How to purify propolis powder?

- Jan 07, 2021-

Although the various contents of natural propolis are very complicated, most of the effective ones are well soluble in ethanol and sodium hydroxide solution, while only a few substances are soluble in non-polar solutions, such as beeswax. Mixing petroleum ether and ethanol can bring out most of the effective substances in propolis, but the process is more complicated, which is only suitable for large-scale production due to process limitations. The polarities of acetone and ethanol are close, but the extract is not as good as ethanol extraction, which can be directly made into tincture. The extract is used in medical preparations, food, cosmetics, etc.

The following introduces several feasible purification technologies of propolis powder:

natural propolis

1. Ethanol and petroleum ether two-phase solvent extraction method

Place the crushed natural propolis powder in the extractor, add 90% ethanol 4 times and 60-90° petroleum ether 1 times (weight: volume), stir and extract at a constant temperature of 40°C, repeat 3 times as above process, combine extraction the liquid was separated into layers, filtered after cooling, and concentrated under reduced pressure. The fat-soluble and alcohol-soluble substances are combined to obtain pure propolis powder. It is confirmed by experiments that the volume-weight ratio of petroleum ether and ethanol solution to propolis is in the range of 1:4:1, the extraction rate is higher at 40°C and the content is relatively complete. However, because the equipment and process are more complicated than the single-solvent extraction method, it is suitable for large-scale production.

Ethanol and petroleum ether two-phase solvent extraction method

Sodium hydroxide solvent extraction method

2. Sodium hydroxide solvent extraction method

Add the crushed natural propolis to 1%, 2% sodium hydroxide solution 10 times, stir well to dissolve it and filter it immediately, then add 5% HCL aqueous solution to acidify the propolis to separate out, wash it with water and then injection mold it. the method is difficult to master in terms of technology. In the process of dissolving and acidizing with lye, the time and temperature are too high, so that the precipitated propolis powder is slag-like substance. The analysis proved that although the sodium hydroxide solution has good dissolving for the effective content of propolis, it cannot reduce all the content after acidification, some irreversible reactions such as partial foreignization and partial saponification to acidity occur. Therefore, it is inappropriate to use sodium hydroxide as a solvent effectively contained in natural propolis.

propolis powder

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