Carrageenan, a widely used food additive, belongs to the family of linear sulfated polysaccharides derived from red seaweeds Chodrus crispus and Gigartina stallata. This complex carbohydrate is composed of repeating galactose units and 3,6-anhydrogalactose, creating a unique molecular structure. The degree of sulfation and the type of linkage between these units determine the different forms of carrageenan, such as kappa, iota, and lambda.

There are three fractions of carrageenan that have been isolated: kappa, iota and lambda. The distinct properties stem from variations in their molecular structures, impacting their functionalities in food applications. Kappa carrageenan is known for forming strong, rigid gels in the presence of potassium ions. This characteristic makes it ideal for use in gelling meat products and enhancing the texture of dairy desserts. Iota carrageenan gels in the presence of calcium ions, producing soft and elastic gels. Iota carrageenan is often employed in dairy applications, providing a creamy texture to products like chocolate milk. Lambda carrageenan, in contrast, does not form gels but imparts viscosity and stability to liquid systems. This type is commonly used as a thickening agent in products like salad dressings and sauces. 

Carrageenan's versatility and functionality make it a staple in the confectionery industry. From its extraction process to its role in gel formation, carrageenan's technical aspects contribute significantly to the quality and stability of various confectionery products. With a clear regulatory status, carrageenan remains a trusted and indispensable ingredient in the world of food science.

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Source and Processing

Primarily sourced from various species of red seaweeds, carrageenan extraction involves a straightforward process. The seaweed is harvested, washed to remove impurities, and then subjected to an alkaline treatment. This step promotes the solubilization of carrageenan from the seaweed cell walls. After extraction, the carrageenan is further processed through filtration and precipitation, resulting in a refined product suitable for various applications.

Main function in Confections

In the realm of confections, carrageenan plays a crucial role as a gelling and thickening agent. Its unique ability to form stable gels in the presence of cations, particularly potassium, calcium, and sodium ions, makes it invaluable in the production of jellies, gummy candies, and other confectionery delights. Moreover, carrageenan aids in enhancing texture, mouthfeel, and shelf life, contributing to the overall quality of confectionery products.

Molecular Structure

Carrageenan is a linear sulfated polysaccharide with a complex and repeating structure composed of galactose and 3,6-anhydrogalactose units. The basic building blocks are arranged in alternating fashion, forming the backbone of the molecule. The sulfate groups are attached to specific positions on the galactose units, providing a negative charge to the molecule. The degree of sulfation and the specific linkage patterns between the galactose units contribute to the different types of carrageenan, such as kappa, iota, and lambda.


Gelation mechanism: Carrageenan achieves gel formation through the interaction with cations. The helical structure of carrageenan molecules traps water molecules, resulting in the formation of a gel network. The specific gelling mechanism depends on the type of carrageenan used, whether it is kappa, iota, or lambda.

Hygroscopicity: Carrageenan exhibits minimal hygroscopicity, meaning it has low water absorption properties. This characteristic is advantageous in confections, preventing undesirable changes in texture or structure due to moisture absorption.

Solubility: Carrageenan is soluble in hot water, forming a viscous solution. This solubility property facilitates its incorporation into confectionery formulations, allowing for uniform dispersion and easy processing.

Shelf stability: Carrageenan contributes to the shelf stability of confections by preventing syneresis, the undesirable separation of water from the gel structure. This quality enhances the overall product integrity and extends shelf life.


In the United States, carrageenan is recognized as safe for use in food products by the Food and Drug Administration (FDA). It is listed under 21 CFR 172.620, with specific regulations outlining its application limits and purity standards. The FDA has extensively reviewed scientific data on carrageenan's safety, affirming its suitability for consumption when used in accordance with established regulations.

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