Evaluating the Efficacy of Lemongrass Oil in Treating Fungal Deterioration on Historical Leather: A Case Study on Leather Binding from the Ottoman Era (Volume 4 of the Ruh al-Bayan Manuscript)

This study evaluates the antifungal potential of lemongrass essential oil against three fungal strains isolated from an Ottoman-era leather book-binding. In addition, it investigates the influence of this treatment on the chemical, physical, and mechanical characteristics of the treated leather samples. Several analytical techniques were applied, including Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), tensile strength testing, and elongation measurements, to assess chemical alterations, surface morphological changes, and mechanical behaviour after treatment. The results demonstrated a pronounced antifungal effect of lemongrass oil, with the 5% concentration exhibiting the strongest inhibitory activity against the identified fungal species.The choice of the 5% concentration was justified by its superior antifungal performance and its classification as a moderate concentration among the tested formulations, thereby reducing the likelihood of adverse effects on the leather structure. Moreover, the treated samples showed noticeable improvements in mechanical behaviour and surface condition. Overall, the findings support the use of lemongrass oil as an efficient, eco-friendly, and safe biocidal agent for the conservation of historical leather artefacts—particularly bookbinding—offering both protective and reinforcing benefits that contribute to their long-term preservation.