Physicochemical and structural characterisation of protein isolate, globulin and albumin from soapnut seeds (Sapindus mukorossi Gaertn.)

► Soapnut proteins show a balanced amino acid composition. ► Soapnut proteins except albumin fractions show a typical U-shape PS-pH profile. ► The flexibility in tertiary conformations decrease in the order: SNA > SNPI > SNG. ► Soapnut proteins have a similar secondary conformation. ► SS bonds and hydrophobic interactions contribute to the thermal stability of SNG.