What is Gelatin?
Gelatin is a protein and in aqueous solutions is a hydrophilic colloid.
Gelatin derived from an acid-treated precursor is known as Type A, and
it is derived from an alkali-treated precursor is known as Type B.
What is Gelatin made of ?
Gelatin is obtained by the partial hydrolysis of collagen derived from
the skin, white connective tissue and bones of animals. The top four
commercial sources of gelatin are Cowhide Splits, Bones (ossein) Pork
Skin, and Fish Skin. Gelatin does not occur freely in nature, and
cannot be recovered from horns, hoofs and other non-collagen containing
parts of vertebrate animals. There are no plant sources of gelatin, and
there is no chemical relationship between gelatin and other materials
referred to as vegetable gelatin, such as seaweed extracts.
How is gelatin made?
An explanation of the production of gelatin will help in understanding
the properties and the characteristics which exist among several types
and grades.
Gelatin is derived from collagen, an insoluble fibrous protein that occurs in vertebrates and 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 .It 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 veral varieties of gelatin, the composition of which depends on the source of collagen and the hydrolytic treatment used.
Is all gelatin the same ?
No. Gelatin is tested and "Graded" according to strength. The Grade is based on the "Bloom" test . Higher Bloom result , higher grade of gel set.
It is usually priced according to the gelling ability : higher bloom, higher price ; and also classified according to its ability based on various standards.
What is "Bloom" ?
The measurement of force, in grams, required to depress a standard plunger 4mm into the surface of a 6.67% gelatin sample at 10 °C (50 °F) . The firmer the set of gelatin, the higher , the better bloom strength.
Gelatin consists of :
Approximately 86% protein, 12% moisture & 2% ash.
The difference between Gelatin & Hydrolyzed Gelatin ?
Hydrolyzed Gelatin does not gel. (Hydrolyzed gelatin has had its gelling function enzymatically removed.)
Melting point of gelatin :
Temperature at which gelatin initially melts into a liquid solution. Moisture Percentage of water driven off from gelatin after heating the gelatin to 105 °C for 17 hours.
Residue on Ignition :
Percentage of residue after reducing the gelatin to an ash at 550 °C.
Setting point :
Temperature at which gelatin initially forms a gel.
