Micro-Ecology of Plant Cuticles and Efficiency of Sanitation Methods

The cuticle is a continuous extracellular hydrophobic membrane designed for plant survival by protecting against uncontrolled water loss. The structure of cuticles is variable and consists of cutin with various waxes, polysaccharides, cellulose and hemicelluloses. As in all other air or water interfaces, plant cuticles have dynamic populations of microorganisms. These include plant and human pathogens as well as epiphytes, which can interact forming associations with the cuticle which cannot be destroyed by even vigorous washing. Attachment of microbial propagules to cuticles happens very quickly and often preferentially on specific parts of the plant. Attachment is by adhesive materials specific to the plant and the residing organism (e.g. polysaccharides, lectins, cellulose fibrils, etc.). This presentation will explore the dynamics of cuticle/microbe interactions and the challenge to reduce microbial populations from fruit and vegetable surfaces before processing. Pros and cons of various sanitizing methods will be discussed.