Uses of Hydrocolloids

Pectin is an essential ingredient in jellies and marmalades.

Hydrocolloids are a collection of polymers more commonly known as "gums," which can be of vegetable, animal or synthetic origin. They occur naturally and are artificially added to foods to produce different properties. In particular, hydrocolloids are able to affect the viscosity, thickening and stabilization of foods. They are also commonly used in the photographic, pharmaceutical and scientific industries.

Definition of Hydrocolloid

A colloid is a type of mixture in which one substance is distributed evenly throughout another. A hydrocolloid is defined as a colloid in which the particles are distributed in water. A hydrocolloid can exist in different states, for example a gel or a liquid, depending on the quantity of water present. Hydrocolloids can be either single-state, where the substance is restricted to either a gel or liquid form, or reversible, where the hydrocolloid can exist in both states.

Gelatin

Gelatin is a clear, colorless and almost tasteless hydrocolloid derived from animal collagen. It is used as a thickening agent in foods such as "gummy" candy and low-fat yogurt, and it is the main ingredient in Jell-O. It is also used extensively in the photographic industry, as in the production of almost all photographic film and colored light filters. Gelatin is also used in the manufacturing of pharmaceutical drug capsules.

Agar

Agar is a gelatinous hydrocolloid made from seaweed or algae extract. It is used extensively as an ingredient in Japanese dessert dishes, and as a vegetarian-friendly gelatin substitute to thicken jellies and soups. Agar is approximately 80 percent fiber, so it can also be used as a laxative. In science, agar is used as a medium for microbiological work, and to form salt bridges for use in electrochemistry.

Pectin

Pectin is a polysaccharide compound contained in the cell walls of plants. Commercially, it is extracted from citrus fruits and processed to produce a fine powder. Pectin has the ability to stabilize water and milk-based products, and it is used in food as a thickening or stabilizing agent, particularly in jellies, marmalades, candy, fruit juices and milk-based drinks. In medicine, pectin is considered a dietary fiber and is used as an anti-diarrhea treatment as it increases the thickness of stool.

Medical Dressings

Medical dressings are applied to the skin to promote the healing of wounds. They are frequently used in first aid and nursing during a recovery period. Dressings can be made out of gelatin or other hydrocolloids, have a jelly-like consistency, and are commonly used on blisters, burns and wounds where the skin needs to retain moisture during the initial healing process. They also provide a barrier that helps protect against the ingress of bacteria.

References

• World Wide Wounds: Hydrocolloid Dressings
• Science Toys: Pectin
• London South Bank University: Hydrocolloids and Gums