Physicochemical characterisation of French royal jelly: Comparison with commercial royal jellies and royal jellies produced through artificial bee-feeding

A reliable database is established from the analysis of 500 French royal jellies (RJ). Diversity of geographical origins, harvesting seasons, and forage sources were taken into account. Authenticity intervals for numerous physicochemical parameters have been established from French RJs, obtained without bee-feeding with artificial sugars or proteins.

RJs from Italy and non-European countries, derived from feeding experiments, were analysed and compared with the database. Differences in 10-HDA, δ13C and sugars (sucrose, erlose, maltose, maltotriose) contents were observed. Sucrose and erlose contents in French RJs were less than 1.8 and 0.4%, respectively, whereas they attained 3.9 and 2.0% in some commercial samples and 7.7 and 1.7% in RJs produced by sugarcane feeding. Maltose and maltotriose contents were less than 1.0 and 0.2% in French RJs, and they can attain levels of 2.6 and 0.4% in commercial samples; they can be as high as 5.5 and 1.7% in RJs obtained by bee-feeding with starch hydrolysate syrups.

RJs obtained with and without feeding exhibit δ13C values ranging from −26.45 to −23.73‰, and from −26.05 to −14.65‰, respectively. This study could be used to discriminate different production methods and provide a useful tool for identifying unknown commercial RJs.