Characterization and analysis of keratinous material from waste chicken feathers as protein ingredient for animal feed.

Abstract

Keratin is one of the most abundant proteins, which is derived from wool, feathers, nails, hair, and other sources. Chicken feathers are a well-known keratin waste by-product, produced in large quantities by poultry slaughterhouses. Their disposal is expensive, and includes incineration of the waste thus contributing to greenhouse gases; or disposal in landfills, also leading to environmental pollution or they can be recycled into low-quality feeds for animals. Research is done worldwide for the beneficiation of waste chicken feathers into commercial products; these include cosmetics, pharmaceutical products, and biomedical products, and it is also useful in the production of animal feed. The focus of this research was to characterize and analyze keratinous hydrolysates formed from waste chicken feathers using enzymatic and chemical hydrolysis for their suitable applications in different industries. The novelty of this project is based on looking at analytical techniques of the keratinous hydrolysate produced from newly formed keratinolytic microorganisms and newly optimized chemical methods from the waste chicken feathers. Different fungal and bacterial strains were tested for the degradation of waste chicken feathers. The quality and quantity of the hydrolysate formed were determined by using a combination of analytical techniques, where the characterization is done via proximate and ultimate analysis. We used Fourier Transform Infrared Spectroscopy (FTIR), which showed the presence of the keratinous structure, which is known to have high protein content. Thermogravimetric Analysis (TGA), showed that a thermally stable hydrolysates were obtained, which is known to be formed by the hydrophobic hydrolysate, which is best for animal feed. CHNS analysis showed evidence that we have high protein content in the hydrolysate. Bradford assay revealed different quantities of the hydrolysate while Sodium Dodecyl Sulphate–Poly-Acrylamide Gel Electrophoresis (SDS-PAGE), showed mostly medium to low molecular weight, due to the presence of amino acids and small peptide chain. A low Ash Content was obtained which means a cleaner fraction of keratin. The hydrolysate formed from the enzymatic hydrolysis contains a mixture of amino acids and peptides. These peptides and essential amino acids formed are known to play a special role in various biological activities. The hydrolysates formed from different degradation methods were also compared, focusing on the qualities and quantities formed from enzymatic and chemical hydrolysis. While looking at all the characterization techniques, enzymatic was the best and suitable for animal feed due to the obtained keratin structure, which is more soluble, contains high protein content, has low molecular weights, and has a cleaner fraction of keratin. Future work will be based on obtaining a peptide chain using Liquid Chromatography with tandem Mass Spectrometry (LC-MS/MS), then testing the hydrolysates for bioactivities.