gel·a·tin also gel·a·tine n.
A colorless or slightly yellow, transparent, brittle protein formed by boiling the specially prepared skin, bones, and connective tissue of animals and used in foods, drugs, and photographic film. Any of various similar substances. A jelly made with gelatin, used as a dessert or salad base. A thin sheet made of colored gelatin used in theatrical lighting. Also called gel.
Household gelatin comes in the form of sheets, granules or powder. Instant types can be added to the food as they are; others need to be soaked in water beforehand.
Special kinds of gelatin are made only from certain animals or from fish (known as K-gelatin) in order to comply with Jewish kosher or Muslim halal beliefs. Vegetarians and vegans may substitute similar gelling agents such as agar, nature gum, carrageenan, pectin, or konnyaku sometimes referred to as "vegetable gelatins" although there is no chemical relationship; they are carbohydrates, not proteins. The name "gelatin" is colloquially applied to all types of gels and jellies; but properly used, it currently refers solely to the animal protein product. There is no vegetable source for gelatin.
Vegetarians and/or vegans do not usually eat or use products containing gelatin. Source: http://www.answers.com/gelatin
Probably best known as a gelling agent in cooking, different types and grades of gelatin are used in a wide range of food and non-food products:
Common examples of foods that contain gelatin are gelatin desserts, jelly, trifles, aspic, marshmallows, and confectioneries such as Peeps and gummy bears. Gelatin may be used as a stabilizer, thickener, or texturizer in foods such as ice cream, jams, yogurt, cream cheese, and margarine; it is used, as well, in fat-reduced foods to simulate the mouth feel of fat and to create volume without adding calories. Gelatin is also used in toothpastes.
Gelatin is used for the clarification of juices, such as apple juice, and of vinegar.
Gelatin typically constitutes the shells of pharmaceutical capsules in order to make them easier to swallow. Hypromellose is the vegetarian counterpart to gelatin, but is more expensive to produce.
An alternative is agar, made from a variety of red seaweed, commonly used in Japan where it is known as kanten and used in the manufacture of ice cream.
Nature gum, carrageenan, pectin, or konnyaku are other vegetarian or vegan substitutes for gelatin.
More foods that contain gelatin
Altoids, Skittles (note some Skittles do not contain Gelatin, see article for details), Starburst, Jelly beans, Jelly babies candy corn, Lucky Charms, Pop Tarts, Rice Krispi Treats, Chewy S'mores bars, Twinkies, Mentos, Junior Mints, Frosted Mini Wheats
The fat-free version of "I Can't Believe It's Not Butter"
Some pre-made guacamole
Some dairy products such as ice cream, sour cream, cream cheese, cottage cheese and yogurt.
Planters Dry Roasted Peanuts and other roasted nuts (but not all Planters nut products).