Abstract:

Mung bean protein was modified by ultrasonic-assisted glycosylation for improved functional properties and
thus wider use. The effects of protein-to-glucose ratio, substrate concentration, pH, reaction temperature, ultrasonication
time and ultrasonic power on degree of grafting (DG) and degree of browning (DB, expressed as absorbance at 420 nm,
A420 nm) were analyzed. A Box-Behnken design combined with response surface analysis was employed to optimize the
reaction conditions. Ultrasonic power, reaction temperature and ultrasonication time had significant effects on DG, while the
effects of protein-to-glucose ratio, substrate concentration and pH were not significant. DB showed an upward trend with
an increase in all these reaction conditions. The optimum reaction conditions were determined as 53 min, 300 W and 80 ℃
for ultrasonication time, ultrasonic power and reaction temperature, respectively. Under these conditions, the theoretical DG
(52.28%) closely agreed with the experimental value (52.06%).

Key words: mung bean protein, glucose, ultrasonic, grafting degree, browning degree