JP2007292512A - Freshness evaluation device of edible meat, and freshness-maintaining device for edible meat using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To evaluate the freshness of edible meat in a sanitary state, without contacting edible meat. <P>SOLUTION: This freshness evaluation device of edible meat is equipped with a polarized light irradiation means for irradiating the texture of the edible meat with a polarized light, a polarization measuring means for measuring the light quantity distribution of a polarization angle, with respect to the light transmitted through or reflected from the texture, and an analysis means 6 for analysis the light quantity distribution of the polarization angle for estimating the freshness of the edible light. The freshness state of the edible meat is estimated non-invasively, on the basis of the light quantity distribution of the polarization angle. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a freshness evaluation apparatus for evaluating freshness of edible meat and a freshness maintenance apparatus for maintaining freshness.

  JP-A-2-291947 (Patent Document 1) and JP-A-2005-83929 disclose that agricultural products and livestock products are evaluated using polarized light. The former is to evaluate the taste by surface water retention on the surface of rice, and the latter is to quantitatively evaluate the form evaluation (sensitivity evaluation) of human edible meat by polarization measurement changing with the melting point of fat of edible meat. Is.

On the other hand, with regard to the freshness of edible meat, evaluation based on qualitative human senses such as color and shape has only been made so far, and it is easy to evaluate freshness, especially non-contact using light. Nothing that has been made possible to do so far has been proposed.
JP-A-2-291947 JP 2005-83929 A

  This invention is invented in view of said point, Comprising: It provides the freshness evaluation apparatus of the edible meat which can evaluate freshness in a hygienic state, without touching edible meat, and said evaluation result An object of the present invention is to provide an apparatus for maintaining the freshness of edible meat that can maintain the freshness of edible meat.

  In order to solve the above problems, a freshness evaluation apparatus for edible meat according to the present invention includes polarized light irradiation means for irradiating a tissue of edible meat with polarized light, and a light amount distribution of a polarization angle with respect to light transmitted and / or reflected from the tissue. The present invention is characterized in that it comprises a polarization measuring means for measuring the amount of light and an analysis means for estimating the freshness of the edible meat by analyzing the light quantity distribution of the polarization angle. The freshness state of edible meat is estimated non-invasively based on the light quantity distribution of the polarization angle.

  At this time, if the polarized light irradiating means irradiates light having a wavelength of 1400 nm to 2000 nm, since the absorption wavelength of water is included, the freshness evaluation including the water content can be performed, and the accuracy can be improved. .

  The polarized light irradiating means emits pulsed light, the polarized light measuring means measures the time change of the light distribution of the polarization angle, and the analyzing means analyzes the light distribution of the polarization angle in consideration of the time change. If it is, the change in freshness with time can be obtained.

  The edible meat freshness maintaining apparatus according to the present invention is characterized by comprising a humidity control unit that controls the atmospheric humidity of the edible meat based on the freshness estimation result of the analysis means in the edible meat freshness evaluation apparatus. ing. An optimal freshness state can be maintained.

  Since the present invention evaluates the freshness based on the light quantity distribution of the polarization angle obtained by irradiating polarized meat on the edible meat tissue, the freshness can be easily evaluated in a hygienic state without touching the edible meat. In addition, the freshness deterioration of edible meat can be measured even when stored in a refrigerator or the like.

  Moreover, since atmospheric humidity is controlled based on the said freshness evaluation, the fall of freshness can be suppressed effectively.

  Hereinafter, the present invention will be described based on an embodiment shown in the accompanying drawings. In FIG. 1, a light source 1 capable of irradiation time control, a polarizing plate 2 using light emitted from the light source 1 as linearly polarized light, and a polarizing plate A light receiving element 4 that receives reflected or transmitted light when the tissue surface of the edible meat 9 is irradiated with light that has been linearly polarized through 2, and a polarizing plate 3 disposed immediately before the light receiving element 4, A rotation stage 5 that rotates the polarizing plate 3 around the optical axis by driving a motor, and light amount measurement data obtained from the light receiving element 4 and polarization angle control data when the polarizing plate 3 is rotated by the rotation stage 5 are configured. Analyzing means 6 for performing analysis based on polarization angle light quantity distribution data, which is light quantity data for each polarization angle, is provided.

  First, the effect of the freshness of the edible meat when illuminating the tissue of the edible meat with polarized light and observing the light distribution of the polarization angle of the reflected or transmitted light will be described. When the transmitted light was measured after irradiating polarized light on the edible meat tissue, as shown in FIGS. 2 and 3, it was found that a change in the polarization angle occurred, and the peak of the polarization angle was the time. It has been found that the figure shifts to the right with the passage of time. Incidentally, in the figure, L indicates a case where laser light which is linearly polarized light is received by the light receiving element 4 without passing through the polarizing plate 3. In FIG. 3, A is after 4 days, B is after 6 days, C is It shows after 7 days. Moreover, this polarization angle shift also occurs in units of minutes, and the data when 5 minutes, 15 minutes, 65 minutes, 80 minutes, 115 minutes, 135 minutes, 155 minutes, 175 minutes, 195 minutes, and 215 minutes have passed, respectively. Is shown in FIG. In FIG. 4, D0 indicates 0 minutes, D5 indicates 5 minutes, D15 indicates 5 minutes, D65 indicates 65 minutes, D80 indicates 80 minutes, D195 indicates 195 minutes, and D215 indicates 215 minutes. The vertical axis in FIGS. 3 and 4 is the normalized light intensity.

  Since there is a correlation between the freshness of edible meat and the polarization angle distribution of light, the freshness of edible meat can be estimated by measuring the polarization angle distribution. We also confirmed that when the edible meat was given moisture with a sprayer, etc., the polarization angle returned to the fresh state, so it was edible by supplying moisture when the polarization angle shifted. The freshness of the meat can be maintained.

  On the basis of such an event, in the present invention, the edible meat 9 is irradiated with light emitted from the light source 1 and linearly polarized light through the polarizing plate 2, and the light reflected by the edible meat and / or the polarized light that rotates the transmitted light is rotated. Light is received by the light receiving element 4 through the plate 3 to obtain polarization angle distribution data of the polarization angle and the amount of received light (light intensity), and the analysis means 6 reduces the freshness if there is a change in the polarization angle shift. It is judged that it did.

  In addition, when using reflected light, it is desirable to exclude the light reflected on the surface of the edible meat, but since the light reflected on the surface has the same polarization angle as the linearly polarized light irradiated to the edible meat, The influence of the surface reflected light can be removed by changing the angle of the polarizing plate 3 provided in front. Therefore, it is possible to use not only the transmitted light but also the reflected light reflected inside the edible meat. Further, since measurement with time is performed, it is preferable that the light source 1 is turned on with pulsed light and the polarization angle distribution is measured in synchronization with the lighting timing.

  The light incident on the light receiving element 4 is guided to the spectroscope 7 by rotating the mirror, the light passing through the edible meat is measured, and the internal components (fat and moisture) are also monitored. May also be reflected in the freshness estimation. In this case, if near-infrared light having a wavelength of 1200 nm to 2000 nm is used as the light source 1, light can penetrate into the edible meat, which is advantageous for measuring fat and moisture.

  FIG. 5 shows the light penetration rate by wavelength. In the figure, LD 670p is the transmitted light attenuation rate of light with a wavelength of 670 nm for pork, LD 670c is the transmitted light amount attenuation rate of light with a wavelength of 670 nm for chicken (sasami), and LD 810c is the transmitted light amount attenuation of light with a wavelength of 810 nm for chicken (sasami). LD980c indicates the transmitted light amount attenuation rate of light with a wavelength of 980 nm with respect to chicken (sasami). It can be seen that near infrared light is effective.

  Next, a freshness maintenance device using the freshness evaluation device is shown in FIG. This apparatus includes a low temperature storage 11 for storing edible meat, a spraying device 13 and a spray control unit 12 for driving the spraying device 13, and irradiates linearly polarized light to the edible meat in the storage. Polarization angle distribution data is obtained by measuring the light that has passed through. If the change in the polarization angle is calculated and the change in angle is equal to or greater than the predetermined angle α, the spray control unit 12 operates the spray device 13 to spray the interior, and the humidity in the interior is reduced. increase. This spraying operation and polarization angle distribution measurement / angle shift determination are performed in parallel. When the polarization angle shift is within α, it is determined that the freshness has returned to the original state, and the spraying operation is stopped. In addition, this apparatus can be similarly used in other fresh foods whose moisture content affects freshness. Moreover, although the meat of livestock was taken as an example here as edible meat, it also includes fish meat.

It is a block diagram of an example of an embodiment of the invention. It is explanatory drawing of an example of the time-dependent change data of a polarization angle. It is explanatory drawing of the other example of the time-dependent change data of a polarization angle. It is a block diagram of the other example of embodiment of this invention. It is explanatory drawing of the transmitted light amount attenuation factor according to wavelength.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light source 2 Polarizing plate 3 Polarizing plate 4 Light receiving element 6 Analysis means 9 Edible meat

Claims (4)

  Polarized light irradiation means for irradiating the tissue of edible meat with polarized light, polarization measurement means for measuring the light quantity distribution of the polarization angle for the light transmitted and reflected by the tissue, and analyzing the light quantity distribution of the polarization angle to edible meat An edible meat freshness evaluation apparatus, comprising: an analysis means for estimating the freshness of food.   2. The apparatus for evaluating freshness of edible meat according to claim 1, wherein the polarized light irradiation means irradiates light having a wavelength of 1400 nm to 2000 nm.   The polarized light irradiating means irradiates pulsed light, the polarized light measuring means measures the time change of the light amount distribution of the polarization angle, and the analyzing means analyzes the light amount distribution of the polarization angle in consideration of the time change. The freshness evaluation apparatus for edible meat according to any one of claims 1 to 3, wherein the apparatus is a thing.   An edible meat comprising a humidity control unit for controlling the atmospheric humidity of the edible meat based on the freshness estimation result of the analysis means in the edible meat freshness evaluation apparatus according to any one of claims 1 to 3. Freshness maintenance device.

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