Physicochemical Properties of Royal Jelly and Comparison of Commercial with Raw Specimens

Abstract

Background: Royal jelly is an exclusive diet of the queen larvae of honey bee, Apis mellifera, which affects the body size, development time, lifespan and reproductive output of the queen relative to workers. The chemical composition of royal jelly is complex and it possesses diverse pharmacological activities. In addition to the chemical composition of royal jelly, other indirect parameters such as color, viscosity, sugar and protein content have also been proposed in evaluating the quality of royal jelly. Methods: The present study described total phenolic compounds, proteins, and polysaccharide contents of two samples of royal jelly using spectrophotometric methods along with their total lipid, ash and moisture by gravimetric analysis. Results: The results showed that similar amounts of phenol and polysaccharide were present in the commercial and raw samples of royal jelly (phenol: 22.98 ± 0.34 and 21.99 ± 0.41 µg/mg gallic acid equivalent; polysaccharide: 12.67 ± 0.00 and 12.63 ± 0.00%, respectively). Whereas, lipid (12.00 ± 0.00%) and protein (11.57 ± 0.00%) content of raw sample was calculated to be significantly higher compared to those in the commercial sample, the commercial sample has higher moisture than the raw specimen (61.03 ± 0.00 and 59.01 ± 0.00%, respectively. The similar amounts of ash were analyzed in both of the tested samples. Conclusions: Although, the content of analyzed components was different in analyzed samples, both of them contained comparable amounts of desired compounds. Therefore, the Iranian raw sample of royal jelly could be a suitable source to produce commercial preparations compared to the formulated royal jelly.