Keratinous hydrolysate profiling: comparison of the differences obtained from different extraction methods

The extraction of keratin from chicken feathers is of research interest due to the beneficiation of biomass. This study investigates the impact of the keratin hydrolysate obtained using four different methods. There are two different chemical extraction methods, CH1 and CH2, and two enzymatic hydrolyses, EH1 and EH2. The investigation includes the characterization and analysis using different types of equipment for different applications. The keratin hydrolysates formed were all characterized using FTIR, TGA, SDS PAGE, and CHNS analysis, Bradford assay, and ash content. All the keratin hydrolysate from different methods showed all the amide bonds present in the keratinous structure from the FTIR, while TGA followed the three-phase trend loss of the keratinous structure. Protein concentrations obtained from CH1, CH2, EH1, and EH2 were 1.40, 1.02, 1.08, and 0.45 mg/ml respectively and their protein content was 86.56, 67.63, 78.06, and 90.00%. Their molecular weights were all in different ranges while the ash content for CH1 was 20.7, CH2 was 5.27, and EH1 was 9.19. All the results obtained were compared to the pure keratin azure and EH2 showed high protein content but low protein concentration. CH1 showed the second-highest protein content but with high impurities from the extraction method shown from the ash content.