Every bite of food we eat to satisfy our appetite and physiological needs, including Flammulina velutipes, is chewed with our teeth and tongue and mixed with saliva. First, the starch inside begins to decompose, and then it will be pushed into the stomach if swallowed. Protein in most foods can be preliminarily digested due to the weak acidity of gastric juice and the existence of enzymes, so that the protein in food is unscrewed, the polypeptide chain is cut into pieces, and the food in the stomach becomes chyme for subsequent entry into the small intestine. The undigested part naturally reaches the large intestine and is naturally excreted after a certain period of time.
Flammulina velutipes contains chitin, which is not easily digested by gastric acid. This substance is only soluble in strong acids, such as concentrated hydrochloric acid, phosphoric acid, sulfuric acid and acetic acid, but it is very stable in weak acid, water and alkali environment. Pharmaceutical and food industries also make use of this tough property of chitin, and refined and synthesized chitin products are used for surgical sutures, thickeners, adhesives and so on.
If Flammulina velutipes is eaten by us, gastric acid can digest a part of Flammulina velutipes to a certain extent, but because its strength is relatively small and Flammulina velutipes stays in our stomach for a short time, it is said that Flammulina velutipes cannot be digested without gastric acid after entering the intestine, and it will eventually be excreted with feces, so it seems that not all of us can absorb it.