Wax as a component of propolis

Propolis is a complex material, composed mainly of resins derived from various plant species, but also containing variable amounts of wax produced by the bees themselves.

Crude propolis is widely used commercially, and in general its beeswax content is extracted, removed or possibly returned to beekeepers. The wax content of propolis varies from 16 to 80%. If its composition were better understood, it could be envisaged that this wax might be used in the same applications as native beeswax. Industrial uses of this recovered wax include candle manufacture, protective coatings for cheese, and applications in pharmaceutical and cosmetic formulation.

In a recent article published in the “Journal of Apicultural Research”, New Zealand researchers analysed in great detail (including gas chromatography) the composition of this wax derived from propolis. The samples examined were very similar to native beeswax, suggesting that they could be advantageously used in food packaging (gelatin capsules, medicinal capsules, glazes and food additives, as well as various chewing gums).

Simple lipids and hydrocarbons of New Zealand propolis wax: composition and functional implications

Propolis is a heterogeneous mixture of plant resins combined with beeswax secreted by worker bees. During industrial processing, the wax fraction is often separated from the resin, yet detailed data on the composition of New Zealand propolis wax had been lacking. The study aimed to characterise the neutral lipids and hydrocarbons of this wax and to compare them with conventional beeswax.

The composition was determined using thin layer chromatography, solid phase extraction, gas chromatography and GC-MS. The results demonstrate that the wax consists predominantly of wax esters, accompanied by long-chain hydrocarbons, free fatty acids and low levels of free fatty alcohols, as well as trace amounts of 1-O-alkylglycerols. Wax esters account for roughly three quarters of the total mass, hydrocarbons for about one seventh, and free fatty acids for just over one tenth.

The wax esters are mainly composed of saturated non-hydroxylated fatty acids and fatty alcohols, together with mono-hydroxylated fatty acids, particularly ω-2 and ω-3 hydroxy derivatives of palmitic acid. Non-hydroxylated fatty acids range from 16 to 36 carbon atoms, while hydroxylated acids range from 14 to 26 carbons. Approximately one tenth of the non-hydroxylated fatty acids are monounsaturated, whereas monounsaturated hydroxylated fatty acids occur only at trace levels. The fatty alcohol moieties are predominantly saturated and typically contain 24 to 34 carbon atoms. No polyhydroxylated fatty acids were detected.

The hydrocarbon fraction is dominated by long-chain odd-numbered saturated and monounsaturated hydrocarbons. Free fatty acids are also mainly long-chain and saturated. Overall, the compositional pattern closely resembles that of honeycomb-derived beeswax, indicating that most constituents are of bee origin rather than botanical origin.

The strong similarity to beeswax suggests that New Zealand propolis wax could be used in comparable applications, including food coatings, glazing agents or as a source of long-chain fatty alcohol mixtures such as policosanol. The presence of specific hydroxylated fatty acids may also have biological relevance. In conclusion, New Zealand propolis wax displays a chemical profile highly comparable to conventional beeswax, supporting its potential for functional substitution in industrial and food-related uses. 
 

Read the article in English: “Simple lipids and hydrocarbons of New Zealand propolis wax”: 

See also:

• Propolis
• Practical Guide: 4.1.1 Propolis in the Colony
• Beeswax – A Very Precious Commodity
• Wax Production by Bees
• Beeswax Contamination