Lyophilized royal jelly preparation in nanoscale and evaluation of its physicochemical properties and bactericidal activity.

Royal jelly, due to its unique bioactive components, has special biological activities, but a great extent of its nutritional value is lost during processing and storage. Lyophilization, an effective preservation technique, can feasibly preserve the main bioactive compounds present in royal jelly. In this study, fresh royal jelly was subjected to the freeze-drying process at a pressure and temperature of 100 Pa and - 70°C, respectively, for 40 h.