Pengyu, Zhu, et al. Food hydrocolloids 118 (2021): 106811.
Trehalose functions as a polyhydroxyl osmotic agent that stabilizes the molten globule (MG) state of soybean 11S globulin and enhances its emulsifying properties under acidic conditions.
Experimental Protocol: Soybean 11S globulin is induced into the MG state at pH 1.0 with 12 hours of incubation. Trehalose is added at gradient concentrations of 0, 0.1, 0.4, 0.9, and 1.3 mol/L. Structural characterization employs intrinsic fluorescence spectroscopy (excitation at 290 nm, emission 300 to 400 nm), far-UV circular dichroism (190 to 250 nm), and ANS fluorescence. Emulsifying activity index (EAI) and emulsion stability index (ESI) are measured using 1 mg/mL protein solution homogenized with soybean oil at 10,000 g for 1 minute.
Performance Evaluation: At 1.3 mol/L trehalose, the alpha-helix content of MG 11S globulin increases from 21.63% to 23.50%, approaching the native state value of 24.81%. The Gibbs free energy decreases from 4.56 to -8.94 kJ/mol, indicating enhanced thermodynamic stability. The optimal EAI of 76.67 m2/g is achieved at 0.5 mol/L trehalose, compared to 66.28 m2/g for the MG state without trehalose. The ESI reaches 76.67% at 0.5 mol/L trehalose, nearly double that of the native protein at 40.23%.