Characterization and film-forming properties of acid soluble collagens from different by-products of loach (Misgurnus anguillicaudatus)
Peng-peng Sun, Yuanyuan Ren, Si-yao Wang, Hong Zhu, Jue-jun Zhou
Abstract
In this study, acid soluble collagens (ASCs) from different by-products of loach including skin, head, fins and bone were isolated, characterized and compared. As a result, the highest yield (on wet weight basis) was obtained for ASC from skin (ASC-S, 9.73%) compared with those from fins (ASC-F, 2.01%), head (ASC-H, 1.12%) and bone (ASC-B, 0.84%). By SDS-PAGE, these collagens were classified as type I collagens with slight difference of molecular weight . Glycine was the major amino acid in all ASCs with relatively high contents of alanine , hydroxyproline and proline . Fourier transform infrared spectroscopy indicated that triple helical structures of all ASCs were well preserved and scanning electron microscope exhibited fibrillary structure of ASC-B while sheet structure in others. Thermal stability of ASCs was determined by differential scanning calorimetry , rheometer and thermogravimetric (TG), respectively. It was concluded that all ASCs had different maximum transition (T max ), denaturation (T d ) and onset decomposition (T o ) temperatures. Besides, film-forming properties of ASCs from loach were also evaluated with ASC-F film showing strong tensile strength , best extensibility and barrier property compared with others, which suggested that ASCs from different by-products of loach had tremendous potential for applications in food packaging and coating in future.