Abstract: Maillard reaction products of sodium caseinate with glucose, lactose, galactooligosaccharides and polydextrose were prepared by a small UHT device. The development of Maillard reaction and the emulsifying properties of Maillard reaction products during different heat treatment time were compared and analyzed. The results show that a slower reaction rate among high molecular weight saccharides and protein as compared to lower molecular weight saccharides. With the reaction of Maillard reaction, the browning index of each system increased, the emulsifying activity and degree of graft both increased at first and then decreased, but there is no linear relationship between them, the maximum value of each emulsifying activity was 0.624, 0.506, 0.5486 and 0.4764 respectively. The sodium caseinate-glucose solution has the highest emulsifying activity at 130℃ heat treatment 15s, significantly higher than other groups (p<0.05), that is equivalent to the water bath at 90 ℃ heat treatment 90min, and the emulsion stability also showed a higher level of 123.88 min. Used it as emulsifier to prepare DHA algae oil emulsion, the dynamic instability index is 1.5, were significantly less than the other groups （P<0.05）.Moreover,this method is continuous,it greatly shortens the reaction time, improves the production efficiency and has significant guidance for industrialized production.

Key words: Maillard reaction, sodium caseinate, emulsifying activity, emulsifying stability, DHA algae oil emulsion