Monday, March 24, 2008

What is Gelatin?

Edible gelatine is a natural foodstuff. The raw materials used in its manufacture are skin (pigskin and hide split) and bone taken from slaughtered animals that have been approved for human consumption. The collagen contained in these raw materials is the actual starting material used for the manufacture of gelatine.

Native collagen is a scleroprotein based on a polypeptide chain comprising approximately 1,050 amino acids. Three of these chains form a triple helix.

Superimposition of many of these triple helices produces fibrils of collagen that are stabilized by cross-linking, hence forming a 3-dimensional network structure. This particular structure renders collagen insoluble; it is then brought into soluble form by partial hydrolysis as gelatine or gelatine hydrolysate.

The amino acid content of collagen and hence of gelatine is about one third glycine and a further 22% proline and hydroxyproline; the remaining 45% comprise 17 amino acids. Gelatine has a particularly high content of acidic and basic amino acids. Of the acidic amino acids (glutamic acid and aspartic acid), about 1/3 is present in the amido form as glutamine and aspargine. Cystein is completely absent; of the sulphur-containing amino acids, methionine is the only one present, in low proportion.

Commercially available edible gelatines have the following composition:

• 84 - 90% protein
• 8 - 12% water
• 2 - 4% mineral salts

They contain no fat or carbohydrates, no purine or cholesterol and are in addition free of all preservatives. All edible gelatines comply fully with all bacteriological standards.

Source of information

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