Isolation and characterization of acid soluble collagen (ASC) and pepsin soluble collagen (PSC) extracted from silver catfish (Pangasius sp.) skin

The aims of this study are to isolate and characterize acid soluble collagen (ASC) and pepsin soluble collagen (PSC) extracted from silver catfish (Pangasius sp.) skin. Isolated ASC and PSC collagen were characterized in terms of chemical composition (moisture, protein, fat and ash content), protein concentration, functional group, solubility, and morphological properties as compared to commercial collagen. Yields of ASC and PSC were 4.27% and 2.27%, respectively. The chemical compositions of raw skin were 34.64%, 2.81%, 3.68%, and 0.31%, while the chemical compositions of ASC and PSC were 94.21%, 3.48%, 0.81%, 59.15%, and 88.25%, 3.46%, 0.92%, and 29.24%, for moisture, protein, fat, and ash, respectively. ASC and PSC had protein concentrations of 2.27 mg/mL and 2.70 mg/mL, respectively. Functional group analysis revealed that both isolated collagens exhibited Amide A, II and III as a fingerprint for collagen structure. The highest solubility was found at pH 4 for ASC, pH 1 for PSC, and pH 5 for commercial collagen. The morphology of the isolated collagens was porous and they contained fibril. In conclusion, the characteristics of the isolated ASC and PSC from silver catfish (Pangasius sp.) skin indicate that value-added collagen can be produced from the alternative source of freshwater fish