Objective  Study the effects of coordinated control of rehydration parameters and oxygen-isolating refining on lipoxygenase activity and soybean milk flavor, and provide theoretical and technical support for the development of high-quality soybean drinks.

  Method  The inhibition effects of factors such as rehydration conditions, refining temperature and oxygen-isolating refining on soybean milk lipoxygenase activity were compared, and the better process parameters were obtained. Based on the process parameters, the effect of coordinated control of oxygen-isolating refining on the removal of beany flavor and the color and flavor of soy milk was studied.

  Result  (1) Rehydration temperature is the main factor affecting the activity of lipoxygenase in soybean, the hot alkali (80 ℃, pH 9) rehydration and oxygen-isolating refining treatment process has the best effect on the inhibition of lipoxygenase activity. The activity of lipoxygenase is only 100±2.5 U·mL⁻¹; (2) Under the optimal rehydration conditions obtained in (1), the effect of different oxygen-isolating refining temperatures on soybean lipoxygenase activity is not significant. Therefore, refining temperature is not the key factor to inhibit the activity of lipoxygenase; (3) Compared with oxygen refining at room temperature, the lipoxygenase activity of soymilk prepared by oxygen-isolating refining is reduced by 99.67%, the total flavonoid content is increased by 24.77%, the beany smell is obviously removed, and the comprehensive quality of soy milk, such as brightness and flavor, was also significantly improved. So the optimal processing parameters combined with oxygen-isolating refining has the best effect in removing the beany flavor and improving the comprehensive quality of soy milk.

  Conclusion  The results showed that under the cooperation of oxygen-isolating refining process, the lowest beany flavor and the best comprehensive quality were obtained by the process of rehydration with 80 ℃ soaking temperature, pH 9 and 60 min soaking time. This research is of great significance to the development of high-quality soybean beverages.