JPH07167780A - Food preshness-judging device - Google Patents

Abstract

PURPOSE:To judge the freshness of foods objectively with a potable device by casting light from a light source through a probe on food, spectrum-analyzing the reflected light for obtaining color coordinates and judging the freshness of the food from the relation between the color coordinates and freshness. CONSTITUTION:A food freshness judging device E is constituted of a probe 1 inserted in fish meet (m) and a processing box 2. The light from a light source 21 in a processing box 2 passes through surrounding fiber 15, prism 13 facing to a window 12 and the window 12 to reflect at the fish meet (m). This reflection light goes through the window 12, prism 13 and the central fiber 14 into a processor 22 and the judgment signal is processed. In the CPU in the processor 22, a table indicating the relation between the color coordinate space and freshness for each kind of food is input in advance. Based on the obtained color coordinates space, freshness is judged, which is indicated on a display 36.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a food freshness discriminating apparatus for discriminating the freshness of food such as fish and meat.

[0002]

2. Description of the Related Art Conventionally, as a color measuring method, there are a spectroscopic measuring method and a tristimulus value direct reading method. The spectroscopic measurement method is a method in which a spectral distribution is measured using a spectrophotometer to obtain colorimetric values such as tristimulus values X, Y, and Z. The stimulus value direct reading method uses a photoelectric colorimeter and a meter. This is a method for directly obtaining colorimetric values such as X, Y, Z from the instruction of. The photoelectric colorimeter has various glass filters for X, Y, and Z in front of the three types of light receivers, and the total spectral sensitivity due to the combination of the light source, the filter, and the light receiver is a combination of standard light and the color matching function. The filter is adjusted as follows. However, there is a limit to the adjustment of the spectral sensitivity by the combination of filters, and there is a drawback that changes due to deterioration of the energy distribution of the light source have a great influence on the measured value. On the other hand, the spectrophotometer is a method for obtaining the reflectance by comparing the reflectance for each wavelength with a standard. However, the operability is usually poor because it requires a long time for calibration and measurement, and the sensor has no degree of freedom. Further, when the light is dispersed by using a prism, the light of short wavelength (500 nm or less) has a large attenuation of the prism and the light receiving sensitivity tends to decrease.

[0003]

However, regardless of these color measuring methods, the determination of the freshness grade of fish has hitherto been made by the subjectivity of the determiner. However, these skins generally have different hues and structures in the surface layer portion and the internal tissue, and thus sufficient quantitativeness cannot be obtained by any of the conventional methods. Further, in the above-described method, the spectral sensitivity of the eye changes (color adaptation effect) between different illuminations, and therefore a slight change in skin color due to illumination change cannot be quantitatively evaluated.

In view of the above points, an object of the present invention is to provide a compact and portable food freshness discriminating apparatus capable of objectively discriminating the freshness of food without depending on the subjectivity of the judge.

[0005]

Therefore, the present invention has a probe for contacting food and a processing unit for processing color coordinate space information from the probe, and the light from the light source is transmitted through the probe to the food. The reflected light is radiated to the, and the reflected light is dispersed by a spectroscope in the processing unit to obtain color coordinates, and the freshness of the food is determined from the relationship between the color coordinates and freshness obtained in advance.

[0006]

[Function] The probe is brought into contact with the surface of the food, or inserted into the fish meat, particularly when the freshness of fish such as tuna is measured. The light from the light source is sent to the probe to irradiate the food to be measured, and the reflected light from the food is dispersed by the spectroscope forming the processing unit. The reflected light is spectrally dispersed to determine the color coordinates, and the freshness grade of the food is determined from the relationship table between the color coordinates and the freshness that has been obtained in advance. This makes it possible to objectively measure the freshness of food.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. The International Commission on Illumination (CIE) has standardized the way colors are displayed and displays colors as three tristimulus values X, Y and Z. Converting this into coordinates, chromaticity (brightness of color)
Is displayed. The relationship between the color coordinate space and the food freshness has a fixed relationship as shown in FIG. 1 for each food, and the freshness of the food can be determined by obtaining the color coordinate space.

[0008] In this color coordinate space, the lightness index ^{L * = 116 (Y / Y} 0) 1/3 -16 chromatic Ness indices ^{a * = 500 {(X /} X 0) 1/3 - (Y / Y 0 ^{) 1/3} b * = 200 {} (Y / Y 0) 1/3 - is represented as ^{_{(Z / Z 0) 1/3}}} , tristimulus of in both the official, X, Y, Z is the measurement object The values X ₀ , Y ₀ , and Z ₀ use the tristimulus values of the illumination light source (normally, the standard light C is used).

Further, the object to be measured here is a fish, an animal, etc., having fine irregularities on the surface, elasticity, and different color tone and structure between the surface layer portion and the internal tissue. In addition to the performance such as accuracy and reproducibility necessary for a general spectrophotometer, the performance corresponding to the above-mentioned characteristics is required for skin color measurement.

2 and 3 show a specific example of the food freshness discriminating apparatus of the present invention. Food freshness discriminating apparatus E of the present invention
Is particularly suitable for determining the freshness of fish such as tuna, and has a probe 1 inserted into the fish meat m and a processing box 2 for processing a determination signal from the probe 1. The probe 1 has a cylindrical housing 11 and a pointed tip portion 11a, and a window 12 is formed near the tip portion 11a, and the window 12 is made of a light transmitting material. An optical fiber f is housed in the housing 11, and the optical fiber f extends to the processing box 2 via a protection cord 23.

The optical fiber f is composed of a central fiber 14 and a peripheral fiber 15 covering the central fiber 14, and the peripheral fiber 15 is a light source 2 provided in the processing box 2.
1. The light from the light source 21 is connected to the surrounding fiber 1
5, the prism 13 provided to face the window 12, and the reflected light from the fish meat surface through the window 12 and the reflected light.
3 and the central fiber 14 to reach the inside of the processing unit 22 which processes the discrimination signal.

As shown in FIG. 3, this processing unit 22 uses CP
The CPU 30 has a U30, and a ROM 31 in which an arithmetic program is set and a table showing the relationship between the color coordinate space and the freshness for each type of food are input.
The AM 32 is connected, and the freshness determination result is displayed on the display 36 provided in the processing box 2 via the input / output device 34.

The determination signal from the probe 1 is returned to an A / D converter (not shown) via the input / output device 33 and CP
The freshness grade of the measured symmetrical food is read based on the table stored in the RAM 32 according to the program of the ROM 31 and input to the U30, and the grade is displayed on the display 36.

[0014]

Since the present invention is constructed as described above,
The effect is that the freshness of food can be objectively determined.

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between color coordinate space and freshness.

FIG. 2 is a schematic configuration diagram of a food freshness discriminating apparatus of the present invention.

FIG. 3 is a configuration block diagram of a determination signal processing unit.

[Explanation of symbols]

 1 ... Probe 2 ... Processing box 13 ... Prism 22 ... Processing section

Claims (1)

[Claims] 1. A probe for contacting food, and a processing unit for processing color coordinate space information from the probe,
Light from the light source is radiated to the food through the probe,
A food freshness discriminating apparatus that discriminates the reflected light by a spectroscope in a processing unit to obtain color coordinates, and discriminates the freshness of food from the relationship between the color coordinates and freshness obtained in advance.