(2E)-10-hydroxydec-2-enoic acid in royal jelly as determined by liquid chromatography

Abstract

Matična mliječ je proizvod koji izlučuju mlade pčele radilice, a pripisuje joj se višestruko pozitivno djelovanje na organizam. To djelovanje je u najvećoj mjeri rezultat prisutnosti (2E)-10-hidroksidec-2-enske kiseline (10-HDA) koja je prisutna isključivo u matičnoj mliječi, pa se njezin udio smatra jednim od kriterija određivanja autentičnosti i kvalitete matične mliječi. Ne postoje međunarodni standardi za kvalitetu matične mliječi niti standardna metoda za određivanje udjela 10-HDA u matičnoj mliječi. HPLC metoda s detektorom s nizom dioda je validirana i upotrjebljena za određivanje udjela 10-HDA u svježoj matičnoj mliječi. Identifikacija 10-HDA provedena je na osnovi usporedbe vremena zadržavanja i apsorpcijskog spektra sa standardom 10-HDA, a kvantifikacija je provedena internom kalibracijom. Izvedbene značajke metode pokazale su da je metoda prikladna namjeni. Udio 10-HDA u 5 svježih uzoraka matične mliječi iznosio od 1,56 do 3,78 %. Prema preporukama o parametrima kvalitete matične mliječi koji predlažu da udio 10-HDA iznosi minimalno 1 %, uzorci korišteni u ovom istraživanju su svježi i nekrivotvoreni. Vrsta ambalažnog materijala nema utjecaj na udio 10-HDA u svježoj matičnoj mliječi ako se uzorak nakon vađenja smrzne i skladišti u zamrzivaču.Royal jelly is a product secreted by young worker bees, which has multiple positive effects on human health. They are mainly result of the presence of (2E)-10-hydroxydec-2-enoic acid (10-HDA), a component present only in royal jelly and its content is considered as one of the criteria for determining the authenticity and quality of royal jelly. There is neither international standard for the royal jelly quality nor standard method for determination of 10-HDA in royal jelly samples. HPLC method with absorbance detection was validated and used for the determination of 10-HDA in fresh royal jelly samples. Identification of the 10-HDA was performed based on comparison of retention times and absorbance spectrum 10-HDA of royal jelly sample compared with the spectrum of standard 10-HDA, and quantification was carried out by internal calibration. Method performance characteristics showed that the method was fit for purpose. The 10-HDA content in 5 fresh royal jelly samples was from 1.56 to 3.78 %. According to the recommendations on the royal jelly quality, that proposed a minimum 10-HDA content of 1 %, samples used in this study are fresh and authentic. Packaging type has no effect on 10-HDA content in fresh royal jelly, if samples are frozen after extraction and kept in freezer until analysis