Phytochemical profiling of sorghum grains (Sorghum bicolor) irradiated with gamma rays, low energy electron beam (LEEB) and high energy electron beam (HEEB).

The study evaluated the profile of some phytochemicals in sorghum grains decontaminated using gamma rays, low and high energy electron beams. Samples were purchased from a major sorghum outlet and were packaged appropriately. The packaged grains were exposed to target irradiation doses of 2, 4, 6, 8 and 10 kGy, and the un-irradiated sorghum grains served as a control. The ILU-6 accelerator (250 keV), ELEKTRONIKA 10-10 accelerator (9 MeV) and Gamma Chamber 5000 Co-60 source were used for low electron beam, high electron beam and gamma irradiation, respectively. Reverse-phase high-performance liquid chromatography was used to identify and quantify the flavonoids and phenolic acids in the samples. Antioxidant activity was determined using hydrogen peroxide (H2O2) scavenging assay and DPPH (1,1-diphenyl-2-picrylhydrazyl). Results showed that irradiation source and dose generally significantly (p < 0.05) affected all the phytochemical compositions of sorghum grains studied in a non-dose dependent manner either by increasing or decreasing the levels. Gamma irradiation had the highest effects on the antioxidant activity of the sorghum grains as compared to the high and low energy electron beams.