Effect of Harvest Time on Royal Jelly Yield and Chemical Composition

Royal jelly (RJ) was harvested after 24, 48, and 72 hrs of grafting to study the effect of harvest time on the yield of RJ/queen cell. The changes in the nutritional components in RJ harvested at different times post-grafting were also studied. The highest yield of RJ/queen cell was harvested after 72 hrs of grafting, while the lowest yield was harvested after 24 hrs of grafting. The lowest moisture content was found in RJ harvested after 72 hrs of grafting. The maximum concentrations of crude protein, ash, fructose, and glucose were found in RJ harvested after 72 hrs of grafting. Conversely, the highest lipid content was obtained from RJ harvested after 24 hrs of grafting. The pH value decreased and acidity increased over time after grafting. It was concluded that RJ can be harvested after 72 hrs of grafting to obtain maximum yield. The nutritional components in RJ may be changed over time after grafting, and it could differentiate between RJ harvested at different times post-grafting.