An explanation of the production of gelatins will help in understanding the properties and the characteristics which exist among the several types and grades.

Gelatin is derived from collagen, an insoluble fibrous protein which is the principal constituent of connective tissues and bones. Collagen is distinctive in that it contains an unusually high level of the cyclic amino acids proline and hydroxyproline. Collagen consists of three helical polypeptide chains wound around each other and connected by intermolecular cross-links.

Gelatin is recovered from collagen by hydrolysis. There are several varieties of gelatin, the composition of which depends on the source of collagen and the hydrolytic treatment used.

The principal raw materials used in gelatin production today are cattle bones, cattle hides, and porkskins. Extraneous substances, such as minerals (in the case of bone), fats and albuminoids (found in skin), are removed by chemical and physical treatment to give purified collagen. These pre-treated materials are then hydrolyzed to gelatin which is soluble in hot water.

Cattle hides are the least used gelatin raw material in North America today. Gelatin recovered from bone is used primarily in photographic applications: some is used for pharmaceutical purposes. The so-called green bone from the slaughter of cattle is cleaned, degreased, dried, sorted, and crushed to a particle size of about 1-2 cm. The pieces of bone are then treated with dilute hydrochloric acid to remove mineral salts. The resulting sponge-like material is called ossein. From this point on in the manufacture of Type B gelatin, both cattle hides and ossein receive similar treatment.

Cattle hides are available from trimming operations in leather production. Cattle hides are usually dehaired chemically with a lime/sulfide solution followed by mechanical loosening.

For the production of Type B gelatin, both ossein and cattle hide pieces are subjected to lengthy treatment with an alkali (usually lime) and water at ambient temperature. Depending on previous treatment, the nature of the material, the size of the pieces, and the exact temperature, liming takes 5-20 weeks, usually 8-12. The process is controlled by the degree of alkalinity of the lime liquor as determined by titration with acid, or by making test extractions.

Ossein usually requires more liming than cattle hides. Additional lime is added to maintain an excess, thereby compensating for any consumed. During liming some deamination of the collagen occurs, with evolution of ammonia. After conditioning, the raw material is thoroughly washed with cold water to remove excess lime; the pH adjusted with acid; and the product extracted with hot water to recover the soluble gelatin.

Porkskin is currently the most significant raw material source for production of edible gelatin in North America. Supplied as either fresh or frozen, porkskins come from slaughter houses and meat processing plants already trimmed of fat, flesh and hair. Porkskins are usually dehaired by scalding with a hot dilute caustic soda solution.

When porkskins are utilized for production of Type A gelatin they are washed with cold water and then soaked in cold dilute mineral acid for several hours until maximum swelling has occurred. Hydrochloric acid and sulfuric acid are most commonly employed. The remaining acid is then drained off and the material is again washed several times with cold water. The porkskins are then ready for extraction with hot water.

The pH, time, temperature, and number of extractions varies from processor to processor depending on product needs, type of equipment employed, time of operations, and economics. Extraction procedures are closely controlled in the manufacture of both type A and type B gelatin since they influence both quality and quantity. Although continuous extraction is used by some processors, most methods still employ discrete batch fractions. Extraction is normally carried out in stainless steel vessels equipped with provisions for heating and temperature control.

The number of extractions varies, 3-6 is typical. The first extraction generally takes place at 50-60-degrees C. The final extraction is carried out close to the boiling point. Extracts are kept separate, analyzed, and subsequently blended to meet various customer specifications.

Earlier extractions have higher molecular weights, higher viscosity, higher gel strength, and the least color. The later extractions are made at increasingly higher temperatures; the resulting product has lower molecular weight, lower gel strength, and greater color.

The dilute gelatin solutions from the various hot water extractions are filtered, deionized, and concentrated by cross-flow membrane filtration and/or vacuum evaporation. The gelatin solution is then chilled and either cut into ribbons or extruded as noodles, and the gelled material is deposited as a bed onto an endless, open weave, stainless steel belt. The belt is passed through a drying chamber, which is divided into zones in each of which the temperature and humidity of the drying air is accurately controlled. Typical temperatures range from about 30-degrees C in the initial zone up to about 70-degrees C in the final zone. The air is usually conditioned by filtration, dehumidification and tempering.

Drying involves progressive increases in air temperature, often with exhaustion of moist air and replenishment with conditioned air. Drying time is 1-5 hours, depending on the quality and concentration of the material and the exact conditions employed. The rate of drying is carefully controlled to avoid melting and case hardening. The gelatin leaves the dryer with a moisture content of about 10%. The dried bed is then broken into pieces that are ground to the required particle size.

Dried gelatin is tested for quality and gel strength according to standard methods developed by the Gelatin Manufacturers Institute of America.

Throughout the entire process, strict attention is paid to Good Manufacturing Practices to ensure the purity of the gelatin.

Although gelatins are sometimes referred to as edible, pharmaceutical, photographic or technical, these terms refer only to their uses, and not to the methods of manufacture.

Gelatin is defined as a “product obtained from partial hydrolysis of collagen derived from natural sources such as skin, connective tissue, and bones of animals.” It is an easily digestible protein that contains all the essential amino acids except tryptophan. Gelatin is NOT a chemical or chemically modified substance.

The raw materials used in the production of gelatin are from healthy animals and include cattle bone, cattle hides and fresh, frozen pigskins. In the North American market, these raw materials are basically sourced from government-inspected meat processing facilities.

Gelatin is typically produced in a powdered or granulated form. Slightly yellow to light tan in color, it is a rather tasteless and odorless substance.

Gelatin has traditionally been used in three major areas: food, pharmaceutical, and photographic industries.

Gelatin use in the food industry is probably best recognized in gelatin desserts and confectionery applications such as marshmallows and gummi candies. It is also used as a binding and/or glazing agent in meats and aspics.

In the pharmaceutical health industry, gelatin is used to make the shells of hard and soft capsules for medicines, dietary/health supplements, syrups, etc. It is highly digestible and serves as a natural protective coating for medications.

The unique chemical and physical properties of gelatin make it an important component in the photographic industry. Gelatin serves many useful purposes in the preparation of silver halide emulsions in the production of photographic film.

A new, major application for gelatin is in the paintball industry. The classic-style “war games” are played out using projectiles constructed of gelatin.

No. Gelatin is not a complete protein for mammalian nutrition since it lacks essential sulfur-containing amino acids and the essential amino acid tryptophan.

Surprisingly, gelatin is used in a variety of consumer products. Without identifying the application rationale, a short list of products in which gelatin is present include:

• Dairy – ice cream, sour cream, yogurt, cottage cheese, cream pies
• Meat – ham, aspics, canned hams, meat loaves, pates
• Desserts – jellied desserts, puddings, frostings
• Confectionery – gum drops, lozenges, wafers, candy cigarettes, marshmallows, fruit snacks, gummi snacks
• Other – consommé soups, sauces
  

The manufacturing of Gelatin and product specifications must meet regulations established by the Food and Drug Administration in the U.S. and Health Canada in Canada. All raw materials used by GMIA members come from USDA or CFIA approved and inspected facilities. The Gelatin Manufacturers Institute of America have stringent quality control programs to safeguard the production of gelatin.

No. Horse hooves are made of keratin, the same material as your hair and fingernails. Gelatin cannot be made from keratin.

No. Gelatin is tested and “Graded” according to its strength. The Grade is based on the “Bloom” test and the higher the Bloom number the higher the Grade. Gelatin is usually priced according to the Grade; the higher the Grade the higher the price.

Mr. Bloom invented a device for measuring the rigidity of a gelatin film. A sample of Gelatin is prepared with standard proportions of water and gelatin. The sample is processed according to an exacting test protocol and tempered in a series of temperature controlled water baths. A plunger is pushed into the gelatin sample and the force required to reach a predetermined depth is read in “Blooms”; the more rigid the sample, the higher the Bloom number and the higher the Grade (and price!)

There are a number of other physical tests run on gelatin: pH, moisture, viscosity (how thick the liquid gelatin is at a standard temperature), ash content, and heavy metals (e.g., lead) are a few of the more common ones.

Great care is taken in the gelatin plant to produce a pure, clean product. A number of microbiological tests are run to ensure the wholesomeness of the gelatin. At a minimum, microbiological tests are run on Total Plate Count, Salmonella, E. Coli and Total Coliforms.

Some of the finest gelatins, used in pharmaceutical applications, require between 20 and 25 physical tests and a dozen or more microbiological tests.

If kept in its original container at ambient humidity and a controlled temperature, gelatin can last practically forever. Most manufacturers like to limit the shelf life to just two or three years; this has more to do with degradation of the packaging than the deterioration of the gelatin.

While the Jewish and Islamic requirements are quite different, gelatin does carry the approval of both groups.

There are many Jewish Rabbinical agencies that grant approval. While each agency is not universally recognized by all the other agencies (within each religion) it is up to the individual Rabbi, at the plant using the gelatin in a finished product, to accept or reject the certification.

The same is true of Islamic agencies certifying, or accepting, Halal status.