An American man, David Whipple, recently went on an US medical talkshow, “The Doctors” to show a hamburger he bought in 1999 that showed little signs of rotting 14 years later.
The 14-year-old sandwich and burger patty looked slightly shriveled but otherwise similar to the freshly-cooked ones in the store. He had bought the burger for an illustration on how enzymes work and left it in his coat pocket, until his wife found it about two years later. They were surprised to find that there was no mould on the burger. Only the pickle had disintegrated.
This isn’t the first time people have conducted experiments on fast food burgers that don’t seem to rot. Many have speculated that the excessive use of preservatives is the reason.
McDonald’s Canada has the answer. They posted a reply on their website by Dr. Keith Warriner, programme director of the University of Guelph’s Department of Food Science and Quality Assurance:
There have been a lot of online videos and photos touting the fact that when left out for an extended period of time, a McDonald’s hamburger does not rot and that this is because they are laden with chemicals. The reality is that McDonald’s hamburgers, french fries and chicken are like all foods, and do rot if kept under certain conditions.
Essentially, the microbes that cause rotting are a lot like ourselves, in that they need water, nutrients, warmth and time to grow. If we take one or more of these elements away, then microbes cannot grow or spoil food.
In the example of a McDonald’s hamburger, the patty loses water in the form of steam during the cooking process. The bun, of course, is made out of bread. Toasting it reduces the amount of moisture. This means that after preparation, the hamburger is fairly dry. When left out open in the room, there is further water loss as the humidity within most buildings is around 40%. So in the absence of moisture or high humidity, the hamburger simply dries out, rather than rot.
With moisture loss, we take away an element required by microbes to grow and cause spoilage. So to spoil a McDonald’s hamburger, we simply need to prevent the moisture loss. This can be done through wrapping it in cling film to prevent moisture from escaping, or storing it within a high humidity environment, such as a bathroom (notice black mould on your bathroom windows but not in your bedroom). If you try doing the same experiment with a homemade burger with similar moisture content as a McDonald’s hamburger and under similar conditions, you’ll probably get the same results.
True or false? Who wants to experiment with this theory further? Any takers? Anybody?
Sources: Soshiok, McDonald’s Canada.
