JP2003114191A - Method and instrument for nondestructively measuring sugar content of vegetable and fruit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a small-sized instrument by which the sugar contents of vegetables and fruits can be measured nondestructively without using any diffraction grating nor multi-channel detector. SOLUTION: The small-sized instrument is provided with light sources 101a and 101b, a reflecting prism 22, and a condenser lens 21 for projecting monochromatic light rays upon a vegetable or fruit 1. The instrument is also provided with a sampling mirror 33, a condenser lens 31, and a photodetector 32 for detecting parts of the monochromatic light rays 101a and 101b. In addition, the instrument is also provided with a condenser lens 41 and a photodetector 42 for detecting parts of light rays transmitted through the vegetable or fruit 1. Moreover, the instrument is also provided with a signal processing section 230, a central control section 200, a displaying section 210, and a light control section 220. The control section 200 measures the quantities of the projected light rays and transmitted light rays from the voltage or fruit 1 detected by means of the photodetectors 32 and 42 and calculates the transmittance Ta and Tb or absorbance Abs a and Abs b from the detected voltages and the sugar content of the vegetable or fruit 1 from the values of the Ta and Tb or Abs- a and Abs- b by using formulae (1) and (2).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nondestructive method and apparatus for measuring sugar content of fruits and vegetables for measuring an index relating to sweetness of fruits and vegetables, which is obtained by irradiating fruits and vegetables with monochromatic light of a specific wavelength. The present invention relates to a technique for measuring the sugar content of fruits and vegetables which non-destructively measures the sugar content.

[0002]

2. Description of the Related Art In general, when fruits and vegetables such as vegetables and fruits are shipped, it is necessary to select a grade by inspecting internal quality such as sugar content in addition to appearance inspection such as shape and color. Furthermore, it is desired to be able to feed back such internal quality of sugar content to cultivation management. Conventionally, the sugar content of fruits and vegetables is generally performed by using a juice extracted from several samples, by chemical analysis, or by a destructive method using a refractometer.
In the case of this destruction method, the measurement time is long, and the sugar content of individual fruits and vegetables cannot be measured, and there are problems such as variations in sugar content within the sampled lot. Therefore, in recent years, as a nondestructive and quick method for measuring the sugar content of fruits and vegetables, a method using light having a wavelength in the near infrared region has been researched, developed, or put into practical use.

Irradiating fruits and vegetables with light having a wavelength in the near infrared region,
As a conventional device for receiving the reflected light to measure the absorbance at a specific wavelength and measuring the sugar content of fruits and vegetables from the measured value, Japanese Patent Application Laid-Open No. 2-147940, (Journal of Horticultural Science, 61, 44).
5 (1992)) and Japanese Patent Application Laid-Open No. 4-208842. A conventional device disclosed in Japanese Patent Laid-Open No. 4-208842 will be described below with reference to FIG.

A conventional sugar content measuring device for fruits and vegetables using light having a wavelength in the near-infrared region of 2500 nm or less has a light source 300 and a light source 300 including light having a wavelength in the near-infrared region of 2500 nm or less, as shown in the figure. The coaxial optical fiber 50 and the coaxial fiber 5 for irradiating the fruits and vegetables 1 to be inspected with the light 301 from the same and further receiving the reflected light 302 from the fruits and vegetables 1.
Spectrometer 6 for splitting the reflected light 302 received at 0
0, a central control unit 200 that calculates the sugar content from the reflection spectrum measured by the spectroscope 60, and a display unit 210 that displays the sugar content calculated by the central control unit 200. The spectroscope 60 is composed of an entrance slit 61, a diffraction grating 62, and a multi-channel detector 63. The reflected light 302 incident on the entrance slit 61 is dispersed into a spectrum by the diffraction grating 62, and the spectrum of the reflected light 302 is detected by the multi-channel detector 63. A linear array sensor such as a CCD is used for the multi-channel detector 63.

The central control unit 200 also calculates the absorbance and the second derivative of the absorbance from the reflection spectrum of the reflected light 302 detected by the spectroscope 60. The sugar content is calculated by the following formula 5 using the second derivative of the absorbance at two specific wavelengths of 888 and 912 nm.

[0006]

[Equation 5]

Here, C: sugar concentration, A: absorbance, λ: wavelength. Further, k0, k1, and k2 are coefficients determined by the least square method using the actually measured sugar content.

In addition, (Journal of the Horticultural Society, 61, 445 (19
92)), the second derivative of the absorbance is calculated by the same method as the sugar content measuring device described in JP-A-4-208842, and the second derivative at four specific wavelengths is used. A method for estimating the sugar content according to the following equation 6 is proposed.

[0009]

[Equation 6]

Here, λ1 = 870n for four specific wavelengths
m, λ1 = 878 nm, λ1 = 889 nm, λ1 = 906
It is proposed to adopt nm.

[0011]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
940 publication, (Journal of the Horticultural Society, 61,445 (199
2)), in the conventional sugar content measuring device described in JP-A-4-208842, most of the reflected light detected is reflected light from the vicinity of the epidermis, and the obtained sugar concentration is also the sugar concentration near the epidermis. . In the case of this method, it is effective for apples and peaches with thin epidermis, while on the other hand, when the above method is applied to oranges and melons with thick epidermis, the reflected light is only the component from the skin part, and the actual component information is Since it contains almost no sugar, it is difficult to measure the actual sugar content.

To solve such a problem, Japanese Patent Laid-Open No. 6-1
86159, (Journal of the Horticultural Society, 62, 465 (19
93)), JP-A-6-213804 proposes a method of utilizing transmitted light in order to realize sugar concentration measurement using light having a wavelength in the near infrared region for fruits and vegetables with thick skin. In the method described in JP-A-6-186159 using transmitted light and (Journal of the Horticultural Society of Japan, 62,465 (1993)), as in the sugar concentration measuring device shown in FIG. The fruits and vegetables are irradiated with light, the transmitted light is detected on the side substantially opposite to the irradiation position, and the transmitted light spectrum is obtained by the spectroscope 6 similar to FIG. Using the obtained transmitted light spectrum, the absorbance, and further the second derivative of the absorbance is calculated, and the second derivative of the absorbance at the five specific wavelengths is used to calculate the sugar content by the following formula (7). Is proposed.

[0013]

[Equation 7]

Here, C: sugar concentration, A: absorbance, λ: wavelength. Further, ki (i = 1, ... 4) is five specific wavelengths λ1 = 745 nm, λ2 = 769 nm, λ3 = 78.
The coefficients determined by the least squares method using the actually measured sugar content are shown at 6 nm, λ4 = 914 nm, and λ5 = 844 nm. As described above, by detecting the transmitted light from the fruits and vegetables, good measurement accuracy is obtained for a thick-tipped mandarin orange.

By the way, the second-order differential value of the absorbance shown in equation 6 is approximately represented by equation 8 below.

[0016]

[Equation 8]

In order to calculate the second-order differential value of the absorbance, the absorbance of the wavelength around the specific wavelength (λ0) is required. That is, in order to calculate the sugar content using the mathematical formula of Equation 4, the absorbance at 15 or more wavelengths is required by adding the wavelengths before and after the 5 specific wavelengths. As the light source having 15 or more wavelengths, a white light source such as a halogen lamp containing a continuous wavelength component in the near infrared region is generally used. In order to obtain a spectrum of a specific wavelength from transmitted light obtained by irradiating fruits and vegetables with the white light source, an entrance slit 61 and a diffraction grating 6
2. Since a complicated spectroscope 60 including a multi-channel detector 63 and the like is required, most of the practically used devices are large stationary types.

The problem to be solved by the present invention is to solve the above-mentioned conventional problems and to provide a method and apparatus for measuring the sugar content of fruits and vegetables using light having a wavelength in the near-infrared region. Not only can it measure the sugar concentration of fruits and vegetables such as oranges and melons with thick skin in a non-destructive manner, but it does not require a complicated spectroscope composed of a diffraction grating like the conventional sugar content measuring device. It is to provide a method and an apparatus for measuring sugar content.

[0019]

[Means for Solving the Problems] 1) 2 of different wavelengths
By irradiating fruits and vegetables with one monochromatic light, the light transmittance T of each monochromatic light
A measuring device capable of measuring a and Tb is provided, and the coefficients k0 and k1 of the following mathematical formula 1 are determined from the values of the light transmittances Ta and Tb of a plurality of measured examples and the measured sugar content C of the example, The determined coefficients k0 and k1 and the light transmittance T of the two monochromatic lights measured
Nondestructive sugar content measuring method for fruits and vegetables using the data of a and Tb to calculate sugar content C by the following mathematical expression 9

[Equation 9] 2) Two monochromatic lights of different wavelengths are applied to fruits and vegetables, and the absorbance Abs_a, from the transmitted light of each monochromatic light from the fruits and vegetables,
A measuring device capable of measuring Abs_b is provided, and the coefficients k0 and k1 of the following formula 10 are determined from the values of the absorbances Abs_a and Abs_b of a plurality of measured examples and the value of the actually measured sugar content C of the example,
Non-destructive sugar content measuring method for fruits and vegetables using the data of Abs_a, Abs_b of two monochromatic light measured as k0, k1 determined and the sugar content C by the following mathematical formula 10

[Equation 10] 3) The method for measuring the non-destructive sugar content of fruits and vegetables according to the above 1), wherein the wavelengths of the two monochromatic lights are respectively selected from the range of 950 to 1010 nm and the range of 1020 to 1080 nm 4) The wavelengths of the two monochromatic lights Is selected from the range of 900 to 930 nm and the range of 940 to 960 nm, respectively. 5) The method for measuring nondestructive sugar content of fruits and vegetables according to the above 1) 5) The wavelengths of two monochromatic lights are 740 to 750 nm and 760 nm. The method for measuring non-destructive sugar content of fruits and vegetables according to the above 1), which is each selected from the range of ˜780 nm 6) To irradiate the fruits and vegetables with two different monochromatic light sources and the monochromatic light from the light source Irradiating means, an irradiating light amount detecting means for detecting the irradiating light amount of the monochromatic light with which the fruits and vegetables are irradiated, and Transmitted light amount detecting means for detecting the transmitted light amount of colored light from fruits and vegetables, and two light transmittances Ta corresponding to each monochromatic light from the irradiated light amount detected by the irradiated light amount detecting means and the transmitted light amount detected by the transmitted light amount detecting means. , Tb, and an arithmetic means for calculating the sugar content C of the fruit and vegetables from the formula 11 below from the calculated value, and a nondestructive sugar content measuring device for fruit and vegetables.

[Equation 11] 7) Two different monochromatic light sources, an irradiation unit for irradiating the fruits and vegetables with the monochromatic light from the light source, and an irradiation light amount detection unit for detecting the irradiation amount of the monochromatic light with which the fruits and vegetables are irradiated. A transmitted light amount detecting means for detecting the amount of transmitted light from the fruits and vegetables of the two monochromatic lights irradiated to the fruits and vegetables by the irradiating means; the amount of emitted light detected by the emitted light amount detecting means and the transmission detected by the transmitted light amount detecting means. Two absorbances Abs_a, Ab corresponding to each monochromatic light from the light amount
A non-destructive sugar content measuring device for fruits and vegetables, characterized by further comprising: a calculating means for calculating s_b, and calculating the sugar content C of the fruits and vegetables from the equation 12 below.

[Equation 12] 8) The non-destructive sugar content measuring device for fruits and vegetables according to 6) or 7), wherein the wavelengths of two monochromatic lights are respectively selected from a range of 950 to 1010 nm and a range of 1020 to 1080 nm. The non-destructive sugar content measuring device for fruits and vegetables according to the above 6) or 7), wherein the wavelength of light is selected from the range of 900 to 930 nm and the range of 940 to 960 nm, respectively. 10) Two monochromatic light wavelengths are 740 ~ 750nm range and 760 ~ 780nm range respectively selected from the above 6) or 7) non-destructive sugar content measuring apparatus for fruits and vegetables 11) There are two independent light sources of two wavelengths. ,
The projection of two light sources can be switched to select the projection of one light source, and the irradiation means, the irradiation light amount detecting means, and the transmitted light amount detecting means can be operated by each monochromatic light, and the data output of the means is common. The non-destructive sugar content measuring device for fruits and vegetables according to any of 6) to 10) above, wherein the monochromatic light that has operated in the above manner is identified.

[0020]

In the present invention configured as described above, two monochromatic lights having different wavelengths are generated from the light source, the fruits and vegetables are irradiated with the two monochromatic lights by the irradiating means, and the transmitted light from the fruits and vegetables is detected by the transmitted light amount detecting means. Detect light. The irradiation light is scattered inside the fruits and vegetables and is emitted to the outside of the fruits to be transmitted light. The light transmittance is calculated from these two transmitted lights, and the sugar concentration is calculated from the same light transmittance by the formula 1. The transmitted light detected contains the sugar content information of the fruit inside the fruits and vegetables, and it is possible to measure the sugar content of fruits and vegetables with thick skin such as mandarin oranges and melons.
Also, the sugar content C can be calculated by the equation 2 as in the case of the transmittance of the transmitted light, by calculating the water absorption using the transmitted light from the fruits and vegetables of monochromatic light. As described above, in the present invention, by using two monochromatic light sources as the light source, a device that does not require a complicated spectroscope for detecting a transmitted or reflected light spectrum as in a conventional sugar content measuring device using a white light source. Can be realized.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION As the wavelengths of two monochromatic lights used in the present invention, light having a wavelength in the range of 600 nm to 1100 nm is often used. 1010nm and 1024-108
Area selected from the range of 0 nm, 900 to 930
nm and a range of 940 to 960 nm, a range of 740 to 750 nm and a range of 760 to 780 nm are good with a sugar content error of 0.5% or less in a fruit and vegetable model experiment with an aqueous glucose (glucose) solution. It turned out to be a range.

The monochromatic light of the present invention is preferably focused by a lens to irradiate fruits and vegetables, and the transmitted light is also preferably collected by a condenser lens and received by a photodetector. The position of the photodetector 42 of the transmitted light of the present invention is usually placed on the opposite side of the fruits and vegetables of the irradiation light, but it can be measured by placing the photodetector at a position distant from the opposite side.

A laser, a light emitting diode, or a monochromatic electric light source is used as the monochromatic light source of the present invention, and a photodiode or the like is used as the photodetector for receiving the transmitted light. The light transmittances Ta and Tb, the absorbances Abs_a and Abs_b, and the calculation of mathematical expressions and the control of the light source of the present invention are controlled and calculated using an electronic circuit and a computer, and displayed on a display device (display unit).

[0024]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is an explanatory diagram of a non-destructive sugar content measuring device of an example. FIG. 2 is an operation explanatory diagram showing a state of alternate irradiation of the trigger signal and the monochromatic light of the embodiment. FIG. 3 is a wavelength range map diagram showing wavelength regions in which the sugar content measurement accuracy is 0.5% or less and 1% or less. FIG. 4 is a correlation diagram between the ratio of the absorbance and the glucose (glucose) aqueous solution concentration in the example. Figure 5
FIG. 4 is an SN ratio spectrum diagram showing the relationship between the SN ratio η and the wavelength in the example. FIG. 6 is an explanatory view showing a conventional nondestructive sugar content measuring method.

The non-destructive sugar content measuring apparatus of this embodiment shown in FIG. 1 has a light source 10a (light source 10b) for irradiating the fruit 1 with monochromatic light 101a (monochromatic light 101b), a reflecting prism 22, and a condenser lens 21. And monochromatic light 101a
A sampling mirror 33 for detecting a part of the (monochromatic light 101b), a condenser lens 31, and a photodetector 32 are provided. Further, transmitted light 104a (10
4b) to detect the condenser lens 41 and the photodetector 42.
In addition, a signal processing unit 230, a central control unit 200, a display unit 210, and a light source control unit 220 are provided.

The central control unit 200 calculates the sugar content of fruits and vegetables by the method described later based on the detection signals from the photodetectors 32 and 42 digitized by the signal processing unit 230 and displays it on the display 210. . The light source control unit 220 uses the light source 10a.
(10b) has a power supply and a switch unit (not shown) for supplying a current. When the trigger signal TPa (TPb) is input to the switch unit from the central control unit 200, the switch unit is turned on in synchronization with the rising of the trigger signal TPa (TPb), and the current is supplied to the light source 10a (10b).

The operation of the non-destructive sugar content measuring device having the above-described structure will be described. First, the trigger signal TPa transmitted from the central control unit 200 becomes High. Next, the switch unit (not shown) of the light source control unit 220 is turned on in synchronization with the rising edge of the trigger signal TPa, the current is supplied to the light source 10a, and the monochromatic light 101a is generated. On the other hand, the trigger signal TPb remains Low, so that no current is supplied to the light source 10b and the monochromatic light 101b is not generated. Next, the monochromatic light 101a emitted from the light source 10a is transmitted through the reflection prism 22 and becomes parallel light by the condenser lens 24, a part of which is sampled as the monitor light 102a, and the rest is transmitted through the sampling mirror 33 for irradiation. Light 103a
Is radiated to vegetables and fruits 1. The sampled monitor light 102a is collected by the condenser lens 31 on the light receiving surface of the photodetector 32. On the other hand, the irradiation light 1 radiated on the fruit 1
Part of 03a is transmitted as a transmitted light 104a from the fruits and vegetables 1, and the transmitted light 104a is collected by the condenser lens 41 on the light receiving surface of the photodetector 42. Here, the photodetectors 32, 4
For 2, a photodiode or the like is used.

Detection signals proportional to the light intensities of the monitor light 102a and the transmitted light 104a are output from the photodetectors 32 and 42, respectively, and are digitized by the signal processing unit 230. Based on the detection signals from the photodetectors 32 and 42 that have been digitized, the central controller 200 calculates the absorbance Abs_a by a method described later.

When the calculation of the absorbance Abs_a is completed,
The trigger signal TPa becomes Low and the trigger signal TPb becomes High. Based on this trigger signal TPa (TPb), the light source 10a is turned off (turned off) and the light source 10b is turned on (lighted) by opening and closing a switch unit (not shown) in the light source control unit 220. Then, the above-mentioned monochromatic light 1
Similar to the procedure for calculating the absorbance Abs_a by 01a, the absorbance Abs_b by the monochromatic light 101b is calculated. When the calculation of the absorbance Abs_b by the monochromatic light 101b is completed, both the trigger signals TPa and TPb are Low.
Then, the light sources 10a and 10b are both turned off (turned off), and the sugar content measuring operation of the fruit 1 is completed. Central control unit 2
At 00, the sugar content of the fruit 1 is calculated from the calculated absorbances Abs_a and Abs_b by the method described below, and the result is displayed on the display unit.

Next, a method of calculating the absorbances Abs_a and Abs_b performed by the central control unit 200 will be described. Monochromatic light 101a, monitor light 102a, irradiation light 103a,
The amounts of transmitted light 104a are i _101a , i _102a , i
_103a and i _104a . Assuming that the reflectance of the sampling mirror 31 is k, i _102a and i _103a are represented by the following equation 13 using i _101a .

[0031]

[Equation 13]

Assuming that the transmittance of the fruit and vegetables 1 is T, i _104a is expressed by the following equation (14).

[0033]

[Equation 14]

Assuming that the light quantity-voltage conversion coefficients in the photodetectors 32 and 42 are β ₃₂ (V / W) and β ₄₂ (V / W), respectively, the detection signals (voltages detected by the photodetectors 32 and 42 are ) Is expressed by the following equations 15 and 16.

[0035]

[Equation 15]

[0036]

[Equation 16]

From the equations (15) and (16), the transmittance Ta of the fruits and vegetables 1 is calculated by the following equation (17), and is expressed in a form that does not depend on the light amount of the monochromatic light 101a.

[0038]

[Equation 17]

The value in parentheses is a constant peculiar to the sugar content measuring device, and can be easily determined by using a material or the like whose transmittance value is known. The absorbance Abs_a is calculated by the following formula 18 using the transmittance Ta calculated by the formula 17.

[0040]

[Equation 18]

The absorbance Abs_b can be calculated in the same manner. The sugar content C of fruit and vegetables 1 is the calculated absorbance A
It is calculated by the following equation 19 using the ratio of bs_a and Abs_b.

[0042]

[Formula 19]

[0043]

[Equation 20]

Here, k0 and k1 represent coefficients determined by the least squares method using the actually measured sugar content. Further, the estimation accuracy of the sugar content estimated by the equation 19 is two monochromatic lights 101a, 101.
It depends on the combination of the wavelengths λa and λb of b. Formula number 19
In the present embodiment, any combination is used as the optimum wavelength combination for estimating sugar content by using the following equation (21).

[0045]

[Equation 21]

Further, a laser can be used as a light source which emits the monochromatic lights 101a and 101b having the above-mentioned combination or wavelengths. If a semiconductor laser is used for this laser, a small sugar content measuring device can be realized. In addition, a light emitting element such as a light emitting diode is used as the light source 10.
It can also be used for a (10b). A white light source that continuously emits light having a wavelength in the near infrared region is used as the light source 10a.
When it is used for (10b), it may be realized by using an optical filter that allows the light from the light source 10a (10b) to transmit only the wavelengths of the above-mentioned three combinations.

Using the nondestructive sugar content measuring method of this embodiment as a model of fruits and vegetables, an aqueous glucose (glucose) solution was placed in a highly transparent container and irradiated with monochromatic light of various wavelengths to measure the amount of transmitted light. Using the device and method of
The error was calculated by calculating from Equation 2 and measuring the sugar content of the glucose (glucose) aqueous solution. As a result of the calculation, the wavelength regions H1, H2, H3 in which the error is 0.5% or less are shaded, and the boundary lines of the regions in which the error is 1% or less are K1, K2, K.
3 and K4 are shown in FIG.

It can be seen that the wavelength range shown in the equation (21) of the present invention is within the wavelength range H1, H2, H3 where the error is 0.5% or less, and by selecting monochromatic light from this wavelength range, the sugar content error can be reduced. It can be seen that a high accuracy of 0.5% or less can be obtained.

The correlation between the absorbance ratio γ (Abs_a / Abs_b in Equation 2) calculated in this example and the sugar concentration is shown in FIG. Here, the wavelengths λa and λb of the two monochromatic lights are 1060 nm and 980 nm, respectively. This Figure 4
As can be seen from the graph, the ratio (γ) (Abs_a / Abs_b) of the sugar concentration C% of the glucose (glucose) aqueous solution and the absorbance is found to be on the straight line with considerable accuracy. The linearity of the equation (k0, k1) was verified. In the data of FIG. 4, k0 = -134.113 and k1 = 452.489, and the equations of the equations 1 and 2 in this apparatus are as shown in the following equation 22.

[0050]

[Equation 22]

Incidentally, the SN ratio η in FIG. 4 was 14.6 and the estimation accuracy was 0.26%. The SN ratio η (λa, λb) is shown in Fig. 4.
Is a value calculated from the slope β of the regression line and the regression error α of The estimation accuracy is calculated as (1 / η) ^0.5 using the SN ratio η.

[0052]

[Equation 23]

When the wavelength λa of one monochromatic light is fixed to 1060 nm and only the wavelength λb of the other monochromatic light is changed with two monochromatic lights, the SN ratio η and the wavelength λb of the monochromatic light are changed. The relationship is a specific wavelength 930 to 1040 nm as shown in FIG.
It showed a high value in.

As described above, the formula of the sugar content is calculated by the sugar content model experiment or from the measurement example of the fruit and vegetable 1, and the coefficient k0,
When k1 is determined, the coefficient k0 of the characteristic of the device / method,
k1 is determined, and then the actual fruit 1 is measured and the absorbance A
By measuring bs_a, Abs_b or transmittance Ta, Tb,
The central control unit 200 performs the above calculation and processing, and the display unit 2
The sugar content is displayed at 10. With respect to the sugar content shown, an accuracy of 0.5% or less can be obtained in the above wavelength range.

[0055]

As described above, according to the present invention, fruits and vegetables are irradiated with two types of monochromatic light having specific wavelengths, and the transmitted light is detected. The transmitted light detected contains the sugar content information of the fruit inside the fruits and vegetables, and it is possible to measure the sugar content of fruits and vegetables with thick skin such as mandarin oranges and melons. Further, in the sugar content measuring device of the present invention that uses two types of monochromatic light of specific wavelengths, a complicated spectroscope for detecting a transmitted or reflected light spectrum is used like a conventional sugar content measuring device using a white light source. An unnecessary device can be realized, and a small semiconductor laser or the like can be used as a light source, so that a small and lightweight sugar content measuring device can be realized. Moreover, the accuracy of the sugar content of the measurement is high, 1%,
It can be made 0.5% or less.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a non-destructive sugar content measuring device of an example.

FIG. 2 is an operation explanatory diagram showing a state of alternate irradiation of a trigger signal and monochromatic light according to an embodiment.

FIG. 3 is a wavelength range map diagram showing wavelength regions of sugar content measurement accuracy of 0.5% or less and 1% or less.

FIG. 4 is a graph showing the ratio of absorbance and glucose (glucose) in Examples.
It is a correlation diagram with aqueous solution concentration.

FIG. 5 is an SN ratio spectrum diagram showing the relationship between the SN ratio η and the wavelength in the example.

FIG. 6 is an explanatory view showing a conventional non-destructive sugar content measuring method.

[Explanation of symbols]

1 fruits and vegetables 10a, 10b, light source 21, 31, 41 Condensing lens 22 Prism 32, 42 photo detector 33 Sampling mirror 50 coaxial optical fiber 51, 52 Condensing lens 60 spectroscope 61 slits 62 diffraction grating 63 Linear array sensor 101a, 101b monochromatic light 102a, 102b monitor light 103a, 103b irradiation light 104a, 104b transmitted light 200 Central control unit 210 display 220 Light source control unit 230 Signal processing unit 300 light sources 301 irradiation light 302 reflected light TPa, TPb trigger signal

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] October 24, 2001 (2001.10.
24)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction content]

Here, λ1 = 870n for four specific wavelengths
m, λ 2 = 878 nm, λ 3 = 889 nm, λ 4 = 90
It is proposed to use 6 nm.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0020

[Correction method] Change

[Correction content]

[0020]

In the present invention constructed as described above, two monochromatic lights having different wavelengths are generated from the light source, the irradiating means irradiates the fruits and vegetables with the two monochromatic lights, and the transmitted light amount detecting means transmits the monochromatic light. Detect light. The irradiation light is scattered inside the fruits and vegetables and is emitted to the outside of the fruits to be transmitted light. The light transmittance is calculated from these two transmitted lights, and the sugar concentration is calculated from the same light transmittance by the formula 1. The transmitted light detected contains the sugar content information of the fruit inside the fruits and vegetables, and it is possible to measure the sugar content of fruits and vegetables with thick skin such as mandarin oranges and melons.
Also, by determining the Absorbance using transmitted light from the fruits or vegetables monochromatic light, it is also possible to determine the sugar content C by transmittance as well as the number 2 of the transmitted light. As described above, in the present invention, by using two monochromatic light sources as the light source, a device that does not require a complicated spectroscope for detecting a transmitted or reflected light spectrum as in a conventional sugar content measuring device using a white light source. Can be realized.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0021

[Correction method] Change

[Correction content]

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION As the wavelengths of two monochromatic lights used in the present invention, light having a wavelength in the range of 600 nm to 1100 nm is often used. 1010nm and 1024-108
Area selected from the range of 0 nm, 900 to 930
nm and a region selected from the range of 940 to 960 nm, a region selected from the range of 740 to 750 nm and 760 to 780 nm uses an aqueous glucose (glucose) solution .
In a fruit and vegetable model experiment, it was found that the sugar content error was 0.5% or less, which was in a good range.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0034

[Correction method] Change

[Correction content]

The light quantity-voltage conversion coefficients in the photodetectors 32 and 42 are β ₃₂ (V / W) and β ₄₂ (V / W), respectively.
Then, the detection signals (voltages) detected by the photodetectors 32 and 42 are expressed by the following formulas 15 and 16.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0051

[Correction method] Change

[Correction content]

Incidentally, the SN ratio η in FIG.
No. 6, the estimation accuracy was 0.26%. SN ratio η (λa, λ
b) is the slope β of the regression line in FIG. 4 and the regression error is σ
And the value calculated by the following equation (23). The estimation accuracy is calculated by (1 / η) ^0.5 using the SN ratio η.

[Procedure correction 6]

[Document name to be corrected] Drawing

[Name of item to be corrected] Fig. 4

[Correction method] Change

[Correction content]

[Figure 4]

[Procedure Amendment 7]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 5

[Correction method] Change

[Correction content]

[Figure 5]

Continued front page    F term (reference) 2G051 AA05 AB20 BA06 BA08 BA10                       BA20 CA02 CA07 CB02 EA12                       FA10                 2G059 AA01 BB11 EE01 GG01 GG02                       GG05 GG10 HH01 HH06 JJ11                       JJ12 JJ13 JJ22 KK01 KK03                       MM01 MM09 PP04

Claims (11)

[Claims] 1. A measuring device capable of irradiating fruits and vegetables with two monochromatic light beams having different wavelengths to measure the light transmissivity Ta, Tb of each monochromatic light, and the values of the light transmissivity Ta, Tb of a plurality of actual measurement examples. And the value of the actually measured sugar content C in that example, the coefficient of the following mathematical formula 1
Determine k0 and k1 and measure with the determined coefficients k0 and k1 2
A non-destructive sugar content measuring method for fruits and vegetables, wherein the sugar content C is calculated by the following mathematical formula 1 using the data of the light transmittances T _a and T _b of one monochromatic light. [Equation 1] 2. The fruits and vegetables are irradiated with two monochromatic lights having different wavelengths, and the absorbance Ab is obtained from the transmitted light of the monochromatic lights from the fruits and vegetables.
Equipped with a measuring device capable of measuring s_a and Abs_b, the coefficients k0 and k1 of the following equation 2 are determined and determined from the values of the absorbances Abs_a and Abs_b of a plurality of measured examples and the measured sugar content C of the example. A non-destructive sugar content measuring method for fruits and vegetables, wherein the sugar content C is calculated by the following mathematical formula 2 using the data of absorbances Abs_a and Abs_b of two monochromatic lights measured as k0 and k1. [Equation 2] 3. The wavelengths of two monochromatic lights are 950 to 1010.
The method for measuring non-destructive sugar content of fruits and vegetables according to claim 1, wherein the method is selected from the range of nm and the range of 1020 to 1080 nm. 4. The wavelengths of two monochromatic lights are 900 to 930n.
The method for measuring non-destructive sugar content of fruits and vegetables according to claim 1, which is selected from the range of m and the range of 940 to 960 nm. 5. The wavelengths of two monochromatic lights are 740 to 750n.
The method for measuring non-destructive sugar content of fruits and vegetables according to claim 1, which is selected from the range of m and the range of 760 to 780 nm. 6. Two different monochromatic light sources, and an irradiation means for irradiating fruits and vegetables with the monochromatic light from said light sources.
An irradiation light amount detecting means for detecting an irradiation light amount of the monochromatic light with which the fruits and vegetables are irradiated, and a transmitted light amount detecting means for detecting an amount of transmitted light from the fruits and vegetables of the two monochromatic lights with which the fruits and vegetables are irradiated by the irradiation means. , T _{a of} two light transmittances corresponding to each monochromatic light from the irradiation light amount detected by the irradiation light amount detecting means and the transmitted light amount detected by the transmitted light amount detecting means,
Calculating a T _b, further non-destructive sugar content measuring apparatus fruit or vegetable to be from that value, characterized in that a calculating means for calculating a sugar content C of fruits or vegetables from the following equation number 3. [Equation 3] 7. Two different monochromatic light sources, and an irradiation means for irradiating fruits and vegetables with the monochromatic light from said light sources.
An irradiation light amount detecting means for detecting an irradiation light amount of the monochromatic light with which the fruits and vegetables are irradiated, and a transmitted light amount detecting means for detecting an amount of transmitted light from the fruits and vegetables of the two monochromatic lights with which the fruits and vegetables are irradiated by the irradiation means. , Two absorbances Abs_ corresponding to each monochromatic light based on the irradiation light amount detected by the irradiation light amount detecting means and the transmitted light amount detected by the transmitted light amount detecting means.
A non-destructive sugar content measuring device for fruits and vegetables, comprising: a, Abs_b; and an arithmetic means for calculating the sugar content C of the fruit and fruits from the mathematical formula of the following formula 4 from the values. [Equation 4] 8. The wavelengths of two monochromatic lights are 950 to 1010.
The non-destructive sugar content measuring device for fruits and vegetables according to claim 6 or 7, which is selected from the range of nm and the range of 1020 to 1080 nm. 9. The wavelength of two monochromatic lights is 900 to 930n.
The nondestructive sugar content measuring device for fruits and vegetables according to claim 6 or 7, which is selected from the range of m and the range of 940 to 960 nm. 10. The wavelengths of two monochromatic lights are 740 to 750.
The non-destructive sugar content measuring device for fruits and vegetables according to claim 6 or 7, which is selected from the range of nm and the range of 760 to 780 nm. 11. A light source having two independent wavelengths is two.
The two light sources are switchable and can be selected to project one light source, and the irradiating means, the irradiating light amount detecting means and the transmitted light amount detecting means can be operated by each monochromatic light. The non-destructive sugar content measuring device for fruits and vegetables according to any one of claims 6 to 10, wherein the monochromatic light that has been operated is output for the data output.