Differential scanning calorimetry applied to the storage at ultra low temperatures of olive and hop in vitro grown shoot-tips

Differential scanning calorimetry was used for monitoring the survival cond itions of olive in vitro grown shoot-tips under cryopreservation (-196 degr ees C), as well as for establishing the storage conditions at temperatures higher than liquid nitrogen. Olive survival is related to the absence of fo rmation and growing of ice crystals during the cooling process. These resul ts are compared with those obtained in hop. The final storage temperature i s given as a function of the shoot tip survival to the dehydration step and the absence of ice crystal growth during cooling and warming. (C) 2000 Els evier Science B.V. All rights reserved.