Many faults are attributed to fast-food, first of all that of promoting obesity. But excess calories, sugars, and cheap fats don’t seem to be enough for junk food detractors. It has been rumored for some time that McDonald’s burgers never get moldy. This story would prove that the fast-food chain uses mysterious concoctions that shouldn’t end up on the plate. A blogger has taken the trouble to dispel what is, in its own right, an urban legend: carrying out an experiment where it is shown that the McDonald’s sandwich ages like the homemade one.
Since 2007 he has been shooting a video on YouTube, Len Foley’s Bionic Burger , in which a young man claims to have collected 18-year-old burgers. The video is also mentioned by Italian sites although, in truth, it seems to have a promotional purpose, since it refers to an online address where natural products are sold.
However, the history of the eternal hamburger has aroused a lot of curiosity and there are dozens of “documented” cases. For example, Sally Davis, a New York artist, has photographed a Happy Meal (sandwich and chips) 145 times , to prove that the products do not get moldy, while blogger Keren Hanrahan in her Best of Mother Earth tells of a purchased hamburger. in 1996 and used by her for 14 years to explain to children and parents what are the damages of a bad diet.
The American food site Serious Eats has entrusted Kenji Lopez-Alt, curator of the A Hamburger Today section with the task of verifying the issue in a rigorously scientific manner.
The theories proposed in the sites to justify the eternal youth of the hamburger are many: the chemical preservatives in the meat or bread, the high salt content, the small size of the sandwich and the meat that facilitate rapid dehydration, the impossibility to act of molds because they are stored in sterile or vacuum-packed environments.
The first consideration is that the newly purchased product is practically “sterile” because it is cooked at high temperatures. Immediately after, however, when it comes out of the hot grill, molds are present everywhere and contamination can occur at any time. The other thing to consider is that the bread used to make burgers contains the same additives as packaged bread for sale at the supermarket. Finally, the McDonald’s burger examined for the experiment contains no sauce, ketchup, mayonnaise, gherkins, lettuce or onions.
Kenji Lopez-Alt then observed for 25 days a group of 9 hamburger buns with different characteristics: one purchased from McDonald’s placed on a plate, another left in the original packaging, a homemade hamburger with the same size and the same ingredients, another made with McDonald’s meat and bread bought at the supermarket or vice versa, then there were two more samples – one homemade and one from McDonald’s – without salt, and other proposals.
The result of the experimentIt’s simple: after 25 days all small rolls kept in the same condition are not moldy. So, there is nothing miraculous in the fact that McDonald’s burgers do not age: the same thing happens to any sandwich with the same characteristics. It remains to be seen why since salt is not involved (even the salt-free sandwiches have kept well). Signs of aging and mold formation were found in larger sandwiches purchased from McDonald’s (Quarter Pounder and Angus Third Pounder) and similar home-made sandwiches that showed obvious colonies of mold. This result supports the theory of dehydration: when the size of the sandwiches increases, the humidity inside is greater and this gives the possibility for molds to develop.
To confirm this, Lopez-Alt measured the loss of moisture and found that in the smallest burger 93% of the moisture evaporates in three days: if the mold does not develop within this time, it will not form again. It takes McDonald’s Quarter Pounder a week to lose the same amount of moisture and in this interval molds form and grow as long as there is sufficient moisture (and in fact the burger looks the same after 7 and after 14. days).
In short: the hamburger does not get moldy because the reduced thickness and the large enough surface allow the humidity to evaporate very quickly. Without moisture, there is neither mold nor bacterial growth. Obviously the fact that the meat is almost sterilized by the high cooking temperature helps.
The author points out that even small homemade burgers mold if they are closed in a plastic bag: this happens because the humidity, not evaporating into the air, collects in the bag and allows the molds to grow.
The process, on the other hand, has nothing miraculous, and has been known for thousands of years: dried meat – such as the very Italian bresaola – is an excellent example of preservation without additives. The author stresses not to cheer for anyone, but not to put up with “bad science” and invites the detractors of the fast-food chain to “rest assured”, recalling that there are many reasons to disapprove of the brand without inventing poor stories. scientific