Extraction of Propolis Powder by Ethanol Solution Dipping Method

- Jan 11, 2021-

The crushed propolis powder was added to 5 times the ethanol aqueous solution, the concentration was 75%, 85%, 95%. After immersing for 24 hours at room temperature, the immersion liquid is taken out, added twice, the combined immersion liquid is cooled to below 5°C and filtered, the solvent is recovered under reduced pressure. Its concentrate is dark brown to black pure propolis.


Extraction process:

(1) The raw materials are pre-selected and classified to remove impurities.

(2) Put the pre-selected raw materials into a refrigerator and freeze them at -18°C for 48h.

(3) The frozen raw materials are quickly put into the crusher and crushed. Due to the physical properties of propolis, it is in a semi-plastic state at room temperature and is difficult to break, but it is easy to break at a temperature below -5°C.

(4) The crushed raw materials immediately enter the vibrating screen (14 mesh), and particles larger than 14 mesh are returned to the refrigerator.

propolis powder

(5) Put the crushed and sieved raw materials into the impregnation kettle, and the impregnation kettle is preferably a reaction kettle equipped with a reflux condenser. Add 90% ethanol [propolis (weight): ethanol (volume = 1:4)], soak at room temperature, and stir constantly. After 6h, stop stirring, let stand for 2h, release the supernatant, add 90% ethanol, repeat the above process 3 times, and combine the solutions. During the dipping process, the temperature should be kept at about 25°C. Too high temperature will cause a large amount of beeswax to melt, causing difficulty in filtration; too low temperature will reduce the solubility and lead to prolonged time and increase the amount of solvent.

(6) The immersed solution enters the cooling reactor, and the reactor jacket is passed through circulating cooling, mechanically stirred, and the temperature is lowered to 5°C.

(7) The cooled solution enters the plate and frame filter through the pump while it is cold for filtration. The temperature of the solution should be kept below 5°C, so that the beeswax dissolved in the ethanol solution which can be precipitated and filtered out with the filter residue.

(8) The filtrate enters the decompression evaporator and is heated by a water bath. At this stage, the temperature should be kept below 50℃, which can reduce the evaporation of volatile oil and effectively contain heat denaturation.

(9) The evaporated ethanol vapor is recovered by the condenser and injected into the solvent storage tank for recycling.

(10) The evaporated propolis is ready-made (pure propolis) after injection molding. If your condition does not meet any of the above, then don't do it casually, let alone try to eat.

Ethanol Solution Dipping Method

The purification of propolis powder needs to reach a very sophisticated level of scientific technology. It is also because of that the price of propolis will be more expensive. In fact, it is expensive in processing. If the personal level of craftsmanship and equipment is not up to the level, harmful substances are difficult to remove. It is recommended to buy the finished propolis. After all, what you eat for yourself cannot be treated carelessly, let alone trivial.

For Further Information of propolis powder, please contact: information@sxrebecca.com