Abstract:

Response surface methodology (RSM) was employed to optimize the ultrasonic-assisted extraction of lectin from
soybean protein. A regression model was developed to describe the yield of lectin from soybean protein as a function of 4
independent variables including ultrasonic irradiation time, extraction temperature, extraction time and liquid-to-solid ratio.
The optimum extraction parameters were determined as follows: ultrasonic irradiation time, 38 min; extraction temperature,
32 ℃; extraction time, 5.6 h; and liquid-to-solid ratio, 10:1 (mL/g). Under these conditions, the yield of lectin was 9.82%,
which was in good agreement with the result predicted by the model. The stability test showed that the optimal pH for the
soybean lectin was 7–8. Ca2+ played an important role in the agglutination reaction induced by it. The agglutination activity
of the lectin could be inhibited by D-acetyl glucosamine and D-acetyl galactose amine.

Key words: soybean protein, lectin, ultrasonic, response surface methodology, stability