Chemical and biological characterisation of 3D keratin-fibre chitosan-based films from goose feathers

The rapid increase in the world's population leads to increased consumption of animal products. Its impact on the environment is also an increase in the amount of solid waste such as feathers of poultry after processing. Feathers arise as a by-product of poultry farming, which makes them a sustainable resource in areas where feathers can be used as raw materials. The need for biopolymers alternative to synthetic ones which are not biocompatible and/or environmentally harmful, is increasing in various fields. With more than 90% keratin content, the feathers are a durable reinforcement product. Herein, it is aimed to produce 3D keratin-fibre chitosan-based film obtained from goose feathers for the first time. The method of this research involves Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) to characterise and compare the structure of films. Additionally, thickness and antioxidant activity tests were performed. The result obtained from SEM images showed that feather films (100, 200 and 300 mg 3D keratin-fibre) have the roughest surface compared to the control (only chitosan solution and glycerol). Keratin-fibre blending with chitosan showed structural changes, especially at the -1 absorption bands of 3272-2961 cm as well as the amide I, II and III regions. Moreover, thermal properties of the 3D keratin-fibres were increased by increasing the amount of feathers. The present study suggests a new natural material from goose feathers, e.g., for medical applications and reduces the problem of environmentally sensitive waste disposal of feathers. Thus, biological recycling of feathers will provide benefits to the poultry industry and ecosystem.