Microwaves transfer plastic ingredients to potatoes Sciences

Supermarkets increasingly offer vegetables that are ready to eat after being microwaved for just a few minutes in the same plastic bag you bought them in. Potatoes, cabbage or a mixture of different vegetables come pre-cooked and, according to the producers' instructions, it is not necessary to change them to another container to cook them, although it is certainly necessary to bring them to the table. investigation…

Supermarkets increasingly offer vegetables that are ready to eat after being microwaved for just a few minutes in the same plastic bag you bought them in. Potatoes, cabbage or a mixture of different vegetables come pre-cooked and, according to the producers' instructions, it is not necessary to change them to another container to cook them, although it is certainly necessary to bring them to the table. Research shows that it is probably best to change the backing before cooking it. Researchers from the University of Almería led by Francisco Jose Diaz Galeano, They found that the microwave cooking process results in a “very visible” transfer of plastic components from the bag to the vegetables. Investigation, Published in the magazine Food chemistryThey also determined that microwave action in these cases creates a new compound in the potato, which they named HMPP-maltose. According to Diaz Galeano, it is a “potentially toxic” compound, although new studies are still needed to confirm this toxicity or not. It does mean, however, a new way to ingest a toxic component of plastic that sticks to the food itself.

The researchers from Almeria had the feeling that “in a very energetic situation like a microwave, it was very possible for certain components of the plastic to transfer into the food.” They started doing all kinds of tests on potatoes of different brands distributed in bags and ready to be cooked in them. They were made with all possible options: “in the microwave in a plastic bag and in the microwave in a glass bowl, in both cases using the time recommended for the bag, or cooked in water over a fire. “The potatoes were also decomposed before being cooked,” says Díaz Galeano, who recalls that the potatoes were also decomposed before being cooked. “In this case, we gave them more time, between 10 and 15 minutes.” They did 27 repetitions of the experiment and “the same differences always emerged.”

The experiment led to two results, “one intuitive and the other completely unexpected,” the researcher comments. The thing that did not cause them particular surprise was the transfer of the polymer from plastic to food. “It has been shown that there is a very pronounced migration of polypropylene glycol (PPG) polymers from plastic bags into potatoes only when they are cooked in the microwave and in contact with the plastic. That is, the PPGs, if present in the bags, do not migrate into the food, unless they are cooked together as It's like in the microwave,” says Diaz Palacios. He adds that this specific transfer does not rule out the transfer of “other compounds found in the plastic.” “It is possible that others migrate to the food solely through contact, but in this case, we focused on differences during the cooking process in food contact.” For the researchers, the conclusions are not Be open to doubt because “there are chemical compounds that are the exclusive result of the process of cooking potatoes in contact with plastic, and are not observed either in raw potatoes, in potatoes cooked in water, or in boiled potatoes, in glass, in the microwave.”

Besides this somewhat expected result, the experiment presented an unexpected experiment that still has a way to go until its significance is determined. It is the emergence of a new compound. Diaz Galeano details that the plastic contains among its components “artificial photocatalysts, reactive compounds eager to react and find something to join with to create new plastic molecules, and new polymers that will arise from creating structures that multiply and multiply.” He adds: “The microwave energy in the bag seems to To a process whose end result is a combination of one of those synthetic photocatalysts used in plastic manufacturing, HMPP, and maltose, a natural product made from starch. potato. Because this structure, which they have tentatively named HMPP-maltose, “has not been described before, its properties cannot yet be determined, including its toxicity or safety,” the researcher says.

But the signs are not positive for health, because in any case, the professor of analytical chemistry also explains, “We can confirm on the one hand that HMPP -2-hydroxy-2methylpropiophenone- itself is toxic On the other hand, studies using software models suggest that the HMPP-maltose combination may be toxic to organisms. Currently, they are investigating potential synthetic methods to create the aforementioned compound. “Then, its properties can be evaluated,” he concludes.

The toxicity or non-use of plastic for food use has been regulated by the European Union since 2011 in its report List of plastic materials and objects intended for contact with food. In short, the suitability of the material is determined through tests that analyze the interaction of foods with so-called “food simulants”, which are products that in tests simulate being plastic wrappers. There are six simulation materials, five of which are liquid – acetic acid, vegetable oil, and three dilutions with different proportions of ethanol and water – and a final solid called Tenax TA, which is used, for example, to analyze bags of crushed soup. The interaction between food and these mimics determines their safety based on whether they are transferred to the food or not. Díaz Palacio believes that this method is not completely reliable today because it reduces all the nutritional possibilities to only six groups, and because after experimenting with potatoes also with mimetics, no transfer of them to tubers has been determined, so they have not finished practicing their theory of the role of plastics judging by the results. With real material. He says: “The tests found that the simulated food substance was not transferred either once it came into contact with the plastic, or before or after cooking,” which contradicts what happens when cooking potatoes in their bag.

“The transfer of plastic polymer components and their additives into food is a well-known and studied issue,” says Nicolás Olea, a physician and professor at the Faculty of Medicine of the University of Almería, when analyzing this study from the University of Almería. Granada and expert in health and environment. This transfer “puts plastic materials intended for food and kitchen use in constant doubt about their safety and makes it imperative for any new material to be subjected to analysis, given the large number of chemical compounds that plastic transfers to food.” “Unfortunately, as the researchers in this pioneering work explain, the protocols for investigating this transfer fail in two respects. On the one hand, because they do not cover all possible combinations of cooking methods and food type. On the other hand, what is most surprising about this work is that The new chemical compounds that appear in food when plastic is used to prepare it have never before been evaluated. Olya's conclusion was resounding: “It is not only necessary to impose stricter control on any proposed innovation – a task that goes far beyond the capabilities of the current food safety system.” And censorship – but it is the duty of the producer and seller to warn the public. About the dangers of changes in the usual cooking method. It is not ethical to wait for the European Food Safety Authority (EFSA) to express its opinion on this issue; You simply must inform the public that cooking potatoes in the microwave using pre-cooked plastic containers poses a risk of exposure to toxic contaminants that you would never find boiling in your regular pot. There is nothing simpler than that,” concludes the Granada researcher, author of the book Free yourself from toxins.

You can follow Theme in Facebook, s And Instagramor sign up here to receive Our weekly newsletter.