High sugar content impacts microstructure, mechanics and release of calcium-alginate gels
Journal article, 2018

The use of calcium-alginate gels as carriers of food and pharmaceutical compounds is of great interest due the versatile properties of such systems. In this work, we investigated the influence of sugars (glucose: fructose) as cosolutes (15-60% (wt)) on the physico-chemical properties of calcium-alginate gel particles. Sugar concentrations above 15% (wt) reduced extensibility of alginate molecules, as shown by intrinsic viscosity measurements, and lead to a more open or less connected gel network with aggregated alginate strands. Furthermore, it is shown for the first time that sugar impacted swelling-deswelling ability of calcium alginate gels under simulated gastric (pH 1.2) and intestinal (pH 6.6) conditions. Release of sugar from calcium alginate gels with 15% (wt) and 30% (wt) sugar was close to Fickian diffusion mechanism, in both simulated gastric and intestinal fluid, with diffusion coefficient close to that previously reported for calcium-alginate gels with lower sugar contents. However, release from 60% (wt) gels in gastric fluid was slower than for 15 and 30% (wt) and, there was a drastic shrinkage of the gels under acid conditions. In intestinal fluid 60% (wt) gels showed slower release than gels with lower sugar content, this was hypothesised to be due to the lower surface area of these gels. Understanding the structure-function relationship of these gels is key to the successful design of delivery systems for food and biotechnological applications.


Intrinsic viscosity

Solvent quality





Patricia Lopez-Sanchez

Maurten AB

Nils Fredriksson

Maurten AB

Anette Larsson

SuMo Biomaterials

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Annika Altskär

RISE Research Institutes of Sweden

SuMo Biomaterials

Anna Ström

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

SuMo Biomaterials

Food Hydrocolloids

0268-005X (ISSN)

Vol. 84 26-33

Subject Categories

Polymer Chemistry

Physical Chemistry

Food Engineering

Areas of Advance


Materials Science



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Latest update

3/5/2021 1