The Dipping Effect Causing Increased Drying of Grapes Demonstrated with an Artificial Cuticle

The dipping effect, which is the increased evaporation of water through a grape cuticle after immersion in dipping solution and its reversal by washing, has been demonstrated with an artificial system. The model cuticle was prepared by coating with grape wax a plastic film similar in water permeability to the cutin membrane of the grape. The addition of fatty acids and their esters to this nonliving, artificial, wax-covered membrane system increased evaporation and established that the dipping effect is not restricted to natural grape cuticles.