Herbal oils may be obtained by extraction using solvents having low point. Percolation or maceration with a volatile solvent and subsequently stripping the solvent to yield the essential oil effectuates this extraction. When the solvent is removed, the resulting product is called a "Concrete".

United Engineering Corporation is one of the leading manufacturers of Vegetable Oil Extraction Equipment and an expert in Herbals Oil Extraction.

Herbal Oils Extraction generally consist of four fractions:

1. Terpenes
2. Oxygenated Derivates
3. Sesquiterpenes
4. Non-volatile Residue

Product Groups & Classification:

Essential Oils
Essential Oils find their applications in the food industry and in the fragrance industry like perfume, soaps, detergents etc. and in pharmaceutical products.

About 3000 essential oils are known, of these only 150-300 of them are of commercial importance. These may be categorized as under: herbaceous essential oils and non-herbaceous essential oils.

a) Including Terpenes
    Citrus Fruit Oils
    Other Oils

b) Without Terpenes
    Citrus Fruit Oils
    Other Oils

c) Others
    Resinoids

EXTRACTION

Enclosed is a brief profile on the extraction system that we are using for extraction of oleoresins etc. from Spices and from other herbs, flowers, vegetable etc.

The different kinds of Herbal Oils Extraction SYSTEMS are:

Solvent based
Where the use Hexane for extraction of spice oils. However as hexane boils at 69 deg C, it is necessary to boil the mixture to a temperature of 90-100 deg C to ensure that the hexane has evaporated. This damages the spice extract and there is a loss in the aroma. Also there is a strong danger for the extract to have a higher than permissible content of solvent in the final product. This usually creates a loss, as many a consignment is lost as the hexane is usually higher than 10 ppm and is rejected by the Western buyers.

Super Critical Fluid Extraction (SCFE)
In this case Carbon Dioxide is used as the solvent. The extract is very pure and commands a premium. However the disadvantage is that the plant cost due to working at pressures of 350 kg per sq.m. Plant costs are usually 4-5 million US Dollars.

Hydro Fluoro Carbon Extraction (HFC)
Hydro fluoro carbons are complex molecules that have very low boiling points. These materials can easily be compressed to obtain a very selective solvent. The pressure involved is about 10 kg/cm2. The residual solvent present in the process is about 1 ppb. This method is increasingly becoming more acceptable. HFC Extract: In this case these Hydro Fluoro Carbons are environmentally friendly as only CFC are banned. By compressing them we get a highly selective solvent. In this case the quality of the extract is same as SCFE but the pressures are 10 kg per sq. m. This causes the equipment cost to be reasonable (half the SCFE) cost and lower and a residual solvent content of 1 part per billion. The low temperature of extraction ensures a high activity of the oleoresin in terms of purity.