Characterization of Royal Jelly by Electrospray Ionization Mass Spectrometry Fingerprinting

Abstract

Royal jelly is an apicultural product, fed to the queen bee and consumed by humans as a health food and traditional medicine; its beneficial effects on human health have been the subject of several studies. As royal jelly is obtained in small amounts and reaches a high market price, it could be adultered with other cheaper substances. As it is prone to degradation at room temperature, lyophilization is used to prolong its shelf life. Due to the complex composition of royal jelly, several different parameters need to be evaluated to determine of freshness, purity and quality; consuming an appreciable amount of sample and time. Electrospray ionization mass spectrometry (ESI-MS) fingerprinting was carried out in the negative ion mode on a high resolution FT-ICR mass spectrometer; marker compounds were identified by comparison of their high resolution mass with data from literature. ESI-MS fingerprinting was capable of characterizing natural, lyophilized, degraded and adultered samples of royal jelly, and indicate marker compounds for each set of samples, with the aid of Principal Component Analysis. The complete analysis, from a simple extraction procedure to ESI (-)-MS fingerprinting, takes only a few minutes and consumes only 50 mg per sample. Therefore, large numbers of samples can be quickly evaluated for purity and freshness in a single-shot approach, while using small amounts of royal jelly per analysis.