Components of Royal Jelly II. The Lipid Fraction, Hydrocarbons and Sterols

Abstract
Quantitative differences were found in the chemical composition of royal jelly samples collected in spring and summer by the same producer. The main difference was in the free fatty acids, which showed a marked increase in 10-hydroxydecanoic acid in summer. The sterol and hydrocarbon fractions were also investigated. The most significant sterols were identified by gas chromatography—mass spectrometry. The hydrocarbon components, identified by their retention times, were a homologous series of straight-chain compounds, from C16 to C33, with even and odd numbers of carbon atoms. Considerable amounts of some hydrocarbons were found. Of the sterols identified, the most abundant was 24-methylene cholesterol; stigmasterol, β-sitosterol, Δ5-avenasterol, Δ7-avenasterol and cholesterol were also present.