Weird news - Burger does not rot in 6 years

Fast food restaurants can be found in all corners of the globe, with people eating in them in large numbers. Fast food items are very popular, although there are a number of people who decry the existence of these food chains and the type of food that they offer; it is alleged that they provide processed food that is full of salt and many chemicals, that they are responsible for obesity and many other health problems. Over a period of time, these chains have been hit by bad public perception and many of them are trying to counter by modifying their menu and providing more healthy food options.
Accusations that have come across them from time to time (although without rigorous scientific checking) state that their food is full of chemicals that it will not rot even if you leave it as it is for extended periods of time. It could be left for months or years and there will be no mold formation, no typical process of the food getting spoiled and so on. In this article, there is a claim that there is almost no change in the food even after many years (link to article):

The owner of an Alaska chiropractic clinic shared a photo she alleges to show a 6-year-old McDonald's Happy Meal that shows no outward signs of aging. Jennifer Lovdahl, owner of Balanced Health Chiropractic in Anchorage, shared photos on Facebook showing the receipt for the Happy Meal she purchased Jan. 8, 2010, alongside the chicken nuggets and French Fries from the 6-year-old meal. The fries and nuggets appear slightly discolored, but show no signs of mold, rot or decomposition.