Waxes

The term "wax" (lat. cera) stands for a collective technological term used to describe a range of natural (vegetable, animal or mineral) or synthetic substances. All waxes are characterized by their insolubility in water and their solubility in organic, non-polar media.

Waxes are defined by their physical properties as substances which "are kneadable at 20 °C, are hard to brittle, have a coarse to finely crystalline structure, appear translucent to opaque in colour, melt at above 40 °C without decomposition, are slightly liquid slightly above their melting point, have a consistency and solubility which is highly dependent on temperature, and are polishable under slight pressure".

In food technology, some waxes are approved as food additives (mostly as release agents). In detail these are:

• E 901 beeswax
• E 902 Candelilla wax
• E 903 Carnauba wax
• E 904 Shellac
• E 905 Microcrystalline wax
• E 912 Montanic acid ester
• E 914 Polyethylene wax oxidates

Usually hidden under a "wax" are mixtures of esters of higher linear fatty acids (usually C18-C34) with higher monohydric alcohols of equal length (wax alcohols) and smaller proportions of free acids and alcohols. Natural waxes usually have a more complex composition. Animal waxes are mostly esters of fatty alcohols and carboxylic acids (e.g. palmitic acid). Vegetable waxes contain, among others, long-chain aliphatic hydrocarbons, fatty acids, primary and secondary alcohols as well as ketones and aldehydes.

Examples of wax types

Animal and vegetable waxes: Animal and vegetable waxes belong to the group of lipids. Main components of these mixtures are esters of fatty acids with long-chain aliphatic primary alcohols.

Animal waxes are exemplary:

• Shellac (E 904): Shellac consists of excrements of the female lacquer shield house. The insects live on versch, ficus species, suck the juice of young shoots and produce a red resinous secretion as a metabolic product.
• Beeswax (E 901):
• Cera alba (Ph.Eur.2) is a beeswax treated with bleaching agents (peroxides, chromic acid).
• Cera flava (Ph.Eur.2) is the untreated yellow beeswax obtained by melting the honeycombs with hot water.
• Wool waxes:
• Cera lanae (also known as Adeps lanae or wool wax) is the purified anhydrous waxy fatty mass obtained during the processing of sheep wool.

Vegetable waxes:

Vegetable waxes are products of deposition stored in or on the cuticle of leaves or fruits. They protect the above-ground parts of the plant against external influences (evaporation, wetting by water, infestation by microorganisms).

• Cera carnauba (Ph.Eur.2; E 903) - the wax of the wax palm (carnauba palm) with which the palm protects the surface of its leaves.
• Cotton wax
• Rice bran wax
• Flax wax
• Soy wax is obtained from soya by hydrogenation.

Bacterial waxes:

• Mycobacteria are the only known bacteria that form an outer shell of special waxes, the phthioceroles.

Earth waxes:

• Geological earth waxes (ozokerite and the ceresine produced from it) consist essentially of hydrocarbons.

Synthetic waxes:

Synthetic waxes are obtained mainly from petroleum. These include:

• Cera mineralis corresponds to the microcrystalline wax which is permitted as a food additive (E 905).

Waxes are used in various functions in medicine and food technology. As components of ointments and creams, for polishing dragées, for the production of gastric juice resistant tablets. Their technical use ranges from leather polishes, floor polish to soap and candle production.