Could algal cellulose be an alternative gelling agent?
"useful alternative" to commercial gelling agents, says new
research from Sweden.
Writing in the Elsevier journal Food Hydrocolloids, lead author Albert Mihranyan and his colleagues from Uppsala University in Sweden report that alpha-cellulose from the green algae can form gels at significantly lower concentrations than some sources commercially available.
"The results of the current study clearly indicate that Cladophora cellulose powder could be a useful alternative to commercially available dispersible cellulose grades," wrote Mihranyan. "Its usage may even provide certain advantages over the currently used products whenever stronger gelling action is required and/or the addition of as little solid phase as possible to the primary dispersive system is stipulated."
Algae are currently exploited by the food industry for a range of ingredients, including carrageenans extracted from red algae as a stabilising and gelling agentm, and alginates from brown algae as thickeners and stabilisers.
However, according to Mihranyan, very little is known about the properties of cellulose of algal origin.
The researchers dispersed Cladophora cellulose powder in carboxymethylcellulose (CMC - Cekol 30,000, Noviant) solutions of varying concentrations, and the rheological properties of cellulose hydrogels and compared to a commercially available dispersive cellulose grade (Avicel RC-591).
"Cladophora cellulose forms gel structures at cellulose concentrations of as low as 0.2 per cent, whereas the lower threshold for the commercially available analogue is around 1.5 per cent solids contents," report the researchers.
Indeed, they report that almost ten timed the concentration of Avicel RC-591 was required to achieve gels of comparable strength to those obtained by the Cladophora cellulose.
On the other hand, when the CMC was used in high concentrations a negative effect on the gelling properties of the Cladophora cellulose, said the researchers.
"It is therefore likely that the interactions between CMC and Cladophora cellulose somewhat impair the overall gel strength; however, addition of CMC to Cladophora cellulose gel preparations could still be justified because of a more homogeneous texture of the product after dispersion," they said.
Mihranyan and his colleagues called for future studies to examine the interaction of Cladophora cellulose with hydrocolloids beside CMC.
"Cladophora cellulose powder could be a useful alternative to commercially available dispersible cellulose grades when very low quantities of stabilizing agents are required," concluded the researchers.
Source: Food Hydrocolloids Volume 21, Pages 267-272 "Rheological properties of cellulose hydrogels prepared from Cladophora cellulose powder" Authors: A. Mihranyan, K. Edsman and M. Stromme