Effects of gamma and electron-beams irradiations on cytotoxicity and physicochemical characteristics of turmeric powder

This study aimed to compare the effects of electron beams (e-beams) and gamma irradiation on the cytotoxicity, total phenolic content, color values and antioxidant characteristics of turmeric powder and to determine whether these two irradiation technologies produce differential impacts on its safety and quality properties. Turmeric powder was irradiated at 10 kGy using e-beams (10 MeV, TT-200 accelerator) and gamma rays (⁶⁰Co, Gamma Cell 220). Three groups were evaluated: control (non-irradiated), gamma-irradiated, and e-beams irradiated samples. Chemical structure changes of the compound were assessed using Fourier transform infrared spectroscopy (FTIR) and its cytotoxicity was assessed on MCF-7 and L-929 cell lines. Also, the antioxidant activity of treatments was evaluated using the DPPH radical-scavenging assay. Results showed total phenolic content of irradiated and non-irradiated samples had no significant differences (79.182–79.571 mg GAE/gdw; p ≥ 0.05), while antioxidant activity was significantly higher in e-beam-irradiated samples (IC50 = 71.050 μg/mL) than in gamma-irradiated (72.968 μg/mL) or non-irradiated samples (73.334 μg/mL; p < 0.05). FTIR analysis revealed no significant changes in functional groups between the irradiated and non-irradiated samples. Both irradiation types significantly reduced redness ( a* ) relative to the control. Overall color change ( ΔE ) was significantly greater in e-beam- (0.42) than gamma-irradiated (0.60) samples, though all ΔE values remained below the threshold generally considered visually perceptible. Among the treatments, e-beam irradiation showed the lowest IC₅₀ (6.94 μg/mL) in MCF-7 cells, although it did not differ significantly from that of non-irradiated turmeric. In contrast, gamma-ray irradiation resulted in the highest IC₅₀ value (18.46 μg/mL) for MCF-7 cells and the lowest IC₅₀ value (5.41 μg/mL) for L-929 cells. In conclusion, compared with gamma irradiation, e-beams indicated higher antioxidant activity, whereas cytotoxicity did not differ significantly from that of the non-irradiated samples. This study supports that e-beam irradiation is a suitable approach for the processing of turmeric powder and can also increase its usage advantages for food and pharmaceutical applications by enhancing the antioxidant activity.