Yes, and it is still used:
The gelatin in Jell-O is what lets you transform it into all sorts of different shapes. What exactly is gelatin? Gelatin is just a processed version of a structural protein called collagen that is found in many animals, including humans. Collagen actually makes up almost a third of all the protein in the human body. It is a big, fibrous molecule that makes skin, bones, and tendons both strong and somewhat elastic. As you get older, your body makes less collagen, and individual collagen fibers become crosslinked with each other. You might experience this as stiff joints (from less flexible tendons) or wrinkles (from loss of skin elasticity).
The gelatin you eat in Jell-O comes from the collagen in cow or pig bones, hooves, and connective tissues. To make gelatin, manufacturers grind up these various parts and pre-treat them with either a strong acid or a strong base to break down cellular structures and release proteins like collagen. After pre-treatment, the resulting mixture is boiled. During this process, the large collagen protein ends up being partially broken down, and the resulting product is called gelatin. The gelatin is easily extracted because it forms a layer on the surface of the boiling mixture.
Gelatin is a common ingredient in foods because it is so versatile. It can be used as a gelling agent (as in Jell-O), as a thickener, an emulsifier, and a stabilizer. You'll find it in a variety of foods, from yogurt to chewing gum. Here is a list of some other foods that commonly contain gelatin:
* gummy bears
* sour cream
* cream cheese
* cake icing and frosting
* marshmallows
* soups, sauces and gravies
* canned ham and chicken
* corned beef
* sausage
Gelatin is even used to make the coating for pills that makes them easier to swallow. It's also in cosmetics, lozenges, and ointments.
When you buy a box of Jell-O (or another brand of gelatin) at the grocery store, you get a small packet of powdered gelatin with artificial flavorings and colors. At room temperature, the gelatin protein is in the form of a triple helix. This is a fairly ordered structure not unlike that of DNA. With DNA, two chains of nucleotides are twisted together in a spiral pattern. (To learn more about DNA, see How Cells Work). In the gelatin protein, there are three separate chains of amino acids (polypeptide chains) have lined up and twisted around each other, and the helix is held together by weak bonds that form between the amino acids that end up on the inside of the coiled structure. Gelatin is a substantially pure protein food ingredient, obtained by the thermal denaturation of collagen (1), which is the structural mainstay and most common protein in the animal kingdom. Today gelatin is usually available in granular powder form, although in Europe, sheet gelatin is still available.
Tech terms:
There are two main types of gelatin. Type A, with isoionic point of 7 to 9, is derived from collagen with exclusively acid pretreatment. Type B, with isoionic point of 4.8 to 5.2, is the result of an alkaline pretreatment of the collagen. However, gelatin is sold with a wide range of special properties, like gel strength, to suit particular applications.
Gelatin (2) forms thermally reversible gels with water, and the gel melting temperature (<35°C) is below body temperature, which gives gelatin products unique organoleptic properties and flavour release. The disadvantage of gelatin is that it is derived from animal hide and bone (not from trotters as is a common perception), hence there are problems with regard to kosher and Halal status and vegetarians also have objections to its use. Competitive gelling agents like starch, alginate, pectin, agar, carrageenan etc. are all carbohydrates from vegetable sources, but their gels lack the melt in the mouth, elastic properties of gelatin gels.