JP2642971B2 - Fruit and vegetable ingredient measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a fruit and vegetable component measuring device applied to a fruit and vegetable sorting machine and the like.

[Conventional technology]

Measurement of the components of fruits and vegetables applied to conventional fruit sorting machines, etc., indirectly estimate the components from the shape elements of fruits and vegetables,
Using a light having a wavelength of 685 nm, the concentration of chlorophyll (chlorophyll) was measured to judge the ripeness and sugar content indirectly.

[Problems to be solved by the invention]

In the conventional measurement of the components of fruits and vegetables, the components of the fruits and vegetables are indirectly measured, and the measurement error is large.

An object of the present invention is to provide a device capable of directly and non-destructively measuring content components of fruits and vegetables, for example, sugar content, acidity, ripeness and the like.

[Means for solving the problem]

(1) The component measuring device for fruits and vegetables according to the present invention is a rotatable disk-shaped filter having a non-constant thickness, which is capable of selecting near-infrared rays from a light projecting device and selecting a wavelength of transmitted light, and a transmitted light of the filter. Light from one end and irradiates fruits and vegetables from the other end
An optical fiber, a second optical fiber that receives reflected light from the fruit and vegetable from one end coaxial with the first optical fiber and irradiates one semiconductor sensor from the other end, and one of transmitted light of the filter. A third optical fiber that receives light from one end as a reference light and irradiates the reflecting object from the other end, and receives reflected light from the reflecting object from one end coaxial with the third optical fiber and receives the other end. A fourth optical fiber for irradiating the other semiconductor sensor, and an arithmetic unit for inputting an absorbance signal from the one semiconductor sensor and the other semiconductor sensor to calculate a content component of the fruits and vegetables are provided.

(2) The present invention provides the apparatus for measuring a component of fruits and vegetables according to the invention (1), wherein the wavelength range having an absorbance having a high correlation with the sugar content of the transmitted light transmitted through the filter is 1300 to 1320.
nm, 1660-1680 nm, and 2170-2190 nm.

[Action]

In the above invention (1), the near-infrared light emitted from the light projecting device enters the filter, and by rotating the disc-shaped filter having a non-constant thickness, the wavelength is within a certain range during one rotation. Transmits light that changes continuously within. The transmitted light is radiated to the fruits and vegetables via the first optical fiber, and a part thereof is absorbed in proportion to the sugar content of the fruits and vegetables, and the rest is reflected.

The reflected light irradiates one semiconductor sensor via the other end of the first optical fiber and a second optical fiber whose one end is coaxial, and the sensor measures the absorbance of the fruit or vegetable from the reflected light.

The transmitted light transmitted through the filter irradiates a reflecting object through a third optical fiber, and the reflected light is transmitted through a fourth optical fiber whose one end is coaxial with the other end of the third optical fiber. Irradiates the other semiconductor sensor, which measures the absorbance of the reflecting object.

Note that light output from the filter and whose wavelength continuously changes due to its rotation is received by an optical fiber having an extremely small light receiving area, so that light with a high resolution can be applied to fruits and vegetables.

Each of the one semiconductor sensor and the other semiconductor sensor inputs its absorbance signal to a calculation unit.

Since the absorbance of the fruits and vegetables and the reflection object change similarly depending on the environmental conditions, the arithmetic unit corrects the absorbance of the fruits and vegetables by the absorbance of the reflection object to obtain the sugar content of the fruits and vegetables.

As described above, it has become possible to quickly and accurately measure the content components such as sugar content and acidity of fruits and vegetables without processing the fruits and vegetables at a processing speed of about 0.5 seconds per one.

In the above invention (2), 1300 to 1320 nm, 1660 to 1680
Light in the wavelength range of nm and 2170 to 2190 nm is well absorbed by sugar, and since this absorbance has a high correlation with the sugar content, irradiating the light in this wavelength range to fruits and vegetables enables highly accurate component measurement. Become.

〔Example〕

 One embodiment of the present invention is shown in FIG.

The embodiment shown in FIG. 1 includes a light projecting device 1 that emits near-infrared rays 2, a rotatable disk-shaped filter 4 that enters the near-infrared rays via a condenser lens 3, and a rotatable filter 4 having the same thickness. A light fiber 6 that receives most of the near-infrared ray 5 having a specific wavelength transmitted through the filter 4 from one end and irradiates the fruits and vegetables 8 from the other end, and receives reflected light from the fruits and vegetables 8 from one end and semiconductors from the other end. A coaxial fiber 9 for irradiating the sensor 10, an optical fiber 7 for irradiating the rest of the near-infrared ray 5 transmitted through the filter 4 from one end and irradiating the Teflon sphere 11 from the other end, and a reflected light from the Teflon sphere 11 from one end. A coaxial fiber 12 that receives light and irradiates the semiconductor sensor 13 from the other end; and a calculation unit that receives an absorbance signal from the semiconductor sensors 10 and 13 via wires 14 and 15 and outputs a calculation result signal from the wire 17. 17 Drivers 6 and 7 and coaxial fiber 9 and 12 are respectively the length and material same.

In the above, the near-infrared ray 2 emitted from the light emitting device 1
Is focused by the condenser lens 3 and condensed on the filter 4.

The filter 4 can be rotated to select light of a specific wavelength, and the near infrared rays 5 of a specific wavelength transmitted through the filter 4 and dispersed are mostly radiated to the fruits and vegetables 8 by the optical fiber 6. . The rest of the near-infrared ray 5 transmitted through the filter 4 is irradiated on the Teflon sphere 11 by the optical fiber 7 as reference light.

The light irradiating the fruits and vegetables 8 by the optical fiber 6 transmits through the inside of the fruits and vegetables 8 and a part of the light having a specific wavelength constitutes the sugar of the fruits and vegetables 8 (in the case of peach, 80% is sugar). Resonate with the functional groups (eg, CH ₂ , CH, etc.) and are absorbed in proportion to the sugar content.

Light other than the light absorbed in proportion to the sugar content is reflected from the inside of the peach and guided to the semiconductor sensor 10 by the coaxial fiber 9, and the absorbance of the peach is measured based on the amount of the reflected light.

Generally, when a material is irradiated with light, the material absorbs light, and the energy state of atoms constituting the material changes from a low energy state (ground state) to a high energy state (excitation state).
Transition to.

The relationship between the intensity of light absorption and the concentration of the absorbing substance can be expressed by the following equation (1) according to Pier's law.

Where α: absorption coefficient of the substance, C _X : concentration of the absorbing substance, I
₀ : energy irradiated into the substance, _IX : energy reflected from the substance and output The above equation (1) is converted to the following equation (2) with α = 2.3ε.

log (I ₀ / I _X ) = εC _X (2) Further, a part of the rest of the near-infrared ray 5 radiated as the reference light to the Teflon sphere 11 is partially reflected as described above,
The light is guided to the semiconductor sensor 13 via the coaxial fiber 12, and the semiconductor sensor 13 measures the absorbance of the Teflon sphere 11.

The absorbance signal of the fruits and vegetables 8 is led to the arithmetic unit 16 via the electric wire 14, and the absorbance signal of the Teflon bulb is led to the arithmetic unit 16 via the electric wire 15.

Since the absorbances of the fruits and vegetables 8 and the Teflon spheres 11 similarly vary depending on the environmental conditions (temperature, humidity, etc.), the arithmetic unit 16 performs an arithmetic operation using the corrected expression (2) and the expression (3). Then, minute changes due to environmental conditions (temperature, humidity, etc.), filters, fibers, and the like are corrected, an OD value signal is output from the electric wire 17, and the concentration of sugar content is obtained.

OD = log (I ₀ · R / I _X ) = ε'C _X (3) where R: energy reflected from the Teflon sphere,
ε ′: extinction coefficient corrected for environmental conditions, etc., OD: optical density The above OD value is proportional to the concentration of the absorbing substance, and the concentrations are C ₁ , C ₂ ..., and the extinction coefficients are ε ₁ , ε ₂ , respectively. For a substance containing a plurality of substances, the OD value is represented by the sum of the OD values of the respective substances.

The results of a near-infrared irradiation experiment based on Peer's law on peach are shown below.

The near-infrared 2 which is projected from the light projection apparatus 1 1310 nm by the filter 4, 1670 nm, and light having a wavelength of 2180nm, R when the I ₀ = 1 for first several peaches by irradiating the light , I _X, and the sugar content C _X of each of the portions exposed to light was measured by a Brix meter, and the above I ₀ = 1, R, I _X , C
Ε 'was determined from _X. Next, for 100 peaches, R and _IX were measured when the above light was irradiated and I ₀ = 1, and the calculated sugar content C ′ _X was calculated from ε ′ obtained from the above several peaches. The measured sugar content _CX was measured with a Brix meter. The calculated brix C _'X and the measured Brix C _X comparison result, the average value or average error of the error is 0.42%, and calculated sugar content C' was plotted the _X and measured sugar content C _X as vertical and horizontal axes, respectively When the correlation was high, the multiple correlation coefficient approaching 1 was 0.93, and the sugar content in the sugar content measurement by near-infrared light was good.

Note that without performing the correction by the reference beam, to measure only the peach reflected light (2) was calculated to calculate sugar content C _'X from equation
The average error between the calculated sugar content C ′ _X and the measured sugar content C _X was 0.62%, and the multiple correlation coefficient was 0.89. The average error was large and the correlation was low as compared with the case where the correction was performed using the reference light.

According to the above experiment, when near-infrared rays are irradiated on fruits and vegetables through an optical fiber and the non-destructive measurement of content components is performed based on the absorbance, the same material as that used for the fruits and vegetables with a part of the light passing through the filter is used. It was found that high-precision measurement was possible by taking out as a reference light with a fiber having a length and irradiating it to a Teflon sphere and using its absorbance for correction.

Further, when the above measurement was performed with the wavelength of the near infrared ray 2 further changed, the wavelength was found to be 1,300 to 1,320 nm, 1,660 to 1,68
A range of 0 nm, 2,170-2,190 nm has been found to be appropriate.

As described above, the components such as the sugar content and the acidity of the fruits and vegetables can be measured accurately with a processing speed of about 0.5 seconds per one without damaging the fruits and vegetables.

〔The invention's effect〕

The present invention irradiates fruits and vegetables with near-infrared light emitted from a light emitting device and transmitted through a filter through a first optical fiber,
The reflected light is radiated to one of the semiconductor sensors via a second optical fiber, and a part of the near-infrared light transmitted through the filter is radiated to a reflecting object via a third optical fiber, and the reflected light is emitted. By irradiating the other semiconductor sensor via the fourth optical fiber and inputting an absorbance signal from the one semiconductor sensor and the other semiconductor sensor to a calculation unit,
The components such as sugar content and acidity of fruits and vegetables can be measured accurately with a processing speed of about 0.5 seconds per one without damaging the fruits and vegetables.

[Brief description of the drawings]

 FIG. 1 is an explanatory view of one embodiment of the present invention. DESCRIPTION OF SYMBOLS 1 ... Projection device, 2 ... Near infrared light, 3 ... Condensing lens, 4 ... Filter, 5 ... Near infrared light of specific wavelength, 6, 7 ... Optical fiber, 8 ... Fruits and vegetables, 9 ... Coaxial fiber, 10… Semiconductor sensor, 11… Teflon sphere, 12… Coaxial fiber, 13… Semiconductor sensor, 14,15… Wire, 16… Calculator, 17… Wire.

 ──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-53-15890 (JP, A) JP-A-54-92790 (JP, A) JP-A-63-11841 (JP, A)

Claims (2)

(57) [Claims] 1. A rotatable disk-shaped filter that receives near-infrared light from a light projecting device and has a selectable wavelength of transmitted light, and has a non-constant rotatable thickness. A first optical fiber for irradiating more fruits and vegetables, and a second optical fiber for irradiating reflected light from the above fruits and vegetables from one end coaxial with the first optical fiber and irradiating one semiconductor sensor from the other end.
An optical fiber, a third optical fiber that enters a part of the light transmitted through the filter as reference light from one end and irradiates a reflective object from the other end, and coaxially reflects the reflected light from the reflective object with the third optical fiber. A fourth optical fiber that receives light from one end and irradiates the other semiconductor sensor from the other end, and absorbs light signals from the one semiconductor sensor and the other semiconductor sensor to calculate the content component of the fruits and vegetables An apparatus for measuring ingredients of fruits and vegetables, comprising a calculation unit. 2. The fruit and vegetable component measuring device according to claim 1, wherein the wavelength range having an absorbance having a high correlation with the sugar content of the transmitted light transmitted through the filter is 1300 to 13
An apparatus for measuring a component of fruits and vegetables, characterized by using three wavelength ranges of 20 nm, 1660 to 1680 nm and 2170 to 2190 nm.