Neutrons and Food 8 at MLZ

Increasing the temperature of protein dispersions initiates the denaturation via breaking of hydrogen and disulfide bonds. These denatured proteins undergo hydrophobic attraction due to exposure of the hydrophobic sites of the protein, resulting in the formation of smaller protein aggregates, which finally leads to protein gelation by forming an intermolecular network structure at the gelation temperature (TG). Protein gels can also be obtained at lower relative temperatures, a process called cold-set gelation. This method holds significant potential in various applications, including medicine and the food industry, due to its mild processing conditions. In this work [1], we examine the ethanol-driven cold-set gelation of BSA protein, where gelation could be achieved at temperatures as low as room temperature. The gel formation has been established by both macroscopically, using visual inspection and tube inversion tests and microscopically, using rheology measurements. We further probed the modification in inter-protein interactions during such gelation and resultant structures using SANS and DLS techniques. Interestingly, alcohol-induced cold gelation of protein could be completely suppressed on the addition of the ionic surfactant, SDS. The underlying mechanism has been explained based on competing interactions in the presence of alcohol and SDS.
[1] D. Saha et al., Food Hydrocolloids 172, 111991 (2026).