Rosa rugosa, native to China, is a Rosa shrub of the rose family and an important aromatic plant. Roses are rich in vitamin C, amino acids, soluble sugars, alkaloids, calcium, iron and other minerals. They have the effects of activating blood stasis, warming stomach and strengthening spleen, soothing liver and relieving depression, and nourishing beauty. First published in "Food Materia Medica", it is a new resource for both food and medicine, integrating ornamental, aromatic, edible and medicinal values.

Rose cultivation has a long history. The main producing areas of rose in China are Pingyin Shandong Province, Weinan Shaanxi Province, Zaoyang Hubei Province, Wushui Gansu Province, Miaofeng Mountain Beijing and Xinjiang Province, and the main producing areas abroad are Bulgaria, Morocco, France, Turkey, Iran and other countries.

Pingyin rose

Origin:  Pingyin County, Shandong Province

Function: It has the effect of beauty, promoting blood circulation and removing blood stasis

Application: Both edible and medicinal, among the many flower teas, only Pingyin rose was written into the "Chinese Pharmacopoeia".

Bittersweet rose

Origin: Bitter water Town, Lanzhou

Function: It has the function of promoting digestion, weight loss, beauty and so on

Application: Both edible and medicinal, often used for soaking water and drinking.

Damascus rose

Origin: Originally from Damascus, Syria

Function: It has the effect of relieving pressure and desalting scar, anti-sensitivity and whitening

Application: Often refined as essential oil, Damascus rose essential oil is considered to be the best rose essential oil.

Chiba rose

Origin: Originally from France

Function: Chiba rose is known as the "queen of flowers", with acne, beauty, whitening skin, make the role of red skin

Application: Chiba rose is currently the best variety for refining essential oil.

The rose oil extracted from the rose is called "liquid gold", which is an irreplaceable raw material for the world's spice industry and is mostly used in the manufacture of high-end perfume and other cosmetics. It takes about 5kg of rose petals to extract a single drop of pure rose essential oil. The extracted rose oil does not contain any additives or chemical raw materials, is a pure natural skin care product, with excellent anti-aging and anti-itching effect, can promote cell regeneration, prevent skin aging, smooth skin fine lines, but also has the effect of making people relaxed and happy.

Extraction method of rose essential oil

At present, there are many extraction methods for rose essential oil, which are generally divided into traditional extraction technology and new extraction technology. The common traditional extraction technologies of rose essential oil include steam distillation technology, organic solvent extraction technology, mechanical pressing technology, and the new extraction technologies include supercritical CO2 extraction technology, subcritical fluid extraction technology, molecular distillation purification technology and other methods.

Steam distillation technique

The process flow of steam distillation technology: rose → soaking → steam distillation → oil-water separation → rose essential oil.

Rose steam distillation technology is to soak the rose in water directly with steam distillation, through high temperature water vapor, so that the oil flavor vaporization with water vapor separation, this technology is the most common technology to extract plant natural spices, its equipment, process, operation and other aspects of technology are relatively mature, with low cost, large output, equipment and simple operation advantages. Water vapor distillation technology is generally divided into three forms: water vapor distillation, water distillation and water distillation. The whole process without the application of chemical reagents, more safe, and rose essential oil is difficult to dissolve in water, volatile, chemical properties are more stable, therefore, the domestic rose essential oil uses this traditional technology. However, in actual production, because the distillation speed and distillation time are difficult to control, the oil yield of rose essential oil is greatly affected, and high temperature will destroy the organic matter in the essential oil, thus affecting the color and smell of the essential oil. At the same time, it will produce a large amount of industrial wastewater, which not only increases the operating costs of enterprises, but also causes environmental pollution.

Mechanical press technique

Mechanical press technology process flow: rose → physical pressure → press → oil-water mixture → Centrifugation or filtration → rose essential oil.

Mechanical press technology is the use of physical pressure directly from the shredded rose by pressing the way to separate the oil and water mixture, and then through centrifugation or filtration methods to get rose essential oil, the whole process without any chemical additives, product safety, health, pollution-free, and nutritional content is not damaged. This method is relatively old, the required technology and equipment is simple, the cost is low, the oil is fast, but the oil is less, the composition is not pure, and it is suitable for family production and use.

Organic solvent extraction technology

Organic solvent extraction technology is the use of compounds in two kinds of mutually insoluble (or slightly soluble) solvents in the solubility or distribution coefficient is different, so that the compound is transferred from one solvent to another solvent, after repeated extraction, the vast majority of the compound is extracted. Rose petals are soaked in organic solvent (such as petroleum ether, n-hexane, etc.), heated extraction to get rose extract, and then concentrated and dewaxed to get rose essential oil.

Organic solvent extraction technology can better maintain the fragrance of raw materials, simple process operation, to a certain extent, improve the yield of essential oil, but the extract obtained by solvent extraction is dark in color, contains impurities such as waxy pigments, and there is solvent residue, which will cause solvent pollution, has a great impact on the purity of essential oil, poor natural feeling, currently only used in the laboratory, not applied to production.

Supercritical CO2 extraction technology

Supercritical CO2 extraction technology process flow:

Rose → Supercritical CO2 fluid → Dissolution → Pressure reduction or temperature rise → Extraction → separation → Rose essential oil.

Supercritical CO2 extraction technology uses supercritical CO2 to dissolve some special natural products, and is carried out through the influence of temperature and pressure on the dissolution capacity of supercritical CO2. That is, the density of CO2 under high pressure is similar to that of liquid. Put rose petals into supercritical CO2 fluid, the rose is quickly dissolved, and then extract the organic components in the rose from the liquid by reducing pressure or heating up, so as to obtain rose essential oil with high purity.

As an extraction medium, CO2 is considered to be safe, non-toxic, non-combustible, easy to obtain, and safe to use. Under the protection of CO2, this method can prevent the destruction of effective components in rose, good product quality, high extraction rate, strong extraction ability, no organic solvent residue and green environmental protection. However, because the whole process needs to be carried out in the ultra-high pressure state of more than 25 MPa, the enlargement of the effective volume of the equipment is limited, and the high equipment and operating costs restrict the application of the technology, and the industrial application is less.

Subcritical fluid extraction technique

Subcritical fluid extraction technology is based on the principle of similar dissolution of organic matter. In a closed, oxygen-free, low-pressure pressure vessel, subcritical fluid is used as an extractant. Through the molecular diffusion of rose and extractant during immersion, the fat-soluble components in rose are transferred to the liquid extractant. A new extraction and separation technique for separating extractant from rose essential oil by vacuum evaporation.

The subcritical fluid extraction technology overcomes the shortcomings of the traditional process and retains the advantages of supercritical fluid extraction. Compared with other separation technologies, it also has the advantages of harmless, non-toxic, environmental protection, energy saving, low cost, non-thermal processing, no oxidation, no destruction of the active ingredients of the extract, easy to separate from the product, etc., and can be industrialized and large-scale production.

Molecular distillation purification technology

Molecular distillation purification technology is a special liquid-liquid separation technology, in the state of high vacuum, using the different characteristics of the mean free path of molecular motion of different substances, to separate various substances. Compared with the traditional distillation technology, the material residence time is short, will not destroy the composition of the organic matter itself, can effectively separate, purify and concentrate natural substances, very suitable for high boiling point, easy oxidation and heat sensitive material separation. Therefore, it is extremely suitable for the extraction of rose essential oil.

Sum up

At present, there are roughly 6 extraction methods for rose essential oil, including steam distillation technology, organic solvent extraction technology, mechanical pressing technology, supercritical CO2 extraction technology, subcritical fluid extraction technology, molecular distillation purification technology and other methods. Each extraction method has its own advantages and disadvantages, and should be selected according to the actual situation