Cold Plasma Effects on Changes in Physical, Nutritional, Hydration, and Pasting Properties of Pearl Millet (Pennisetum Glaucum)

Abstract

Atmospheric pressure cold plasma treatment on pearl millet (Pennisetum glaucum) with air as feed gas at an input voltage of 40 and 45 kV for 5, 10, and 15-min exposure time was studied. The influence of cold plasma on the physical, nutritional, hydration, and pasting properties of pearl millet was assessed. There was no significant difference in loose and tapped bulk density, whereas the color intensity (ΔE) and the delta chroma (ΔC) have significantly differed with the treatment. The nutritional properties, such as crude fat (3.46% ± 0.25%-4.71% ± 0.07%) were increased, whereas crude fiber (2.21% ± 0.02%-1.32% ± 0.02%), protein (10.064% ± 0.43%-8.89% ± 0.50%), and moisture (11.92% ± 0.10%-10.25% ± 0.03%) had significantly diminished. The results of hydration properties, such as swelling capacity (0.213 ± 0.003-0.320 ± 0.008 g/g), solubility (183% ± 1.00%-212% ± 2.00%), and water absorption (1.11 ± 0.02-1.51 ± 0.01 g/mL) have shown significant increment with treatment time and voltage. Besides, the pasting properties of the treated millet were significantly improved. The infrared thermal imaging was used and observed a maximum of 7 °C rise in the plasma treatment zone's temperature throughout the treatment time. It can be concluded that the plasma treatment ameliorates hydration and pasting properties of pearl millet, paving the path for their usage in a wide range of convenient foods.