Enzymatic and Protein-Based Treatments for Surface Activation and Property Modification of Vegetal Leathers

The fashion and textile industry is increasingly challenged by the environmental impact of conventional animal leather and of petroleum-based synthetic alternatives, which show limited biodegradability [1]. These concerns have driven growing interest in leather-like materials obtained from agricultural and food-processing waste, such as orange peel, which has shown promising mechanical properties for vegan leather applications [2]. However, such waste-derived composites remain insufficiently characterized from a biochemical standpoint. Enzymatic treatments have recently been proposed as effective biotechnological tools to valorize vegetal waste and tune the structural and functional properties of leather-like materials [3], providing the scientific basis for the experimental work presented in this thesis. This study focuses on two plant-waste-based leather materials produced by Ohoskin®, with the aim of evaluating whether enzymatic and protein-based biotechnological approaches can enhance their performance. Both materials were first subjected to baseline characterization, including surface water and oil interaction and flexibility. Mild enzymatic surface treatments, using cellulase, pectinase and xylanase, were then applied to selectively activate and functionalize the material surface while preserving the bulk structure, thereby increasing surface reactivity through an environmentally sustainable biotechnological route. Building on this surface activation, a treatment with proteins extracted from Okara, soybean byproduct, was applied to investigate potential surface properties modification. Results show that enzymatic activation modifies leather surface properties and protein-based functionalization was successfully obtained. Data show that biotechnological tools used can be applied to modify the overall quality and performance of these bio-based leather alternatives. References: [1] Muthu, S. S. (Ed.). (2020). Leather and footwear sustainability: Manufacturing, supply chain, and product level issues. Springer Nature Singapore. [2] Rimantho, D., Chaerani, L., & Sundari, A. S. (2024). Initial mechanical properties of orange peel waste as raw material for vegan leather production. Case Studies in Chemical and Environmental Engineering, 10, Article 100786. [3] Mecca, S., Digiovanni, S., Milanesi, R., et al. (2025). Development of leather-like materials from enzymatically treated green kiwi peel and valorization of by-products for microbial bioprocesses. ACS Sustainable Chemistry & Engineering, 13(38), 15924–15934.