Royal jelly quality during storage

The changes in quality of royal jelly stored at 50 degrees C for 2h 30', 5h, 7h 30' and at 37 degrees 0 for 7 and 15 days were investigated. Browning, pH, acidity, enzymatic activity (diastase, invertase, glucose-oxidase) as quality indexes were analyzed. During the ageing the colour of royal jelly changed: the browning reaction increased proportionally to both temperature and storage time. pH and acidity values didn't change. Glucose-oxidase, the only enzyme detected in royal jelly, was subjected to an exponential decrease: the same value of glucose-oxidase in the sample stored at 37 degrees C for 7 days was reached after 7 hours at 50 degrees C.