Have you ever wondered what happens to the burgers and pizzas after you eat them? Or what happens to all the processed food after it goes into your stomach?An experimenter has uploaded a video online explaining the biological process of digesting processed foods. The setup of this experiment is pretty simple: Take one cheeseburger from a fast-food restaurant and stick it in hydrochloric acid in the lab for three and a half hours to see what happens.But Why Hydrochloric Acid?The stomach is composed of gastric acid, which is primarily made up of hydrochloric acid (HCl). This acid kickstarts the digestive process and helps break food down into usable components that provide energy and nutrients. In the video, it is clearly seen that after getting immersed in the HCL, the burger turns into a black-coloured sludge. ]]> However, while it's easy to assume that the resulting black sludge is caused by harmful ingredients and preservatives used in fast foods, that is not necessarily the case. The fats in the burgers haven't dissolved very well simply because they’re soaking in nothing but concentrated HCl. Meanwhile, bile, which plays a crucial role in fats and fatty acids, is missing from the experiment.Related ExperimentsLast year, another video went viral after it showed a range of fast food burgers 30 days after purchasing. While some of them were covered in mould, others from fast food giants like McDonald's hadn't changed at all. A person later conducted the same experiment with his homemade burgers. He discovered that even they did not rot after 25 days. His burgers were homemade with no preservatives and varying amounts of salt. He concluded that it is because of factors like large surface area, that burgers do not get infected with moulds.ALSO READ: Your Protein Powder May Be Toxic! A New Study Reveals High Levels Of Lead And CadmiumHow Does Digestive System Function?The digestive system is made up of the gastrointestinal (GI) tract—also called the digestive tract—and the liver, pancreas, and gallbladder. The GI tract is a series of hollow organs joined in a long, twisting tube from the mouth to the anus. The hollow organs that make up the GI tract are the mouth, oesophagus, stomach, small intestine, large intestine—which includes the rectum—and anus. The digestion process begins as food enters the mouth and passes to the anus through the hollow organs of the GI tract. The liver, pancreas, and gallbladder are the solid organs of the digestive system. The digestive system helps the body digest food. How Is Digestive Process Important To Health? Digestion is important for breaking down food into nutrients, which the body uses for energy, growth, and cell repair. Food and drink must be changed into smaller molecules of nutrients before the blood absorbs them and carries them to cells throughout the body. The body breaks down nutrients from food and drink into carbohydrates, protein, fats, and vitamins.ALSO READ: Foods That Might Contain Insects: The List Will Left You Surprised