Influence of Storage and Sanitizing Protocols on the Physiology of Fresh-Cut Watermelon

Jorge M. Fonseca1, James W. Rushing*2, and Robert F. Testin3.
Clemson University, Horticulture Department, Clemson, SC 29634;
Clemson University, Coastal Research and Education Center (REC), Charleston, SC 29414;
Clemson University, Packaging Science Department, Clemson, SC 29634.

Fresh-cut watermelon cubes stored at selected temperatures within the range of 1.1 to 14.5o C had decreasing quality shelf life corresponding with increasing temperature.  At lower temperatures there was a random occurrence of chilling injury symptoms in some cubes that was associated with the section of watermelon from which the cubes were cut.  Cubes removed from the top side of the intact watermelon fruit were more susceptible to chilling injury than cubes from other sectors of the fruit.  Sanitizing cubes with chlorine (40 ul/l) or ozone (0.04 ul/l) solutions caused an initial reduction in microbial count but during storage the effect diminished and became insignificant compared to controls.  Overall quality was lower in cubes receiving aqueous sanitizing treatments, possibly due to mechanical injury occurring during centrifugation to remove excess solution.  Overall quality of cubes exposed to UV light (ca. 250 nm for 1-5 min) was better than cubes receiving aqueous sanitizing treatment.  The effectiveness of UV treatment in reducing microbial load was dependent on the amount of cube surface exposed to the light.  The results emphasize the importance of preventing microbial contamination during processing of fresh-cut watermelon.


CATEGORY:  Postharvest/Plant Biotechnology