Premium
Dynamics of water in agar gels studied using low and high resolution 1 H NMR spectroscopy
Author(s) -
Davies Erika,
Huang Yang,
Harper Jason B.,
Hook James M.,
Thomas Donald S.,
Burgar Iko M.,
Lillford Peter J.
Publication year - 2010
Publication title -
international journal of food science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.831
H-Index - 96
eISSN - 1365-2621
pISSN - 0950-5423
DOI - 10.1111/j.1365-2621.2010.02448.x
Subject(s) - diffusion , spectrometer , agar , relaxation (psychology) , analytical chemistry (journal) , nuclear magnetic resonance , chemistry , agar gel , proton nmr , nuclear magnetic resonance spectroscopy , macromolecule , resolution (logic) , spin–lattice relaxation , molecule , chromatography , materials science , organic chemistry , thermodynamics , optics , physics , psychology , social psychology , biochemistry , genetics , microbiology and biotechnology , biology , bacteria , artificial intelligence , nuclear quadrupole resonance , computer science
Summary The aim of this work was to determine whether the decreased motion of water in agar gels (2.5–12.5% agar) resulted not only from the chemical interaction of the water molecules with the agar macromolecules but also from obstruction by the gel networks. Relaxation experiments were conducted using a 500‐MHz nuclear magnetic resonance (NMR) spectrometer. Diffusion experiments were conducted using a 23‐MHz NMR spectrometer with diffusion times ranging between 15 and 200 ms and a 500‐MHz NMR spectrometer with a fixed diffusion time of 10 ms. This study shows that the interaction of water with hydroxyl groups of agar macromolecules resulted in faster relaxation and slower self‐diffusion of water. The time‐dependent self‐diffusion coefficient of water provides clear evidence of the obstructive effects of the agar gel network on diffusion. This work is the first report on restricted diffusion of water in agar gel systems.