Geographical influences on content of 10-hydroxy-trans-2-decenoic acid in royal jelly in China.

The content of 10-hydroxy-trans-2-decenoic acid (10-HDA), a marker compound in royal jelly (RJ), is the most important criterion in grading RJ for commercial trade and varies with its origin. To identify the effect of geographical origin on 10-HDA content in RJ, 138 samples were collected from 19 provinces of China (divided into three groups) produced by either Apis mellifera ligustica Spinola, 1806 or a hybrid of A. m. ligustica and Apis mellifera carnica Pollman, 1879 and analyzed for moisture, sugar, crude protein, ash, acid, and 10-HDA concentration. The results show that RJ from western China has a significantly higher 10-HDA level (2.01 +/- 0.05%) than those from northeastern (1.87 +/- 0.05%) and eastern (1.75 +/- 0.03%) China. RJ secreted by hybrid bees contained more 10-HDA (1.89 +/- 0.03%) than that secreted by A. m. ligustica (1.78 +/- 0.03%). The 10-HDA content of RJ produced during flowering of rape (Brassica campestris L.), lime (Tilia amurensis Ruprecht), and vitex (Vitex negundo L. variety heterophylla (Franch.) Rehder) was 1.92, 1.80, and 1.68%, respectively. The results would be helpful during the process of price determination of RJ by providing some basis of geographical, bee strain, and botanical information for commercial trade.