Evaluation of some chemical, antibacterial and biological properties of fresh and refrigerated Royal Jelly

ABSTRACT

Fresh and refrigerated royal jelly samples were examined to evaluate their chemical composition, antibacterial properties and biological effect. The results indicated that a major component of all tested samples was moisture; the range measured was 59.4-66.5%. Whereas, for protein, the range measured was 12.8-15.1%, for fats 7.9-9.9%, for carbohydrates 11.0-12.3% and for ash 0.9-1.5%. Potassium was the most abundant element rather calcium, sodium, iron and phosphorus. Measured amounts of vitamins in fresh samples were 6.3, 7.1, 12.4, 8.3 and 3.2 ug/g for vitamins B1, B2, B3, B6 and C, respectively. Storage of royal jelly under refrigeration conditions could not alter significantly either chemical composition or antibacterial activities except acidity of tested samples, which undergoes noticeable elevation fructose representing the major sugar fraction [52.6%-54.4%] followed by glucose and sucrose [28.6%-29.6 and 8.0%-8.6%, respectively]. Proline, lysine, arginine, glutamic and aspartic acids were the major amino acids present, while tryptophane was not detected. The antibacterial activities of royal jelly appeared at 25% [aqueous solution] and above concentrations. Royal jelly had a clear effect on the reduction of blood cholesterol and the increase of blood hemoglobin in the tested rats