Changes on Apparent Structure and Protein Conformation of Feather Residue in Degradation

To understand the degrading mechanism of feather, the changes of feather residues on apparent structure and protein conformation in degradation were studied with Scanning Electron Microscope (SEM) and Fourier Transfer Infrared Reflectance (FTIR) techniques. SEM images showed the similarity between feather and feather rod on their protein conformation, although their apparent structures were different. Direct extrusion treatment didn't change the apparent structure of feather but resulted in void structure while treated initially with hydrolysis. The conformations of treated feathers were stable. Alkali degradation and enzymatic degradation could break off the linkage of chemical bonds for feather protein, such as breaking the disulfide bond remarkably into S-O in cysteine sulfonate and cysteic acid, which was indicated by shifting of IR absorption peak at 1075cm-1 towards 1030cm-1 and 1109cm-1. In addition, some salt crystal appeared on the surface of alkali degraded samples.