Evaluation and utilization of lemongrass oil nanoemulsion for disinfection of documentary heritage based on parchment

This study aimed to evaluate for the first time the antimicrobial activity of lemongrass oil in its normal (Lg-EO) and nanoform (Lg-NE) against four microbial strains previously isolated from a historical parchment manuscript dated back to the third century AH (9th century AD). In addition, examine their impact on the aesthetic, physical, and chemical characteristics of the disinfected parchment before and after artificial aging. The nanoemulsion of the oil was prepared using the low energy emulsification technique. The antimicrobial activity of Lg-EO and Lg-NE was assessed qualitatively and quantitatively. Fourier transform infrared, scanning electron microscopy (SEM), tensile strength and elongation, and color change investigations were conducted to monitor any chemical, morphological, mechanical, or physical variations of treated parchment samples before and after artificial aging. The obtained results declared that preparing essential oils in the form of nanoemulsions improves their antimicrobial performance that facilitates achieving biocidal activity in lower concentrations without adversely affecting any of the examined characteristics of the disinfected parchment. On the other hand, using the oil in its normal state affected the optical properties of treated samples before and after aging. Additionally, while improving the mechanical properties of the disinfected parchment, the accelerated aging of the treated samples had brought about an obvious decrease in those properties. Thus, essential oils nanoemulsions which are considered an ecofriendly system can be used effectively in the disinfection of historical parchment manuscripts without any adverse effect on their distinctive characteristics.