Biochemical properties of acid-soluble collagens extracted from the skins of underutilised fishes

摘要

Acid-soluble collagens (ASCs) were extracted from the skins of several underutilised fishes, namely dusky spinefoot (Siganus fusces-cens), sea chub (Kyphosus bigibbus), eagle ray (Myliobatis tobijei), red stingray {Dasyatis akajei) and yantai stingray (Dasyatis laevigata). The yields of the ASCs from skins of dusky spinefoot and sea chub were about 3.4-3.9%, and from ray species were about 5.3-5.7%, on a dry weight basis. According to the electrophoretic pattern, ASCs consisted of two different α-chains (α1 and α2) and were classified as type I collagen. However, the molecular weights of α2-chain for ray species were lower than those of bony fishes. ASC from ray species contained a higher content of imino acids than those from dusky spinefoot and sea chub. The denaturation temperatures (T_d) of ray species were about 33℃, which was about 5℃ higher than those of dusky spinefoot and sea chub. The high T_d of ray species suggested the possibility of its utilisation as a substitute for mammalian collagen.