Recovery of keratin from feather meal: a new route to valorize an agro-industrial co-product

The valorization of agro-industrial by-products/co-products represents a sustainable pathway to produce high-value biomaterials. Feather meal is an agro-industrial co-product derived from clean and undecomposed poultry feathers processed under high heat and pressure that offers an economically viable and scalable alternative for keratin extraction compared to native feathers. This study explores the recovery of keratin from feather meal through an optimized alkaline hydrolysis process, achieving a yield of 20 wt.% at 15°C and 90 min of extraction by using 2 mol L^-1 sodium hydroxide solution. A negative temperature dependence was observed in keratin extraction yield, suggesting the occurrence of thermal degradation at elevated temperatures. Protein analyses by different techniques confirmed the characteristic diffraction peaks, functional groups, and elemental composition (carbon, nitrogen, oxygen, and sulphur) of feather keratin. The extracted keratin presented a low molar mass of 9 kg mol^-1. Considering the circular economy principles, this work proposes a novel valorization route for feather meal and highlights its potential in creating value-added materials for several applications in medicine, pharmaceuticals, and engineering areas.