The effect of electron beam irradiation on the sterilization and physicochemical properties of Codonopsis Radix

ABSTRACT  Background: Codonopsis Radix is a famous“medicine food homology”of the Campanulaceae family. Study: This research examined the efficacy of electron beam irradiation (2–10 kGy) for the decontamination of Codonopsis Radix, with subsequent profiling of its effects on critical quality attributes, namely microbiological limits, physicochemical indices, color characteristics, active ingredients, fingerprint similarity, and antioxidant activity. To investigate the effects of electron beam irradiation on microbial sterilization efficacy and quality of Codonopsis Radix, irradiation doses ranging from 2 to 10 kGy were applied. The study examined the impacts on microbial load, physicochemical properties, color characteristics, active ingredient content, fingerprint similarity, and antioxidant activity of Codonopsis Radix. Results: Electron beam irradiation at absorbed doses of 2–10 kGy significantly reduced the total aerobic bacterial, mold, and yeast counts in Codonopsis Radix, demonstrating effective decontamination. No significant effects of irradiation were observed on the moisture content, alcohol-soluble extract content, or total color difference (ΔE) of the samples. Furthermore, the contents of key bioactive compounds, namely total flavonoids, total saponins, lobetyolin, tangshenoside I, and syringin, remained stable across the applied absorbed dose range.A dose of 2-10 kGy significantly reduces the total aerobic bacterial count, as well as mold and yeast populations in Codonopsis Radix, demonstrating effective sterilization. Irradiation showed no significant effects on the moisture content, alcohol-soluble extract content, or total color difference of the samples. Within the 2–10 kGy dose range, no notable changes were observed in the contents of total flavonoids, total saponins, lobetyolin, tangshenoside I, or syringin Following electron beam irradiation (2–10 kGy), the HPLC fingerprint similarity of all Codonopsis Radix samples exceeded 0.98, demonstrating remarkable stability in their overall chemical profile. Furthermore, the antioxidant activity of the ethanol extracts remained largely unaltered post-irradiation.The similarity of the fingerprint profiles of Codonopsis Radix exceeded 0.98 after irradiation at various doses. Furthermore, the antioxidant activity of the ethanol extract of Codonopsis Radix did not show significant alterations due to irradiation. Conclusion:The application of 6–8 kGy electron beam irradiation effectively inactivates microorganisms while preserving the overall quality of processed Codonopsis Radix , thereby providing critical data and parameters to support the optimization of its storage and processing, as well as to advance the utilization of this technology in traditional Chinese medicine.The results of this study indicate that 6 kGy electron beam irradiation effectively inactivates microorganisms while well preserving the overall quality of Codonopsis Radix. This research provides a theoretical basis and technical reference for optimizing storage and processing techniques of Codonopsis Radix, as well as for the application of electron beam irradiation in traditional Chinese medicine.