Modifying the Structural and Functional Properties of Walnut Glutenin Through Atmospheric Cold Plasma Treatment: Evaluation of Treatment Times Effects

Walnut gluten (WGLU) is a plant-based protein rich in essential amino acids for the human body. Due to its poor water solubility and functional properties, its application in the food industry is limited. For the first time, this study looks into how different durations (0, 30, 60, 90, and 120 s) of atmospheric cold plasma (ACP) treatment affect the structure and functional properties of WGLU. ACP processing destroys the spatial structure of the WGLU and alters its functional properties. The comprehensive performance reached its best after 60 s of ACP treatment, the main manifestations included increased β-sheet content, reduced α-helix content, and unfolding of the tertiary structure, which ultimately improved the stability of emulsification and foam. Meanwhile, the solubility (86.35%), water retention rate (2.15 g/g), oil retention rate (5.31 g/g), emulsification rate (10.59 m²/g), and foaming rate (24.67%) of WGLU reached their maximum values. However, longer treatment times (90 and 120 s) induce WGLU aggregation, followed by decreased functional properties. In summary, the physicochemical and functional properties of WGLU can be significantly enhanced through ACP treatment, enhancing the bioavailability of gluten and providing an effective strategy for its application in food processing.