Ossein is the organic extracellular matrix of

bone A bone is a rigid organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red and white blood cells, store minerals, provide structure and support for the body, ...

, which is made of 95%

collagen Collagen () is the main structural protein in the extracellular matrix of the connective tissues of many animals. It is the most abundant protein in mammals, making up 25% to 35% of protein content. Amino acids are bound together to form a trip ...

. This substance is used in industry for the production of

gelatin Gelatin or gelatine () is a translucent, colorless, flavorless food ingredient, commonly derived from collagen taken from animal body parts. It is brittle when dry and rubbery when moist. It may also be referred to as hydrolyzed collagen, coll ...

and bone glue. In the early 20th century, bones were found to consist of three types of proteins: ossein (collagens), osseomucoid ( proteoglycans) and osseoalbuminoid (

elastin Elastin is a protein encoded by the ''ELN'' gene in humans and several other animals. Elastin is a key component in the extracellular matrix of gnathostomes (jawed vertebrates). It is highly Elasticity (physics), elastic and present in connective ...

). Advances in molecular biology rendered these terms

obsolete Obsolescence is the process of becoming antiquated, out of date, old-fashioned, no longer in general use, or no longer useful, or the condition of being in such a state. When used in a biological sense, it means imperfect or rudimentary when comp ...

Applications

When processed industrially, 1,000 kg of bones yield 300 kg of ossein, which can be rapidly degraded and partially denatured by the prolonged action of slightly acidic boiling water, yielding

. The product is specifically known as ossein gelatin in contrast to

skin Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation. Other animal coverings, such as the arthropod exoskeleton, have different ...

gelatin, which is generated from animal hides. Depending on the method of extraction, there are various types of ossein gelatin (acid ossein gelatin, limed ossein gelatin, etc.). Another prominent use of ossein is the production of bone glue, whose yield is 16-20% of the mass of dry bone. Bones that are unsuitable for ossein production are carbonized to generate bone char.

Extraction methods

Ossein can be isolated by treating bones with

hydrochloric acid Hydrochloric acid, also known as muriatic acid or spirits of salt, is an aqueous solution of hydrogen chloride (HCl). It is a colorless solution with a distinctive pungency, pungent smell. It is classified as a acid strength, strong acid. It is ...

, which dissolves the inorganic matrix ( calcium phosphate and

calcium carbonate Calcium carbonate is a chemical compound with the chemical formula . It is a common substance found in Rock (geology), rocks as the minerals calcite and aragonite, most notably in chalk and limestone, eggshells, gastropod shells, shellfish skel ...

). The process was discovered no later than 15th century but only really spread in the 18th century, after Glauber's publications. The resulting liquor carrying calcium chloride and

phosphoric acid Phosphoric acid (orthophosphoric acid, monophosphoric acid or phosphoric(V) acid) is a colorless, odorless phosphorus-containing solid, and inorganic compound with the chemical formula . It is commonly encountered as an 85% aqueous solution, ...

may then be treated with

calcium hydroxide Calcium hydroxide (traditionally called slaked lime) is an inorganic compound with the chemical formula Ca( OH)2. It is a colorless crystal or white powder and is produced when quicklime ( calcium oxide) is mixed with water. Annually, approxim ...

to recover dicalcium phosphate for fertilizers or animal feed supplement. However, the most popular technique of treating the bone meal is steaming or boiling. This process requires no acid but much more energy and may also produce tricalcium phosphate. As an alternative, the deproteinized bone residue left after the removal of ossein can be used to produce bone ash for the manufacture of

bone china Bone china is a type of vitreous, translucent pottery, the raw materials for which include bone ash, feldspathic material and kaolin. It has been defined as "ware with a translucent body" containing a minimum of 30% of phosphate derived from c ...

References

{{Reflist Bone products Extracellular matrix

Applications

Extraction methods

See also

References