Freshness evaluation device for fresh produce and freshness evaluation method for fresh produce

Abstract

To provide a method and a device for evaluating the freshness of a perishable item easily and rapidly.SOLUTION: A freshness evaluation device 10 includes a light source 12, a fluorescence selection unit 13, and an electric signal converter 14. The light source 12 irradiates a perishable item 11 with an excitation light. The fluorescence selection unit 13 selectively transmits fluorescence from a glycation end product of the perishable item 11 of private fluorescence emitted from the perishable item 11 by irradiation with the excitation light. The electric signal converter 14 receives fluorescence which has passed through the fluorescence selection unit 13 and converts the fluorescence into an electric signal.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an apparatus for evaluating the freshness of fresh products and a method for evaluating the freshness of fresh products. [Background technology]

[0002] A biochemical index of freshness known as the "K value" is known as an index of freshness for fresh produce. The K value is an index that indicates the degree of decomposition of ATP (adenosine triphosphate) present in the muscle of animals.

[0003] Patent Document 1 describes a method for evaluating the freshness of fresh produce using the K value, in which the fresh produce and a color-developing medium are sealed in a transparent container, and the K value is estimated from the color change associated with a chemical change in the color-developing medium to evaluate the freshness of the fresh produce. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2005-345263 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, freshness evaluation methods using the K value, such as the evaluation method described in Patent Document 1, use a chemical reaction to measure the degree of ATP decomposition, and therefore require time-consuming preparations before measuring the K value, and it takes time for the chemical reaction to stabilize.

[0006] The present invention has been made in view of the above problems, and an object of the present invention is to provide a freshness evaluation device and a freshness evaluation method that can easily and quickly evaluate the freshness of fresh products. [Means for solving the problem]

[0007] The freshness evaluation device according to the present invention is a device for evaluating the freshness of fresh products. The freshness evaluation device according to the present invention includes a light source, a fluorescence selection unit, and an electrical signal conversion unit. The light source irradiates the fresh product with excitation light. The fluorescence selection unit selectively transmits fluorescence from advanced glycation end products in the fresh product from among autofluorescence emitted by the fresh product in response to irradiation with the excitation light. The electrical signal conversion unit receives the fluorescence that has transmitted through the fluorescence selection unit and converts the fluorescence into an electrical signal.

[0008] In one embodiment, the fluorescence selection unit has a cut filter that blocks light with a wavelength of 420 nm or less from the autofluorescence emitted by the fresh produce, and a bandpass filter that selectively transmits light with a wavelength in the range of -50 nm or more from the peak wavelength of the fluorescence from advanced glycation end products and +50 nm or less from the peak wavelength of the fluorescence from the advanced glycation end products from the light that passes through the cut filter.

[0009] In one embodiment, the electrical signal conversion section is an image sensor.

[0010] In one embodiment, the freshness evaluation device further includes an image processing unit that maps a distribution of advanced glycation endproducts on an image of the fresh product using the electrical signal converted by the electrical signal conversion unit.

[0011] In one embodiment, the fresh produce is fruit or vegetable, meat, or flowers.

[0012] The freshness evaluation method according to the present invention is a method for evaluating the freshness of a fresh product. The freshness evaluation method according to the present invention includes an irradiation step and a conversion step. In the irradiation step, excitation light is irradiated onto the fresh product. In the conversion step, fluorescence from advanced glycation end products in the fresh product is selectively converted into an electrical signal from autofluorescence emitted by the fresh product in response to irradiation with the excitation light.

[0013] In one embodiment, the freshness assessment method further comprises an image processing step of mapping a distribution of advanced glycation endproducts on an image of the fresh product using the electrical signal converted by the conversion step. Effect of the Invention

[0014] According to the present invention, it is possible to provide a freshness evaluation device and a freshness evaluation method that can easily and quickly evaluate the freshness of fresh products. [Brief description of the drawings]

[0015] [Figure 1] 1 is a diagram showing an example of the configuration of a freshness evaluation device according to a first embodiment of the present invention. [Diagram 2] 10 is a flowchart showing an example of a freshness evaluation method according to a second embodiment of the present invention. [Diagram 3] 13(a) and 13(b) are images after image processing in the first embodiment. [Figure 4] 13(a) and 13(b) are images after image processing in the second embodiment. [Diagram 5] 13(a) and 13(b) are images after image processing in the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] The following describes preferred embodiments of the present invention. However, the present invention is not limited to the following embodiments, and can be implemented in various forms without departing from the spirit of the present invention. Note that where the description overlaps, the description may be omitted as appropriate.

[0017] First, the terms used in this specification will be explained. "Perishable goods" refers to goods that are required to be perishable (fresh). Examples of perishable goods include fruits and vegetables, meat, and flowers.

[0018] "Advanced glycation end products" is a general term for structures that are generated in the later stages of the reaction between sugar and protein (Maillard reaction). Hereinafter, advanced glycation end products may be referred to as "AGEs."

[0019] An "imaging sensor" refers to an electronic component that converts light into an electrical signal.

[0020] <First embodiment: freshness evaluation device> The freshness evaluation device according to the first embodiment of the present invention will be described below. The freshness evaluation device according to the first embodiment includes a light source, a fluorescence selection unit, and an electrical signal conversion unit. The light source irradiates excitation light onto the fresh product. The fluorescence selection unit selectively transmits fluorescence from AGEs in the fresh product among the autofluorescence emitted by the fresh product when irradiated with the excitation light. The electrical signal conversion unit receives the fluorescence that has transmitted through the fluorescence selection unit and converts the fluorescence into an electrical signal.

[0021] The freshness evaluation device according to the first embodiment, having the above-mentioned configuration, can easily and quickly evaluate the freshness of fresh products. The reason for this is presumed to be as follows.

[0022] AGEs are the products of biochemical reactions that occur to maintain the vital activities of living organisms. Therefore, as the freshness of fresh produce decreases, the amount of AGEs in the produce tends to increase. In other words, the amount of AGEs in fresh produce is an indicator of the freshness of the produce.

[0023] The freshness evaluation device according to the first embodiment includes a light source, a fluorescence selection unit, and an electrical signal conversion unit. The light source irradiates the fresh product with excitation light. The fluorescence selection unit selectively transmits fluorescence from AGEs in the fresh product among the autofluorescence emitted by the fresh product when irradiated with the excitation light. The electrical signal conversion unit receives the fluorescence that has transmitted through the fluorescence selection unit and converts the fluorescence into an electrical signal. Thus, according to the freshness evaluation device according to the first embodiment, the fluorescence from AGEs in the fresh product (more specifically, the intensity of the fluorescence) can be selectively converted into an electrical signal by irradiating the fresh product with excitation light from the light source, so that the amount of AGEs in the fresh product can be easily and quickly recognized as an electrical signal. Therefore, according to the freshness evaluation device according to the first embodiment, the freshness of the fresh product can be easily and quickly evaluated.

[0024] Furthermore, with the freshness evaluation device according to the first embodiment, by irradiating a fresh product with excitation light, the amount of AGEs in the fresh product can be recognized as an electrical signal, making it possible to accurately evaluate the freshness of fresh products in which changes in freshness are difficult to confirm based on appearance, without destroying the product.

[0025] In the first embodiment, in order to more easily and quickly evaluate the freshness of a fresh product, the fresh product is preferably fruit or vegetables, meat, or flowers.

[0026] Examples of the fruits and vegetables include fruits (more specifically, strawberries, peaches, apples, pears, bananas, figs, pineapples, mangoes, persimmons, cherries, etc.) and vegetables (more specifically, eggplants, cucumbers, tomatoes, cherry tomatoes, spinach, carrots, radishes, cabbage, edamame, corn, bean sprouts, mizuna, broccoli, lettuce, etc.). Examples of meat include beef, lamb, pork, chicken, horse meat, and venison. Examples of flowers include gerberas, roses, chrysanthemums, carnations, lisianthus, statice, stocks, begonias, cyclamen, and sweet peas. In the first embodiment, in order to more easily and quickly evaluate the freshness of fresh produce, strawberries, beef, or gerberas are preferred as fresh produce.

[0027] Next, the freshness evaluation device according to the first embodiment will be described in detail with reference to Fig. 1. Note that Fig. 1, which is referred to, shows each component mainly in a schematic manner for ease of understanding, and the size, number, shape, etc. of each component shown in the figure may differ from the actual size, number, shape, etc. for convenience of drawing.

[0028] FIG. 1 is a diagram showing an example of the configuration of a freshness evaluation device according to the first embodiment. The freshness evaluation device 10 shown in FIG. 1 is a device for evaluating the freshness of a fresh product 11. The freshness evaluation device 10 includes a light source 12, a fluorescence selection unit 13, an electric signal conversion unit 14, and an image processing unit 15. The light source 12 is provided diagonally above the fresh product 11 to be evaluated in FIG. 1. The fluorescence selection unit 13 and the electric signal conversion unit 14 are provided above the fresh product 11 to be evaluated in FIG. 1. The fluorescence selection unit 13 is disposed between the fresh product 11 and the electric signal conversion unit 14. The electric signal conversion unit 14 and the image processing unit 15 are connected via wiring 16. The freshness evaluation device 10 may include a placement table (not shown) on which the fresh product 11 is placed.

[0029] The light source 12 irradiates the fresh product 11 with excitation light L1 from diagonally above in FIG. 1. The light source 12 is not particularly limited as long as it is a light source that can irradiate excitation light L1 that excites AGEs in the fresh product 11. Specific examples of the light source 12 include an ultraviolet lamp, a mercury lamp, a xenon lamp, a deuterium lamp, a halogen lamp, a tungsten lamp, a laser, a light-emitting diode (LED), and an electroluminescence (EL) element. In order to more easily and quickly evaluate the freshness of the fresh product 11, the light source 12 is preferably an LED, and more preferably an LED (LED lamp) with a maximum peak wavelength of 365 nm. Note that the excitation light L1 emitted from the light source 12 may contain light other than the light that excites the substances in the fresh product 11.

[0030] The fluorescence selecting unit 13 selectively transmits fluorescence L4 from AGEs in the fresh product 11 from autofluorescence L2 emitted by the fresh product 11 when irradiated with excitation light L1. In the freshness evaluation device 10 shown in FIG. 1, the fluorescence selecting unit 13 has a cut filter 20 and a band pass filter 21. The cut filter 20 blocks light with a wavelength of 420 nm or less from the autofluorescence L2 emitted by the fresh product 11. The band pass filter 21 selectively transmits light with a wavelength in the range of the peak wavelength of the fluorescence L4 from AGEs -50 nm or more and the peak wavelength of the fluorescence L4 from AGEs +50 nm or less from the light L3 transmitted through the cut filter 20. In the freshness evaluation device 10, the fluorescence selecting unit 13 (more specifically, the cut filter 20 and the band pass filter 21) are detachably provided. Hereinafter, the peak wavelength (unit: nm) of the fluorescence L4 from AGEs may be referred to as "L4W".

[0031] The cut filter 20 does not have to completely block light with wavelengths of 420 nm or less. However, in order to more easily evaluate the freshness of the fresh product 11, it is preferable to use a cut filter 20 with a transmittance of 1% or less for light with wavelengths of 420 nm or less. Note that the cut filter 20 may block not only light with wavelengths of 420 nm or less contained in the autofluorescence L2, but also, for example, reflected light from the fresh product 11.

[0032] In order to more easily evaluate the freshness of fresh product 11, it is preferable to use a bandpass filter 21 having a transmittance of 2.6% or less for light other than light with wavelengths in the range of L4W-50 nm or more and L4W+50 nm or less (L4W±50 nm). Also, in order to more easily evaluate the freshness of fresh product 11, it is preferable that the peak of fluorescence L4 used to evaluate the freshness does not overlap with the peaks of other light. Therefore, in order to more easily evaluate the freshness of fresh product 11, it is preferable to use a bandpass filter 21 that can selectively transmit fluorescence L4 (more specifically, fluorescence L4 from AGEs) whose peak does not overlap with other light.

[0033] The bandpass filter 21 that selectively transmits light with a wavelength in the range of L4W±50 nm includes a bandpass filter that selectively transmits light in any wavelength region within the range of L4W±50 nm. For example, as the bandpass filter 21, a bandpass filter that selectively transmits fluorescence L4 from AGEs (a bandpass filter that selectively transmits light in a wavelength region including L4W) can be selected from commercially available bandpass filters that selectively transmit light with a wavelength in the range of L4W±50 nm.

[0034] Specific examples of the bandpass filter 21 that selectively transmits light of a wavelength in the range of L4W±50 nm include a bandpass filter that selectively transmits light of a wavelength in the range of L4W±50 nm (half width for L4W is 50 nm), a bandpass filter that selectively transmits light of a wavelength in the range of L4W±40 nm (half width for L4W is 40 nm), a bandpass filter that selectively transmits light of a wavelength in the range of L4W±30 nm (half width for L4W is 30 nm), a bandpass filter that selectively transmits light of a wavelength in the range of L4W±20 nm (half width for L4W is 20 nm), a bandpass filter that selectively transmits light of a wavelength in the range of L4W±10 nm (half width for L4W is 10 nm), a bandpass filter that selectively transmits light of a wavelength in the range of L4W-50 nm or more and L4W+40 nm or less, a bandpass filter that selectively transmits light of a wavelength in the range of L4W-40 nm or more and L4W+50 nm or less, Examples of such a filter include a bandpass filter that selectively transmits light having a wavelength in the range of L4W-40 nm or more and L4W+30 nm or less, a bandpass filter that selectively transmits light having a wavelength in the range of L4W-30 nm or more and L4W+40 nm or less, a bandpass filter that selectively transmits light having a wavelength in the range of L4W-30 nm or more and L4W+20 nm or less, a bandpass filter that selectively transmits light having a wavelength in the range of L4W-20 nm or more and L4W+30 nm or less, a bandpass filter that selectively transmits light having a wavelength in the range of L4W-20 nm or more and L4W+10 nm or less, a bandpass filter that selectively transmits light having a wavelength in the range of L4W-10 nm or more and L4W+20 nm or less, a bandpass filter that selectively transmits light having a wavelength in the range of L4W-13 nm or more and L4W+7 nm or less, and a bandpass filter that selectively transmits light having a wavelength in the range of L4W-7 nm or more and L4W+13 nm or less.

[0035] The electrical signal conversion unit 14 receives the fluorescence L4 transmitted through the fluorescence selection unit 13 and converts the fluorescence L4 into an electrical signal. In order to more easily evaluate the freshness of the fresh product 11, an imaging element is preferable as the electrical signal conversion unit 14. Examples of the imaging element include a charge coupled device (CCD) and a complementary metal oxide semiconductor (CMOS).

[0036] Furthermore, the electrical signal conversion section 14 may be configured so as to be able to capture an image of the fresh product 11 with the fluorescence selection section 13 removed.

[0037] The image processing unit 15 uses the electrical signals converted by the electrical signal conversion unit 14 to map the distribution of AGEs (specifically, AGEs in the fresh product 11) on the image of the fresh product 11. An example of the image processing unit 15 is a computer on which image processing software is installed. The image processed by the image processing unit 15 is, for example, an image of the fresh product 11 captured using the electrical signal conversion unit 14 with the fluorescence selection unit 13 detached.

[0038] The image processing unit 15 uses the electrical signal converted by the electrical signal conversion unit 14 to process the image so that, for example, the stronger the intensity of the fluorescence L4 is in a portion of the image of the fresh product 11, the higher the image density of the corresponding pixel becomes. This makes it possible to associate the shade of the pixels in the image of the fresh product 11 with the amount of AGEs. As a result, the distribution of AGEs is mapped on the image of the fresh product 11.

[0039] When a computer on which image processing software is installed is used as the image processing unit 15, the image mapped (image processed) by the image processing unit 15 is displayed, for example, on the display of the computer.

[0040] According to the freshness evaluation device 10, by irradiating the fresh product 11 with excitation light L1 from the light source 12, the fluorescence L4 from AGEs in the fresh product 11 can be selectively converted into an electrical signal, so that the amount of AGEs in the fresh product 11 can be easily and quickly recognized as an electrical signal (more specifically, an image processed using the electrical signal). Therefore, according to the freshness evaluation device 10, the freshness of the fresh product 11 can be easily and quickly evaluated.

[0041] Although the freshness evaluation device according to the first embodiment has been described above, the freshness evaluation device of the present invention is not limited to the above-described first embodiment.

[0042] For example, in the first embodiment, a freshness evaluation device including an image processing unit as shown in Fig. 1 has been described as an example, but the freshness evaluation device of the present invention does not need to include an image processing unit. Also, in the freshness evaluation device of the present invention, for example, the electric signal conversion unit may also function as the image processing unit.

[0043] <Second embodiment: freshness evaluation method> Next, a freshness evaluation method according to a second embodiment of the present invention will be described with reference to Fig. 1 and Fig. 2. Fig. 2 is a flowchart showing an example of the freshness evaluation method according to the second embodiment. The freshness evaluation method shown in Fig. 2 is, for example, a freshness evaluation method for evaluating fresh products using the freshness evaluation device 10 shown in Fig. 1. Hereinafter, description of contents that overlap with the first embodiment described above may be omitted.

[0044] The freshness evaluation method according to the second embodiment shown in FIG. 2 includes an irradiation step S1, a conversion step S2, an image processing step S3, and a display step S4.

[0045] In the irradiation step S1, excitation light L1 is irradiated onto the fresh product 11. For example, when the above-described freshness evaluation device 10 is used, the light source 12 is used to irradiate the fresh product 11 with excitation light L1.

[0046] In the conversion step S2, the autofluorescence L2 emitted by the fresh product 11 in response to irradiation with the excitation light L1 is selectively converted into an electrical signal by the fluorescence L4 from AGEs in the fresh product 11. For example, when the above-mentioned freshness evaluation device 10 is used, the fluorescence selection unit 13 selectively transmits the fluorescence L4 from AGEs in the fresh product 11 out of the autofluorescence L2, and the electrical signal conversion unit 14 converts the fluorescence L4 that has transmitted through the fluorescence selection unit 13 into an electrical signal.

[0047] It is preferable that the peak of the fluorescence L4 used in evaluating the freshness does not overlap with the peaks of other light in order to more easily evaluate the freshness of the fresh product 11. Therefore, in order to more easily evaluate the freshness of the fresh product 11, it is preferable to use a bandpass filter 21 that can selectively transmit fluorescence L4 (more specifically, fluorescence L4 from AGEs) whose peak does not overlap with other light.

[0048] In the image processing step S3, the electrical signals converted in the conversion step S2 are used to map (image process) the distribution of AGEs on an image of the fresh product 11 (e.g., an image of the fresh product 11 captured using the electrical signal conversion unit 14). For example, when the above-described freshness evaluation device 10 is used, the image processing unit 15 maps the distribution of AGEs on the image of the fresh product 11 using the electrical signals converted by the electrical signal conversion unit 14.

[0049] In the display step S4, the image processed in the image processing step S3 is displayed. For example, when the above-mentioned freshness evaluation device 10 is used, the image processed by the image processing unit 15 is displayed on the display of the image processing unit 15 (more specifically, a computer or the like).

[0050] According to the freshness evaluation method of the second embodiment, by irradiating the fresh product 11 with excitation light L1, the fluorescence L4 from AGEs in the fresh product 11 can be selectively converted into an electrical signal, and the amount of AGEs in the fresh product 11 can be easily and quickly recognized as an electrical signal (more specifically, an image processed using the electrical signal). Therefore, according to the freshness evaluation method of the second embodiment, the freshness of the fresh product 11 can be easily and quickly evaluated.

[0051] Although the freshness evaluation method according to the second embodiment has been described above, the freshness evaluation method for fresh products of the present invention is not limited to the above-mentioned second embodiment.

[0052] For example, in the second embodiment, a freshness evaluation method including an image processing step and a display step as shown in FIG. 2 has been described as an example, but the freshness evaluation method of the present invention does not have to include an image processing step and a display step. EXAMPLES

[0053] EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to the scope of the examples.

[0054] <Preparation of freshness evaluation device> A freshness evaluation device (hereinafter, sometimes simply referred to as "evaluation device") having the same configuration as the freshness evaluation device 10 shown in FIG. 1 was prepared. Hereinafter, the same components as those shown in FIG. 1 will be described with the same reference numerals as those in FIG. 1. As the light source 12, an LED lamp with a maximum peak wavelength of 365 nm ("ULTRA VIOLET LED Lamp SMD Type NS365L-6SMG" manufactured by Nitride Semiconductor Corporation) was used. As the cut filter 20, a cut filter that blocks light with a wavelength of 420 nm or less ("L42" manufactured by HOYA Corporation) was used. As the bandpass filter 21, a bandpass filter that selectively transmits light with a wavelength of 480 nm or more and 500 nm or less ("HMX0490" manufactured by Asahi Spectroscopic Corporation) was used. As the electric signal conversion unit 14, a CMOS (more specifically, a CMOS mounted on "EOS (registered trademark) 50D" manufactured by Canon Inc.) was used. A computer in which image processing software ("ImageJ" manufactured by the National Institutes of Health, USA) was installed was used as the image processing unit 15. In the evaluation device, the electrical signal conversion unit 14 was configured to be able to capture an image of the fresh product 11 with the fluorescence selection unit 13 (cut filter 20 and band pass filter 21) removed.

[0055] <Example 1> Strawberries were selected as the evaluation subject (fresh product 11) in Example 1, and the freshness of the strawberries was evaluated in the following manner. First, commercially available strawberries were stored in a refrigerator set at a temperature of 1° C. for 8 days from the date of purchase to prepare strawberries stored for 8 days (hereinafter, sometimes referred to as "strawberries 8"). Separately, commercially available strawberries were stored in a refrigerator set at a temperature of 1° C. for 16 days from the date of purchase to prepare strawberries stored for 16 days (hereinafter, sometimes referred to as "strawberries 16 ") has been prepared.

[0056] Next, the evaluation objects (strawberry 8 and strawberry 16 The object to be evaluated (either one of the above) was irradiated with excitation light L1, and fluorescence L4 from AGEs in the object to be evaluated was selectively converted into an electric signal. Then, image processing was performed using the converted electric signal. More specifically, the distribution of AGEs was mapped on the image of the object to be evaluated (image captured by the electric signal conversion unit 14) using the converted electric signal with image processing software ("ImageJ" manufactured by the National Institutes of Health, USA). Note that in the object to be evaluated in Example 1 (strawberry), the peak wavelength of the fluorescence L4 transmitted through the bandpass filter 21 was 493 nm.

[0057] FIG. 3(a) shows an image of strawberry 8 after image processing. FIG. 3(b) shows an image of strawberry 16 The processed images are shown in Fig. 3(a) and (b). 16 Compared to strawberry 8, strawberry 100 had more areas where AGEs were present (areas with high image density). 16 The freshness of strawberry 8 was lower than that of strawberry 8. The fact that the fluorescence L4 transmitted through the band pass filter 21 is fluorescence from AGEs was inferred by the following inference method.

[0058] [Method of inference] Using a preparative high-performance liquid chromatography system (Hitachi's LaChrom system, pump: L-7100, fluorescence detector: L-7485, autosampler: L-7200, column oven: L-7300), strawberries were separated under the following separation conditions.16 The fraction containing fluorescent substances (specifically, substances that emit fluorescence with wavelengths of 480 nm or more and 500 nm or less) was separated and collected.

[0059] (Isolation conditions) Column: Reverse phase column manufactured by Kanto Chemical Co., Ltd. ("Mightysil (registered trademark) RP-18GP", length: 250 mm, inner diameter: 20 mm) Sample: mashed strawberries 16 Acetonitrile solution (strawberry 16 Concentration: 2% by mass Sample injection volume: 0.1 mL Excitation wavelength: 365 nm Liquid A: Distilled water B liquid: acetonitrile Concentration gradient conditions: Conditions shown in Table 1 below

[0060] [Table 1]

[0061] Next, 2 mL of the collected liquid was dried, and 300 μL of distilled water was added to the dried product to obtain a sample liquid for analysis. 100 μL of the obtained sample liquid was analyzed by competitive ELISA using an antibody ("Anti-CML, Mouse-Mono (2G11)" manufactured by Funakoshi Co., Ltd.) and an enzyme-labeled AGEs standard ("CML-BSA" manufactured by Nippi Co., Ltd.). As a result, it was inferred that AGEs emitting fluorescence with wavelengths of 480 nm or more and 500 nm or less were present in the sample liquid. From this result, it was inferred that the fluorescence L4 transmitted through the bandpass filter 21 was fluorescence from AGEs.

[0062] The subject of the evaluation described below (for details, beef 16 For each of the three specimens (either Gerbera daisy or Gerbera daisy), it was inferred that the fluorescence L4 transmitted through the band-pass filter 21 was fluorescence from AGEs, using the same method as the above-mentioned [Inference method].

[0063] <Example 2> Beef was selected as the evaluation subject (fresh product 11) in Example 2, and the freshness of the beef was evaluated by the following procedure. First, beef stored at a temperature of 3°C (hereinafter, sometimes referred to as "beef 3") was prepared by storing commercially available beef in a refrigerator set at a temperature of 3°C for 24 hours immediately after purchase. Separately, beef stored at a temperature of 16°C (hereinafter, sometimes referred to as "beef 4") was prepared by storing commercially available beef in an atmosphere set at a temperature of 16°C for 24 hours immediately after purchase. 16 ") has been prepared.

[0064] Next, the evaluation object (beef 3 and beef 16 The evaluation object (beef) was irradiated with excitation light L1, and fluorescence L4 from AGEs in the evaluation object was selectively converted into an electric signal. The converted electric signal was then used for image processing. More specifically, the converted electric signal was used to map the distribution of AGEs on the image of the evaluation object (image captured by the electric signal conversion unit 14) with image processing software ("ImageJ" manufactured by the National Institutes of Health, USA). Note that in the evaluation object (beef) of Example 2, the peak wavelength of the fluorescence L4 transmitted through the bandpass filter 21 was 490 nm.

[0065] FIG. 4(a) shows an image of beef 3 after image processing. FIG. 4(b) shows an image of beef 16 As shown in Fig. 4(a) and (b), the beef 16 Compared to beef 3, beef 100 had more areas where AGEs were present (areas with high image density). 16 was less fresh than beef 3.

[0066] <Example 3> Gerbera was selected as the evaluation subject (fresh product 11) in Example 3, and the freshness of the gerbera was evaluated in the following procedure. First, a commercially available gerbera was stored in an atmosphere at a temperature of 16°C for one hour immediately after purchase to prepare a gerbera stored for one hour (hereinafter, sometimes referred to as "Gerbera 1"). Separately, a commercially available gerbera was stored in an atmosphere at a temperature of 16°C for four days from the date of purchase to prepare a gerbera stored for four days (hereinafter, sometimes referred to as "Gerbera 4").

[0067] Next, the evaluation device was used to irradiate the evaluation object (either Gerbera 1 or Gerbera 4) with excitation light L1, and the fluorescence L4 from AGEs in the evaluation object was selectively converted into an electrical signal. The converted electrical signal was then used for image processing. More specifically, the converted electrical signal was used to map the distribution of AGEs on the image of the evaluation object (image captured by the electrical signal conversion unit 14) using image processing software ("ImageJ" manufactured by the National Institutes of Health, USA). Note that in the evaluation object (Gerbera) of Example 3, the peak wavelength of the fluorescence L4 transmitted through the bandpass filter 21 was 490 nm.

[0068] 5(a) shows an image of Gerbera 1 after image processing, and FIG. 5(b) shows an image of Gerbera 4 after image processing. As shown in FIGS. 5(a) and (b), Gerbera 4 had more areas 100 (areas with high image density) where AGEs were present than Gerbera 1. Thus, Gerbera 4 was less fresh than Gerbera 1. [Industrial Applicability]

[0069] The freshness evaluation device and freshness evaluation method according to the present invention can be used to evaluate the freshness of perishable goods (more specifically, fruits and vegetables, meat, flowers, etc.). [Explanation of symbols]

[0070] 10: Freshness evaluation device 11: Perishables 12:Light source 13: Fluorescence selection section 14: Electrical signal conversion section 15: Image processing section 20: Cut filter 21: Bandpass filter

Claims

1. A freshness evaluation device for fresh products, which are products required to be fresh, comprising: A light source that irradiates the fresh produce with excitation light; a fluorescence selecting unit that selectively transmits fluorescence from advanced glycation endproducts in the fresh product from among autofluorescence emitted by the fresh product when irradiated with the excitation light; an electrical signal conversion unit that receives the fluorescence transmitted through the fluorescence selection unit and converts the fluorescence into an electrical signal; an image processing unit that uses the electrical signal converted by the electrical signal conversion unit to map a distribution of advanced glycation endproducts on an image of the fresh product; Equipped with A freshness evaluation device, wherein the image of the fresh product is captured using the electrical signal conversion unit without passing through the fluorescence selection unit.

2. The fluorescence selection unit is A cut filter that blocks light having a wavelength of 420 nm or less from the autofluorescence emitted by the fresh produce; a bandpass filter that selectively transmits light having a wavelength in the range of a peak wavelength of the fluorescence from the advanced glycation endproducts −50 nm or more and a peak wavelength of the fluorescence from the advanced glycation endproducts +50 nm or less out of the light transmitted through the cut filter; The freshness evaluation device according to claim 1 .

3. The freshness evaluation device according to claim 1 , wherein the electrical signal conversion unit is an image sensor.

4. The freshness evaluation device according to claim 1 , wherein the fresh product is fruit or vegetables, meat, or flowers.

5. A freshness evaluation device described in any one of claims 1 to 4, wherein the maximum peak wavelength of the excitation light is 365 nm.

6. A method for evaluating the freshness of a perishable product, which is a product required to be fresh, comprising the steps of: an irradiation step of irradiating the fresh product with excitation light; a conversion step of selectively converting fluorescence from advanced glycation endproducts in the fresh product, among the autofluorescence emitted by the fresh product when irradiated with the excitation light, into an electrical signal; an image processing step of mapping a distribution of advanced glycation endproducts on an image of the fresh product using the electrical signal converted by the conversion step; Equipped with A freshness evaluation method, wherein the image of the fresh product is captured using an electrical signal conversion unit without passing through a fluorescence selection unit.

7. The freshness evaluation method described in claim 6, wherein the maximum peak wavelength of the excitation light is 365 nm.

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