Complexes based on collagen and keratin for applications in agriculture

In the circular economy context, the use of proteins from collagen and keratin by-products of leather industry to obtain products for agriculture serves to reduce the carbon footprint generated from industry by reducing the amount of chemical synthesis products administered in agricultural technologies. This paper presents complexes based on collagen and keratin extracts obtained from by-products of the leather industry and their characterization. Thermal and chemical-enzymatic hydrolysis of semi-processed leather and degreased wool by-products was performed for protein extraction. Complexes were obtained by addition and crosslinking with active principles and vegetable tannins to collagen and keratin extracts. The characterization of complexes was performed based on the results of analytical investigations by physico-chemical methods: volumetry, potentiometry, IR spectroscopy, Dynamic Light Scattering and Texture Analysis. It has been found that collagen and keratin extracts contain sufficient proportions of small and medium size components size, of the order of 1-100 nm and of 100-1000 nm, specific for free amino acids and small oligopeptides with a role in bio stimulating seed germination, but also contain large size components, over 1000 nm, in considerable proportions, which provide the adhesive and film-forming properties, with a role in foliar application and retarded release of amino acids.