Physicochemical characterization of Persian fresh royal jelly samples

Abstract

Although the health-promoting properties of Royal Jelly (RJ) have been known for many years, only a few countries have set national quality standards or guidance for RJ quality determination. Data about Persian RJ quality are not widely available; therefore, the results presented in this study can be considered pioneering ones for Persian RJ characterization in terms of trans-10-hydroxy-2-decenoic acid (10-HDA), sugars, protein, and moisture content. In this study, high performance liquid chromatographic method (HPLC) was used to determine the amount of main carbohydrates (fructose, glucose, and sucrose), other sugars (maltose, erlose, and turanose) and 10-HDA in fresh RJ samples. Based on our research, the primary sugar compounds were glucose and fructose, with lower concentrations of sucrose. The total amount of these main sugars available in RJ samples ranged from 8.8% to 12.2%, with an average of 10.5%. Sucrose is always present, but often in highly variable concentrations. This study illuminated that fresh Persian samples contain 60–70% water, 13.7% proteins, 7–18% carbohydrates, and up to 1.4% of 10-HDA. The average value for 10-HDA content was 2.3%. Also, it was cleared that the quality of RJ from mountainous areas were higher than the other regions. The results of this study indicated that RJ limits in some countries should be modified and International Honey Commission (IHC) and International Organization of Standardization (ISO) recommendations should be reviewed according to recent data on diversity. We believe that our proposals could be considered to set global standards for RJ.