Table 1.

Composition of royal jelly.

Compounds	Percentage	Examples	References
Moisture	50–70%	Mainly water.	[96,98,99]
Carbohydrates	7.5–16%	Sugars such as fructose, glucose, maltose, melibiose, and ribose.	[98,99]
Proteins	9–18%	MRJPs (80% of protein content), minor proteins (e.g., aspimin, royalisin and jelleines), peptides (in the form of dipeptides or tripeptides, e.g., alanine-leucine, leucine- aspartic acid-arginine), and free amino acids (e.g., threonine, valine, glycine, isoleucine, leucine, proline, serine, methionine, and tryptophan).	[63,99,102]
Lipidsa	3–6%	10-HDA, sebacic acid, phenols (4–10%), waxes (5–6%), steroids (3–4%), and phospholipids (0.4–0.8%).	[63,98,99,101,102]
Vitamins	?	B5 (52.8 mg/100 g), B6 (42.42 mg/100 g), niacin (42.42 mg/100 g), and traces of B1, B2, B8, B9, B12, ascorbic acid (vitamin C), vitamin E and A.	[63,102]
Minerals	?	Potassium, sodium, magnesium, calcium, phosphor, sulfur, cupper, iron, zinc, selenium, barium, cobalt, manganese, etc.	[42,63,98]
Bioactive compounds	?	ACh and nucleotides both as free bases (e.g., adenosine, guanosine, iridin, and cytidine) and as phosphates (e.g., adenosine 5′-monophosphate, adenosine 5′-diphosphate, and adenosine 5′-triphosphate).	[63,102]
Others	?	Volatile organic compounds (e.g., esters, aldehydes, ketones, and alcohols), and minor heterocyclic compounds.	[63,98,102]

Abbreviations: MRJPs: major royal jelly proteins, 10-HDA: Trans-10-hydroxy-2-decenoic acid, ACh: acetylcholine. N.B. percentages of constituents are reported in fresh RJ, and data on the percentages of RJ constituents denoted by “?” are not clearly available.