To investigate the effects of different treatment methods on soybean protein amyloid fibrils (SPAF), this study examined the effects of ultrasonication, cold plasma, heat, and NaCl treatment on the formation, structure, and functional properties of SPAF. SPAF structural analyses indicated that all treatments promoted SPAF assembly, with the order of effectiveness being: heat treatment > ultrasonication > cold plasma treatment > NaCl treatment. Regarding functional properties, the heat treatment group also demonstrated superior overall performance, including the highest solubility (88.15%), optimal emulsifying activity (79.63 m²/g) and foaming capacity (169.44%), and the highest thermal denaturation temperature (107.49 °C). Conversely, ultrasonication and cold plasma treatments, which generated shorter fibrils, offered moderate functional improvements. In contrast, NaCl treatment provided limited functional enhancement due to the formation of coarse aggregates. Consequently, heat treatment was identified as the most effective approach to promote SPAF formation and enhance functional properties. These findings provide a theoretical basis for the process optimization of SPAF in the food industry.

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.

To evaluate the potential of defatted and dephenolized walnut meal as a modified functional food ingredient, this study examined how ball milling and processing time affect its structural, physicochemical, and functional properties. Walnut meal was ball-milled for 5, 10, 15, and 20 h. Ball milling increased the lightness and whiteness, reduced particle size, and broadened the particle size distribution into a characteristic three-peak pattern. Scanning electron microscopy revealed the progressive formation of flake-like surface structures. With increasing milling duration, free sulfhydryl groups, surface hydrophobicity, and solubility were increased, while dynamic surface tension decreased, leading to improved foaming capacity and foaming stability. SDS-PAGE confirmed that the primary structure remained unchanged, while Fourier transform infrared spectroscopy indicated a decrease in α-helix and β-sheet contents and an increase in random coil structures. X-ray diffraction revealed a reduction in the diffraction peak at 2θ = 8.963°, and differential scanning calorimetry showed irregular changes in the thermal stability with ball milling time. Overall, increasing ball milling time is beneficial for improving the functional properties of walnut meal, providing a preliminary theoretical reference for the potential application of walnut powder in foods with specific functional properties, such as aerated foods.