Protein Hydration in Structure Creation
Book chapter, 2010
Food processors have made structures from natural biopolymers for centuries, so why do we still not know the answers to all the problems of structure design, and its creation, in foods? Proteins are heteropolymers of amino acids, not designed for fabrication by processors, but evolved for particular biological functions at ambient temperature. Their performance derives from their distinctive native structure and that structure ' s peculiar interaction with its aqueous environment. We are left to elucidate their behavior under more extreme conditions of pH, water activity (a w ), temperature, pressure, etc. Adsorption isotherms of water on proteins at least show some similarities, and food processing operates across the entire a w or moisture - content spectrum. This report reviews what we know relative to the operating conditions and water contents used, with reference to general rules and the inevitable exceptions.
Resultant phase composition - relative compatibility of each solute with water
Permeability measurements - made of coarsely aggregated dairy gels
Gelation of proteins - determination by competition between kinetics of denaturation and aggregation
Denaturation - cooperative phenomenon routinely and easily measured
Adsorption - thermodynamic equilibrium line
Key parameter measured for proteins - water-holding capacity
Expanded solid foams - components of breakfast cereals and snacks
Protein hydration - structure creation
Author
P.J. Lillford
University of Birmingham
Anne-Marie Hermansson
Chalmers, Chemical and Biological Engineering, Applied Surface Chemistry
Water Properties in Food, Health, Pharmaceutical and Biological Systems: ISOPOW 10
237-250
9780813812731 (ISBN)
Subject Categories
Food Engineering
DOI
10.1002/9780470958193.ch18
ISBN
9780813812731