Absolute Determination of the Gelling Point of Gelatin under Quasi-thermodynamic Equilibrium

作者：Bellini Franco; Alberini Ivana; Ferreyra Maria G; Rintoul Ignacio^*

来源：Journal of Food Science, 2015, 80(5): C935-C941.

DOI：10.1111/1750-3841.12822

• biopolymers
• gel
• gelation
• kinetics
• phase transitions

Thermodynamic studies on phase transformation of biopolymers in solution are useful to understand their nature and to evaluate their technological potentials. Thermodynamic studies should be conducted avoiding time-related phenomena. This condition is not easily achieved in hydrophilic biopolymers. In this contribution, the simultaneous effects of pH, salt concentration, and cooling rate (Cr) on the folding from random coil to triple helical collagen-like structures of gelatin were systematically studied. The phase transformation temperature at the absolute invariant condition of Cr = 0 degrees C/min (T-T(Cr=0)) is introduced as a conceptual parameter to study phase transformations in biopolymers under quasi-thermodynamic equilibrium and avoiding interferences coming from time-related phenomena. Experimental phase diagrams obtained at different Cr are presented. The T-T(Cr=0) compared with pH and T-T(Cr=0) compared with [NaCl] diagram allowed to explore the transformation process at Cr = 0 degrees C/min. The results were explained by electrostatic interactions between the biopolymers and its solvation milieu.

• 出版日期2015-5