In this study, the foamability of soy protein isolate (SPI), β-conglycinin (7S), soy protein selective hydrolysates (SPSH) and soy protein limited hydrolysate (SPLH) were tested at both acid and neutral conditions (pH 2.0, 3.0, 4.0 and 7.0). The properties of soy proteins (SPI and 7S) and hydrolysates (SPSH and SPLH) were analysed by particle size distribution, zeta potential, surface tension, interfacial rheology, foam expansion and stability. The particle size of soy proteins and hydrolysates decreased near the isoelectric point (pH 4.0). The 7S, SPSH and SPLH under acid conditions had lower surface tension than at pH 7.0. Under acid conditions, the higher foaming expansion of 7S, SPSH and SPLH than those under the neutral condition could be explained by lower surface tension, quicker adsorption and stronger viscoelastic properties; the better foaming stability can be attributed to a robust interfacial film. In summary, the SPSH and SPLH can be effective alternatives to egg white in aerated food due to the high foamability at both acid and neutral conditions.

本研究中，大豆分离蛋白（SPI）的发泡性、β-伴大豆球蛋白 (7S)、大豆蛋白选择性水解物 (SPSH) 和大豆蛋白限制水解物 (SPLH) 在酸性和中性条件下（pH 2.0、3.0、4.0 和 7.0）进行测试。通过粒度分布、zeta 电位、表面张力、界面流变学、泡沫膨胀和稳定性分析大豆蛋白（SPI 和 7S）和水解产物（SPSH 和 SPLH）的特性。大豆蛋白和水解物的粒径在接近等电点 (pH 4.0) 时减小。酸性条件下的 7S、SPSH 和 SPLH 的表面张力低于 pH 7.0。在酸性条件下，7S、SPSH和SPLH比中性条件下的发泡膨胀率更高，可能是因为表面张力更低，吸附更快，粘弹性更强；更好的发泡稳定性可归因于坚固的界面膜。总之，由于在酸性和中性条件下的高发泡性，SPSH 和 SPLH 可以成为充气食品中蛋清的有效替代品。