To improve the soybean protein content (SPC), flavor and quality of soymilk, the effects of dual-frequency ultrasound at different angles (40 + 20 kHz 0°, 40 + 20 kHz 30°, 40 + 20 kHz 45°) on physicochemical properties and soybean protein (SP) structure of raw soymilk were mainly studied and compared with the conventional single-frequency (40 kHz, 20 kHz) ultrasound. Furthermore, the intensity of the ultrasonic field in real-time was monitored via the oscilloscope and spectrum analyzer. The results showed that 40 + 20 kHz 45° treatment significantly increased SPC. The ultrasonic field intensity of 40 + 20 kHz 0° treatment was the largest (8.727 × 10⁴ W/m²) and its distribution was the most uniform. The emulsifying stability of SP reached the peak value (233.80 min), and SP also had the largest particle size and excellent thermal stability. The protein solubility of 40 + 20 kHz 30° treatment attained peak value of 87.09%. 20 kHz treatment significantly affected the flavor of okara. The whiteness and brightness of raw soymilk treated with 40 kHz were the highest and the system was stable. Hence, the action mode of ultrasonic technology can be deeply explored and the feasibility for improving the quality of soymilk can be achieved.

为提高豆浆的大豆蛋白含量（SPC）、风味和品质，不同角度（40 + 20 kHz 0°、40 + 20 kHz 30°、40 + 20 kHz 45°）的双频超声对理化性质的影响主要研究了生豆浆的特性和大豆蛋白（SP）结构，并与常规单频（40 kHz、20 kHz）超声进行了比较。此外，通过示波器和频谱分析仪实时监测超声场的强度。结果表明，40 + 20 kHz 45°处理显着增加了SPC。40 + 20 kHz 0°处理的超声场强最大（8.727 × 10 ⁴ W/m ²) 并且其分布是最均匀的。SP的乳化稳定性达到峰值（233.80 min），同时SP粒径最大，热稳定性优良。40 + 20 kHz 30°处理的蛋白质溶解度达到峰值87.09%。20 kHz 处理显着影响了豆渣的风味。40 kHz处理后的生豆浆白度和亮度最高，体系稳定。因此，可以深入探索超声波技术的作用方式，实现提高豆浆品质的可行性。