Thermoprotective Effect of Sorbitol on Proteins during Dehydration

Thermoprotective properties of sorbitol were evaluated on freeze-dried fish mince and spray-dried egg white and skim milk proteins by measuring changes in functionality. The thermoprotective effect of sorbitol appeared to be a function of sorbitol concentration as evidenced by increased gel-forming ability, water-binding ability, emulsifying capacity, and enthalpy (ΔH) for denaturation, with no significant changes in denaturation temperature (T_d). The greater water-binding ability resulting from the sorbitol treatment before rather than after thermal hydration may be attributed to increased hydrophobic interaction and hydrophilicity from the formation of a protein-sorbitol complex.