Impacts of e-beam irradiation on microbial contamination and quality of Chinese medical formulas QingXuan Tablets

Applying electron beam irradiation (EBI) technology to remove microbial contamination is a potential way to improve the efficiency of Chinese medical formula preservation. In this study, Qingxuan tablets (QXT) were irradiated at doses of 3, 5, 9, and 13 kGy of the electron beam, to investigate the impacts of EBI on the microbial load, physical properties, color, bioactive content, antioxidant activity, chromatograms, and spectral similarity of QXT. The results showed that EBI treatment at 13 kGy reduced the population of the total aerobic bacteria and the total molds and yeast of QXT to < 200 CFU/g. Irradiation had no significant (P > 0.05) effect on the physical properties and color of QXT. However, the bioactive content of QXT was significantly lower at a dose of 13 kGy compared to unirradiated samples. The free radical scavenging capacity of QXT remained preserved after irradiation. High-performance liquid chromatography (HPLC), Fourier transforms infrared spectroscopy (FTIR), and ultraviolet-visible spectroscopy (UV-Vis) analyses showed that the difference in the chemical content between irradiated QXT and unirradiated samples gradually increased as the dose was increased from 0 kGy to 13 kGy. These results suggest that EBI can be used to sterilize and preserve Chinese medical formulas, but the irradiation dose should be controlled to prevent changes in quality.