JP5102271B2 - Method for washing and sterilizing eggshell - Google Patents

Description

  The present invention relates to washing and sterilization of eggshells using electrolyzed water.

Conventionally, as a method for washing eggshells, for example, the following patent documents are known.
Japanese Patent Application Laid-Open No. 2005-027609 discloses an eggshell cleaning apparatus for cleaning eggs with acetic acid and then cleaning with weakly acidic electrolyzed water having an effective chlorine concentration of 200 ppm and a pH of 5.5.
Japanese Patent Application Laid-Open No. 2003-250379 discloses an eggshell cleaning apparatus that cleans eggshells with detergent and then sterilizes them with ozone water.
Japanese Patent Application Laid-Open No. 2003-023907 describes a part for injecting water into an eggshell and a cleaning unit for cleaning the eggshell surface with a brush. Further, regarding electrolyzed water, strong acid electrolyzed water and strong alkaline electrolyzed water are described. Is disclosed.
Japanese Patent Laid-Open No. 2001-045904 discloses an apparatus in which the washing process and the sterilization process of the eggshell washing apparatus are made independent, using alkaline electrolyzed water in the washing process and acidic electrolyzed water in the sterilizing process. Yes.
Japanese Patent Application Laid-Open No. 2000-014269 discloses an egg washing method in which alkaline electrolyzed water is used for primary cleaning and acidic electrolyzed water is used for secondary cleaning.
Japanese Patent Application Laid-Open No. 10-276605 discloses a sterilization cleaning method in which a shelled egg is immersed in strongly alkaline electrolyzed water and then cleaned by spraying (showering) strongly acidic electrolyzed water.
JP2005-027609 JP 2003-250379 A JP2003-023907 JP 2001-045904 A JP 2000-014269 A JP 10-276605 A

  Since chickens have the same tube for producing eggs and stool, freshly produced chicken eggs are dirty and have bacteria such as E. coli attached to them. Therefore, it is necessary to wash and sterilize the eggshell as a pre-stage to pack and split eggs to make liquid eggs.

  At present, mechanical cleaning is performed by an eggshell cleaning apparatus, and sodium hypochlorite is often used as a disinfectant. However, the use of sodium hypochlorite has problems such as effects on the human body and not meeting drainage standards.

  Electrolyzed water is broadly divided according to its pH, pH 2-3 is “strongly acidic electrolyzed water”, pH 5-6 is “slightly acidic electrolyzed water”, and pH 11-13 is “strongly alkaline electrolyzed water”. Yes. Strong acidic electrolyzed water and slightly acidic electrolyzed water have a bactericidal effect, and strong alkaline electrolyzed water has a cleaning effect, and various tests have confirmed the effects of cleaning and sterilizing.

However, since the alkaline electrolyzed water dissolves the eggshell itself, the eggshell becomes thin. Therefore, the eggshell may become too thin and cracks may occur.
On the other hand, acidic electrolyzed water may corrode metals. Therefore, the apparatus is likely to deteriorate.
A method of sterilizing with ozone has also been proposed. However, ozone is harmful to the human body and is more corrosive than acid. Moreover, since the water drainage standard is pH 5.8 to 8.6, there is a problem that any water cannot be drained as it is.

  Therefore, the main object of the present invention is to provide a method for sterilizing and washing eggshells by the sterilizing effect of neutral electrolyzed water.

  In the method for washing and sterilizing raw eggs with shells of the present invention, the residual chlorine concentration is 1.5 mg / L or more (the upper limit is not particularly limited, but it will generally be 30 mg / L or less to 50 mg / L or less). The eggshell is washed and sterilized using generally neutral electrolyzed water having a pH of 5.8 to 8.6. When tap water is used, the pH is about 6.8 to 8.0. In this case, the advantage that the electrolyzed water is neutral is further increased. If a large amount of electrolyzed water is sprayed onto the egg or the contact time with the electrolyzed water is increased, the residual chlorine concentration can be 1.5 mg / L, but a residual of about 2 mg / L to 5 mg / L. Electrolyzed water having a chlorine concentration is preferred in terms of the balance between bactericidal power and production cost.

In this method, since the electrolyzed water in the neutral range is used, there is an advantage that treatment for meeting the drainage standard is not necessary. Further, unlike the conventional strong acid / strong alkaline electrolyzed water system, the electrolyzed water itself can be generated by the non-added and non-transparent membrane system, so that the running cost is reduced and the generation labor is reduced.
Moreover, unlike the alkaline electrolyzed water, there is no possibility that the eggshell is dissolved, or unlike the acidic electrolyzed water, the piping material or the like is corroded.
Moreover, unlike ozone water, there is no risk of being harmful to the human body.

In the method of the present invention, the diaphragm is electrolyzed in order to maintain the pH in a neutral range, but water according to tap water can be used before electrolysis.
Basically, tap water to which nothing has been added is used for electrolysis as raw water, but in order to increase the sterilizing power of the generated electrolyzed water, within the range where the pH is in the neutral range, sodium hypochlorite, etc. It is also possible to add chlorite to the raw water before electrolysis. When sodium hypochlorite or the like is added, the pH shifts closer to alkali.
In addition, in order to increase the bactericidal power of electrolyzed water while keeping the pH in a neutral range, it is also possible to add an acidic agent such as hydrochloric acid or citric acid to the raw water before electrolysis together with hypochlorite.

In this invention, it is preferable to set the temperature of electrolyzed water to 30 to 50 degreeC, and it is still more preferable to set to 35 to 45 degreeC. In such a temperature range, the indoor temperature does not increase so much, and the working environment is improved.
The egg has a problem that if the ambient temperature is lower than the egg internal temperature (about 26 ° C.), the surrounding bacteria easily enter the egg, so the water temperature used for washing is “the egg internal temperature + 10 ° C. It is preferable to say “above”. On the other hand, when the water temperature of the electrolyzed water is increased, the residual chlorine concentration, which is a sterilization factor, is lowered and the sterilization efficiency is lowered.
Therefore, the water temperature of the electrolyzed water is preferably set to around 40 ° C.

  A system for carrying out such a method is a cleaning and sterilizing system for cleaning and sterilizing raw eggs with shells, which takes in raw water to increase the residual chlorine concentration of the raw water and has a pH of about 5.8 to 8.6. An electrolyzed water generating device for generating electrolyzed electrolyzed water, a plurality of nozzles for injecting the electrolyzed water in the passage path of the shelled raw eggs to clean and sterilize the shelled raw eggs, and sprayed from the nozzles A holding means for forming a liquid phase in which the electrolyzed water comes into contact with the shelled raw egg, a cleaning brush that comes into contact with the surface of the shelled raw egg during or after passing through the holding means, and the shelled raw egg An eggshell washing and sterilizing system including a conveyor for discharging eggs from the holding means can be employed.

According to this system, the electrolyzed water permeates into the surface of the shell in the liquid phase of the holding means, and the solidified stool becomes inflamed, and the stool is scraped off with the cleaning brush. Thereafter, uncontaminated electrolyzed water is sprayed onto the eggshell, and the entire eggshell is cleaned and sterilized.
Here, since the electrolyzed water has small clusters and easily penetrates into dirt, the dirt is easily removed.

  Here, feces that could not be scraped off by the cleaning brush may remain on the eggshell surface. In this case, moisture remains in the stool portion even after subsequent drying. Therefore, there is a concern that the bacteria will grow. However, since the remaining water is electrolyzed water, it exhibits sterilizing power, so that the sterilizing effect is not easily lowered even if it is not completely dried.

Hereinafter, the electrolyzed water generating device will be described prior to the description of the sterilization method.
1 to 3, the electrolytic cell 1 having pressure resistance forms an accommodation space S. An electrode unit U is accommodated in the accommodation space S. The electrode unit U includes, for example, five electrode plates 2 ₁ to 2 ₅ disposed in the electrolytic cell 1 substantially along a vertical plane and close to each other in parallel.

  The electrolytic cell 1 includes first and second pressure plates 1a and 1b, and an annular third pressure plate 1c sandwiched between the pair of pressure plates 1a and 1b. An introduction hole 14 is provided at the lower end of 1c so as to discharge upward. The introduction hole 14 is provided in the lower part of the electrolytic cell 1 and pumps the liquid L into the electrolytic cell 1.

  On the other hand, a lead-out hole 15 is formed at the upper end of the pressure plate 1c. The lead-out hole 15 leads the electrolytic water L1 generated by electrolyzing the liquid L in the electrolytic layer 1 from the top of the electrolytic cell 1.

Insulating members 20 are arranged in at least four corners of each of the electrode plates 2 ₁ to ₂₅ in FIG. The insulating member 20 insulates the electrode plates 2i from each other and maintains the distance between the electrode plates 2i.

The together in a generally central region of the electrode plate 2 ₁ to 2 _5, through the electrode plate 2 ₁ to 2 ₅ having the same polarity of the respective electrode plates 2 ₁ to 2 ₅ in FIG. 2 in the horizontal direction First and second electrode rods 21 and 22 are provided for energizing the electrode plates 2 ₁ to ₂₅ with each other. A DC power source (not shown) for applying a DC voltage is connected between the electrode plates 21 and 22 between the electrode plates.
Note that the electrode plates 2 ₂ and 2 ₄ in FIG. 2 are set to the first polarity via the first electrode rod 21, and the electrode plates 2 ₁ , 2 ₃ and 2 ₅ are interposed via the second electrode rod 22. Set to the second polarity.

As clearly shown in FIG. 4, a plurality of rows of first flow paths 11 and second and third flow paths 12 and 13 are formed in the electrolytic cell 1. In the first flow path 11, the liquid L flows from the bottom to the top along the surface of the electrode plate 2 _i between the electrode plates 2 _i in the electrode unit U. The second flow path and the third flow paths 12 and 13 are formed between the electrode unit U and the wall surface of the electrolytic cell 1, and the first or second end electrode plate at one or the other end of the electrode unit. The liquid L flows from bottom to top along 2 ₁ and 2 ₅ .

  At the lower end of the electrode unit U, the opening 14 (FIG. 1) of the introduction hole 14 faces the lower end opening 11a of the first flow path 11 that opens downward. Thereby, the liquid L from the introduction hole 14 smoothly flows into the first flow path 11.

Each of the electrode plates 2 _i is formed with a plurality of through holes 23. Each through-hole 23 is substantially matched with each other. Therefore, the gas generated from the liquid L in the first flow path 11 and the liquid L merge at the plurality of through holes 23 formed in the electrode plates 2 _i , and the through holes 23 are And flows out from the first flow path 11 toward the second flow paths 12 and 13.

As shown in FIG. 2, a spacer 1s is disposed between the electrode unit U and the first pressure plate 1a. The spacer 1s, the disposed proximate to the first end electrode plates 2 ₁ in the lower part of the housing space S of the electrolytic cell 1, at the upper end of the housing space S is not arranged the spacer 1s can Accordingly, the upper end portion of the second flow path 12 is formed wider than the lower portion.

  Next, a process in which electrolyzed water L1, that is, a liquid having sterilizing power is generated from the liquid L made of tap water will be described.

The liquid L is introduced into the first flow path 11 of FIG. 4 from the introduction hole 14 of FIG. 2 through the opening 14a and the lower end opening 11a. The liquid L is electrolyzed in the first channel 11 while flowing in the first channel 11 from below to above. At this time, the hydrogen gas and oxygen gas is produced, the chlorine ions Cl in tap water ^- water H ₂ O or the like exhibits a predetermined chemical reaction, hypochlorous acid HClO and hypochlorite ions in the germicidal ClO ⁻ is generated, and electrolyzed water L1 is generated.

  The electrolyzed water L1 containing the gas flows through the first flow paths 11 and merges in the through holes 23, and the gas is highly likely to flow out to the second flow paths 12 and 13 having a low pressure. On the other hand, since the liquid component in the electrolyzed water L1 has a mass larger than that of the gas, the probability of flowing into the upper first flow path 11 due to inertia is high. Therefore, the bubble presence rate in the upper first flow path 11 is lower than that in the second flow paths 12 and 13, and the electrolytic efficiency is less likely to be reduced.

The electrolytic water L1 further flows upward medium first flow path 11, while being electrolyzed, the HClO and ClO ^- concentration (. Hereinafter, the concentration of "residual chlorine concentration D") becomes higher. Although the gas abundance ratio in the electrolyzed water L1 is further increased, the gas is discharged from the upper through hole 23 to the space Sa above the spacer 1s in FIG. 2, and the gas abundance ratio in the electrolyzed water L1 is also above. Is suppressed from increasing. Therefore, it is difficult for the electrolytic efficacy to be reduced.

Next, an example will be shown in order to clarify that the electrolyzed water L1 has sterilizing power.
Tap water having a Cl ⁻ concentration of 0.285 mg / L was circulated in the electrolytic cell 1 to obtain electrolyzed water L1 of Examples 101 to 103 shown in the table of FIG.

  On the other hand, the electrolyzed water L1 of Examples 101 to 103 was dropped into the culture medium in which the bacteria of FIG. 5 (b) were cultured, contacted for a predetermined time (10, 20, 30 seconds), and then cultured for about 2 days. The number of bacteria was measured. The result is shown in FIG.

  As can be seen from FIG. 5 (c), E. coli is completely killed if the residual chlorine concentration D is 16 mg / L or more. Since the E. coli is similar to Salmonella, it is presumed that it can be suitably used for sterilizing eggshells. In addition, if the residual chlorine concentration D is 10 mg / L or more from the contact time and the relative volume of the electrolyzed water L1, a very strong bactericidal effect can be expected, and it may be about 6 to 7 mg / L depending on pH.

  Moreover, even if the residual chlorine concentration D is about 6.7 mg / L, it seems that it can be sufficiently used for disinfection of general bacteria.

Next, the relationship between the pH of the electrolyzed water L1 and the sterilizing power will be considered.
As shown in FIG. 6, the abundance ratio of ClO ^- and HClO greatly depends on the pH value. Sterilizing power of the HClO is ClO ^- significantly greater than the bactericidal activity of. Therefore, it is preferable to generate the electrolyzed water L1 in the region of about pH 1 to pH 7.7 where the abundance ratio of HClO is large.
In particular, the electrolyzed water L1 having a pH of 6.8 to pH 7.7 can be generated using tap water as it is, and does not cause any adverse effects due to acid or alkali.

Next, a reference example useful for understanding the egg washing method by the egg washing system will be described with reference to FIG.
An egg (raw egg with shell) E put in a washing tank (an example of a storage means for forming a liquid phase) 50 is washed by an egg transfer conveyor 51 while removing some dirt in the washing tank 50. It is carried to the egg part 52. In the egg washing section 52, the washing liquid is sprayed from the shower nozzle 53, and the egg E is washed and wetted. Further, the egg E is washed by the rotating brush 54 brushing the eggshell. Thereafter, the eggs E are finally washed in the shower nozzle 55 by the shower nozzle 55, and are transferred to a pack packing and egg breaking step through a drying step using an egg drying blower.

  Usually, the shower nozzles 53 and 55 are often sprayed with a solution obtained by diluting sodium hypochlorite for the purpose of cleaning and sterilization. Electrolyzed water is supplied to the shower nozzle 53 from the outlet hole 15 (FIG. 2) of the electrolyzed water generator, and the egg E is washed and sterilized with electrolyzed water L1 in a substantially neutral range (pH 5.8 to 8.6). From the shower nozzle 55, tap water is jetted and washed.

  The electrolyzed water sprayed from the shower nozzle 53 is structured to flow into the cleaning tank 50. Thereby, the electrolyzed water which did not hit the eggshell and was not used can also be used for cleaning and sterilization in the cleaning tank.

  The washing tank 50 may be a holding means that forms a liquid tank in which the electrolyzed water contacts the egg E. For example, as shown in the embodiment of FIG. 8A, the lower half of the egg E contacts the electrolyzed water. It may be. Also in this case, since the egg E rotates while passing through the liquid tank, the electrolyzed water is immersed in the entire egg E.

  Further, the holding means may be formed in a bowl shape. This bowl-shaped holding means forms a groove-like path through which the egg E is conveyed. Moreover, a part or all of the ridges may be inclined obliquely upward toward the upstream. Furthermore, in this case, it is preferable to provide a storage tank in which the lower half of the egg E is immersed in the conveyance path.

Next, another eggshell cleaning and sterilization system will be described.
In the embodiment of FIG. 8A, a temperature raising device 100 for raising the temperature of the raw water (tap water) is provided.
The electrolyzed water generating apparatus 200 takes in the heated raw water (warm water) to increase the residual chlorine concentration of the raw water and generate electrolyzed water having a substantially neutral pH. The electrolyzed water is supplied to a plurality of nozzles 56. The nozzle 56 sprays the electrolyzed water from above in the passage route of the egg E to wash and sterilize the egg E.
The cleaning tank 50 temporarily stores the electrolyzed water sprayed from the nozzle 56.
The cleaning brush 54A is in rotational contact with the surface of the egg E during or immediately after passing through the cleaning tank 50.
The conveyor 51 supplies the egg E to the cleaning tank 50 and discharges it from the cleaning tank 50.

FIG. 8C shows a variation of the eggshell cleaning and sterilization system.
In this system, the system includes a hot water shower 55 </ b> A that jets hot water toward the egg E upstream of the cleaning tank 50. Further, a drying blower 59 is provided downstream of the cleaning tank 50. Below the blower 59, a drying brush 54 </ b> B that is in rotational contact with the egg E after washing is provided. In this case, in order to sterilize the drying brush 54B, a nozzle 56A that injects electrolytic water toward the drying brush 54B may be provided.

Next, an embodiment of the cleaning and sterilization method using the system of FIG. 8A will be described in comparison with the case of using the system of the comparative example of FIG. 8B.
Example Group 1 to Group 5:
Using the system shown in FIG. 8A, electrolyzed water having a temperature of about 40 ° C. was sprayed from the nozzle 56 to perform egg washing E.
Comparative Examples Group 1 to Group 5:
Using the system of FIG. 8B, washing was performed by injecting hot water (55 ° C.) from a nozzle upstream of the washing tank and injecting a sodium hypochlorite solution (55 ° C.) from a nozzle downstream of the washing tank. .
Comparative Examples 14th and 15th groups:
Using the system of FIG. 8B, the eggs were washed by spraying hot water at 55 ° C. from the nozzles before and after the washing tank.

The results of measuring the residual chlorine concentration, the number of general bacteria after washing, and the number of bacteria after one week for the examples and comparative examples are shown in the table of FIG.
The sample collection method will be described. Washing a certain number of eggs, immediately after the start of washing, 10 samples each at the end of work and at the middle of each, measure the number of bacteria, average the number of bacteria The values are shown in the table of FIG.
In addition to the above-described collection, 10 specimens were collected in the middle, and after storing them for one week, the number of bacteria was measured, and the average values are shown in the table of FIG.

  For hygiene purposes, the eggshell does not have to be completely sterile, and if the number of bacteria is less than or equal to a predetermined amount after a predetermined period, the eggshell is sufficiently hygienic. On the other hand, feces may be firmly attached to the eggshell, and the solidified stool contains a large amount of bacteria. Remains or grows.

  Example The 170 eggs E of the first group to the fifth group are washed and sterilized with electrolyzed water having a water temperature of 35 ° C. to 38 ° C., a pH of 6.9 to 7.4, and a residual chlorine concentration of 2.09 to 3.22. Thus, both after washing and after one week of storage, small variations and good results are obtained. This is presumably because the cluster of electrolyzed water was small and the sterilizing power was also demonstrated in the solidified stool.

  The 170 eggs E from the first group to the fifth group of the comparative examples have large variations in results. Presuming the reason, it is considered that sodium hypochlorite has a bactericidal power, but has a large viscosity due to its large viscosity, and therefore it is difficult to penetrate into the solidified stool.

  The 80 eggs E of Comparative Group 14 and Group 15 have good results immediately after washing, but the bacteria are likely to grow after storage for one week. Assuming the reason, the clusters are not so large and are washed at a high temperature (55 ° C.), so that the dirt is easily removed, but it does not have a bactericidal action. The fungus seems to grow.

For example, the following modifications can be considered.
The electrolyzed water L1 is sprayed not only from the shower nozzle 53 of FIG. 7 but also from the shower nozzle 55 to wash and sterilize the eggshell (the electrolyzed water itself is safe. It is estimated that there is no problem even if it is brought to the egg process).
Leave it to dry naturally without using an egg drying blower.
Although the number of the egg-washing parts is one, it may be increased to two or more to increase the washing and sterilizing effect.
The egg E may be passed between non-rotating brushes.

  The electrolyzed water which concerns on this invention can be used for various sterilization washing | cleaning besides eggshell.

It is a schematic exploded perspective view which shows an example of the electrolyzed water generating apparatus of this invention. It is the longitudinal cross-sectional view. It is a schematic exploded perspective view of an electrode unit. It is an expanded sectional view in a tank. It is a chart which shows the relationship between residual chlorine concentration and bactericidal power. HC1O and C1O by ph changes in the ^- is a characteristic diagram showing the presence ratio of. It is a schematic block diagram which shows the eggshell washing | cleaning apparatus useful for an understanding of this invention . It is a schematic block diagram which shows the Example and comparative example of a washing | cleaning sterilization system. It is a graph which shows the Example and comparative example of a washing | cleaning sterilization method.

50: Washing tank 51: Conveyor 53, 56: Nozzle 54, 54A: Washing brush 59: Brush for drying 100: Temperature raising device 200: Electrolyzed water generating device

Claims (5)

A way to cleaning and sterilizing the eggshell of the shell with a raw egg,
And apparatus for producing electrolyzed water the pH is to generate a generally electrolyzed water neutral 5.8 to 8.6 with increasing the residual chlorine concentration of the tap water takes in tap water,
A plurality of nozzles for cleaning and sterilizing the egg shell of raw egg with the shell of the electrolytic water is injected in the pass route shelled raw eggs,
Retaining means for forming a liquid phase in which the electrolyzed water sprayed from the nozzle contacts the eggshell ;
A cleaning brush that contacts the surface of the eggshell during or after passing through the holding means;
Using the eggshell washing and sterilization system comprising a conveyor for discharging the shelled raw eggs from the holding means , the method comprises:
A step of obtaining approximately neutral electrolyzed water having a pH of 5.8 to 8.6 by passing water through the electrolyzed water generator without adding an additive to tap water containing chlorine; and
A step in which the raw eggs with shells pass through the liquid phase of the holding means for storing the electrolyzed water;
A step of rotating the cleaning brush in contact with the surface of the eggshell during or after the passage;
Injecting the electrolyzed water from the nozzle to the eggshell without diluting downstream of the cleaning brush and storing the electrolyzed water in the holding means;
Drying the eggshell while the electrolyzed water remains attached to the surface of the eggshell. The method according to claim 1 , further comprising a step of raising the temperature of the tap water or electrolyzed water . 3. The method according to claim 2, wherein the tap water that has been heated and contains no chlorine is added between the electrode plates facing and adjacent to each other with no diaphragm in the electrolyzed water generator. The electrolyzed water is obtained by passing water along the surface of the electrode plate. The method according to any one of claims 1 to 3, further comprising a step of drying the eggshell to which the electrolyzed water adheres with a drying device provided downstream of the nozzle . In the method of any one of Claims 1-4 , the said drying apparatus is provided with the brush for drying which rotates and contacts the surface of the said shelled raw egg,
The method further includes a step of discharging the electrolyzed water from another nozzle in order to clean and sterilize the drying brush .