Collagen is a kind of fiber protein which is in the animal's bodies most, and is the main
element of dermis and connective tissues and there is 90% of collagen in the protein which
composes bone. Some collagen, for medical and cosmetics extracted by animal's bones
and skins, is the high molecular protein composed by 3 polypeptides in the spiral structure
that are about each 100,000 molecular weight. And those kind of collagen and gelatins are
dealt with hydrolysis with some enzymes and lower the molecular weight to 3000~20,000
for the good digestion. Then we call them collagen peptides which are used for the food
companies now