Protein Composites from Collagen By-Products for Safe Use in Circular Economy

Sustainable economy means reducing the carbon footprint and minimizing the amount of waste released from productive activities. This paper presents the characterization of composites obtained from by-products of the leather industry based on collagen and keratin extracts. The protein composites have specific properties for the agricultural field and industrial applications in accordance with the current recommendations for a sustainable economy. Chemical-enzymatic hydrolysis of leather and wool by-products was performed for protein extraction. The composites were obtained by addition and crosslinking of collagen and keratin extracts with tannins from vegetable by-products. The characterization of composites was performed based on the results of analytical investigations by physico-chemical methods: volumetry, potentiometry, Texture Analysis, Dynamic Light Scattering, colorimetry, microscopy. It has been found that new collagen and keratin extracts contain small and medium components size, useful for the biostimulation of agricultural crops, but also contain large size components which give adhesive and film-forming properties, useful in industrial applications.