Influence of atmospheric pin-to-plate cold plasma on surface properties and cooking behavior of split red lentils (Lens culinaris): A mechanistic approach.

The current study investigated the effects of atmospheric cold plasma (ACP) on modifications in split red lentils at different voltages (170-230 V) and treatment times (5-15 min). Among the parameters studied were the physicochemical properties like moisture content, water activity and color profile, hydration kinetics, surface hydrophilicity, cooking quality, total phenolic content (TPC), antioxidant capacity (AOC), and phytic acid content (PAC). Mechanistic investigations were conducted through scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC). ACP treatment reduced the cooking time by 31.22% without significantly affecting the physicochemical characteristics of the lentils. Rate constants for hydration from Peleg's equation fitting revealed enhanced water-uptake rate and greater hydration extent in the treated lentil kernels. Although the ACP treatment negatively affected the TPC and AOC, which dropped by up to 12.47% and 4.89%, respectively, the maximum PAC reduction obtained was 57.21%. Further insights from electron microscopy and infrared spectroscopy revealed structural changes not only at the surface level but also at the molecular level, leading to stretching of FT-IR bands. X-ray diffractograms further revealed a decrease in the crystallinity of the ACP-treated samples, while the differential scanning calorimetry data showed a significant decrease in the peak temperature and enthalpy, providing mechanistic support to the improved cooking quality.