JPH11173985A - Apparatus and method for judging inside quality of fruit or vegetable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an apparatus and a method in which the inside quality of an afterripening- type fruit or vegetable can be measured nondestructively by computing the difference between an absorbance in the central part and that in the lower part, which are measured by a light receiving means and judging the inside quality on the basis of a computed result. SOLUTION: Light sources 11 and light sources 13 are installed in respective measuring parts. The light source 11 in the first measuring part 7 projects near-infrared light to the central part 12 of an object 1 to be measured, which reaches the first measuring part 7. The light source 13 in the second measuring part 9 projects near-infrared light to the lower part 14 of an object 1 to be measured, which reaches the second measuring part 9. Light which is transmitted through the object 1 to be measured is received by a light receiving optical fiber 17 and a light receiving optical fiber 19 through opening parts 5 in the lower part of a tray 3. It is introduced into a spectroscope 21, and respective absorbances are measured. A difference absorbance is computed by a computing device 25 on the basis of the difference between the two absorbances. In addition, when a main component is analyzed by using difference absorbances of a plurality of wavelengths, a normal fruit or vegetable is discriminated from an abnormal fruit of vegetable irrespective of the size of a fruit or vegetable, and its inside quality can be measured nondestructively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for non-destructively measuring the internal quality of fruits and vegetables such as pears, bananas and kiwi fruits.

[0002]

2. Description of the Related Art Among fruits and vegetables, especially ripening fruits such as pears, bananas and kiwifruits, when harvested in a ripe state, have a decrease in taste, flour of flesh and drought of flesh. To prevent this, harvest in an immature state, that is, in a state where the pulp is not firm and ripe,
After that, ripening is performed by leaving it at a constant temperature.
By doing so, the ripening fruits and vegetables are first made edible. Therefore, ripening is the most important step in determining the quality of ripening fruits and vegetables.

[0003] In the ripening type fruits and vegetables, physiological disorders such as a stone pear phenomenon may be present. The stone pear phenomenon is
The pulp tissue hardens and becomes sandy, forming stone cells. In the part where the stone pear phenomenon has occurred (stone pear part), the absorption of near infrared light to the flesh having normal cells is large (that is, the absorbance is large). In the early stage of ripening, the difference in the absorbance of near-infrared light between the stone pear part and the part where the stone pear phenomenon does not occur (normal flesh part) is slight, but appears more noticeably as the ripening progresses. .

Conventionally, judgment of completion of ripening and judgment of physiological disorders such as a stone pear phenomenon have been made visually. The experienced person judges the ripening degree and physiological disorder visually, but there is no clear standard for the judgment, and the judgment of the ripening degree and the presence / absence of physiological disorder tended to vary. In particular, it was extremely difficult to judge the stone pear phenomenon at the beginning of ripening.

[0005] On the other hand, as a method of nondestructively determining the internal quality of fruits and vegetables, there is a method of projecting near-infrared light onto fruits and vegetables. In this method, the sugar content of the fruit or vegetable can be known from the transmission spectrum of light transmitted through the fruit or vegetable. However, this method has made it difficult to determine the ripening of fruits and vegetables and the presence or absence of physiological disorders.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide an apparatus for non-destructively measuring the internal quality of ripening fruits such as pears, bananas and kiwifruits.

[0007]

Means for supporting the fruits and vegetables, light projecting means for projecting light by giving a time difference to different positions on the fruits and vegetables, and wherein the projected light passes through the fruits and vegetables, respectively. Receiving the emitted light, the light receiving means for measuring the absorbance of the fruits and vegetables with respect to each projection light, and a calculation unit for taking the difference between the two absorbances measured by the light receiving means, based on the calculation result, the fruit and vegetables Judge internal quality.

[0008]

FIG. 1 is a diagram showing the configuration of a first embodiment of the present invention. The plurality of pears as the subject 1 are placed on individual trays 3, respectively. Each tray 3 has an opening 5 in the center. The material of the tray 3 may be any material that blocks light, but is preferably elastic. The trays 3 are arranged in a row and are arranged at equal intervals. The tray 3 advances in one direction 6 of the row.

A first measuring section 7 and a second measuring section 9 are provided at two places on the way of the tray 3 in the traveling direction. Each measuring unit is provided with a light source 11 and a light source 13 respectively. The light source 11 of the first measuring unit 7 irradiates near-infrared light to the central portion 12 of the subject 1 that has entered the first measuring unit 7. On the other hand, the light source 13 of the second measuring unit
Near-infrared light is applied to the lower part 14 of the subject 1 entering the measuring section. Each of the measuring units 7 and 9 covers one tray and the subject 1 thereon, and blocks external light to each of the measuring units 7 and 9. The material constituting the wall portions of the measuring units 7 and 9 may be any material as long as it blocks external light.

Below each of the measuring units 7 and 9, a light receiving fiber 1 is provided at a position facing the opening 5 of the tray 3.
7 and 19 are provided, and a spectroscope 21, an amplification device 23, and a calculation device 25 are sequentially connected to the light receiving fiber.

Next, the operation of this embodiment will be described.
The subject 1 is placed on each of the plurality of trays 3 arranged in a row and transported at a constant speed. When the subject 1 reaches the first measurement unit 7, near-infrared light is emitted from the light source 11 to the central part 12 of the subject 1. Light 1 transmitted through subject 1
Is a light receiving fiber 17 through the opening 5 at the lower part of the tray 3.
Is received at. Further, when the subject 1 already irradiated with the near-infrared light by the first measurement unit 7 reaches the second measurement unit, the light source 1
From 3, near-infrared light is applied to the lower part 14 of the subject 1. The light 2 transmitted through the subject 1 is transmitted to the opening 5 at the bottom of the tray 3.
Through the light receiving fiber 19. The light received by the light receiving fibers 17 and 19 is introduced into the spectroscope 21 and the absorbance is measured, and the difference absorbance is calculated from the difference between the two absorbances. Note that a belt conveyor may be used instead of the tray. On the belt,
At the center, openings are provided at regular intervals in the longitudinal direction of the belt, and the subject is placed on the openings.

FIG. 2 shows a measurement example of the absorbance according to the present embodiment. The horizontal axis represents the wavelength of near-infrared light emitted from the light source 11 or 13 to the subject 1, and the vertical axis represents the absorbance of the subject 1. Curves A and B show the absorbance of the subject 1 in the first measuring section 7 and the absorbance of the subject 1 in the second measuring section 9, respectively. The curve A is almost similar to the shape obtained by moving the curve B in the upper direction in parallel. This is because the first measuring unit 7 irradiates the central part 12 of the subject 1 with near-infrared light, while the second measuring unit 9 irradiates the lower part 14 of the subject 1. When the measurement is performed by the 1 measurement unit, the optical path length, that is, the distance from the light irradiated to the subject 1 to the transmission through the subject 1 to the emission toward the opening 5 of the tray 3 becomes long, so that the absorbance is large. Corresponding to becoming. Also,
The curve C is obtained by calculating the difference absorbance from the curves A and B. When the light absorption rate distribution of the subject 1 is uniform, the difference absorbance becomes a constant value regardless of the wavelength, but in this example, the difference in the difference absorbance is slightly different depending on the wavelength. It can be seen that the absorption rate distribution is not uniform.

FIG. 3 shows the absorbance before and after ripening of a normal fruit and vegetable (normal fruit) and a subject with a stone pear disorder (abnormal fruit). In this figure, a cross section of a fruit or vegetable is schematically shown. The color coding indicates the difference in absorbance. Abs1 indicates the portion with the highest absorbance, Abs3 indicates the portion with the lowest absorbance, and Abs2 indicates the absorbance between A and B.

FIGS. 3 (1) and 3 (2) show the absorbance of normal fruit before and after ripening, respectively.
The absorbance of the subject in the case of (2) is smaller than that of (2), indicating that light passes through the ripening and the absorbance decreases. FIGS. 3 (3) and (4) show the absorbance before and after ripening of the abnormal fruit, respectively, and a stone pear part is present below the abnormal fruit. The stone pear portion exists before ripening, and it is extremely difficult for light to pass through before and after ripening, and has a large absorbance. In FIGS. 3 (3) and (4), the absorbance of normal flesh other than the stone pear portion decreases as ripening progresses, as in FIGS. 3 (1) and (2).

In FIG. 3, the first measuring section 7 and the second
The projection positions 11a and 13a of irradiation light from the light sources 11 and 2 in the measurement unit are shown. That is, the light source 1
The light projecting position 11 a from the light source 13 is substantially at the center of the subject 1, and the light projecting position 13 a from the light source 13 is a lower part of the subject 1. The difference absorbance used in the present invention is a difference in absorbance at the light projecting positions 11a and 13a.

In the present invention, the absorbance is measured from the amount of light emitted from the lower part of the object when the light irradiated on the side surface of the object passes through the object. Therefore, in a subject having a stone pear portion at the lower portion, the absorbance of the stone pear portion is large, so that the absorbance of the subject is determined by the absorbance of the stone pear portion.
This means that when the difference in absorbance of fruits and vegetables is considered, the difference in absorbance between normal fruit and normal fruit is larger in normal fruit. That is, in a subject having a stone pear part, the difference (differential absorbance) becomes very small because both the absorbance when the central part and the lower part are irradiated with light are determined by the absorbance of the stone pear part. . On the other hand, in the normal fruit, the light path length in the fruits and vegetables differs between the case where light is irradiated to the central part and the part below, so that a difference appears in the absorbance. Therefore, it is possible to distinguish a normal fruit and an abnormal fruit having a stone pear part from the difference absorbance.

On the other hand, when the size of the fruits and vegetables as the subject 1 varies, it may be difficult to determine the fruits and vegetables by the difference absorbance. That is, a small normal fruit has a short optical path length, so the difference absorbance is small, and it is difficult to distinguish it from an abnormal fruit having a stone pear portion.

FIG. 4 shows a plurality of fruits and vegetables before ripening.
The difference absorbance for two wavelengths of light of 900 nm and 810 nm is plotted on the vertical and horizontal axes, respectively.
FIG. 5 shows two wavelengths 9 for fruits and vegetables after ripening.
The difference absorbances for light at 00 nm and 810 nm are plotted on the vertical and horizontal axes, respectively. Point N indicates the difference absorbance of the normal fruit, and point E indicates the difference absorbance of the abnormal fruit having the stone pear. In this figure, normal fruits are distributed on the upper right, while abnormal fruits are distributed on the lower left. As described above, by using the difference absorbance at the two wavelengths, it is possible to discriminate between a normal fruit and an abnormal fruit regardless of the size of the fruit or vegetable. However, even in this case, there is a region where the distribution of normal fruits and abnormal fruits overlap as shown in the figure,
For this region, it is preferable to make a more precise judgment of fruits and vegetables using a certain discrimination value set empirically. The wavelength used for the determination may be other than 900 nm and 810 nm.

FIGS. 6 and 7 show the results of principal component analysis of a plurality of subjects before and after ripening, using the difference absorbance at every 10 nm from 650 nm to 940 nm.
The horizontal axis indicates the second main component (PC2), and the vertical axis indicates the third main component (PC3). Point N indicates a normal fruit and point E indicates an abnormal fruit. The subscripts indicate the relative size of the fruits and vegetables, s indicates small, m indicates medium, and l indicates large. In this figure, normal fruits are distributed in the upper right, while abnormal fruits are distributed in the lower left. As described above, by performing the principal component analysis using the difference absorbances at a plurality of wavelengths, it is possible to discriminate normal fruits from abnormal fruits regardless of the size of fruits and vegetables. However, even in this case, as shown in the figure, there is an area where the distribution of normal fruits and abnormal fruits overlap, and for this area, it is necessary to make a more precise judgment of fruits and vegetables using a certain discriminant value set empirically. Is preferred.

FIG. 8 is a diagram showing a second embodiment of the present invention. The plurality of pears as the subject 1 are placed on individual trays 3, respectively. Each tray 3 has an opening 5 in the center. The material of the tray 3 may be any material that blocks light, but is preferably elastic. The trays 3 are arranged in a row and are arranged at equal intervals. The tray 3 advances in one direction 6 of the row.

In the middle of the tray 3 in the traveling direction, the measuring unit 50
Is provided. The measuring section 50 is provided with a light source 52 and a mirror 54. The measuring unit 50 covers one tray and the subject 1 thereon, and the measuring unit 5
Block external light to zero. The material constituting the wall portion of the measurement unit 50 may be any material as long as it blocks external light. A light receiving fiber 56 is provided below the measuring unit 50 at a position facing the opening 5 of the tray 3, and a spectroscope 58, an amplifying device 60, and a computing device 62 are sequentially connected to the light receiving fiber. .

FIG. 9 is a side view showing the inside of the measuring section 50. The near-infrared light irradiating the subject is emitted from the light source 52, reflected by the mirror 54 via the lens 64, and then emitted to the subject 1. The near-infrared light emitted from the light source 52 is appropriately condensed by the lens 64 and projected on the mirror 54. The direction of the mirror 54 can be changed by a solenoid 66. By changing the direction of the mirror 54, the projection position on the subject 1 can be adjusted.

The subject 1 is placed on each of the plurality of trays 3 arranged in a row and is conveyed at a constant speed. When the subject 1 reaches the measuring unit 50, near-infrared light is emitted from the light source 52 to the central part 68 of the subject 1 as a first step. The light transmitted through the subject 1 is transmitted through the opening 5 at the bottom of the tray 3.
Through the light receiving fiber 56. Next, the second
As a step, the orientation of the mirror 54 is changed by the solenoid 66, and in the first step, near-infrared light is irradiated on the lower part 70 of the subject 1 whose central part 68 has been irradiated with near-infrared light. Light transmitted through the subject 1 is received by the light receiving fiber 56 through the opening 5 below the tray 3 as in the first step. The light received by the light receiving fiber 56 is introduced into the spectroscope 58, the absorbance of each of the first and second steps is measured, and the difference absorbance is calculated from the difference between these two absorbances.

The determination of the internal quality of ripening fruits and vegetables by the difference absorbance is the same as in the first embodiment. In the present embodiment, a solenoid is used to change the direction of the mirror, but a stepping motor may be used instead of the solenoid. Further, the tray may be moved up and down in order to change the light projection position on the subject. Alternatively, the light may be projected onto the subject without using the mirror, and the light source may be moved up and down.

[0025]

According to the present invention, it is possible to nondestructively measure the internal quality of ripening fruits regardless of their size.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a first exemplary embodiment of the present invention.

FIG. 2 is a diagram showing absorbance and difference absorbance of fruits and vegetables.

FIG. 3 is a diagram schematically showing the absorbances of normal fruits and abnormal fruits before and after ripening.

FIG. 4 is a diagram in which difference absorbances of fruits and vegetables before ripening with respect to light of two wavelengths are plotted on a vertical axis and a horizontal axis, respectively.

FIG. 5 is a diagram in which the vertical axis and the horizontal axis respectively represent the difference absorbance of ripened fruits and vegetables with respect to light of two wavelengths.

FIG. 6 is a main component distribution diagram based on a difference absorbance before ripening.

FIG. 7 is a main component distribution diagram based on a difference absorbance after ripening.

FIG. 8 is a diagram showing a configuration of a second exemplary embodiment of the present invention.

FIG. 9 is a side view showing the inside of the measurement unit in the second embodiment.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 subject 3 tray 5 opening 7 first measuring section 9 second measuring section 11 light source 13 light source 17 light receiving fiber 19 light receiving fiber 21 spectrometer 23 amplifying device 25 arithmetic device

Claims (9)

[Claims] 1. A supporting means for mounting fruits and vegetables, a light projecting means for projecting light by giving a time difference to different positions on the fruits and vegetables, and the projected light is transmitted through the fruits and vegetables, respectively, and emitted. A light receiving unit that receives light and measures the absorbance of the fruits and vegetables with respect to each projection light; and a calculating unit that takes a difference between the two absorbances measured by the light receiving units. An apparatus for judging the internal quality of fruits and vegetables characterized by judging the internal quality. 2. A transporting means capable of continuously transporting fruits and vegetables, detecting whether the fruits and vegetables are at a first position on the transporting means, and projecting light to a first portion of the fruits and vegetables. A first light projecting means, a second light projecting means for detecting whether or not the fruits and vegetables are at a second position on the transport means, and projecting light to a second portion of the fruits and vegetables; A light-receiving means for receiving the light emitted from each of the light beams transmitted through the fruits and vegetables, and measuring the absorbance of the fruits and vegetables with respect to each of the projected lights; and calculating the difference between the two absorbances measured by the light-receiving means. A continuous-transportation-type fruit / vegetable internal quality determination device, comprising: determining whether or not the internal quality of the fruit / vegetable belongs to a determination criterion based on the calculation result. 3. The interior of a fruit or vegetable according to claim 1, wherein the internal quality of the fruit or vegetable is determined by using a difference in absorbance at two wavelengths within a certain wavelength range of the projection light used. Quality judgment device. 4. The internal quality of fruits and vegetables is determined by performing principal component analysis using a difference in absorbance at a plurality of wavelengths within a certain wavelength range of projection light to be used. Or the apparatus for determining the internal quality of fruits and vegetables according to 2 above. 5. The fruits and vegetables according to claim 1, wherein said support means has an opening at a lower portion thereof, and light emitted through said fruits and vegetables is received through said opening. Internal quality judgment device. 6. The apparatus according to claim 1, wherein said support means is a belt conveyor. 7. The interior of a fruit or vegetable according to claim 1, wherein the light emitting means emits light by changing the position of the light emitting means to give a time difference to different positions on the fruit or vegetable. Quality judgment device. 8. The fruit and vegetable according to claim 1, wherein the light projecting means emits light by changing a light projecting direction of the light projecting means to give a time difference to different positions on the fruit and vegetable. Internal quality judgment device. 9. Light is emitted by giving a time difference to different positions on the fruits and vegetables, and the projected lights receive light emitted through the fruits and vegetables, respectively, and each projection from each of the received lights is performed. Measuring the absorbance of the fruit or vegetable with respect to light, performing an operation to take the difference between the two absorbances measured by the light receiving means, and judging the internal quality of the fruit or vegetable based on the result of the computation. Quality judgment method.