Carrageenan is a hydrocolloid extracted from some red seaweeds belonging to the Gigartina, Hypnea, Eucheuma, Chondrus and Iridaea species.
It is used in a wide variety of applications in the food industry as a thickening, gelling, stabilizing and suspending agent in water and milk systems.
Carrageenan is a multi-functional ingredient and it behaves differently in water and in milk systems. In water it shows typical hydrocolloid properties of thickening and gelling, while in milk systems it also has the property of reacting with proteins to furnish additional stabilizing abilities.
Carrageenan has a unique ability to form a wide variety of gel textures at room temperature: rigid or elastic, clear or turbid, tough or tender, heat stable or thermally reversible, low or high melting/gelling temperatures. It may also be used as a suspending, gelling, emulsifying, stabilizing and water retaining agent in other industrial applications.
Types of Carrageenan
There are several carrageenans, differing in their chemical structure and properties, and therefore in their uses.
The carrageenans of commercial interest are called iota, kappa and lambda.
Their uses are related to their ability to form thick solution or gels, and they vary as follows.
1. Iota * Elastic gels formed with calcium salts.
* Clear gel with no bleeding of liquid (no synaeresis).
* Gel is freeze/thaw stable.
2. Kappa * Strong, rigid gel, formed with potassium salts.
* Brittle gel forms with calcium salts.
* Slightly opaque gel, becomes clear with sugar addition.
3. Lambda * No gel formation, forms high viscosity solutions.
How Carrageenan is used?
• Carrageenan is unlike simple salts or sugar which simply dissolves if added to water.
• Carrageenan powders are composed of finely ground dehydrated gels which must swell before dissolution can take place.
• The dehydrated gel fragments are hard and completely non-tacky.
Stability of Carrageenan Powder
• Carrageenan powders contain 8-10 % moisture, most of it bound to the molecule. It does not absorb moisture from the atmosphere or cause other ingredients to cake.
• The dry powder may be stored for a year or more under standard warehousing conditions without deterioration or loss in quality so long as it remains dry.
• Unlike other gums, carrageenan is insensitive to enzymes, especially cellulase.
• In both gel and solution form, food preservatives must be added to prevent bacterial contamination, which may cause fermentation and eventually, the degradation of the carrageenan. However, aseptically packed products do not require preservatives.
• Carrageenan is highly stable in boiling neutral or alkali solutions without loss in viscosity or gel potential.
• In acidic systems, carrageenan solutions are susceptible to viscosity losses specially at high cooking temperature.
• In gel form, carrageenan is stable even at low pH.
Applications
• Processed Poultry > controls dehydration while frozen; enhances juiciness and increases yield
• Milk/Chocolate Milk Drink/Juice > stabilizes and improves viscosity
