Enhancing the Functional, Antioxidant, and Microbiological Properties of Pearl Millet Flour: A Comprehensive Study on the Effects of Gamma Irradiation Dose

ABSTRACT Aims This study evaluated the impact of gamma irradiation (0–10 kGy) on the physicochemical, functional, antioxidant, microbiological, and structural properties of pearl millet flour, with an emphasis on quality improvement. Methods Pearl millet flour was exposed to 0, 0.5, 1, 2.5, 5, or 10 kGy doses. The physicochemical properties (pH, color, reducing sugars, and peroxide value), functional properties (water and oil absorption and foaming capacity), antioxidant indices (total phenolic content, % DPPH inhibition, and FRAP), and microbiological load were assessed. Results Irradiation decreased the pH from 6.11 (control) to 5.75 (10 kGy) and reduced the lightness ( L *) from 68.3 to 67.8. The reducing sugars increased from 0.41% to 0.47% during storage, and the peroxide values increased from 6.92 to 11.71 meq/kg lipid (petroleum ether extract). The microbial counts decreased sharply: TBC (6.87 log CFU/mL) and TYMC (5.16 log CFU/mL) were reduced > 50% at 5 kGy and nearly eliminated at 10 kGy. The functional properties improved, with the water absorption capacity increasing from 1.31 to 1.72 g/g and the oil absorption capacity increasing from 1.12 to 1.74 g/g, although the foaming capacity decreased. The antioxidant activity increased markedly: the total phenolic content peaked at 206.48 mg GAE/100 g (5 kGy), the % DPPH inhibition doubled (10.85%–21.15%), and the FRAP values rose from 0.23 to 0.87 mmol AAE/100 g. FTIR confirmed irradiation‐induced structural shifts in the hydroxyl, carbonyl, and protein‐associated bands. Conclusions Gamma irradiation significantly ( p < .05) enhanced the functional, antioxidant, and microbiological qualities of pearl millet flour. These improvements highlight irradiation as a promising nonthermal technology to increase flour stability, safety, and usability in cereal‐based food systems.