Family: Rosaceae
Genus: Rosa
Species: spp
(i) General background on the plant
A family of shrubs, sometimes trailing or scrambling, usually deciduous. Leaves are pinnate, very rarely simple. Stems are usually prickly. Flowers are terminal, solitary or in corymbs and are hermaphrodite. There are over 100 species of rose, possibly many more than this. The rose is native to the middle east and has been cultivated for at least 3000 years. Garden roses are hybrids with complex origins and have been developed over a long period of time.
Two species of rose are cultivated for production of flavour and fragrances:
The rose that is generally used for oil production is a hybrid involving R. centifolia, R. gallica and a few other roses, known as Rose de Mai. It is cultivated in France, Algeria, Morocco and Egypt. It is used for the production of rose de mai concrete/absolute.
Rosa damascena is cultivated in Turkey, Bulgaria, Morocco, India and China and is used for both rose oil and absolute.
The plant grows to 2.5 m high and has a mass of pink or rosy-purple flowers
(ii) Details of quality characters
It is generally agreed that about 82-88% of the constituents of Rose oil are covered by nine components, though they are not totally "responsible" for the character. They are:
| Citronellol Methyl Eugenol Geraniol Linalool Nerol Ethanol b -Phenyl Ethyl Alcohol Farnesol Parrafin Hydrocarbons |
38% 3% 14% 2% 7% 1% 3% 1% 15% |
(Aqua Oleum 1993)
(iii) Current production and yields
Harvesting of roses starts in the second year after planting, reaching its maximum yield in year five. After twelve years the productivity of a planting declines rapidly. On average, in France, a single rose bush produces 250 g of flowers per season. A yield of 3,000 kg of roses per hectare is considered very satisfactory.
Yields of flowers and oil are very variable, depending on variety, region and weather conditions, and time of picking. Kitchounow (1937) reported that flowers picked after 10 am yielded 59% less oil than those picked during early morning hours.
According to experience in Bulgaria, around 400 to 450 kg of Rosa damascena Mill are required to yield 1 kg of rose concentrate which in turn produces about 520 g of alcohol-soluble absolute.
In Bulgaria, Naves & Mazuyer (1939) reported yields of concentrate ranging from 0.22 to 0.25%. The concentrate gives 50 to 60% of absolute, and contains 35 to 41% of steam-volatile oil.
(iv) Constraints on production
(v) Markets and Market Potential
The total world production of Rose Otto and Absolute is estimated to be 17 tonnes annually, with absolutes making up the vast majority. (Aqua Oleum 1993).
The essential oil is used in aromatherapy as a mildly sedative antidepressant and anti-inflammatory remedy.
(vi) Other Information
Extraction
Rose Otto (rose oil): This is not a distilled oil as this would seriously damage the petals and the essence obtained from them, but it is a blend of decanted and recovered oil.Because of its low yield at only 0.02 - 0.05% of plant material used, it is one of the most expensive raw materials used in flavours and fragrances. Initially, the rose petals are hydro-distilled and both the oil and water are collected. The floating oil on the water is separated by decanting while the water is transferred to a more efficient still where it is subject to steam distillation. The oil obtained from this distillation is known as recovered oil, distilled oil or sometimes just water oil. The decanted and recovered oil are blended to make Rose Otto for commerce. It has a very warm, floral odour with hints of tea, fruit and honey. It is used in high class floral perfumes.
Rose Absolute is prepared by volatile solvent extraction from rose petals which yields first concrete and then extraction from the concrete is with alcohol, normally hexane or benzene. The extract is cooled in order to precipitate the waxes which are eventually filtered off. The alcohol solution is finally distilled under reduced pressure to remove the alcohol leaving behind the floral absolute. It is an orange-yellow / orange-brown viscous liquid with a long-lasting, deep rich rosy odour with spicy tones. Its price is very high and it is only used in high class perfumes, often in combination with jasmine absolute and rose oil. It is also often used to enhance fruit flavours and flavouring of tobacco.
See the following pages in the NF-2000 Database
(vii) Contacts
(viii) References
Guenther, E. 1949. The Essential oils. R.E. Krieger Publishing Company, Inc. Florida. USA
Naves & Mazuyer (1939) Les Parfums Naturels Paris pp.271
Kitchounow (1939) Parfumerie moderne 31. 175.
Zoebelein, H. Dictionary of Renewable Resources (1997). Weinheim.