Stable carbon-isotope analysis of harvested and commercial royal jelly
Paul S. Dimick and Susan R. Howe
Del 13C-isotope ratios were determined in royal jelly samples harvested from 4 Apis meillfera colonies at Pennsylvania State University. One sample, collected in July 1981, had a 13C-isotope ratio of -13.3%0. This ratio indicates that the carbon of the dietary organic material utilized by the bees was predominantly from C4 plants. The other samples, collected during August of the same year, had 13C isotope ratios ranging from - 25.2 to -25.6%0; thus the carbon of the dietary sources of these bees was primarily from C3 plants. The isotope ratios for 6 samples of commercial royal jelly products (pure royal jelly or royal jelly + honey) ranged from -6.9%0 to -28.9%0. The possibility that some of these products were adulterated is discussed.
13C -isotope ratios, carbon-isotope analysis, commercial royal jelly, harvested royal jelly, Royal jelly