Alginate, or alginic acid is a linear polysaccharide
composed of D-mannuronic and L-guluronic acid subunits.
I have been preparing calcium alginate gels from sodium
alginate purchased from Sigma Chemicals. However, under low
ionic, specifically low calcium concentration, conditions,
eventually my alginate gels have been breaking down.
I have come across a reference that states that a stronger
gel, one with a greater affinity for calcium, can be
achieved by using alginate with a higher guluronic acid
content.
The chemical suppliers I have found so far that sell sodium
alginate only carry grades which differ in their chain
length (viscosity), not by their relative guluronic acid to
mannuronic acid ratio.
Does anyone know of any supplier of sodium alginate which
carries different grades based upon gul/mannuronic acid
ratio?
Thanks in advance.
Tom Merchant
