Chapter 16 - Extraction, properties, and applications of keratin-based films and blends

Abstract

The development of biobased protein materials for applications in several areas, from food packaging to regenerative medicine, has been explored for their great availability, excellent biocompatibility, and biodegradability. Among the proteins, keratin deserves to be highlighted. Keratin is present in many natural fibers and found in the epithelial cells of vertebrates as the main structural constituent of wool, hair, feathers, thorns, and hooves. Its high cysteine content differentiates it from other proteins, presenting good stability and a three-dimensional structure. Several methods of keratin extraction are found in the literature, resulting in various structure–property relationships. This work brings together the studies carried out in this area, addressing the different sources of keratin, their physicochemical properties, and methods of keratin extraction. We also explore keratin applications, especially focusing on films and blends, bringing a broad vision of keratin applications in medical-pharmaceutical, food, and environmental areas.