Assessment of Dose-Dependent Effect of Linear Accelerator Electron-Beam Irradiation on Bacterial Load of Selected Animal Hides and Skins: Implications for Preservation

Abstract

The preservation of freshly flayed animal hides and skins is necessary to prevent microbial deterioration and maintain their suitability for subsequent leather processing. This study assessed the effect of electron-beam irradiation generated by a medical linear accelerator on the bacterial load of selected animal skins. Goat, cow and sheep skins were exposed to absorbed doses of 5, 10, 20, 30 and 50 Gy, while untreated samples served as controls. Bacterial load was determined using a viable plate-count method, with 30–300 CFU/mL considered the acceptable counting range. The untreated goat and cow samples were recorded as too numerous to count (TNC), whereas untreated sheep skin had a bacterial load of 112 CFU/mL. Irradiation produced a progressive reduction in bacterial load. Goat skin decreased from 159 CFU/mL at 10 Gy to 87 CFU/mL at 50 Gy, while cow skin decreased from 258 CFU/mL at 30 Gy to 104 CFU/mL at 50 Gy. Sheep skin demonstrated the clearest measurable response, decreasing from 112 CFU/mL in the untreated sample to 31 CFU/mL at 50 Gy, representing a 72.3% reduction. The findings indicate that electron-beam irradiation can reduce bacterial contamination of animal skins at Gy-range absorbed doses, although the response varies among animal species. Further evaluation of physico-mechanical, thermal, chemical and structural properties is required before an optimum preservation dose can be established.