Method for sorting ovomucoid-free egg with shell

Abstract

To provide a method for nondestructively and simply sorting an egg with a shell containing no ovomucoid.SOLUTION: A method for sorting an egg with a shell containing no ovomucoid includes: a measurement step of irradiating the egg with the shell with light including light having a specific wavelength and measuring an amount of absorption of the light having the specific wavelength; a calculation step of calculating a discriminant value by substituting the amount of absorption into a conversion formula; and a sorting step of sorting the egg with the shell containing no ovomucoid based on the discriminant value. The conversion formula is derived from measurement results of the amount of absorption of the light having the specific wavelength relative to the egg with the shell containing ovomucoid and the egg with the shell containing no ovomucoid.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a method for selecting shell eggs that do not contain ovomucoid. [Background technology]

[0002] Various technical means have been proposed as a method for measuring the components in chicken eggs. For example, Patent Document 1 discloses a method for determining shell eggs, which includes the steps of irradiating a shell egg with light, receiving the light transmitted through the shell egg, acquiring the spectrum of the transmitted light, performing multivariate analysis on the spectrum, and determining whether the egg is a shell egg or not based on the spectrum. Patent Document 2 also discloses that the cholesterol content in a chicken egg can be quantified with high accuracy without cracking the egg by irradiating a chicken egg with near-infrared light in a specific wavelength range and detecting the transmitted light. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-49177 A [Patent Document 2] Patent No. 5959061 Summary of the Invention [Problem to be solved by the invention]

[0004] One of the allergens in chicken eggs is a protein called ovomucoid, which is contained in egg white. Ovomucoid is stable to heat and digestive enzymes, so its allergenicity is not easily lost even when it is subjected to heat treatment and processing using digestive enzymes. For this reason, research is being conducted on the creation of chicken eggs that do not contain ovomucoid.

[0005] On the other hand, ovomucoid in chicken eggs is generally measured, for example, by liquid chromatography, ELISA, or the like using egg white obtained by cracking eggs. However, such measurement methods are commercially unsuitable because the procedures are complicated and the eggs are cracked, limiting their applications. Therefore, there is a need for a non-destructive and simple method for selecting shell eggs that do not contain ovomucoid.

[0006] An object of the present invention is to provide a method for non-destructively and simply selecting shell eggs that do not contain ovomucoid. [Means for solving the problem]

[0007] The inventors discovered that by irradiating shell eggs with light containing light of a specific wavelength, measuring the amount of light absorbed by the specific wavelength, and then calculating a discrimination value from the absorption amount using a predetermined conversion formula, it is possible to determine whether or not a shell egg does not contain ovomucoid based on the discrimination value, and thus completed the present invention.

[0008] That is, the present invention relates to, for example, the following inventions. [1] 1. A method for sorting shell eggs, comprising the steps of: A measuring step of irradiating a shell egg with light containing light of a specific wavelength and measuring the amount of light absorbed by the shell egg with light of the specific wavelength; A calculation step of calculating a discrimination value by substituting the absorption amount into a conversion formula; and A selection step of selecting shell eggs that do not contain ovomucoid based on the discrimination value, The above conversion formula is a formula derived from the results of measuring the amount of light absorbed at the specific wavelength for shell eggs containing ovomucoid and shell eggs not containing ovomucoid. A method for selecting shell eggs that do not contain ovomucoids. [2] The sorting method according to [1], wherein the light of the specific wavelength is light having a wavelength within the range of 310 nm or more and 2500 nm or less. [3] The selection method according to [1] or [2], wherein the transformation formula is an equation derived by partial least squares discriminant analysis. [4] The above transformation formula is an equation derived by partial least squares discriminant analysis, with the discrimination value of the shell eggs containing ovomucoid being 1 and the discrimination value of the shell eggs not containing ovomucoid being 0, In the sorting step, when the discrimination value calculated in the calculation step is less than a threshold value, the egg is sorted as a shell egg that does not contain ovomucoid, The method for selecting according to any one of [1] to [3], wherein the threshold value is within a range of more than 0 and not more than 0.6. [5] A method for producing ovomucoid-free shell eggs, comprising: A production method comprising a step of carrying out the selection method according to any one of [1] to [4] to select shell eggs that do not contain ovomucoid. Effect of the Invention

[0009] According to the present invention, a method for selecting shell eggs that do not contain ovomucoid in a non-destructive and simple manner can be provided. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described in detail. However, the present invention is not limited to the following embodiment.

[0011] (Method for selecting shell eggs that do not contain ovomucoid) The present invention is characterized by providing a method for selecting shell eggs that do not contain ovomucoid, comprising a measurement step of irradiating shell eggs with light containing light of a specific wavelength and measuring the amount of light absorbed at the specific wavelength, a calculation step of calculating a discrimination value by substituting the amount of absorption into a conversion formula, and a selection step of selecting shell eggs that do not contain ovomucoid based on the discrimination value, wherein the conversion formula is an equation derived from the results of measuring the amount of light absorbed at the specific wavelength for shell eggs that contain ovomucoid and shell eggs that do not contain ovomucoid.

[0012] (Measurement step) The method for selecting shell eggs that do not contain ovomucoid according to this embodiment includes a measurement step of irradiating the shell eggs with light containing light of a specific wavelength and measuring the amount of light absorbed at the specific wavelength.

[0013] (Shell eggs) In the present specification, a "shelled egg" refers to an unbroken egg that has all of the eggshell, egg yolk, and egg white. Shelled eggs may have cracked eggshells, etc., so long as they have all of the eggshell, egg yolk, and egg white. Shelled eggs may be those that are used as food materials, etc. There are no particular limitations on the breed of laying hens and / or the egg-laying time for shelled eggs. Furthermore, the eggshell of a shelled egg may be a white eggshell or a colored eggshell, such as brown or reddish brown.

[0014] (Ovomucoid-free shell eggs) In the present specification, "shell eggs not containing ovomucoid" are shell eggs not containing ovomucoid, and are as described above for shell eggs, except that they do not contain ovomucoid. Ovomucoid is a protein contained in egg white, and is one of the substances that are allergens in chicken eggs. Ovomucoid is also water-soluble and has extremely high physicochemical stability. Therefore, its allergenicity is not easily lost even when subjected to heat treatment and processing using digestive enzymes.

[0015] As used herein, "not containing ovomucoid" means that the ovomucoid content in egg white is less than 1 μg / mL, preferably 0 μg / mL, based on the total amount of egg white.

[0016] (Uses of ovomucoid-free shell eggs) Examples of uses of ovomucoid-free shell eggs include boiled eggs, confectionery, cooking, bread making, ice cream, water kneading, ham, noodles, and the like. "For boiled eggs" refers to use as a raw material for boiled eggs. "For confectionery" refers to use as a raw material for producing confectionery. Ovomucoid-free shell eggs for confectionery can be used, for example, as a raw material for sponge cakes, etc. "For cooking" refers to use as a raw material for producing food and drink (excluding confectionery). Ovomucoid-free shell eggs for cooking can be used, for example, as a raw material for scrambled eggs, scrambled eggs, egg soup, fried eggs, omelets, rolled eggs, and the like. The method for selecting ovomucoid-free shell eggs according to the present embodiment can also be used as a method for selecting ovomucoid-free shell eggs for boiled eggs, confectionery, or cooking. In particular, since ovomucoid is an allergenic protein, shell eggs that do not contain ovomucoid can also be used to develop hypoallergenic foods. Hypoallergenic foods refer to foods that are unlikely to cause allergies.

[0017] Ovomucoid-free shell eggs may be distributed in the form of shell eggs, or may be distributed in the form of cracked eggs containing egg white and egg yolk, or may be distributed in the form of egg white or egg yolk after cracking and further separating the egg white and egg yolk.

[0018] (Method of measuring the amount of light absorbed at a specific wavelength) The amount of light absorbed at a specific wavelength (hereinafter also referred to as "absorption amount") is measured using spectroscopy, in which light containing a specific wavelength is irradiated onto a shell egg and the transmitted or reflected light is detected. That is, in the measurement step, the amount of absorption is measured by irradiating the shell egg with light containing a specific wavelength and detecting the transmitted or reflected light. The amount of absorption measured may be an absolute value or a relative value (e.g., absorbance, etc.). The amount of absorption measured may be the amount of absorption of light of a single wavelength, or may be the amount of absorption of light of multiple wavelengths. When the amount of absorption measured is the amount of absorption of light of multiple wavelengths, it may be light of multiple continuous wavelengths, or may be light of multiple discontinuous wavelengths. When the amount of absorption of light of multiple wavelengths is measured, for example, an absorption spectrum including the amount of absorption of light of specific wavelengths may be measured.

[0019] In the method for selecting shell eggs not containing ovomucoid according to the present embodiment, it is preferable to measure the absorption amount by detecting transmitted light or reflected light. The absorption amount can be measured, for example, by a visible near-infrared spectrophotometer, a near-infrared spectrophotometer, or the like. As the visible near-infrared spectrophotometer, for example, Handy Lambda II NIR enh manufactured by SpectraCorp, Inc. can be used. As the near-infrared spectrophotometer, for example, near-infrared spectrometer Matrix-F manufactured by Bruker Optics, Inc. can be used. The obtained data on the absorption amount can be analyzed using commercially available software. As commercially available software, for example, The Unscrambler X (manufactured by CAMO Software) and OPUS (manufactured by Bruker Optics, Inc.) can be used.

[0020] (light of a specific wavelength) The light of a specific wavelength in the measurement step may be light present within a wavelength range of, for example, 310 nm to 2500 nm, 310 nm to 2000 nm, 310 nm to 1500 nm, or 310 nm to 1100 nm, or 600 nm to 2500 nm, 800 nm to 2500 nm, or 1100 nm to 2500 nm. As described above, the light of a specific wavelength may be light present within the above wavelength range, and may be light of a single wavelength within the above wavelength range, or light of multiple wavelengths within the above wavelength range. Since the amount of light of a wavelength within this wavelength range that is absorbed by shell eggs differs between shell eggs that do not contain ovomucoid and shell eggs that contain ovomucoid, it becomes possible to select shell eggs that do not contain ovomucoid based on the amount of absorption.

[0021] (Wavelength of light irradiated onto shell eggs) The light irradiated to the shell eggs in the measurement step (hereinafter also referred to as "irradiation light") is not particularly limited as long as it is light that contains light of the specific wavelength. In other words, the irradiation light may contain light of a wavelength other than the specific wavelength, or may be light of the specific wavelength. The absorption amount is measured by irradiating the shell eggs with irradiation light. The irradiation light may be, for example, light in a wavelength range of 100 nm to 3000 nm, 150 nm to 2500 nm, 200 nm to 2000 nm, 300 nm to 1500 nm, or 310 nm to 1100 nm, or 500 nm to 3000 nm, 600 nm to 3000 nm, 700 nm to 2800 nm, 750 nm to 2600 nm, or 800 nm to 2500 nm.

[0022] (Shell egg placement conditions) In the measurement step, the shell egg may be arranged, for example, so that the long axis connecting the blunt end and the sharp end of the shell egg is parallel or approximately parallel to the horizontal plane, or so that the long axis is perpendicular or approximately perpendicular to the horizontal plane. When the long axis is perpendicular or approximately perpendicular to the horizontal plane, the shell egg may be arranged so that the blunt end faces downward. In the measurement step, the shell egg may be fixed so that it is arranged as described above.

[0023] (Light irradiation conditions for shell eggs) In the measurement step, the irradiation light can be irradiated from various directions to the shelled egg. The irradiation of the irradiation light may be performed in a state where the shelled egg is fixed so that the shelled egg is disposed as described above, or in a non-fixed state. The irradiation light may be irradiated in a direction intersecting the long axis line connecting the blunt end and the sharp end of the shelled egg, or in a direction along the long axis line. The measurement of the absorption amount may be performed, for example, by irradiating the shelled egg in a direction intersecting the long axis line connecting the blunt end and the sharp end of the shelled egg in a state where the long axis line connecting the blunt end and the sharp end of the shelled egg is parallel or approximately parallel to the horizontal plane, and detecting transmitted light or reflected light. The measurement of the absorption amount may also be performed, for example, by irradiating the shelled egg in a direction intersecting the long axis line connecting the blunt end and the sharp end of the shelled egg in a state where the blunt end of the shelled egg is downward and the long axis line connecting the blunt end and the sharp end of the shelled egg is perpendicular or approximately perpendicular to the horizontal plane, and detecting transmitted light or reflected light.

[0024] (detection of specific wavelengths of light) When irradiating with irradiation light and detecting transmitted light, it is preferable to irradiate a portion of the egg yolk that does not pass through with the irradiation light and detect the transmitted light, from the viewpoint of enabling more accurate measurement. When irradiating with irradiation light and detecting reflected light, it is also possible to detect reflected light originating from the egg white portion of a shelled egg.

[0025] (Calculation step) The method for selecting shell eggs that do not contain ovomucoid includes a calculation step of calculating a discrimination value by substituting the above absorption amount into a conversion formula.

[0026] (Conversion formula) In the calculation step, the conversion formula is used to calculate a discrimination value from the absorption amount measured in the measurement step. The conversion formula is a formula derived from the results of measuring the absorption amount for shell eggs containing ovomucoid and shell eggs not containing ovomucoid. More specifically, it is a relational formula between the absorption amount and the discrimination value derived with the measured absorption amount as an explanatory variable and the discrimination value as a response variable. The conversion formula may be, for example, a formula derived by multivariate analysis, or a formula derived by partial least squares discriminant analysis (PLS-DA), logistic regression analysis, or the like, and is preferably a formula derived by partial least squares discriminant analysis. The discrimination value is a numerical value set by associating a predetermined numerical value with shell eggs containing ovomucoid and shell eggs not containing ovomucoid, and is a numerical value for discriminating shell eggs not containing ovomucoid. For example, shell eggs containing ovomucoid may be associated with numerical values, with the discrimination value being 1 for shell eggs containing ovomucoid and the discrimination value being 0 for shell eggs not containing ovomucoid. In this case, the conversion equation may be an equation derived by partial least squares discriminant analysis from the results of measuring the above absorption amounts, with the discrimination value being 1 for shell eggs containing ovomucoid and the discrimination value being 0 for shell eggs not containing ovomucoid.

[0027] (Multivariate analysis) Multivariate analysis is a statistical technique used to classify subjects by simultaneously analyzing multiple data (variables) obtained from the subject, to analyze the interrelationships between multiple data, and to comprehensively summarize multiple data. Multivariate analysis may be performed in combination with a spectral filtering method, such as orthogonal signal correction (OSC) to remove interfering components, as necessary. Many analysis tools are commercially available as software, and any one of them can be obtained. Such commercially available tools generally come with an operation manual so that multivariate analysis can be performed without knowledge of difficult mathematics and statistics. Multivariate analysis may be performed using a part or all of the obtained analysis data.

[0028] (Partial Least Squares Discriminant Analysis (PLS-DA)) PLS-DA is a method of constructing a model for discriminating between two groups by applying partial least squares (PLS) to discriminant analysis (DA). In the method for selecting shell eggs that do not contain ovomucoid according to this embodiment, a model (transformation formula) is constructed that discriminates between shell eggs that contain ovomucoid and shell eggs that do not contain ovomucoid based on the above measured absorption amount.

[0029] (Shell eggs containing ovomucoid in the calculation step) The shell eggs containing ovomucoid in the calculation step are used to derive the conversion formula. The shell eggs containing ovomucoid are as described above for the shell eggs, except that they contain ovomucoid. Examples of shell eggs containing ovomucoid in the calculation step include shell eggs obtained from laying hens of wild-type chicken species. The shell eggs containing ovomucoid in the calculation step may be ones that are known to be shell eggs containing ovomucoid when the absorption amount of light of the specific wavelength is measured, or may be ones that are found to be shell eggs containing ovomucoid after the absorption amount is measured.

[0030] (Shell eggs not containing ovomucoid in the calculation step) The ovomucoid-free shell eggs in the calculation step are used to derive the conversion formula. The ovomucoid-free shell eggs are as described above. Examples of ovomucoid-free shell eggs in the calculation step include shell eggs obtained from chicken species in which the ovomucoid gene has been deleted (knocked out) by genetic manipulation or the like. The ovomucoid-free shell eggs in the calculation step may be ones that are known to be ovomucoid-free shell eggs when the amount of light absorption at the specific wavelength is measured, or may be ones that are found to be ovomucoid-free shell eggs after the absorption amount is measured.

[0031] (Calculation method of discriminant value) The discrimination value is calculated by substituting the absorption amount measured in the measurement step into the above conversion formula.

[0032] (Sorting step) The method for selecting shell eggs that do not contain ovomucoid includes a selection step of selecting shell eggs that do not contain ovomucoid based on the above discrimination value.

[0033] (Selection method) The selection of shell eggs that do not contain ovomucoid is performed based on the calculated discrimination value of shell eggs. For example, the selection may be performed by comparing the calculated discrimination value of shell eggs with a preset threshold value. The above-mentioned threshold value may be preset depending on the purpose, and for example, from the viewpoint of the accuracy of the determination of shell eggs that do not contain ovomucoid, the threshold value may be set low to reduce false positives, and from an economic viewpoint, the threshold value may be set high to reduce false negatives. In other words, the above-mentioned threshold value can be appropriately set taking into consideration the degree to which the false negative rate and the false positive rate are balanced, etc.

[0034] In the case where the conversion formula is derived by PLS-DA from the results of measuring the absorption amount, with the discrimination value of shell eggs containing ovomucoid being 1 and the discrimination value of shell eggs not containing ovomucoid being 0, when the discrimination value of the shell eggs whose absorption amount has been measured is, for example, less than a threshold value, the shell eggs may be selected as shell eggs not containing ovomucoid. The threshold value may be, for example, within a range of more than 0 and not more than 0.6, or within a range of 0.05 or more and not more than 0.6, 0.1 or more and not more than 0.6, 0.1 or more and not more than 0.5, 0.1 or more and not more than 0.4, or 0.1 or more and not more than 0.3, or within a range of 0.2 or more and not more than 0.6, 0.3 or more and not more than 0.5, or 0.4 or more and not more than 0.5. Furthermore, since the proportion of shell eggs that do not contain ovomucoid among the selected shell eggs increases as the threshold value is set lower, when it is desired to reduce false positives, the threshold value may be set within the range of, for example, 0.1 to 0.4, 0.1 to 0.35, 0.1 to 0.3, 0.1 to 0.25, or 0.1 to 0.2. Since the proportion of shell eggs that do not contain ovomucoid that are selected increases as the threshold value is set higher, when it is desired to reduce false negatives, the threshold value may be set within the range of, for example, 0.35 to 0.6, 0.4 to 0.6, 0.45 to 0.6, or 0.5 to 0.6. When it is desired to reduce false positives while also reducing false negatives, the threshold value may be set within the range of, for example, 0.2 to 0.5, 0.2 to 0.4, 0.2 to 0.35, 0.3 to 0.5, 0.35 to 0.5, 0.4 to 0.5, or 0.3 to 0.4.

[0035] In the method for selecting shell eggs not containing ovomucoid according to the present embodiment, the measurement step to the selection step may be performed once, and then some or all of the measurement step to the selection step may be performed multiple times. In such a case, the conditions for the first measurement step to the selection step may be changed. For example, the wavelength of the light of a specific wavelength in the measurement step may be changed to measure the absorbance, or the threshold value in the selection step may be changed.

[0036] (Method of manufacturing ovomucoid-free shell eggs) The present invention is characterized by providing a method for producing ovomucoid-free shell eggs, which includes a step of carrying out the above-mentioned method for selecting shell eggs that do not contain ovomucoid, and selecting shell eggs that do not contain ovomucoid.

[0037] The method for selecting shell eggs that do not contain ovomucoid is as described above. EXAMPLES

[0038] The present invention will be described in more detail below with reference to examples, etc. However, the present invention is not limited to the following examples.

[0039] [Test Example 1: Determination of shell eggs that do not contain ovomucoid (1)] (1. Deriving the conversion formula) A total of 453 shell eggs containing ovomucoid and shell eggs not containing ovomucoid (both unbroken eggs) for use in deriving the conversion formula shown in Table 1 below were irradiated with light having a wavelength of 310 nm or more and 1100 nm or less, and the absorbance (absorption spectrum) of light at a specific wavelength was measured. The measurement data of the absorbance was then used to derive the conversion formula.

[0040] The absorbance (absorption spectrum) of light of a specific wavelength was measured by irradiating light with a wavelength of 310 nm or more and 1100 nm or less in a direction intersecting with the long axis line connecting the blunt end and the sharp end of the shell egg for deriving the conversion formula in a state where it is arranged so that it is approximately perpendicular to the horizontal plane, and detecting the transmitted light. The above absorbance measurement data was obtained using a visible near-infrared spectrophotometer. The measurement equipment and conditions for the absorbance (absorption spectrum) are as follows. Equipment: Handy Lambda II NIR enh (SpectraCorp, Inc.) Analysis software: The Unscrambler X (CAMO Software)

[0041] The conversion equation was derived using the following procedure. The discrimination value was set as 1 for shell eggs containing ovomucoid for use in deriving the conversion equation, and 0 for shell eggs not containing ovomucoid for use in deriving the conversion equation, and the discrimination value was used as the objective variable. Savitzky-Golay fitting was performed on the measured absorption spectrum with 25 smoothing points on both sides, and second-order differentiation (The Unscrambler X (CAMO Software)) was performed. PLS-DA was performed on the above objective variables using the second-order derivative value of the absorbance of light of a specific wavelength in the absorption spectrum after the second-order differentiation process as the explanatory variable. The R 2 The coefficient of determination was 0.579, a high figure, and the goodness of fit of the transformation formula was high.

[0042] (2. Determination of shell eggs that do not contain ovomucoids) A total of 125 shell eggs containing ovomucoid and shell eggs not containing ovomucoid (both unbroken eggs) for evaluation, shown in Table 1 below, were similarly irradiated with light having a wavelength of 310 nm or more and 1100 nm or less. Next, the absorbance (absorption spectrum) of light at a specific wavelength was measured, and a discrimination value was calculated using the conversion formula derived in 1 above, and the discrimination value was compared with a threshold value to determine whether or not the shell eggs did not contain ovomucoid.

[0043] The absorption spectrum was measured in the same manner as in 1 above. Thereafter, the discrimination value was calculated by substituting the absorbance of light at the same wavelength as that used to derive the conversion formula in the measured absorption spectrum of the shell eggs into the conversion formula. For the selection of shell eggs not containing ovomucoid, threshold values ​​were set to 0.5, 0.4, 0.3, 0.2, and 0.1, and when the discrimination value was less than each threshold, the egg was determined to be a shell egg not containing ovomucoid. The results of evaluation of the discrimination rate 1 calculated using the following formula (1) are shown in Table 2, and the results of evaluation of the discrimination rate 2 calculated using the following formula (2) are shown in Table 3. Formula (1) Discrimination rate 1 (%) = (number of correct answers for shell eggs not containing ovomucoid / number of shell eggs with discrimination values ​​below the threshold) × 100 Equation (2) Discrimination rate 2 (%) = {(number of correct answers for shell eggs not containing ovomucoid + number of correct answers for shell eggs containing ovomucoid) / total number of shell eggs evaluated} × 100

[0044] [Table 1]

[0045] [Table 2]

[0046] [Table 3]

[0047] As shown in Table 2, when the threshold was set to 0.5, the determination rate 1 was 96.30%. Furthermore, the determination rate 1 tended to be higher as the threshold was set to a lower value. This is considered to be due to a decrease in the number of shell eggs containing ovomucoid that were determined to be shell eggs not containing ovomucoid (false positives). This result demonstrated that the method performed in Test Example 1 above allows for the selection of shell eggs not containing ovomucoid with high accuracy.

[0048] Furthermore, as shown in Table 3, the determination rate 2 calculated by a calculation method such as formula (2) tended to decrease as the threshold was set to a lower value. This is thought to be because, as the threshold was lowered, the number of false positives decreased, while the number of shell eggs not containing ovomucoid that were determined to be shell eggs containing ovomucoid (false negatives) increased. Conversely, the determination rate 2 tended to increase as the threshold was set to a higher value. This is thought to be because the number of shell eggs not containing ovomucoid that were false negatives decreased. Therefore, the results of Tables 2 and 3 demonstrated that shell eggs not containing ovomucoid can be selected with high accuracy by setting an appropriate threshold according to the purpose.

[0049] [Test Example 2: Determination of shell eggs that do not contain ovomucoid (2)] (1. Deriving the conversion formula) The derivation of the conversion equation was performed in the same manner as in Test Example 1, except that the wavelength of the light irradiated to the shell eggs was changed, and the wavelength of the specific wavelength of light was changed accordingly. A total of 119 shell eggs containing ovomucoid and shell eggs not containing ovomucoid (both in an unbroken state) for use in deriving the conversion equation, as shown in Table 4 below, were irradiated with light having a wavelength of 800 nm or more and 2500 nm or less, and the absorbance (absorption spectrum) of the light of the specific wavelength was measured. The absorbance measurement data was then used to derive the conversion equation. The R of the derived conversion equation 2 The coefficient of determination was 0.701, which was a fairly high value, and the goodness of fit of the transformation formula was quite high.

[0050] (2. Determination of shell eggs that do not contain ovomucoids) The determination of shell eggs not containing ovomucoid was performed in the same manner as in Test Example 1, except that the wavelength of the light irradiated to the shell eggs was changed, and the wavelength of the light of the specific wavelength was changed accordingly. A total of 29 shell eggs containing ovomucoid and shell eggs not containing ovomucoid for evaluation (both eggs in an unbroken state) shown in Table 4 below were similarly irradiated with light of a wavelength of 800 nm or more and 2500 nm or less. Next, the absorbance (absorption spectrum) of the light of the specific wavelength was measured, and a discrimination value was calculated using the conversion formula derived in 1. of Test Example 2 above, and the discrimination value was compared with a threshold value to determine whether the shell eggs were not containing ovomucoid. The results of evaluation of the determination rate 1 calculated by the above formula (1) are shown in Table 5, and the results of evaluation of the determination rate 2 calculated by the following formula (2) are shown in Table 6.

[0051] [Table 4]

[0052] [Table 5]

[0053] [Table 6]

[0054] Even when the wavelength of the specific wavelength of light was changed, the same results as in Test Example 1 were obtained. As the threshold value was set to a lower value, the determination rate 1 tended to be higher and the determination rate 2 tended to be lower. The conversion formula derived in Test Example 2 had a higher R than the conversion formula derived in Test Example 1. 2 Because the coefficient of determination is high, it is believed that the accuracy of the judgment will be improved by increasing the number of lots. The above results demonstrate that the method performed in Test Example 2 above can also be used to select shell eggs that do not contain ovomucoid with high accuracy.

Claims

1. 1. A method for sorting shell eggs, comprising the steps of: A measuring step of irradiating a shell egg with light containing light of a specific wavelength and measuring the amount of light absorbed by the specific wavelength; A calculation step of calculating a discrimination value by substituting the absorption amount into a conversion formula; and A selection step of selecting shell eggs that do not contain ovomucoid based on the discrimination value, The conversion formula is a formula derived from the results of measuring the amount of light absorbed at the specific wavelength for shell eggs containing ovomucoid and shell eggs not containing ovomucoid. A method for selecting shell eggs that do not contain ovomucoids.

2. The sorting method according to claim 1 , wherein the light of the specific wavelength is light having a wavelength within a range of 310 nm or more and 2500 nm or less.

3. The selection method according to claim 1 or 2, wherein the transformation formula is an equation derived by partial least squares discriminant analysis.

4. The transformation formula is an equation derived by partial least squares discriminant analysis, with a discrimination value of 1 for shell eggs containing ovomucoid and a discrimination value of 0 for shell eggs not containing ovomucoid, In the sorting step, when the discrimination value calculated in the calculation step is less than a threshold value, the egg is sorted as a shell egg that does not contain ovomucoid, The method according to claim 1 or 2, wherein the threshold value is in the range of more than 0 and not more than 0.

6.

5. A method for producing ovomucoid-free shell eggs, comprising: A production method comprising a step of carrying out the selection method according to claim 1 or 2 to select shell eggs that do not contain ovomucoid.

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