Abstract
Fruit etching is rapidly becoming an alterative means to label produce. The alphanumerical characters are formed by laser beam generated dot-matrix pin-holes which disrupt the cuticular and epidermal barriers. The present study describes anatomical characteristics of the pin-hole depressions in the cuticle/epidermis of several fruits and vegetables grown in Florida. Descriptions were made immediately after labeling and after 4 days in storage at 20C and 95% relative humidity. Regardless of the energy impact durations, pin-holes were fairly homogeneous averaging 200 m in diameter and 25 m in depth. Immediately after etching, the two- to five-cell-deep depressions contained cuticle/wax deposits. Additional cuticle/wax material was deposited in and around the depressions during storage as demonstrated by confocal, fluorescent, and light microscopy. In addition, the cells underlining the etch depression increased phenolic and lignin deposits in their walls, creating a potential barrier against pathogenic organisms.
