Mucin

It is a type of glycoprotein that is included in the slimy of NAMEKO.
It is a viscous substance consisting of a complex of proteins and sugars, such as gastric juice, saliva and white egg.
This Mucin for canned products may react with tin plate, the inner surface of the can might change to black with the passage of time after production.
Also, if canned products are caused by black discoloration, tin and iron will elute in a can, but do not have a significant impact on the human body.