The normal absorption range of amide II position occurs in between 1550 and 1600 cm-1 and is associated with N-H bonding coupled with C-N stretching vibrations Amide III band (1235-1240 cm-) is related to N-H deformation and C-N stretching vibrations.The amide I of collagen from skins of carp at 1650 cm- (Duan et al., 2009) and deep-sea redfish at 1653 cm-1 (Wang et al., 2008) has been reported. The amide I and II peaks showed that PSC had a greater degree of molecular order compared to ASC. It could be suggested that pepsin disrupted a non-helical portion of telopeptide regions, leading to an increase in the molecular order of collagen structure (Matmaroh et al., 2011). Absorption peaks around 1446.9–1454.4 cm-1 were also found in PSC and ASC. These absorption peaks extensively corresponded to pyrrolidine ring vibration of proline and hydroxyproline. An absorbance ratio about one between amide III band and the 1450 cm- band indicates that the triple helical structure of collagen is intact (Liu et al., 2012; Matmaroh et al., 2011).