Abstract:
In one aspect, the present invention relates to a method of disinfecting an eggshell surface. In various embodiments, the method may include wetting the eggshell surface with a disinfecting agent and exposing the eggshell surface to ultraviolet light after wetting with the disinfecting agent occurs. The combination of wetting the eggshell surface with the disinfecting agent and exposing the eggshell surface to ultraviolet light reduces a number of microbes on the eggshell surface.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to, and incorporates by reference the entire disclosure of, U.S. Provisional Patent Application No. 61/665,609, filed Jun. 28, 2012. 
     
    
     BACKGROUND 
       [0002]    1. Field of the Invention 
         [0003]    The present application relates generally to methods and systems for sanitizing eggs and more specifically, but not by way of limitation, to methods and systems for sanitizing eggs utilizing hydrogen peroxide in combination with exposure to ultraviolet light. 
         [0004]    2. History of the Related Art 
         [0005]    Disinfection of eggshells plays an important role in reducing transmission of pathogens such as  Salmonella  during egg incubation and hatching. Disinfection of eggshells is also important in the productions of eggs for human consumption (known as “table eggs”) as well as the production of eggs for vaccine production. Facility hygiene is an important factor for reducing egg and equipment contamination. In commercial operations, eggshell microbial growth results in cross-contamination of adjacent eggs as well as cross-contamination of egg incubation and hatching equipment. Further, egg incubation and hatching equipment often maintain temperatures and humidity levels that allow microorganisms to proliferate. Microorganisms found on surfaces of eggshells can be distributed throughout a commercial facility, potentially affecting other eggs and chicks. In general, lack of eggshell disinfection has been shown to negatively impact embryo mortality and chick quality resulting in increased production costs. Additional research regarding eggshell disinfection is described in Gottselig, Steven M., Microbial Reduction on Eggshell Surfaces by the Use of Hydrogen Peroxide and Ultraviolet Light (2011). 
         [0006]    An important consideration for eggshell disinfection is to ensure that eggshell disinfecting agents do not alter the eggshell or penetrate into the interior of the egg. Of particular importance is the degree to which a disinfecting agent will affect a cuticle of the eggshell. The cuticle (or bloom) is a protein layer surrounding the eggshell. The cuticle acts as a barrier to prevent contaminants, such as bacteria, from entering the interior of the egg. The cuticle also regulates exchange of gases such as carbon dioxide and water vapor. Thus, any alteration of the cuticle, such as by a disinfecting agent, can change a porosity of the eggshell and adversely impact the viability of the egg. 
         [0007]    Traditional methods of eggshell disinfection involve fumigation with formaldehyde gas. Formaldehyde has been shown to limit microbial growth on eggshell surfaces without penetrating into the interior of the egg. Formaldehyde, however, is considered to be a hazardous chemical by the U.S. Occupational Health and Safety Administration. Thus, commercial use of formaldehyde requires implementation of significant infrastructure and managerial controls to prevent human exposure to toxic fumes. In addition, quarternary ammonium compounds have been utilized is eggshell disinfection. However, quarternary ammonium, is believed to alter the cuticle of the eggshell. Altering the cuticle changes gas exchange between the egg and the environment and can be damaging to the egg. 
       SUMMARY 
       [0008]    The present application relates generally to methods and systems for sanitizing eggs and more specifically, but not by way of limitation, to methods and systems for sanitizing eggs utilizing hydrogen peroxide in combination with exposure to ultraviolet light. In one aspect, the present invention relates to a method of disinfecting an eggshell surface. In various embodiments, the method may include wetting the eggshell surface with a disinfecting agent and exposing the eggshell surface to ultraviolet light after wetting with the disinfecting agent occurs. The combination of wetting the eggshell surface with the disinfecting agent and exposing the eggshell surface to ultraviolet light reduces the number of microbes on the eggshell surface. 
         [0009]    In another aspect, the present invention relates to an eggshell disinfecting system. In various embodiments, the system may include a spray chamber. The spray chamber may deliver a disinfecting agent to an eggshell surface. A light chamber may be arranged adjacent to the spray chamber. The light chamber may expose the eggshell surface to ultraviolet light. A conveyor may pass through the spray chamber and the light chamber. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    For a more complete understanding of the present invention and for further objects and advantages thereof, reference may now be had to the following description taken in conjunction with the accompanying drawings in which: 
           [0011]      FIG. 1  is a systematic diagram of an egg-sanitization system according to an exemplary embodiment; 
           [0012]      FIG. 2  is a flow diagram illustrating a process utilizing the egg-sanitization system of  FIG. 1 ; 
           [0013]      FIG. 3  is a systematic diagram of an egg-sanitization system with secondary treatment according to an exemplary embodiment; and 
           [0014]      FIG. 4  is a flow diagram illustrating a process for use of the egg-sanitization system of  FIG. 3 . 
       
    
    
     DETAILED DESCRIPTION 
       [0015]    Various embodiments of the present invention will now be described more fully with reference to the accompanying drawings. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. 
         [0016]    Commercial poultry operations typically include houses equipped with conveyor belts that collect eggs. Once collected on the conveyor belts, the eggs are transported to a sorting room where settable eggs are separated from unsettable eggs. In egg production for breeding, food, and vaccine purposes, the term “settable eggs” refers to eggs that are not excessively dirty, have a sound shell with no breaks or cracks, and are not excessively large or small. The eggs are arranged on incubator flats and stored in coolers until the eggs are transported to the hatchery. At the hatchery, the eggs are placed in an incubator for eighteen days after which, the eggs are transferred to a hatching cabinet. Once the eggs have hatched, the chicks are separated from the eggshells and vaccinated. It has been suggested that, for maximum effectiveness, eggs should be sanitized as close to lay as possible. 
         [0017]      FIG. 1  is a systematic diagram of an egg-sanitization system  100 . The egg-sanitization system  100  includes a spray chamber  104  arranged adjacent to a light chamber  106 . A conveyor  102  is arranged to pass through the spray chamber  104  and the light chamber  106  in sequence. The spray chamber  104  includes a plurality of spray nozzles  105  arranged above and below the conveyor  102 . The light chamber  106  includes a plurality of lamps  107  arranged above and below the conveyor  102 . A pump  108  is fluidly coupled to the plurality of spray nozzles  105 . In a typical embodiment, the pump  108  provides a liquid disinfecting agent such as, for example, hydrogen peroxide (H 2 O 2 ) to the plurality of spray nozzles  105 . In other embodiments, disinfecting agents such as, for example, peracetic acid (“PAA”) or aqueous ozone are utilized as the liquid disinfecting agent. At least one ballast  110  is electrically coupled to the plurality of lamps  107 . In a typical embodiment, the at least one ballast  110  regulates an electrical current to the plurality of lamps  107 . A supporter  112  is placed on the conveyor  102 . In a typical embodiment, the supporter  112  is operable to hold at least one egg in an upright position. In other embodiments, the supporter  112  may be omitted. In such embodiments, the at least one egg is placed directly on the conveyor  102 . 
         [0018]      FIG. 2  is a flow diagram of a process  200  for using the egg-sanitization system  100 . The process  200  begins at step  202 . At step  204 , at least one egg is placed into the supporter  112 . At step  206 , the supporter  112  is placed on the conveyor  102 . At step  208 , the conveyor  102  moves the supporter  112  through the spray chamber  104 . In the spray chamber  104 , the at least one egg is sprayed with a liquid disinfecting agent such as, for example, H 2 O 2 . Research has shown H 2 O 2  to be an effective eggshell disinfecting agent. Lower concentrations of H 2 O 2  reduce microbial levels on eggshell surfaces without alteration or damage to the cuticle. Further, H 2 O 2  is safe for human skin contact. H 2 O 2  is inexpensive and is readily incorporated into existing spray equipment. In other embodiments, disinfecting agents such as, for example, PAA or aqueous ozone are utilized as the liquid disinfecting agent. 
         [0019]    Still referring to  FIG. 2 , at step  210 , the conveyor  102  moves the supporter  112  through the light chamber  106 . In the light chamber  106 , the at least one egg is exposed to, for example, ultraviolet (UV) light. In a typical embodiment, the exposure to UV light lasts approximately 3 seconds or less; however, any length of exposure may be utilized. Research has shown that UV light alters genetic material within a microorganism thereby preventing the microorganism from successfully replicating. Further, UV light will not damage or otherwise alter the cuticle. UV light is environmentally friendly and does not involve the storage of hazardous chemicals. The process  200  ends at step  212 . Although the process  200  is described herein as utilizing the supporter  112 , one skilled in the art will recognize that, in other embodiments, the supporter  112  is omitted and the at least one egg is placed directly on the conveyor  102 . 
         [0020]      FIG. 3  is a systematic diagram of an egg-sanitization system  300  with secondary treatment. The egg-sanitization system  300  includes a first spray chamber  304  arranged adjacent to a first light chamber  306 . A second spray chamber  310  is arranged adjacent to a second light chamber  312 . A conveyor  302  is arranged to pass through the first spray chamber  304 , the first light chamber  306 , the second spray chamber  310  and the second light chamber  312  in sequence. The first spray chamber  304  and the second spray chamber  310  include a plurality of spray nozzles  305  arranged above and below the conveyor  302 . The first light chamber  306  and the second light chamber  312  include a plurality of lamps  307  arranged above and below the conveyor  302 . In certain embodiments, the turning device  308  is located between the first light chamber  306  and the second spray chamber  310 ; however, in a typical embodiment, the turning device  308  is omitted. In a typical embodiment, the turning device  308  may include, for example, rubber fingers, a brush, a belt, a foam pad and the like. A pump  314  is fluidly coupled to the plurality of spray nozzles  305 . In a typical embodiment, the pump  314  provides a liquid disinfecting agent such as, for example H 2 O 2 , PAA, or aqueous ozone, to the plurality of spray nozzles  305 . A ballast  316  is electrically coupled to the plurality of lamps  307 . In a typical embodiment, the ballast  316  regulates an electrical current to the plurality of lamps  307 . 
         [0021]      FIG. 4  is a flow diagram of a process  400  for utilizing the egg-sanitization system  300 . The process  400  begins at step  402 . At step  404 , at least one egg is placed on the conveyor  302 . In certain embodiments, the at least one egg is placed into the supporter  112  (shown in  FIG. 1 ); however, in other embodiments, the at least one egg is placed directly on the conveyor  302 . At step  406 , the conveyor  302  moves the at least one egg through the first spray chamber  304 . The at least one egg is sprayed with a liquid disinfecting agent such as, for example, H 2 O 2 , PAA, or aqueous ozone. At step  408 , the conveyor  302  moves the at least one egg through the first light chamber  306 . The at least one egg is exposed to, for example, UV light. In a typical embodiment, the exposure to UV light lasts approximately 3 seconds or less; however, any length of exposure may be utilized. In embodiments utilizing the turning device  308 , at step  410 , the at least one egg is turned, for example, approximately 180 degrees by the turning device  308 . The turning device  308  rotates and contacts the at least one egg to provide sufficient resistance to allow the at least one egg to move or roll on the conveyor  302  so that a portion of the at least one egg not exposed to the first spray chamber  304  and the first light chamber  306  is exposed to the second spray chamber  310  and the second light chamber  312 . At step  412 , the conveyor  102  moves the at least one egg through the second spray chamber  310 . In the second spray chamber  310 , the at least one egg is sprayed with a liquid disinfecting agent such as, for example, H 2 O 2 , PAA, or aqueous ozone. At step  414 , the conveyor  302  moves the at least one egg through the second light chamber  312 . In the second light chamber  312 , the at least one egg is exposed to, for example, UV light. In a typical embodiment, the exposure to UV light lasts approximately 3 seconds or less; however, any length of exposure may be utilized. The process  400  ends at step  416 . 
         [0022]    Application of H 2 O 2  followed by exposure to ultraviolet light produces nearly instantaneous anti-microbial effects. When H 2 O 2  is exposed to UV light, the UV light splits covalently bonded H 2 O 2  molecule into two hydroxyl radicals. An exemplary reaction is illustrated below in Equation 1. 
         [0000]      H 2 O 2 +hv→HO+HO  Equation 1:
 
         [0023]    A hydroxyl radical is an example of a reactive oxygen species with a single unpaired electron. The hydroxyl radical acts to deprive other substances of an electron, which makes the hydroxyl radical a strong oxidizing agent. Research has shown that microorganisms such as, for example, gram negative anaerobes are highly sensitive to hydroxyl radicals. The oxidizing properties of the hydroxyl radical is highly effective in the destruction of microorganisms such as, for example, bacteria. It is further contemplated that application of the liquid disinfecting agent and application of UV light could be completed in approximately 10 to approximately 30 seconds. Thus, the processes  200  and  400  are rapid and highly effective. Further, the processes  200  and  400  do not leave chemical residue on the eggshell surface and do not result in human exposure to hazardous chemicals. Further, eggs treated according to the processes  200  and  400  demonstrate improved hatch rate and chick quality thus indicating that a porosity of the eggshell is not effected by the processes  200  and  400 . 
         [0024]    Although various embodiments of the method and system of the present invention have been illustrated in the accompanying Drawings and described in the foregoing Specification, it will be understood that the invention is not limited to the embodiments disclosed, but is capable of numerous rearrangements, modifications, and substitutions without departing from the spirit and scope of the invention as set forth herein. It is intended that the Specification and examples be considered as illustrative only.