JPS60220849A - Detecting device for addled albumen - Google Patents

Abstract

PURPOSE:To detect an addled albumen and prevent an error in decision making by using an optical filter system which has a transmission band nearly from the upper-limit wavelength of ultraviolet rays nearly to the lower-limit wavelength of the fluorescent spectrum of a normal yolk. CONSTITUTION:The optical fiber system 9 of a fluorescence detecting means 7 is constituted by combining an optical fiber 91 which removes light with shorter wavelength than nearly the upper-limit wavelength of ultrasonic rays with an optical fiber 92 which removes light with longer wavelength than nearly the lower-limit wavelength of the fluorescent spectrum of the normal yolk. Then, a sample albumen 1 is irradiated with ultraviolet rays and if the albumen 1 is addled, the albumen emits fluorescence, which is converged on the lens of the means 7. At this time, the ultraviolet rays reflected by the albumen 1 and the fluorescence characteristic to the yolk when the albumen 1 contains the yolk are converged on the lens 1. The transmitted fluorescence of the filter system 9 is inputted to a discrimination means 8 through a photodetecting element 4, which outputs a signal indicating the addled albumen when the input level exceeds a reference value.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a spoiled albumen detection device using an optical method.

Generally, when producing processed egg white products such as mayonnaise, it is necessary to determine whether the egg whites of raw materials (chicken eggs) are rotten.

In the past, rottenness of egg whites was determined based on empirical judgment using human senses such as sight and smell, and was generally carried out by visual inspection, transillumination inspection, egg-breaking inspection, etc. However, with such a determination method, it is difficult to automate the determination of rottenness of egg white. Although the process of processing egg whites has been mechanized and automated, since workers are required to directly determine whether the egg whites are spoiled, it is not possible to automate the entire manufacturing process, which hinders work efficiency. It had become.

Therefore, recently, we irradiated the egg white after breaking with ultraviolet rays,
A method of determining rottenness of egg white based on the presence or absence of fluorescence is being considered. The principle of this method is shown in Figures 1 and 2.
This will be explained with reference to FIG. 1 is a sample egg white that has been broken and the yolk has been removed, leaving only the albumen, and this sample egg white 1
300 to 410 with a peak wavelength of 365 nm.
Irradiate ultraviolet light of about nm. If sample egg white 1 is normal, it emits very weak blue-white fluorescence, and if sample egg white 1 is rotten by some kind of bacteria, it emits strong blue or green fluorescence. It is known. The certain bacteria referred to here are Pseudomonas fluorescens) m (Ps
It refers to fluorescent substance-producing bacteria such as eudmonas fluorescent). Then, the fluorescence emitted from the sample egg white 1 is detected by a fluorescence detection means and converted into an electrical signal, which corresponds to a threshold value determined in advance by measuring the intensity of normal and non-zero fluorescence. The level of the reference electric signal is compared with the output electric signal of the fluorescence detection means, and when the output electric signal exceeds the level of the reference electric signal, it is determined that the egg white is spoiled.

FIG. 2 is a block diagram showing the configuration of the fluorescence detection means.
In this fluorescence detection means, fluorescence and ultraviolet rays are collected by a condensing lens 2, ultraviolet rays are removed by an optical filter 3, and visible fluorescence (i.e., 400 ~700 nm) is received by the light receiving element 4, and the intensity of the visible fluorescence is converted into an electrical signal by the light receiving element 4. This electrical signal is further amplified by the amplifier 5 and sent to the discrimination means. is input. To explain the role of the optical filter 6 here, a part of the ultraviolet rays irradiated onto the sample egg white 1 is reflected by the sample egg white, but when the reflected ultraviolet rays enter the light receiving element 4, an output voltage corresponding to this ultraviolet ray is generated. Since a signal is emitted, an optical filter 6 is used to prevent this. As the optical filter 6, colored glass filters such as product names L-42, Y-43, Y-44, or G-558 (all manufactured by Toshiba Glass Co., Ltd.) have conventionally been used. Further, as the light receiving element 4, a QaAs P-based photodiode was used.

Therefore, the light receiving range of the light receiving element 4 is limited by the short wavelength side line optical filter 6, and the long wavelength side is limited by the characteristics of the light receiving element 4. For example, the light receiving range is limited from 400 nm to 7 nm.
It was up to 00 nm. FIG. 3 shows the optical filter 6
This is a graph showing an example of the transmission characteristics, etc. of
1) is the spectral transmittance of the optical filter 6, and the solid curve (2)
indicates the light-receiving characteristics of the light-receiving element 4, and the broken line curve (3) indicates the fluorescence spectrum of rotten egg white. It is understood from these graphs that only visible fluorescence from rotten egg white is efficiently received by the light receiving element 4.

However, the single-voltage egg detection device (using the method described above) has the following drawbacks. In other words, there are currently automatic egg breakers that separate egg whites and egg yolks, and non-separator types that do not separate them. It can be applied to eggs that have been cracked using an egg machine, but not to eggs that have been cracked using a non-separating machine. -The reason is that when a normal egg yolk is irradiated with ultraviolet light, it emits fluorescence, and the fluorescence spectrum is
As shown by the broken line (4) in the figure, the fluorescence spectrum of normal egg yolk partially overlaps with the fluorescence spectrum of rotten egg white, so for example, the threshold for the fluorescence intensity of normal egg white is 50%.
%, it is impossible to distinguish between the fluorescence of rotten albumen and the fluorescence of normal egg yolk, and as a result, rotten albumen cannot be detected. Furthermore, even when eggs are broken using a separate egg breaker, "disturbance" may occur in which the egg yolk is mixed into the egg white. Therefore, it is impractical to detect this "disturbance" as rotten egg white and make a false determination.

The present invention was made under these circumstances,
To provide a rotten egg white detection device that can automatically detect rotten egg white regardless of the presence or absence of egg yolk, can be applied to both separable and non-separable egg breakers, and is free from the risk of misjudgment. The purpose is to

The present invention is characterized by the use of an optical filter system whose transmission band ranges from near the upper limit wavelength of ultraviolet rays to near the lower limit wavelength of the fluorescence spectrum of normal egg yolk.

Embodiments of the present invention will be described below with reference to one drawing.

FIG. 4 is a configuration diagram showing an embodiment of the present invention, in which ID, 6, a light source for ultraviolet irradiation for irradiating sample egg white 1 with ultraviolet rays, and 7
8 is a fluorescence detection means, and 8 is the level of an output electric signal from this fluorescence detection means 7 and the level of a reference electric signal corresponding to a threshold value determined by measuring the fluorescence intensity of normal egg white in advance. This is a method for determining whether the egg white is spoiled or not based on the comparison results. FIG. 5 is a block diagram showing the fluorescence detection means 7, and the same reference numerals as in FIG. 2 indicate the same parts or parts corresponding to L. Reference numeral 9 denotes an optical filter system, and the optical filter system 9 used has a transmission band from around the upper limit wavelength of ultraviolet rays to around the lower limit wavelength of the fluorescence spectrum of egg yolk (that is, about 400 nm to about 500 nm). . The optical filter system 9 that satisfies these conditions includes, for example, a first optical filter 91 that removes light with a shorter wavelength than near the upper limit wavelength of ultraviolet rays, and a first optical filter 91 that removes light with a shorter wavelength than near the upper limit wavelength of ultraviolet rays, and a first optical filter 91 that removes light with a shorter wavelength than near the upper limit wavelength of the fluorescent spectrum of normal egg yolk. It is configured in combination with a second optical filter 92 that removes long wavelength light. As the first optical filter 91, similar to the conventional example shown in FIG.
4. A color/glass filter such as G-558 (both manufactured by Toshiba Glass Co., Ltd.) can be used. For example, the fluorescence spectrum of a normal yolk of a chicken egg has a peak of about 520 nm and a wavelength of about 500 nm, as shown by the dotted line (5) in Figure 6.
Therefore, as the second optical filter 92, it is possible to use an interference filter made of a dielectric multilayer film that removes light having a wavelength longer than 500 nm, for example. In this case, the optical filter system 9 includes a second optical filter 92 made by forming a multilayer film of the dielectric material by full vapor deposition on the surface of the first optical filter 91 made of the colored glass filter described above. configured. FIG. 6 shows an optical filter 90 made in this way.
The optical filter 9 according to this example uses a colored glass filter with the trade name L-42 as the first optical filter 91, and the surface of this filter is coated with light having a wavelength as long as 500 nm. It is formed by forming a multilayer dielectric film that removes the . In FIG. 6, the first optical filter 9
The light transmission characteristics of the first optical filter system 9 and the light transmission characteristics of the second optical filter 92 are shown by solid curves (6) and (7), respectively, and therefore the transmission band of the optical filter system 9 is defined by these solid curves (
This is the part sandwiched between 6) and (7). And the fluorescence spectrum of normal egg yolk can be changed.

In an embodiment with such a configuration, when the sample albumen 1 is irradiated with ultraviolet rays from the ultraviolet #irradiation light source 6, the albumen itself emits fluorescence if the sample albumen 1 is rotten. This fluorescent light is focused on the condensing lens 2 of the fluorescent light detection means 7, but at this time, the ultraviolet rays reflected by the sample egg white 1 and
If the image contains egg yolk, the fluorescent light unique to the egg yolk is also focused on the focusing lens 1. The ultraviolet rays are passed through a first optical filter 91, and the fluorescent light peculiar to egg yolk is passed through a second optical filter 9.
As a result, only the fluorescent light from the egg whites is selectively transmitted through the optical filter system 9. The transmitted fluorescent light is converted into an electrical signal according to the intensity of the fluorescent light by the light-receiving element 4, and this electrical signal is compared with the level of the reference electrical signal, and a level signal of this reference electrical signal is output. On the other hand, when the sample egg white is not rotten, even if normal egg yolk is mixed in, the fluorescent light peculiar to the egg yolk is removed by the optical filter system 9, and ultraviolet rays are also removed, so that the light receiving element 4 The output signal does not exceed the level of the electrical signal corresponding to the threshold of fluorescence intensity for normal albumen, and therefore no judgment signal for spoiled albumen is output.

FIG. 7 shows an optical filter consisting only of a colored glass filter (trade name L-42) (prior art), and a colored glass filter (trade name L-42) and a filter with a wavelength of 500 nm or less formed on its surface. The amount of normal egg yolk mixed in the normal egg white of one egg is changed in the case of the prior art and the case of the present invention by using a filter (the present invention) consisting of a multilayer film of a dielectric material that removes light and an interference filter consisting of a multilayer film of a dielectric material that removes light. This figure shows the results of measuring how the ratio of the output signal of the fluorescence detection means changes when normal egg white is used and the output signal of the fluorescence detection means when only normal egg white is used. In FIG. 7, the vertical axis shows the output ratio of normal egg white mixed with normal egg yolk, and the horizontal axis shows the amount of normal egg yolk mixed into normal egg white, and the solid line curve +ilA is , the solid line curve B shows the measurement results according to the present invention. From FIG. 7, it can be seen that in the conventional rotten egg white detection device, the output ratio increases due to the influence of egg yolk contamination, but in the rotten egg white detection device according to the present invention, it is not affected by egg yolk contamination. I understand.

As described above, according to the present invention, since the transmission band of the optical filter system of the fluorescence detection means exists up to around the upper limit wavelength of ultraviolet rays, the fluorescence of normal egg yolk is removed by the optical filter system. It is possible to automatically detect rotten egg white regardless of the presence or absence of normal egg yolk, and therefore it can be applied to both separating and non-separating egg breakers. Then, normal egg yolk is mixed into the egg white that is broken using a separate egg breaker.
Even if "disturbance" occurs, this "disturbance" will not be detected as spoiled egg white, so there is no risk of misjudgment.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram schematically showing the principle of an automatic method for detecting rotten egg white, FIG. 2 is a block diagram showing the configuration of a fluorescence detection means of a conventional rotten albumen detection device, and FIG. 3 is a conventional FIG. 4 is a graph showing the transmission characteristics of the optical filter, the light receiving characteristics of the light receiving element, and the fluorescence spectrum of the rotten albumen detection device according to an embodiment of the present invention. Fig. 5 is a block diagram showing the configuration of the fluorescence detection means of the rotten egg white detection device, and Fig. 6 shows the spectral transmittance of the optical filter system of the rotten egg detection device and the fluorescence from rotten albumen and normal albumen. FIG. 7 is a graph showing the measurement results of the influence of the amount of normal egg yolk mixed into the egg white for the rotten egg white detection device according to the present invention and the rotten egg white detection device according to the prior art. . DESCRIPTION OF SYMBOLS 1... Sample albumen, 2... Condensing lens, 6... Optical filter, 4... Light receiving element, 6... Light source for ultraviolet irradiation, 7... Fluorescence detection means, 8...・Discrimination means, 9...
- Optical filter system, 91... first optical filter, 9
2...Second optical filter. Figure 4 61 Sword Figure 7

Claims (5)

[Claims] (1) A light source for ultraviolet irradiation to irradiate the sample cracked egg with ultraviolet rays, and the fluorescent light emitted from the sample cracked egg by the ultraviolet ray irradiation from this light source is transmitted to the light receiving element through a condensing lens and an optical filter system. a fluorescence detection means for receiving light and outputting an electrical signal corresponding to the fluorescence; an output electric signal from the fluorescence detection means; and a preset threshold value for the fluorescence intensity of normal albumen. and a discriminating means for discriminating rottenness of the albumen in the sample cracked egg by comparing it with an electric signal corresponding to the sample, and the transmission band of the optical filter system ranges from near the upper limit wavelength of ultraviolet rays to the fluorescence spectrum of normal egg yolk. A rotten egg white detection device characterized by a band extending around the lower limit wavelength. (2) The rotten egg white detection device according to claim 1, wherein the transmission band of the optical filter system is from around 420 nm to around 500 nm. (3) The optical filter system is composed of first and second optical filters, the first optical filter is composed of a colored glass filter, and the second optical filter is composed of an interference filter composed of a dielectric multilayer film. A rotten egg white detection device according to claim 1 or 2. (4) The rotten egg white detection device according to claim 3, wherein the colored glass filter is L-42 (trade name). (5) fi! 4. The spoiled egg white detection device according to claim 3, wherein a multilayer film of an electric body is formed by adhering to a transparent surface of a colored glass filter.