Technology of extracting jasmine essential oil and applying in tea industry

In our country, jasmine plants are evaluated as high economic value crops. Jasmine is the main raw material used in flavoring technology to process tea. However, due to the harvest time of jasmine and tea trees in contrast, the use of jasmine for tea marinated technology has encountered certain difficulties. In order to overcome the seasonal difficulties and improve the efficiency of jasmine in our country, researchers have introduced technical solutions for industrial technology and equipment to extract jasmine essential oil for tea marinating industry. This solution aims to stimulate people to grow mass-produced jasmine in our country, while contributing to the development of the essential oil industry in general and jasmine essential oil in particular. This research was honored to receive the award of encouragement of VIFOTEC 2003.

The first content of the solution is to find out the method of extracting natural jasmine essential oil with high extracting efficiency, keeping the characteristic aroma of fresh jasmine.

The second content of the solution is to research and manufacture technological equipment for extracting jasmine essential oil with high extraction efficiency, retain the characteristic aroma of natural jasmine, ensure the purity of essential oils be extracted, reduce production costs.

Sambac jasmine

In order for this technical solution not only to be at the laboratory level but to be put into practical production, researchers have tested the raw material sources of raw solvent available in the country to serve the production. export, avoid the use of high-priced imported solvents and research and manufacture industrial equipment suitable for the production of jasmine essential oils, especially for Sambac jasmine varieties in our country.

Currently, there are some methods to extract essential oils from flowers in the world such as: In France, Bulgaria, people have used volatile solvents (such as beef fat treated impurities) to absorb incense. flower.The disadvantage of this method is that the process of separating incense from the solvent is carried out at high temperature, so the incense components are easily decomposed, the ability to separate is not completely. In addition, it takes a lot of space to install equipment.

The steaming method uses steam rising from the stove to pass through a tray of flowers to attract the incense to follow the steam, then separate the flower fragrance (essential oil) from the steam by the distillation method.The disadvantage of this method is that the oil content is not high, the essential oil has no characteristic odor of natural flowers because the boiling temperature of water is much higher than the constituent temperature segment of flowers.

The method of leaching with petroleum ether solvents has the disadvantage that the appealing flavor is not entirely due to the wide temperature range of ether, ranging from 30oC to 90oC, so the separation of the solvent from the oil will be difficult, Heat control devices in the system are difficult to program because the boiling range is too large.

In Vietnam, the method of extracting jasmine essential oils has been carried out by researchers as follows:

Tea tree leaves

Jasmine and solvents are added to the reaction vessel at the rate of one part of the flower and three parts of the solvent. The mixture of flowers and solvents is stirred continuously for a period of 12 hours to 32 hours (depending on capacity and season) at a temperature of 30 - 32oC. Thanks to the pressure of mixing, the cells containing the essential oil will be broken and dissolved in the solvent to form the extract. After fractional distillation under low pressure to separate the solvent from the essential oil, the crude oil (flower wax) will be obtained. Flower wax is dissolved in ethanol. After conducting filtration and distillation at low pressure to separate ethanol from essential oil, pure jasmine essential oil will be obtained.

To meet the production needs in accordance with the existing conditions of Vietnam, researchers have designed and manufactured industrial equipment with a capacity of 0.5 tons of flowers / batch. The equipment (including flower mixing device, low pressure distillation system, cooling welding system .) is designed according to the continuous and closed method. The system designed by this method ensures maximum decomposition of the constituents in jasmine oil, in order to retain the natural scent of flowers.

The method of extracting natural jasmine essential oil has high extraction efficiency of over 99% and preserves the characteristic aroma of fresh jasmine. This method has been successfully tested on jasmine scented tea products and has been applied to practical production, bringing benefits to society. At the same time, it is also an encouragement for people to expand the area of ​​jasmine cultivation in our country.

Nguyen Huong