Comparison of characteristics and fibril-forming ability of skin collagen from barramundi (Lates calcarifer) and tilapia (Oreochromis niloticus).

The present study isolated and characterized the barramundi (Lates calcarifer) skin collagen (BC) and tilapia (Oreochromis niloticus) skin collagen (TC). The yields of BC and TC by enzymatic extraction were 47.3±3.7% and 52.6±6.1% respectively, dry weight. The SDS-PAGE profile indicated both collagens were mainly type I with two different α chains. FTIR spectra and X-ray diffraction confirmed that the triple helical structure of both collagens was not affected by pepsin digestion. The denaturation (Td ) and melting temperature (Tm ) were 36.8 and 109.6°C for BC, 37.6 and 113.7°C for TC, measured by rheometer and DSC. This high thermal stability could be attributed to the high imino acid content (205.9 and 210.9 residues/1000 residues) of BC and TC. Fibril-forming studies indicated BC exhibited higher ability than (p<0.05) that of TC, especially under the effect of NaCl. One major characteristic of this result showed that NaCl had the markedly effects of promoting collagen forming fibrils, and electron microscopic observation corroborated this phenomenon. In general, barramundi and tilapia skin collagen with high thermal stability and good fibril-forming ability may be suitable for use as an alternative to mammalian-derived collagen in biomaterials, pharmaceuticals and cosmetics.