Abstract: Mung beans are rich in protein as well as a variety of amino acids, and are an excellent protein source with good processing suitability. In this experiment, mung beans were steamed or boiled in distilled water before being used for the preparation of mung bean protein by alkali extraction and acid precipitation. The structure and functional properties of mung bean protein were determined. Experimental results showed that the large subunits of steamed or boiled mung bean protein became lighter in color with the extension of heat treatment time evidencing reduced content of large proteins. The 57.5 kDa 8S globulin subunit band gradually disappeared, and a 35.4 kDa band was found in the boiled mung bean protein but not in the steam one. Either cooking treatment time-dependently improved the water-holding capacity, oil-holding capacity, and emulsifying capacity and emulsion stability of mung bean proteins, and steaming was better than boiling. The foaming capacity, foam stability and solubility increased first and then decreased with treatment time, reaching the maximum values of 25.6%, 77.1%, and 13.6% at 20–25 min, respectively. This study provides a theoretical basis for the modification of mung bean protein and is of guiding significance for improving the application of mung bean protein in the food industry and the intensive processing of mung bean products.

Key words: mung bean protein, subunit, functional properties, processing methods