Comparison of the Lipid Content, Fatty Acid Profile and Sterol Composition in Local Italian and Commercial Royal Jelly Samples

Royal jelly (RJ) is a beehive product that has gained a significant scientific and commercial interest due to its healthy properties. In the present study, lipid content, fatty acid profile and phytosterol amount were determined in eight local and four commercial pure RJ samples. A mixture of diethyl ether/isopropanol 50/1 (v/v) was chosen to extract fat matter from RJ. Lipid amounts ranged from 2.3 and 7.2 % and from 2.0 to 3.2 % of the fresh product in local and commercial RJ, respectively. Fourteen fatty acids and three phytosterols were identified. About 70 % of the total fatty acids consisted of (E)-10-hydroxy-2-decenoic and 10-hydroxydecanoic acid. No significant difference was observed between local and commercial samples in regards to the relative amount of individual fatty acids. Sterols were in the range 179-701 and 329-1,097 mg kg(-1) of fat in local and commercial RJ, respectively. A significant difference (p a parts per thousand currency sign 0.05) was observed within RJ types in regards to the 24-methylenecholesterol fraction, amounting to 77 and 67 % of identified sterols in local and commercial products, respectively.