Pulsed Ultraviolet Light to Decontaminate Egg Shells


Dr. Paul Patterson of the College of Agricultural Sciences, Pennsylvania State University has demonstrated the efficacy of pulse ultraviolet light to decontaminate shell surfaces.  Dr. Patterson considers that the technology could replace the use of immersion and sanitizers.


Pulse UV irradiation also has application in decontaminating hatching eggs.  During a 27-second period of exposure, eggs are exposed to high intensity ultraviolet light generated by a xenon flash lamp generating 90 pulses with a duration of 360 micro-seconds.


The economics of pulse ultraviolet irradiation has yet to be determined for commercial egg packing plant and hatchery application.  In the case of table eggs, the principle of reducing surface contamination is self-evident.  The process will however not remove fecal staining and accordingly downgrades will be far higher than with conventional washing. The cost of diverting otherwise saleable eggs to breaking should be considered in the cost of the alternative technology.

Dr. Paul Patterson


In the case hatching eggs, many of the pathogens involved in increasing embryonic and first- week chick mortality are motile and penetrate the shell within 30 minutes of lay.  Although subsequent shell decontamination at the hatchery will reduce bacterial load, the installation of equipment in hatcheries may not materially increase hatchability or livability.  Weekly USDA broiler data indicate an average hatch of between 81 and 82 percent of eggs set and the restraints to hatchability and broiler chick viability relate to factors other than bacterial contamination except in specific complexes.


Irrespective of the eventual commercial deployment of pulsed ultra violet technology, the studies conducted by Dr. Patterson represent an advance in applying a physical process to a biological system with potential improvement of food safety.