Characteristics of Collagen from Nile Tilapia (Oreochromis niloticus) Skin Isolated by Two Different Methods

Abstract

Acid-solubilized collagen (ASC) and pepsin-solubilized collagen (PSC) isolated from Nile tilapia skin using two different methods were compared for biochemical properties and thermal stability. Method 1 (the Noitup method) was performed at 4-6°C for the whole process with a centrifuge speed of 30,000 g, while Method 2 (the Ogawa method) was performed at a higher temperature of 22-23°C, with a centrifuge speed of 10,000 g. The dry weight yields of ASC from Methods 1 and 2 were 38.84 and 20.70%, while the dry weight yields of PSC were 48.21 and 38.27%, respectively. The denaturation temperatures of ASC from Methods 1 and 2 were 34.29 and 34.43°C, while those of PSC were 34.32 and 34.61°C, respectively. From these amino acid and molecular weight profiles and SDS-PAGE results, ASC and PSC obtained by both methods were characterized as type I collagen with no disulfide bond, which were composed of α-1 (2 chains) α-2 (1 chain), β, and γ subunits. Amino acid profiles of ASC and PSC obtained from both methods were similar. Except for the lower yield obtained from Method 2, there were no differences in the molecular weight, amino acid composition and denaturation temperature between ASC and PSC obtained from both methods.