Quality Parameters for Commercial Royal Jelly

Abstract

Royal jelly has become a high-value commercial product and the standardization of this product is required to guarantee its quality on the market. The objective of the research activity was to pursue the chemical composition of commercial samples of Royal Jelly in Romania in order to propose standardization for this product. The physico-chemical composition of commercial Royal Jelly samples was analysed by determining quality parameters like: carbohydrates, lipids, proteins, 10-hydroxy-2-decenoic acid (10-HDA) and mineral elements. Carbohydrates analysis showed values between 3.4 % and 5.87 % for fructose, 4.12 % and 7.05 % for glucose, while for sucrose the values ranged between 0.95 % and 2.56 % (determined by HPLC-RI). The lipids content ranged between 1.85 % and 6.32 % (determined by the Soxhlet method). The protein values extended from 13.10 % (RJ2) to 17.04 % (RJ10) (the total protein content was determined by the Kjeldahl method). The values for the major fatty acid in Royal Jelly, 10-HDA, ranged between 1.35 % (RJ8) and 2.03 % (RJ10) (determined by high-performance liquid chromatography). The concentration of minerals varied between 3188.70 mg/kg and 4023.39 mg/kg (the concentration of minerals was measured using flame atomic absorption spectrometry). Potassium, followed by magnesium, sodium and calcium, occurs in the highest concentrations. The commercial Royal Jelly samples analysed presented variable physico-chemical characteristics that correspond with the values given by international quality standard proposals for Royal Jelly.