Carrageenans: gelling, thickening and stabilizing agents

Carrageenans are natural polysaccharides obtained from red algae. These hydrocolloids can act as thickeners and gelling agents, as well as stabilizers in a wide range of foods, pharmaceutical products and cosmetics.

Carrageenans are used to impart a wide variety of textures, from viscous solutions to gels. In addition, they lend an image of naturalness and safety.

From a chemical point of view, carrageenan is a family of polysaccharides with varying levels of sulfation, leading to different functionalities ranging from non-gelled to highly viscous, with high gelation and low viscosity.

The main functional properties of carrageenan are the viscosity and gel-forming capacity mentioned, but there are many other important factors to consider, such as solubility, syneresis, milk reactivity, salt sensitivity and film-forming capacity. All these characteristics influence the ways in which carrageenans interact with the various components in which they are used.

Carrageenan production is divided between America, Europe and Asia (particularly China).

Significant growth has been observed over the last decade. The carrageenan market has developed in direct relation to the growth of the world's population, the evolution of food technology and the changing lifestyles of many people who have little time for cooking.

As with many other food ingredients, a certain amount of "bad press" has arisen in countries such as the USA, where pressure groups based on "poor science" have discredited the long history of safe carrageenan consumption.

On the contrary, numerous studies reaffirm the safety of carrageenan and, more importantly, its ability to be used to prevent the transmission of several viruses.

The article is organized as follows. First, we give a general presentation of carrageenans, including the different species of red algae used in their manufacture, as well as their chemical composition and production methods. We then move on to the functional part, with physico-chemical characteristics and functional properties. After showing the interactions with food products, we present the specific applications where carrageenans can be found, before concluding with the safety and legislation section, as well as the economic section.

At the end of the article, readers will find a glossary and a table of the symbols used.