Editors: | F. Kongoli, M. Barinova, F. Ahmed, H. Ozgunay, K. Tang, N. Thanh, C. Gaidau, X. GUO. |
Publisher: | Flogen Star OUTREACH |
Publication Year: | 2022 |
Pages: | 156 pages |
ISBN: | 978-1-989820-42-1(CD) |
ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
KEYWORDS: Collagen, Keratin, By-products, Circular Economy Industrial and agricultural by-products represent an important resource of raw materials and added value, whose processing and introduction into the economy, produces a significant reduction of the environmental impact. The leather industry generates a large amount of collagen and keratin by-products, which are generous energy sources for biostimulation and organic fertilization of plants [1], soil enrichment, but are also suitable for industrial applications: biodegradable packaging, adhesives, surfactants, auxiliaries for leather processing [2] etc. The literature information in this field refers to the study of specific properties for individual application. In connection with our new research in valorisation of collagen and keratin from by-products, we have investigated the structural and textural properties of protein composites obtained from leather industry by-products, in order to identify the complementary properties, for directing the same composites obtained with minimum manufacturing costs to several applications. This paper presents results obtained in the analytical investigation of gelatin extracts, collagen and keratin hydrolysates and proteinic composites made on the basis of these extracts. For this purpose, texture analyses were performed by the TEX'AN equipment provided with tools for the analysis of gels and films, structural analyses by FTIR-ATR, particle size distribution by Dynamic Light Scattering. 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. The small peptides usually show better bioactivities than larger peptides [3] and can penetrate plant cell membranes and induce immediate systemic effects on biostimulation and protection. However, collagen and keratin extracts contain large size components, over 1000 nm, in considerable proportions, which provide film-forming properties with controlled biodegradability and thus a delayed release of amino acids, for a gradual nutrition of plants in vegetation. In industrial applications, small and medium-sized compounds are associated with the surfactant properties [4], while large molecular compounds induce the adhesive and film-forming properties [5].
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