What are Hydrocolloids?

Hydrocolloids are polymers that increase viscosity or gel strength when added to water or aqueous systems. Some common hydrocolloids used in food processing include alginate, carrageenan, gelatin, gellan, guar gum, pectin, starch, tara gum, xanthan gum and more.

Sources and Properties

Alginate: Derived from brown seaweeds, alginate forms Hydrocolloids gels when combined with calcium ions. It is used to thicken products and form edible films or casings.

Carrageenan: Extracted from red seaweeds, carrageenan forms firm gels either cooled or acidified. It is commonly used as a stabilizer and thickener.

Gelatin: Obtained by hydrolysis of collagen from animal bones and skins. Gelatin gels upon cooling and melting at higher temperatures, making it suitable for creating various textures.

Gellan: Produced by the fermentation of Sphingomonas elodea bacteria. Gellan forms clear, heat-stable gels with different properties based on gel strength.

Guar Gum: Derived from guar beans, guar gum is highly effective at increasing viscosity even at low concentrations. It stabilizes emulsions and suspensions.

Pectin: Found naturally in citrus fruit cell walls and apple pomace. Pectin forms gels in the presence of acid and sugar. It is used for jams, jellies, fillings and more.

Starches: Come from corn, wheat, rice and other cereal grains. Starches provide body, texture and shelf stability to foods when cooked.

Xanthan Gum: Produced through fermentation of corn sugar by Xanthomonas campestris bacteria. Xanthan gum is very effective at stabilizing emulsions and foams.

Functions  in Food Processing

Thickening: Many hydrocolloids are excellent thickeners, able to increase viscosity with only small amounts added. This property is useful for sauces, dressings, syrups and more.

Gelling: Certain hydrocolloids like gelatin, alginate, pectin and carrageenan can form self-supporting semi-solid gels. This allows for products like jams, yogurt and meat analogs.

Stabilization: They prevent ingredients from separating or crystals from forming. They stabilize emulsions in mayonnaise and dressings as well as foams in whipped toppings.

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