l “Water binding” and “hydration” – Tendency of water to associate with hydrophilic substances l Water holding capacity – Ability of a matrix of molecules to entrap large amounts of water in a manner such that exudation is prevented General concepts
l “Water binding” and “hydration” – Tendency of water to associate with hydrophilic substances l Water holding capacity – Ability of a matrix of molecules to entrap large amounts of water in a manner such that exudation is prevented General concepts
Forces acting in water l Electrostatic – interactions between charges l Hydrogen bonds – hydrogen shared between two electronegative atoms l van der Waals – weak induced dipole interactions between any two atoms in close contact l Hydrophobic interactions
Forces acting in water l Electrostatic – interactions between charges l Hydrogen bonds – hydrogen shared between two electronegative atoms l van der Waals – weak induced dipole interactions between any two atoms in close contact l Hydrophobic interactions
Water Solute Interactions l Water – Ionic groups: some of the most tightly bound water in food – Strong electrostatic attraction between the permanent charge of the ion and the dipole of water l Water – Polar but uncharged solute – Weaker – Hydrogen bonding of dipole-dipole interactions – Allow polar components to dissolve
Water Solute Interactions l Water – Ionic groups: some of the most tightly bound water in food – Strong electrostatic attraction between the permanent charge of the ion and the dipole of water l Water – Polar but uncharged solute – Weaker – Hydrogen bonding of dipole-dipole interactions – Allow polar components to dissolve
l Water – non-polar molecules – Thermodynamically unfavorable _ decrease in entropy – Formation of rigid ice-like clathrate at interface – Dipole – induced dipole – Hydrophobic interactions _ association of apolar and nonpolar groups in aqueous environments Water Solute Interactions
l Water – non-polar molecules – Thermodynamically unfavorable _ decrease in entropy – Formation of rigid ice-like clathrate at interface – Dipole – induced dipole – Hydrophobic interactions _ association of apolar and nonpolar groups in aqueous environments Water Solute Interactions
l Amphiphilic molecules Water Solute Interactions
l Amphiphilic molecules Water Solute Interactions