Analysis of diffusion of _L-glutamic acid, sodium ions and _D-glucose in agar gel containing xanthan gum

Abstract

　We studied the diffusion processes of seasoning materials (_L-glutamic acid, sodium ion and _D-glucose) in gels. In the present study, the gel was soaked in a solution containing 0.30% (W/V) monosodium glutamate, 1.0% (W/V) NaCl and/or 3.0% (W/V) _D-glucose, and the apparent diffusion coefficient (D) was determined in 2.0% (W/W) agar gel containing xanthan gum (0%, 0.20% or 0.50% (W/W)) after 24 hr at 30℃ in a one-dimensional diffusion system. As the results, the D of _L-glutamic acid increased in the presence of NaCl in the agar gel containing xanthan gum, but the increasing effect disappeared by the further addition of _D-glucose. The increase in D of sodium ion by the addition of xanthan gum was also suppressed by the addition of _D-glucose. It was obvious that the diffusion of sodium ions was facilitated by the carboxyl-group in the xanthan gum, and that the diffusion of _L-glutamate increased with the flow of the sodium ions.