Atmospheric-pressure cold plasma-assisted enzymatic extraction of high-temperature soybean meal proteins and effects on protein structural and functional properties

To increase the extraction rate of high-temperature soybean meal proteins and improve their functional properties, we used atmospheric-pressure cold plasma (ACP)-assisted enzymatic method to extract proteins from high-temperature soybean meal, and studied the effects of different ACP conditions on the structural and functional properties of the proteins. At the power of 300 w, time of 45 s, and air inlet volume of 120 mL/min, the extraction rate maximized to 83.26 ± 0.89%, which was about 1.2 times that of enzymatic hydrolysis alone (70.03%). After ACP treatment, the proteins' solubility, emulsifying activity and stability, foaming capacity and stability, hydrophobicity, and oil holding capacity were all improved. Fourier transform infrared spectroscopy, fluorescence spectroscopy, and scanning electron microscopy showed ACP changed the proteins' secondary, tertiary and microscopic structures. Thus, the ACP-assisted enzymatic method can improve the extraction rate of high-temperature soybean meal proteins, change the structures, and improve the functional properties of the proteins. This is a very potential method for the extraction of high-temperature soybean meal proteins.