Gelatin, or gelatine, is a substance derived from the processing of animal collagen. Commercially, this is most typically obtained from cattle hides and bones and pigskins. Contrary to popular belief, it is not rendered from the feet or horns of animals, which are made primarily of keratin rather than collagen.
In its most basic form, commercially processed edible gelatin is a tasteless beige or pale yellow powder or granules. It is composed of mostly protein, with a small percentage of mineral salts and water making up the balance. Gelatin contains 18 amino acids. Of the ten essential amino acids necessary for human health, it lacks only tryptophan.
Edible gelatin is extraordinarily versatile. Aside from the ubiquitous Jell-O® desserts popular both in institutional cafeterias and home kitchens around the world, it can be found in an amazing array of food products. In the processed food industry, it is used a thickener, a gelling agent, a stabilizer, and an emulsifier. As such, it can be found in foods as diverse as yogurt, pate, aspic, marshmallows and gummy candy, soups, salad dressings, and canned ham.
Edible gelatin is also widely used in the pharmaceutical industry. Because it is easily digested, it is favored as a coating for medicinal tablets and caplets. Medicine-containing capsules are also made from this substance.
Other, inedible uses include the production of film in the photographic industry. In the entertainment industry, it is used to produce the paint-containing capsules shot from paintball guns.
Extracting the collagen from the raw animal materials to produce gelatin commercially requires a process that involves stages of boiling and soaking in a strong acidic or basic solution to liberate, or hydrolyze, the protein. Once extracted, the protein is then dried. The gelatin may be formed into sheets, termed leaf gelatin, or ground into granules or powder. Its shelf life is a lengthy one, providing it is kept at a regulated temperature and is protected from humidity.
As it is refined from animal products, strict processing guidelines are observed to ensure the purity and quality of the finished product. Numerous tests examine the gelatin for the presence of pathogens, contaminants, and other impurities.
The home cook who desires to render gelatin for use in aspic or other culinary purposes may easily do so by simmering collagen-containing animal or fish bones, then straining and cooling the liquid. The gelatin will congeal upon refrigeration.
Gelatin, served in a broth or in a shimmering, jewel-toned mound studded with fruit chunks, offers some nutritional perks. Many believe it is beneficial for maintaining healthy bones and joints and attractive hair and nails. It has, for ages, been valued as a digestive aid and intestinal soother, hence the popularity of gravies and soups containing it served alongside rich fare.
As a food additive, however, this substance contributes little but texture to its host product. Very little, if any, nutritional benefit is gained when it is added to processed foods.