Ollagen is a biopolymer, the main component of animal connective tissues, and is also the abundant and widely distributed functional protein in mammals, accounting for 25% to 30% of the total protein, and some organisms even up to more than 80% .

Animal tissue derived from livestock and poultry is the main way for people to obtain natural collagen and collagen peptides.

There are many types of collagen, the common types are type Ⅰ, type Ⅱ, type Ⅲ, type Ⅴ and type Ⅺ. Collagen is widely  used in food, medicine, tissue engineering, cosmetics and other fields due to its good biocompatibility, biodegradability  and bioactivity.