Extraction and characterization of type 1 collagen from the skin and scales of Heterotis niloticus and Lates niloticus

The study is aimed to extract and characterize collagens from the skin and scale of two selected Nigerian freshwater fish species (Heterotis niloticus and Lates niloticus) using either pepsin (PSC) or acid-soluble (ASC) extraction. The collagen was extracted using 0.5M acetic acid and pepsin. The collagen yield was determined and characterized by SDS PAGE, and FTIR. Collagen extraction yields varied with the extraction process; the yield was significantly higher in the skin (5.08±0.34–33.97±1.78 %) than in the scale (1.76–8.05 %). The absorption peaks of the extracted collagen using acetic acid and pepsin show that only ASC of skin (3344.27 cm-1) and scale (3495.85 cm-1) of H. niloticus shows the peaks characteristic of Amide A, while Amide B peaks of collagen extracted from the skin and scale of H. niloticus and L. niloticus were found at 2974.46 cm-1 and 2925.7 cm-1, representing an asymmetrical stretch of CH2. Similarly, ASC on the skin (1558.36 cm-1) and scale (1576.46 cm-1) of H. niloticus shows the absorption peak characteristics of amide II. ASC on the skin of H. niloticus (1671.05 cm-1), PSC on scale of H. niloticus (1658.55 cm-1), and on scale of H. niloticus (1678.65 cm-1) shows absorption peaks in range characteristic of amide 1. There were no differences in the skin and scale collagen profiles among the two fish species when characterized by SDS-PAGE. Our data revealed that the skin and scale of Lates niloticus and Heterotis niloticus could be a good alternative source of high-quality collagen for industries.