Non-thermal atmospheric cold plasma treatment inhibits lipid oxidation and improves quality attributes of common buckwheat (Fagopyrum esculentum Moench) flour

Common buckwheat is susceptible to lipid oxidation from its high content of unsaturated fatty acids, causing quality deterioration during storage and processing. This study investigated the effects of atmospheric cold plasma (ACP) as an emerging non-thermal processing technology to inhibit lipid oxidation and maintain the functional and sensory qualities of common buckwheat flour. Optimisation via response surface methodology yielded conditions of 36 kV, 41 min and 12.3 cm electrode plate spacing. Validation assays at the optimised parameters revealed that ACP treatment significantly suppressed lipase, lipoxygenase, and peroxidase activities, with residual levels of 46.45%, 37.96%, and 39.85%, respectively. Moreover, ACP treatment improved the functional quality of flour, as evidenced by increased total polyphenol content (2.38 mg GAE/g), elevated levels of phenolic monomers, and enhanced antioxidant capacity (ABTS IC₅₀ = 150.38 μg/mL; DPPH IC₅₀ = 131.13 μg/mL). Notably, the treatment preserved flour color, with a minimal color difference (ΔE = 0.5) between control and ACP-treated samples. Furthermore, ACP treatment significantly increased levels of ketones, terpenoids, and esters while decreasing alcohols, reflecting a favourable alteration of the volatile composition. Collectively, these findings demonstrate that ACP is a promising non-thermal technology for inhibiting lipid oxidation-related enzymatic activities while improving the functional and sensory quality of common buckwheat flour.