Food preservation with dehydration

Food dehydration can preserve food without for several years if it stays dry enough. One upside of this method is that it can preserve any solid foodstuff from sweet plants to raw or cooked meat. Although highly enough concentrated salt or sugar preserves food against decay they have the downside of affecting how the food tastes.
Although people have known for thousands of years that drying can preserve meat and other foodstuff they may still forget it when thinking about new foodstuff or about some specific company.

For example some McDonald's critics use logic that because their burgers don't rot or get moldy then they are supposedly full some scary preservatives or have no nutrition (even if they believe that its food makes people fatter). One McD burger had been kept for 14 years in room temperature without signs of rotting. Author of this article made his own burgers that he just dried out thoroughly enough. Small size of burgers made it easier to dry them but drying (article mentions ~93% water loss) could still take 3-7 days (depending on size) with the 73 C author knew about. Burgers without salt preserved about as well as salted ones. If burgers were kept in open air so they could absorb then McDonald's and homemade burgers both got moldy at same speed. If homemade humid burger was but in plastic bag with McD burger then within week they were both almost covered with mold.

Problem with water content is that it keeps enzymes/proteins working. Cells may die but proteins in this dead mass may keep breaking it up it there are any nutrients and large molecules left in this watery mix. That's one reason why pickles and homemade jams keep decaying no matter how thoroughly sterile they are. Proteins that build larger molecules mostly use energy so they can't function much after cell dies but the ones that break up glucose, fats, proteins and starch create energy in the process so old food keeps softening and losing nutrients with slow partial metabolism going on years after their cells died. On a small side note this relative independence of proteins from living cells means that if someone dies from alcohol or other drug overdose then their body would keep on breaking the drugs up if drug could be degraded by living body. 
Proteins can be deactivated by high enough heat but that denaturation temperature can be hundreds of degrees. Simple and ancient way to deactivate proteins is to use drying as proteins need water to function. Proteins involved in metabolism don't seem to work in liquid cooking oil which also preserve well. Replacing water with cooking oil can give sense that food is humid (cooking oil is one way to make dried burgers feel soft, moist and juicy).