Specific heat determination of plant barrier lipophilic components: biological implications

The specific heat of isolated plant cuticles and their corresponding cuticu lar waxes have been measured for the physiological temperature in the range of 273-318 K at regular intervals. Cp values ranged from 1.5 up to 4 J K-1 g(-1) indicating a high cohesion, at the molecular level, of the molecular lipophilic components that constitute the plant cuticle. Second order phas e transitions around 293 K, assigned to the cuticular matrix mainly constit uted of the biopolyester cutin, have been detected and measured. Ecophysiol ogical and physical implications of these thermodynamic data are discussed. (C) 2001 Elsevier Science B.V. All rights reserved.