/library/admin ... 621301.pdf

Not all foods are recommended for cooking in a pressure cooker though, especially the ones that bubble and boil over when covered, like pasta. So I guess the recipes could be more limited, but I was going for limiting the ingredients in my diet (hopefully the toxins anyway). In general, they say that the nutritional benefits of grain and other plant foods outweigh the risks of mycotoxins, and also help to counteract their toxicity. However, this isn't always true (especially for corn it seems), so I wouldn't limit my nutrition to one type of grain at least. Like what's going on in Guatemala (and Texas perhaps), another study mentioned tamales with beef in the diet of mothers, which has been associated with birth defects. I think cornfed beef may have compounded the problem of mycotoxins there. I know tortillas can be made out of other ingredients (like wheat, and rice, even potatoes, and there may be recipes for those with any grain).

Something else I just read indicates that using sugar (or corn/glucose syrup) as an ingredient while cooking could possibly reduce mycotoxicity, and be more effective than nixtamalization.

Mycotoxin Reduction in Grain Chains

"Heating combined with alkaline pH may destroy some mycotoxins, but these effects may be reversible, especially if the treated material is exposed to acidic conditions."

"Heating mycotoxins in the presence of sugars, especially glucose, increases their reduction."

"The inclusion of sugars in the dough also alters the stability of fumonisins... levels were reduced in extruded maize grits that contained 2.5% or 5.0% glucose, fructose, or sucrose. Significant reductions in fumonisin B1 levels occurred in all treatments. The toxin losses with glucose were greater (45-67%) than those with either fructose (32-52%) or sucrose (26-43% reduction)."

"In aqueous solutions heated to 100-150°C containing fumonisin B1 and maize starch, zein, or glucose as individual matrix components, the greatest losses of fumonisin B1 occurred in solutions containing glucose".

https://books.google.com/books?id=73p-A ... se&f=false

It sounds like that could even work at the usual boiling point, and make pressure cooking most effective too. Maybe highly refined cookies are health food after all.

Well, it looks like there could be mixed results with that too, depending on the type of mycotoxin involved, though it mostly seems to help (I gather)...

Distribution of aflatoxins in product and by-products during glucose production from contaminated corn

"A survey of Egyptian corn and corn-based products and by-products shows that the majority of the samples had higher limits of aflatoxin. We have conducted experiments to determine the fate and distribution of aflatoxin during wet-milling process fractions and investigate the aflatoxin destruction during starch conversion to glucose syrup...

It can be concluded that aflatoxins were destroyed during starch conversion. Consequently, glucose syrup produced from contaminated starch was found aflatoxin-free."

https://www.ncbi.nlm.nih.gov/pubmed/12428450


Fumonisin B-glucose reaction products are less toxic when fed to swine

"The effects of fumonisin B-glucose reaction products in swine diets was examined...

Results suggest that dietary FB-G products are less toxic to swine and may provide an detoxification approach in instances of widespread FB grain contamination."

https://www.ncbi.nlm.nih.gov/pubmed/15884870

Metabolism of the Fusarium mycotoxins

"Plants have a high capacity to transform and thereby detoxify deleterious or poisonous compounds, like mycotoxins. The formation of glucose conjugates has a central role in this process. Mammals, however, are able to (partly) release the precursor substances during digestion, reactivating the mycotoxins."

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4351913/


Mycotoxin Metabolism

"Since plants are able to change the chemical structure of numerous masked mycotoxins, the toxicity of the latter may increase. Since modified mycotoxins are usually not detected by analytical methods commonly used to determine mycotoxins, their impact on food safety may be even more serious than it seems to be. The toxicology of these substances needs to be studied in greater detail. For these reasons, there are no established legal regulations related to the admissible levels of such mycotoxins in food...

Conjugation is a well-known detoxification strategy. The metabolism of xenobiotics in plants is assisted by the participation of plant enzymes, i.e., glucosyltransferases attaching a molecule, such as glucose, to the toxin and increasing its water solubility...

Enzymes also play an important role in the baking process and can act directly on the DON-3Glc molecule, reconverting it to the parent mycotoxin DON. The addition of enzymes such as xylanase or α-amylase during the baking process resulted in an increased DON. The use of cellulases, proteases, and glucose oxidases can also promote an increase in the concentration of DON at the fermentation stage...

Studies performed by De Angelis, Monaci, and Visconti confirmed the high stability of DON during the digestion of bread contaminated with DON and DON-3Glc in the stomach when evaluated under simulated digestion conditions. A decrease of 43% in DON levels was found in the passage from the stomach to the duodenum, unlike DON-3Glc, which was not significantly altered between the beginning and the end of digestion in the stomach. However, increased levels of DON-3Glc were observed after digestion in the duodenum. The authors suggested that the increase in DON-3Glc during food digestion, between leaving the stomach and the end of digestion in the duodenum, was a result of the interaction between DON and glucose units released as a result of the activity of enzymes present in the duodenum. The increase in DON-3Glc after the digestion of bread in the duodenum may also be explained by the presence of matrix interactions and/or by physical trapping within the matrix structure, which prevents mycotoxin detection using the standard method."

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6017960/


Stability of fumonisins in food processing

"Fumonisins are mycotoxins produced by Fusarium verticillioides (moniliforme) and Fusarium proliferatum that are found in corn and processed corn-based food products. Although generally heat stable, fumonisin concentrations appear to decline as processing temperatures increase. At processing temperatures of 125 degrees C or lower, losses of fumonisin are low (25-30%), whereas at temperatures of 175 degrees C and higher, losses are greater (90% or more). Processes such as baking and canning, where product temperatures rarely reach 175 degrees C, result in little or no loss of fumonisin. Processes such as frying and extrusion cooking, where temperatures can exceed 175 degrees C, result in greater losses. Heating fumonisin in the presence of glucose results in an apparent first order loss of the toxin. Adding glucose to corn muffins and extrusion mixes results in high losses of fumonisins during baking and extrusion processing. Little information exists on the effects of chemical and bioprocessing on fumonisins. Alkaline processing of corn, such as in the nixtamalization process, hydrolyzes fumonisins and results in a more toxic product. Additional research is needed to identify and to determine the toxicity of fumonisin decomposition products."

https://www.ncbi.nlm.nih.gov/pubmed/11922088

That, and we're full circle at the end of the last one, it essentially says that the way corn flour tortillas are made "results in a more toxic product".

[brimstoneSalad]

Moral of the story: Soak your tortillas in glucose syrup then cook them in a pressure cooker on a rack.

[cornivore]

Sounds like a brimstoneSalad...

[brimstoneSalad]

Or some kind of weird corn bread pudding.
You'd probably need to wrap them in foil or put them in a sous vide bag to keep them from turning to mush.

Maybe we'll see corn processing change some day, or maybe we'll just see an enzymatic approach to attacking these toxins.

[cornivore]

So far, they've said that preventing them from getting in there has been the only effective solution. I guess it can add up from other foods too, which couldn't necessarily be prepared in a pressure cooker. Reading about how many foods were found in Japan with mycotoxins, even though the levels were said to be relatively low, I'd think this could be similar to eating corn tortillas, if most of the foods in your diet have some (since it depended on how many tortillas were eaten daily whether they were toxic).

Four-year surveillance for ochratoxin a and fumonisins in retail foods in Japan
Occurrence of aflatoxins, ochratoxin A, and fumonisins in retail foods in Japan

That's in Japan, but there are acceptable levels anywhere else, I guess. The question would be if acceptable levels added up to unacceptable ones, when they occurred in several foods in each meal, along with the snacks. Aha, I may not be a cornivore anymore, but I'll still try to eat like a bird.

[cornivore]

They also say it's better if you don't drink like a fish...

Current State Of Knowledge Of Human Dietary Carcinogens

"Unfortunately, mycotoxins are ubiquitous. They can and must be minimized, but they cannot be eliminated entirely from our diet... In addition, a synergistic interaction between chronic alcohol consumption and aflatoxin exposure appears to play a role in human hepatocarcinogenesis. This causative role of aflatoxins in human hepatocarcinogenesis has recently been further supported by evidence from molecular epidemiology (see section on aflatoxins). There now can be no doubt that elevated exposure to aflatoxins, and especially to B1, is a major contributor to human liver cancer."

https://www.ncbi.nlm.nih.gov/books/NBK2 ... dd00043%5F

[brimstoneSalad]

They also say it's better if you don't drink like a fish...

That makes a lot of sense, since it wasn't really clear how ethanol would be carcinogenic but the correlations were undeniable.

[cornivore]

It seems that ethanol (alcohol) is associated with a wider array of carcinogenicity, and is specifically a synergist for that of aflatoxin in the liver, versus it being the alcohol causing it elsewhere (noted in the article about diet and cancer); it is also a synergist or co-carcinogen with tobacco.

Thinking more about maize, I suppose that canned sweet corn could be safer to eat than fresh or frozen, if you couldn't pressure cook it as much as it would be for the canning process, and the sweet kind naturally has more sugar in it. The difference between packaged whole corn and tortillas would be that corn flour uses a different kind of corn, and the testing for mycotoxins shouldn't be fooled by masked ones in whole corn, like it could be in the flour, even though they say that more may be removed in the process of grinding it up (maybe they are simply masked instead of removed). I'd guess that canned foods would contain fewer mycotoxins in general, because they are processed at higher heat to prevent endotoxins and enterotoxins as well... (or actually I looked up enterotoxins in canning, and those could still be a problem with something like canned tamales, which usually include meat, so the canned corn is probably safer by itself), for the sake of comparison.

Another canned food to avoid might be pickled vegetables. My guess would be because the vinegar is a synergist like alcohol, since there seems to be a variety of issues there. Or it's like how acid reverses the mycotoxic reduction in corn flour. Anyway, besides me taking wild guesses, I was reading about how some of that could be related to damage caused by ingesting the food at least: "Residents with EC in a high-incidence area have diets characterized by hot food, dry food, pickled vegetables, barbecued food, and spicy food, which can cause chronic physical and chemical damage to the esophageal mucosa, increasing its susceptibility to carcinogenic factors and carcinogenesis"...

Not to get off topic there, some of the spicy foods mentioned above would seem related to toxic tortillas, because there could be co-carcinogens involved with those, such as contaminated red chilies in a Tex-Mex meal:

"Human exposure to capsaicin, the most abundant pungent chili pepper component, is ubiquitous... Several small epidemiological studies suggest a link between capsaicin consumption and stomach or gall bladder cancer, but contamination of capsaicin-containing foods with known carcinogens renders their interpretation problematic"...

"Aflatoxins are toxic carcinogens produced by several species of Aspergillus section Flavi, with some aflatoxin producers associated with specific crops. Red chilies (Capsicum spp.) are grown in warm regions that also favor aflatoxin-producers. Aflatoxins in red chilies may result in serious health concerns"...

This could make any flour tortilla toxic, I guess, or throw in some tequila and you might as well have opened a can of worms.