JP2003083952A - Method and apparatus for selecting fruit and vegetables - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide fruit and vegetables selection method for estimating the relish period limit of fruit and vegetables only by one measurement, and to provide an apparatus for executing the method. SOLUTION: An operation means 11 for storing a modulus-of-elasticity change expression for indicating the change in a modulus-of-elasticity with time to the same kind of fruit and vegetables is allowed to predict the relish period limit of fruit and vegetables according to the modulus-of-elasticity when selecting the fruit and vegetables, and the modulus-of-elasticity where the fruit and vegetables can be relished.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for selecting fruits and vegetables and an apparatus for carrying out the method.

[0002]

2. Description of the Related Art The fruit and vegetable selection method is a method for selecting harvested vegetables and fruits, and is practiced by experience by hand at retail stores such as a production market, a wholesale market, a fruit and vegetable dealer, and a supermarket. Usually, marketable fruits and vegetables such as kiwifruit, melon, pear, tomato, apple, etc. are not eaten immediately after harvest, but edible (at the time of eating) after ripening for a certain period after harvest. Conventionally, as a method for determining the eating season of fruits and vegetables, as shown in Japanese Patent Laid-Open No. 19538/1999, a method of determining the ripeness of fruits and vegetables by pushing with a force that does not destroy the surface of the fruits and vegetables. Was known.

Further, focusing on the close relationship between the elastic modulus of fruits and vegetables and its maturity, the elastic modulus of fruits and vegetables was measured,
A method for determining when to eat fruits and vegetables has been proposed. For example, a method of calculating the elastic modulus of fruits and vegetables from E = f ² · m ^2/3 (E: elastic modulus, f: secondary resonance frequency, m: weight of fruits and vegetables) disclosed by Cooke et al. of ASASE,
15 (6): 1075-1080p), a method of determining the ripeness of fruits and vegetables is disclosed in Japanese Patent Laid-Open No. 11-18344.
It is proposed in Japanese Patent No.

[0004]

It is only the ripeness of the fruits and vegetables at the time of measurement that can be understood by measuring the hardness or elastic modulus of the surface of the fruits and vegetables in this way, and once measured,
It was not possible to predict when the fruits and vegetables would be ready for eating. Hereinafter, in this specification, the time when the fruits and vegetables are about to be eaten is referred to as the "best before" date.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a method of selecting fruits and vegetables capable of estimating the expiration date of fruits and vegetables by a single measurement, and an apparatus for carrying out the method. .

[0006]

To solve the above problems, the present invention utilizes the fact that the elastic modulus of fruits and vegetables decreases in accordance with a constant curve as time passes. The fruit and vegetable selection method according to the present invention is a mathematical expression of the relationship between the elastic modulus of fruit and time in advance, and by substituting the elastic modulus of the fruit and vegetables measured at the time of fruit selection in this mathematical expression, the change over time in the elastic modulus of the fruit and vegetables is calculated. It calculates and predicts the period until the fruits and vegetables are ready for eating, and tries to select fruits and vegetables based on this.

The first method for selecting fruits and vegetables according to the present invention is to measure the elastic modulus of fruits and vegetables at the time of fruit selection, and from the elastic modulus at the time of fruit selection and the elastic modulus at which the fruits and vegetables can be tasted, It is characterized in that the shelf life of the fruits and vegetables is predicted in accordance with an elastic modulus change expression representing a change in elastic modulus over time. That is, according to the method for selecting fruits and vegetables of the present invention, it is possible to predict the shelf life of fruits and vegetables by only selecting fruits and vegetables once.

More specifically, in the first method of ^selecting fruits and vegetables, the elastic modulus change equation is ^{expressed as follows:} Et = ^{Em.multidot.10-Bt for the} elastic modulus Em during fruit selection and the elastic modulus Et after a lapse of time t.
(However, B is preferably represented by an additional ripening temperature coefficient determined for the same type of fruits and vegetables).

In the first method of selecting fruits and vegetables, the temperature coefficient B for ripening is a function of the ripening temperature of fruits and vegetables,
It is preferable to set the additional temperature coefficient B so as to correspond to the additional temperature.

Further, in the first method of selecting fruits and vegetables,
The elastic modulus change equation can also be expressed by Et = Em · exp (−B′t) (where B ′ is the temperature coefficient of ripening defined for the same kind of fruits and vegetables).

In the first method of selecting fruits and vegetables, since the temperature coefficient B'of ripening is a function of the ripening temperature of fruits and vegetables,
It is preferable to set the additional temperature coefficient so as to correspond to the additional temperature.

The second method of selecting fruits and vegetables according to the present invention is to measure the same type of fruits and vegetables in advance and set the elastic modulus Er at the start of the seasoning and the elastic modulus E0 at the end of the season, and then the elastic modulus Em of the fruits and vegetables to be selected. Was measured, and Em was compared with Er and E0, and when fruits and vegetables were Er <Em, E0 ≦ E before the expiration period.
When m ≦ Er, during the best season, when Em <E0, it may be determined that the best season has expired, and fruits and vegetables may be selected.

A third method for selecting fruits and vegetables according to the present invention is to measure the same kinds of fruits and vegetables in advance and set the elastic modulus Er at the start of the seasoning and the elastic modulus E0 at the end of the seasoning to obtain the elastic modulus Em of the fruits and vegetables to be selected. Is compared with Er and E0, and when Er <Em, the taste start period t1 and / or the end season period t2 of the fruits and vegetables is t1 = (1 / B) · log.
(Em / Er), and / or t2 = (1 / B) · log
Calculated from (Em / E0), when E0 ≦ Em ≦ Er, the end-of-season period t2 of fruits and vegetables is t2 = (1 / B) · log
It is preferable to determine from (Em / Eo) and, when Em <E0, determine that the expiration date has expired and select fruits and vegetables. In this way, the shelf life of fruits and vegetables can be predicted quantitatively.

In the third method of selecting fruits and vegetables, the temperature coefficient B for ripening is a function of the ripening temperature of fruits and vegetables,
It is preferable to set the additional temperature coefficient B so as to correspond to the additional temperature.

According to a fourth method for selecting fruits and vegetables of the present invention, the elasticity modulus Er at the start of the seasoning and the elasticity modulus E0 at the end of the seasoning are measured in advance by measuring the fruits and vegetables of the same kind, and the elasticity modulus Em of the fruits and vegetables to be selected is Em. Is measured and Em is compared with Er and E0, and when Er <Em, the taste start period t1 or the end season period t2 of the fruits and vegetables is t1 = (1 / B ′) · ln (Em
/ Er) and / or t2 = (1 / B ') · ln (Em
/ E0), and when E0 ≦ Em ≦ Er, the end-of-life period t2 of the fruits and vegetables is t2 = (1 / B ′) · ln (Em
/ Eo), when Em <E0, it can be determined that the best-before period has expired, and fruits and vegetables can be selected (however, B ′
Is the temperature coefficient of ripening defined for the same type of fruits and vegetables).

Further, in the fourth method for selecting fruits and vegetables according to the present invention, the temperature coefficient B'of additional ripening is a function of the temperature of additional ripening of the fruits and vegetables, so that the temperature coefficient B of additional ripening corresponds to the temperature of additional ripening. It is preferable to set '.

In the first to fourth fruit and vegetable selection methods of the present invention, the elastic modulus measuring method detects the surface signal of the fruit and vegetables to which mechanical vibration of a variable frequency is applied as a vibration signal, and detects the vibration. Secondary resonance peak frequency f obtained from the signal
(Hz) and the weight of fruits and vegetables m (g), the elastic modulus Em (according to the following expression Em = f ² · m ^N (where N is in the range of ⅓ to 1 and set for fruits and vegetables of the same kind) Em ( dyne / cm
² ) is preferred.

Further, in the first to fourth fruit and vegetable selection methods of the present invention, it is preferable that the means for detecting the signal on the surface of the fruit and fruits detects the vibration by the laser Doppler method without contacting the fruits and vegetables.

An apparatus for carrying out the above-described fruit and vegetable selecting method is a fruit and vegetable selecting apparatus equipped with a calculating means for measuring the elastic modulus of the fruit and vegetables, and the elastic modulus change representing the temporal change of the elastic modulus of the same type of fruit and vegetables. It is characterized in that the arithmetic means, to which the formula is input, predicts the shelf life of the fruits and vegetables according to the elastic modulus change equation from the elastic modulus at the time of fruit selection and the elastic modulus at which the fruits and vegetables can be tasted. .

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION (Embodiment 1) The method for selecting fruits and vegetables according to Embodiment 1 of the present invention is to measure the elastic modulus of fruits and vegetables at the time of fruit selection, and to calculate the elastic modulus at the time of fruit selection. It predicts the elastic modulus of fruits and vegetables and displays the result. Since there is a close relationship between the elastic modulus of fruits and vegetables and the ripeness, predicting the elastic modulus after fruit selection will determine how long it will take for the fruits and vegetables to reach their ready-to-eat (best-before period) and the expiration date. You can predict how long it will take to reach the end of the shelf life. Note that the first embodiment is for selecting fruits and vegetables that have been aged after harvesting, and in the present specification, the ripening of fruits and vegetables after harvesting is particularly referred to as additional ripening, and the start of additional ripening means harvesting of fruits and vegetables. Shall mean time. Hereinafter, a method for predicting the time change of the elastic modulus of fruits and vegetables will be described.

Elastic modulus of fruits and vegetables E (× 10 ⁶ dyne / c
m ² ) can be calculated from the second-order resonance peak frequency f of the transfer function of fruits and vegetables, the weight (mass) m of fruits and vegetables, and the density σ of fruits and vegetables from the following known elastic modulus calculation formula. E = f ² · m ^2/3 · σ ^1/3 ... Equation (1)

In the above equation (1), the density σ of fruits and vegetables is close to 1 and is constant depending on the kind of fruits and vegetables, so the equation (1) can be simplified as follows. E = f ² · m ^2/3 Formula (2)

In the present embodiment, the elastic modulus of fruits and vegetables is calculated from the above equation (2), but the present invention is not limited to this. Hereinafter, another formula for calculating the elastic modulus of fruits and vegetables will be described. Equation (2) shows that the elastic modulus of fruits and vegetables changes in proportion to the 2/3 power of the weight of fruits and vegetables, but when the fruits and vegetables have almost the same weight, the elastic modulus of fruits and vegetables is proportional to their weight. Therefore, the elastic modulus of fruits and vegetables can be calculated more easily using the following known formula. E = f ² · m Equation (3) That is, when the variation in the weight of fruits and vegetables is small, Equation (3)
The error between the elastic modulus calculated from and the actual elastic modulus is so small that it can be practically ignored. Specifically, the weight is, for example, 20
The above formula (3) is particularly effective for fruits and vegetables in the range of 0 g to 300 g. Furthermore, for fruits and vegetables of the same type, N is set in the range of 1/3 to 1, and the following formula (2
The elastic modulus of fruits and vegetables may be obtained from ′). Em = f ² · m ^N ... Formula ( ² ′)

In order to obtain the secondary resonance peak frequency of the transfer function of fruits and vegetables, it is necessary to obtain the frequency response curve of fruits and vegetables in a predetermined frequency section. The frequency response curve is obtained as follows. First, a plurality of input frequencies are selected in a predetermined frequency section. Specifically, input frequencies are selected at appropriate frequency intervals in a predetermined frequency section. For example, in the first embodiment, the frequency section is set to 20
Hz to 3000 Hz and the frequency interval is 10 Hz, the input frequencies are 20, 30, 40. ． ． ． ． 29
70, 2980, 2990 and 3000 Hz. The fruits and vegetables are vibrated by the input vibration of each of the above frequencies. At this time,
The vibration of the surface of fruits and vegetables is detected as the output vibration, and the frequency response function for each input frequency is obtained from the input vibration and the output vibration. From the frequency response function for each input frequency thus obtained, the frequency response curve of fruits and vegetables in a predetermined frequency section is obtained.

When detecting the surface vibration of fruits and vegetables, in order to detect the surface vibration more accurately, it is preferable to detect the surface vibration by using, for example, a laser Doppler vibrometer without contacting the fruits and vegetables.

The weight of fruits and vegetables may be measured by known means.

In the first embodiment, fruits and vegetables are kiwi fruits, and a frequency response curve of the kiwi fruits is obtained.
FIG. 1 shows the frequency response curves of kiwifruit at immature, proper ripening, and overripe. It can be seen from FIG. 1 that some peaks of the resonance point appear in the frequency response curves of the kiwifruit at the time of immature, proper ripening, and overripe. Also,
As fruits and vegetables ripen, their weight does not change and the elastic modulus decreases. Therefore, from FIG. 1, the resonance peak that shifts to the lower frequency side as the fruits and vegetables ripen is the secondary resonance that is involved in the ripeness of the fruits and vegetables. It can be seen that it is the peak frequency.

As described above, when the kiwifruit is selected, the weight of the kiwifruit and the frequency of the secondary resonance peak of the frequency response curve of the kiwifruit are measured, and the secondary resonance peak frequency and the weight are calculated by the above formula ( By substituting in 2), the elastic modulus at the time of selecting the kiwifruit is derived.

Since the elastic modulus of kiwifruit decreases with time, (modulus before the shelf life)> (modulus during the shelf life)> (modulus after expiration of the shelf life). Therefore, when the kiwifruit reaches the ripening period, that is, the elastic modulus Er at the start of the season and when the expiration date reaches the end of the season, that is, the elastic modulus E0 at the end of the season, the elastic modulus of the kiwifruit at the time of selection is determined. By comparing Em with Er and E0, if Er <Em, the kiwifruit is before the shelf life, i.e. immature, and if E0 ≦ Em ≦ Er, the kiwifruit is during the shelf life and Em <E0 In that case, the kiwifruit is presumed to have expired.

That is, by comparing the elastic modulus Em of the kiwifruit at the time of selection with the previously determined Er and E0, whether the selected kiwifruit is in the immature state or during the shelf life, Alternatively, it can be determined whether the expiration date has expired.

Furthermore, by plotting the elapsed time from the time of harvest of kiwifruit and the elastic modulus of kiwifruit on a graph, a curve showing the relationship between time and elastic modulus can be obtained as shown in FIG. It can be seen from FIG. 2 that the elastic modulus of kiwifruit decreases with time according to a constant curve. The curve in FIG. 2 can be expressed by the following elastic modulus as a time change of the elastic modulus E of kiwifruit. Et = En × 10 ^−Bt Formula (4) In Formula (4), En represents the elastic modulus of kiwifruit at the start of additional ripening, that is, at the time of harvest, and t is the elapsed time from the start of additional ripening (however, additional At the beginning of ripening), B indicates a coefficient (hereinafter, B is referred to as an additional aging temperature coefficient), and Et indicates kiwi when an arbitrary time t has elapsed from the beginning of additional ripening. The elastic modulus of fruit is shown.

Next, the equation (4) will be examined. FIG. 3 shows the temperature coefficient B of additional ripening when the peripheral temperature of the kiwifruit is kept constant at 20 ° C. and the kiwifruit having various elastic moduli is additionally ripened. From FIG. 3, the temperature coefficient B of additional ripening does not depend on the elastic modulus of kiwifruit and is 0.07 (1 /
It can be seen that it is almost constant with (day). Therefore, in the above formula (4), it is not necessary to limit En to the elastic modulus of the kiwifruit at the start of additional ripening.
Is the elastic value Em of the kiwifruit measured at the time of fruit selection after harvesting, and the time elapsed from the time of fruit selection is t, the above equation (4) can be modified as follows. Et = Em × 10 ^−Bt Equation (5)

When the above formula (5) is used, kiwifruit is selected at any time after harvesting, and the elastic modulus at the time of selection is calculated, so that kiwifruit at an arbitrary time after selection is obtained. The elastic modulus of can be predicted.

When the selected kiwifruit is immature, that is, the elastic modulus Em at the time of selecting the kiwifruit and the elastic modulus Er of the kiwifruit at the start of the expiration period are compared.
In the case of r <Em, Er = ^Em10-Bt1 (6) is established, where t1 is the predicted start time, that is, the estimated time from the selection of kiwifruit to the start of the taste. By modifying the above equation (6) as follows, the taste start period t1 can be calculated. t1 = (1 / B) * {Log (Em / Er)} ... Formula (6 ')

When the selected kiwifruit is immature or during the savory period, that is, the elastic modulus Em of the kiwifruit at the time of scavenging is calculated as follows: Compared with the elastic modulus E0, Er <
When Em or E0 ≦ Em ≦ Er, E0 = Em · 10 ^−Bt2 (Equation 7) is established, where t2 is the estimated end time period from the selection of kiwifruit to the end of the ^season . . By modifying the above equation (7) as follows, the end of taste period t2 can be calculated. t2 = (1 / B) · {Log (Em / E0)} ... Expression (7 ′)

The kiwifruit selected in the first embodiment is ripened for 4 days in an environment where the ambient temperature is constant at 20 ° C. The temperature coefficient of additional ripening of such kiwifruit was B = 0.07 (1 / day).

When the relationship between the aging state of the kiwifruit and the elastic modulus was examined in detail, the elastic modulus of the unripe kiwifruit was 15 × 10 ⁶ to 70 × 10.
⁶ (dyne / cm ² ) and suitable ripe fruit (during the shelf life)
Kiwifruit has an elastic modulus of 5 × 10 ⁶ to 15 × 10
⁶ (dyne / cm ² ) and the elastic modulus of overripe (expired) kiwifruit is 5 × 10 ⁶ (dyn).
e / cm ² ) or less. Therefore, the elastic modulus Er of the kiwi fruit at the start of the shelf life is 15 × 10 ⁶ (dyn
e / cm ² ) and the elastic modulus E0 of the kiwifruit at the end of the shelf life is 5 × 10 ⁶ (dyne / cm ² ).

Er = 15 × 10 ⁶ (dyne / cm ² ).
By substituting B and 0.07 (1 / day) into the above equation (6 ′), the taste start period t1 can be specifically derived as follows. t1 = (1 / 0.07) · {Log ((35 × 10 ⁶ )
/ (15 × 10 ⁶ ))} = 5.26 (day)

That is, according to the first embodiment, 5.26 days after selection of kiwifruit (after 9.26 days after harvest).
It is predicted that kiwifruit will be ready to eat (see Fig. 2).

Further, E0 = 5 × 10 ⁶ (dyne / cm
² ) Therefore, by substituting this numerical value into the formula (7 ′), the end-of-beverage period t2 can be quantitatively derived as follows. t2 = (1 / 0.07) · {Log ((35 × 10 ⁶ ) /
(5 × 10 ⁶ ))} = 12.07 (day)

That is, according to the first embodiment, it is predicted that the seasoning period of the kiwifruit will be finished 12.07 days after the selection (16.07 days after the harvest) (see FIG. 2).

Next, with reference to FIG. 4, a fruit and vegetable selecting apparatus 20 for executing the above-described fruit and vegetable selecting method will be described.
The fruit and vegetable sorting apparatus 20 includes a weight scale 3 for measuring the weight of the fruits and vegetables 2, a vibration generator 4 which is a vibration source for vibrating the fruits and vegetables 2 by applying an input vibration of a desired frequency to the fruits and vegetables 2, and detecting the input vibrations. It includes a vibration detection means 5, a laser Doppler vibrometer 1 for detecting the vibration of the surface of the fruits and vegetables 2 as output vibration, a microprocessor 11 as an arithmetic means, and a display device 12 for displaying the determination result of the selected fruits and vegetables. .

The weighing scale 3 is connected to the microprocessor 11, and the measured weight data of the fruits and vegetables 2 is input to the microprocessor 11. Vibration generator 4 is fruits and vegetables 2
Is mechanically connected to the pedestal 6 on which the. The vibration generator 4 is composed of, for example, a permanent magnet and an electromagnetic coil, converts an input electric signal into mechanical vibration, and conducts vibration of a desired frequency as input vibration to the fruits and vegetables 2 on the pedestal 6. The input vibration signal is the microprocessor 11
Is output at each set frequency from the signal generator 8 connected to, is amplified by the power amplifier 7, and is then input to the vibration generator 4 as a vibration signal.

The vibration detecting means 5 is provided on the gantry 6 and is composed of, for example, an acceleration sensor or the like. Also, the vibration detection means 5
Detects the input vibration applied to the fruits and vegetables 2, and outputs the detected input vibration to the FFT (Fast Fourier Transform) means 10.

The laser Doppler vibrometer 1 is arranged directly above the fruits and vegetables 2 placed on the pedestal 6, and detects the vibration of the surface of the fruits and vegetables 2 as output vibration without contact of the fruits and vegetables 2. Specifically, the speed at which the surface of the fruits and vegetables 2 vibrates is detected as a beat signal, and the detected beat signal is input to the demodulator 9. The beat signal is proportional to the speed at which the surface of the fruits and vegetables 2 vibrates. Further, the demodulator 9 converts the beat signal from the laser Doppler vibrometer 1 into an output vibration signal and inputs the output vibration signal to the FFT 10.

The surface vibration of the fruits and vegetables 2 is preferably detected by the laser Doppler vibrometer 1 without touching the fruits and vegetables 2. However, the present invention is not limited to this, and the surface vibration of the fruits and vegetables 2 may be detected. May be detected.

Next, using the fruit and vegetable selecting device 20 described above,
A method for selecting fruits and vegetables 2 will be described. Before selecting fruits and vegetables, the microprocessor 11 stores the elastic modulus Er at the start of the seasoning of the fruits and vegetables, the elastic modulus E0 at the end of the season and the elastic modulus change equation representing the temporal change of the elastic modulus of the fruits and vegetables. First, put fruits and vegetables 2 on the scale 3 and
Is measured and the measured weight data is input to the microprocessor 11. Next, after placing the fruits and vegetables 2 on the pedestal 6, the control signal from the microprocessor 11 causes the signal generator 8 to generate the minimum frequency (2 in the first embodiment).
A sine wave of 0 Hz) is generated. This sine wave is sent to the vibration generator 4 as a vibration signal via the power amplifier 7. The vibration signal causes the vibration generator 4 to vibrate the surface of the fruit 2 placed on the pedestal 6. The vibration applied to the fruits and vegetables 2 is detected as an input vibration signal by the vibration detection means 5, and the detected input vibration signal is input to the FFT 10. At the same time, the surface vibration of the fruits and vegetables 2 is detected as an output vibration signal by the laser Doppler vibrometer 1, and the detected output vibration signal is FF through the demodulator 9.
Input to T10. In the FFT 10, the output vibration signal from the demodulator 9 and the input vibration signal from the vibration detecting means 5 are respectively subjected to fast Fourier transform, and then output to the microprocessor 11. In the microprocessor 11, the converted output vibration signal. From the input vibration signal and the input vibration signal, the frequency response function (transfer function) for the minimum frequency is calculated.

Then, the control signal from the microprocessor 11 causes the signal generator 8 to generate a sine wave having a frequency higher than the minimum frequency, and the frequency response function for this frequency is obtained by the above-described method. Thus, between the minimum frequency and the maximum frequency (in the first embodiment,
20 to 30000 Hz), a plurality of sine waves having different frequencies are generated at appropriate frequency intervals in the signal generator 8 and a frequency response function for each frequency is calculated. In this way, the frequency response curve of fruits and vegetables between the minimum frequency and the maximum frequency is calculated, and the frequency of the secondary resonance peak of this curve is obtained.

Next, the frequency of the secondary resonance peak is input to the microprocessor 11. By substituting the frequency of the secondary resonance peak and the weight of the fruits and vegetables 2 previously input into the elastic modulus calculation formula, the fruits and vegetables 2 are calculated. The elasticity value at the time of selecting is calculated. From the elasticity value when fruit and vegetables 2 were selected, the time change of the elasticity value is predicted.

A method of calculating the elasticity value of fruit and vegetables 2 at the time of fruit selection from the frequency of the secondary resonance peak and the weight of the fruit and vegetables 2, and the time change of the elasticity value is predicted from the elasticity value of the fruit and vegetables 2 at the time of fruit selection. , The method of calculating the predicted time from the selection of fruits and vegetables to the start of the expiry period, the method of calculating the predicted time from the selection of fruits and vegetables to the end of the expiry period is the same as described above. is there. Further, the calculated estimated time and the like are displayed on the display device 12.

Since the fruit and vegetable selecting apparatus 20 employs the fruit and vegetable selecting method according to the first embodiment, the time change of the elastic modulus of the fruit and vegetables can be accurately predicted, and how much time is required until the fruits and vegetables are ready to be eaten. As such, it is possible to accurately predict when the expiration date is.

(Embodiment 2) The method of selecting fruits and vegetables according to the above-mentioned Embodiment 1 is as follows: E = Em × 10 ^{−
In Bt} , the temperature coefficient B of ripening is 0.07 (1 / da
As y), which predicts the change in elastic modulus of fruits and vegetables with time, when the change in the elastic modulus of kiwifruit with respect to time is verified, the temperature coefficient B for ripening of the above formula (5) shows that It was found that the temperature changes depending on the temperature. In the fruit and vegetable selection method according to the second embodiment of the present invention, in order to more accurately predict the time change of the elastic modulus of the fruit and vegetables, the ripening temperature coefficient B is set so as to correspond to the temperature at which the fruits and vegetables are ripened. It is characterized by doing.

Hereinafter, the method of selecting fruits and vegetables according to the second embodiment will be described. First, the correlation between the temperature for additional ripening of fruits and vegetables and the additional ripening temperature coefficient B is obtained. Next, the additional temperature coefficient B1 at the temperature at which the fruits and vegetables are about to be added is calculated from the correlation.

In the second embodiment, for example, kiwi fruit ripened at a constant ambient temperature of 15 ° C. is selected. When the correlation between the temperature for ripening kiwifruit and the temperature coefficient for ripening was determined, it was in a direct proportion relationship as shown in FIG. From FIG. 4, the additional temperature coefficient B1 at 15 ° C., which is the temperature at which the kiwi fruit is added, is 0.05
It can be seen that it is (1 / day).

Then, in the same manner as in the first embodiment,
It is possible to calculate the elastic modulus Em of the kiwifruit at the time of selection, and obtain the time change of the elastic modulus of the kiwifruit ripened at 15 ° C. from E = Em × 10 ^−0.05t (Equation 8). . Further, by transforming the equation (8) into the following, the predicted time t1 required from the selection of the kiwi fruit to the start of the season of the kiwi fruit and the taste of the kiwi fruit from the selection of the fruit are the same as in the first embodiment. The predicted time t2 required to reach the end of the period can be calculated. t1 = (1 / 0.05) * {Log ((Em) / (Er))} ... Equation (9) t2 = (1 / 0.05) * {Log ((Em) / (E0))} ... Formula (10)

According to the method for selecting fruits and vegetables according to the second embodiment, by setting the additional ripening temperature coefficient B1 in accordance with the temperature for ripening the fruits and vegetables, the time change of the elastic modulus of the fruits and vegetables can be more accurately predicted. However, it is possible to more accurately predict how long it will take to eat fruits and vegetables and when the expiration date will be.

Next, with reference to FIG. 6, a description will be given of the fruit and vegetable selecting apparatus 21 which adopts the fruit and vegetable selecting method according to the second embodiment. The fruit and vegetable selecting device 21 is characterized by having a temperature input means 13 for inputting a temperature for ripening fruits and vegetables into the microprocessor 11. The procedure is the same as that of the fruit and vegetable selecting apparatus 20 according to the first embodiment, except that the temperature for ripening the fruits and vegetables is input to the microprocessor 11.

Next, using the fruit and vegetable selecting device 21 described above,
A method of selecting fruits and vegetables 2 to be ripened at an arbitrary temperature T will be described. The method of obtaining the elastic modulus Em of the fruits and vegetables 2 at the time of fruit selection from the weight of the fruits and vegetables 2 and the frequency of the secondary resonance peak of the transfer function of the fruits and vegetables 2 is the same as in the first embodiment. Next, the temperature T for ripening the fruits and vegetables 2 is input to the microprocessor 11, and from the correlation of the ripening temperature and the ripening temperature rate coefficient obtained in advance, the microprocessor 11
Sets the ripening temperature rate coefficient B1 corresponding to the temperature T, and predicts the time change of the elastic modulus of the fruit and vegetables 2 to be ripened at an arbitrary temperature T from E = Em × 10 ^−B1t (Equation 9). The method of calculating the predicted time from the selection of fruits and vegetables to the start of the expiration period, and the method of calculating the predicted time from the selection of fruits and vegetables to the end of the expiration period are the same as described above. . Also,
The calculated estimated time and the like are displayed on the display device 12.

Since the fruit and vegetable selecting apparatus 21 employs the fruit and vegetable selecting method according to the second embodiment, the time change of the elastic modulus of the fruit and vegetables is accurately predicted, and how much time is required until the fruits and vegetables are ready for eating. As such, it is possible to accurately predict when the expiration date is.

Further, in the above-mentioned embodiment, the temporal change of the elastic modulus of fruits and vegetables was obtained from Et = En × 10 ^−Bt , but the present invention is not limited to this, and the following equation is used. You may ask for the time change of the elastic modulus of fruits and vegetables. Et = Em * exp (-B't) ... Formula (10) However, let B'be an additional temperature coefficient. In this case, the season start period t1 and the end season period t2 are derived from the following equations. t1 = (1 / B ') * {ln (Em / Er)} ... Equation (11) t2 = (1 / B') * {ln (Em / E0)} ... Equation (12)

[0061]

As described above, according to the fruit and vegetable selection method of the present invention, the elastic modulus at the time of fruit and vegetable selection is measured,
It is possible to predict the shelf life of fruits and vegetables by using the elastic modulus change expression that represents the temporal change in the elastic modulus of the same type of fruits and vegetables. That is, by selecting fruits and vegetables once, it is possible to predict a temporal change in the ripeness of the fruits and vegetables.

Further, in the method for selecting fruits and vegetables according to the present invention,
The elastic modulus change formula is Et = Em · 10 ^−Bt or Et = E
By setting m · exp (−B′t), the elastic modulus of fruits and vegetables can be accurately measured.

Further, in the method of selecting fruits and vegetables according to the present invention, since the temperature coefficient B for ripening is a function of the ripening temperature of fruits and vegetables, the temperature coefficient B for ripening should be set so as to correspond to the ripening temperature. Thus, the elastic modulus of fruits and vegetables can be measured more accurately.

According to the method of selecting fruits and vegetables of the present invention, the elastic modulus Er at the start of the taste and the elastic modulus E0 at the end of the taste are set to be measured in advance and the elastic modulus Em of the fruits and vegetables to be selected Em is set. By measuring and comparing Em with Er and E0, fruits and vegetables can be selected.

According to the method for selecting fruits and vegetables of the present invention, the elastic modulus Er at the beginning of the season and the elastic modulus E0 at the end of the season are set to be measured in advance and the elastic modulus Em of the fruits and vegetables to be selected Em is set. Is measured and Em is compared with Er and E0, so that the season start period t1 and / or the end season period t2 of fruits and vegetables can be predicted.

In the method of selecting fruits and vegetables according to the present invention, the surface signal of fruits and vegetables is detected as a vibration signal, and the secondary resonance peak frequency f (Hz) obtained from the detection signal and the weight m (g) of fruits and vegetables are used to determine Em. = F ² · m ^N , the elastic modulus Em can be accurately obtained.

Furthermore, in the method of selecting fruits and vegetables of the present invention, the laser Doppler method is used as the means for detecting the signal on the surface of the fruits and vegetables, so that the vibration can be detected without contacting the fruits and vegetables, so that the fruits and vegetables can be accurately detected. The elastic modulus of can be calculated.

According to the fruit and vegetable selecting apparatus of the present invention, it is provided with a calculating means for measuring the elastic modulus of the fruit and fruits, and the calculating means is based on the elastic modulus at the time of fruit selection and the sensible elastic modulus of the fruit and fruits. According to the elastic modulus change equation, the shelf life of the fruits and vegetables can be predicted, and the shelf life of the fruits and vegetables can be predicted by only selecting the fruits and vegetables once.

[Brief description of drawings]

FIG. 1 shows frequency response curves of kiwifruit at unripe, proper and overripe.

FIG. 2 shows the diurnal change in the elastic modulus of kiwifruit when the kiwifruit is ripened at a constant ambient temperature of 20 ° C.

FIG. 3 shows the relationship between the elastic modulus and the temperature coefficient of ripening when kiwifruits having different elastic moduli are ripened at a constant ambient temperature of 20 ° C.

FIG. 4 shows the relationship between the temperature for ripening kiwifruit and the temperature coefficient for ripening.

FIG. 5 is a block diagram of the fruit and vegetable selecting apparatus according to the first embodiment of the present invention.

FIG. 6 is a block diagram of a fruit and vegetable selecting device according to a second embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Laser Doppler vibrometer, 2 ... Fruits and vegetables, 3 ... Weight scale, 4 ... Vibration generator, 5 ... Vibration detection means, 6 ... Stand, 7
... power amplifier, 8 ... signal generator, 9 ... demodulator, 10 ... F
FT, 11 ... Microprocessor, 12 ... Display device,
13 ... Temperature input means, 20, 21 ... Fruit and vegetable selecting device.

Claims (24)

[Claims] 1. The elastic modulus at the time of fruit selection of fruits and vegetables is measured, and the temporal change in the elastic modulus of the same kind of fruits and vegetables is expressed from the elastic modulus at the time of fruit selection and the elastic modulus at which the fruits and vegetables can be tasted. A method for selecting fruits and vegetables, which comprises predicting a shelf life of the fruits and vegetables according to an elastic modulus change formula. 2. The elastic modulus change equation is defined as follows: Et = Em · 10 ^−Bt (where B is the same kind of fruits and vegetables) in terms of the elastic modulus Em at the time of selection and the elastic modulus Et after a lapse of time t. The method of selecting fruits and vegetables according to claim 1, which is represented by a temperature coefficient of additional ripening. 3. The ripening temperature coefficient B is a function of the ripening temperature of the fruits and vegetables, and the ripening temperature coefficient B is set so as to correspond to the ripening temperature. The method for selecting fruits and vegetables described. 4. The elastic modulus change equation is expressed by the following equation, where Et = Em · exp (−B′t) (where B ′ is the same kind) with respect to the elastic modulus Em at the time of selection and the elastic modulus Et after a lapse of time t. 2. The method for selecting fruits and vegetables according to claim 1, which is represented by the temperature coefficient of additional ripening defined for the fruits and vegetables. 5. The ripening temperature coefficient B ′ is a function of the ripening temperature of the fruits and vegetables, and the ripening temperature coefficient B ′ is set so as to correspond to the ripening temperature. Item 4. A method for selecting fruits and vegetables according to item 4. 6. An elastic modulus Er at the start of seasoning and an elastic modulus E0 at the end of seasoning of the same kind of fruits and vegetables are preliminarily measured and the elastic modulus Em of the fruits and vegetables to be selected is measured, and Em is Er and E0. Compared with
When m, before the expiry period, when E0 ≦ Em ≦ Er, during the expiry period, when Em <E0, it is determined that the expiry period has expired, and the fruits and vegetables are selected. 7. An elastic modulus Er at the start of the seasoning and an elastic modulus E0 at the end of the season are set for the same type of fruits and vegetables in advance, and the elastic modulus Em of the fruits and vegetables to be selected is measured to obtain Em and Er0. Compared with, when Er <Em, the taste start period t1 and / or the end season period t2 of the fruits and vegetables are t1 = (1 / B) · log (Em / Er) and / or t2 = (1 / B) · log (Em / E0), and when E0 ≦ Em ≦ Er, the end-of-life period t of the above-mentioned fruits and vegetables
2 is obtained from t2 = (1 / B) · log (Em / Eo), and when Em <E0, it is determined that the best-before period has expired and the above-mentioned fruits and vegetables are selected. However,
B is the additional ripening temperature coefficient defined for the same type of fruits and vegetables). 8. The ripening temperature coefficient B is a function of the ripening temperature of fruits and vegetables, and the ripening temperature coefficient B is set so as to correspond to the above ripening temperature. Selection method. 9. An elastic modulus Er at the start of seasoning and an elastic modulus E0 at the end of seasoning are measured in advance for the same type of fruits and vegetables, and the elastic modulus Em of fruits and vegetables to be selected is measured. Compared with, when Er <Em, the taste start period t1 and / or the end season period t2 of the fruits and vegetables are t1 = (1 / B ′) · ln (Em / Er) and / or t2 = ( 1 / B ′) · ln (Em / E0), and when E0 ≦ Em ≦ Er, the end-of-life period t of the fruit and vegetables
2 is obtained from t2 = (1 / B ′) · ln (Em / Eo), and when Em <E0, it is determined that the best-before period has expired, and the fruits and vegetables are selected. (However,
B'is the additional ripening temperature coefficient defined for the same type of fruits and vegetables). 10. The ripening temperature coefficient B ′ is a function of the ripening temperature of fruits and vegetables, and the ripening temperature coefficient B ′ is set so as to correspond to the above ripening temperature. How to select fruits and vegetables. 11. A method of measuring the elastic modulus, wherein a surface signal of fruits and vegetables to which mechanical vibration having a variable frequency is applied is detected as a vibration signal, and a secondary resonance peak frequency f (Hz) obtained from the detection signal is obtained. From the weight m (g) of fruits and vegetables,
Elastic modulus Em (dyne / cm) according to the following equation Em = f ² · m ^N (where N is set in the range of 1/3 to 1 for fruits and vegetables of the same kind).
² ) The method for selecting fruits and vegetables according to any one of claims 1 to 10, which is a method for obtaining. 12. The method of selecting fruits and vegetables according to claim 11, wherein the means for detecting the signal on the surface of the fruits and vegetables detects the vibration by the laser Doppler method without contacting the fruits and vegetables. 13. A fruit and vegetable selecting apparatus comprising a calculating means for measuring the elastic modulus of fruits and vegetables, wherein the calculating means stores an elastic modulus change expression representing a temporal change of the elastic modulus of the same kind of fruits and vegetables. A fruit and vegetable selecting apparatus, which predicts a shelf life of the fruit and vegetables according to the elastic modulus change formula from the elastic modulus at the time of fruit selection and the elastic modulus at which the fruit and vegetables can be tasted. 14. The elastic modulus at the time of fruit selection E
^{14. The} selection of fruits and vegetables according to claim 13, wherein m and the elastic modulus Et after the lapse of time t are represented by Et = Em · 10 ^−Bt (where B is a temperature coefficient of ripening defined for fruits and vegetables of the same kind). Fruit device. 15. The ripening temperature coefficient B is a function of the ripening temperature of the fruits and vegetables, and the calculating means sets the ripening temperature coefficient B so as to correspond to the ripening temperature. The fruit and vegetable sorting apparatus according to claim 14. 16. The elastic modulus E at the time of fruit selection
Regarding m and the elastic modulus Et after the lapse of time t, Et = Em · exp (−B′t) (where B ′ is the temperature coefficient of ripening defined for fruits and vegetables of the same type). 13. The fruit and vegetable sorting apparatus according to 13. 17. The ripening temperature coefficient B ′ is a function of the ripening temperature of fruits and vegetables, and the calculating means sets the ripening temperature coefficient B ′ so as to correspond to the ripening temperature. The fruit and vegetable sorting apparatus according to claim 16. 18. A fruit and vegetable selecting apparatus comprising a calculation means for measuring the elastic modulus of fruits and vegetables, wherein the elastic modulus Er of the same type of fruits and vegetables measured at the start is pre-measured.
And the elastic modulus E0 at the end of the season is stored, the arithmetic means measures the elastic modulus Em of the fruits and vegetables to be selected, compares Em with Er and E0, and when the above fruits are Er <Em, the shelf life is Before, when E0 ≦ Em ≦ Er, during the best-before period, when Em <E0, it is determined that the best-before period has expired, and the above-mentioned fruits and vegetables selecting device is characterized. 19. A fruit and vegetable selecting apparatus comprising a calculating means for measuring the elastic modulus of fruits and vegetables, wherein the elastic modulus Er of the same type of fruits and vegetables measured in advance at the start of taste is Er.
And the elastic modulus E0 at the end of the season is stored, the arithmetic means measures the elastic modulus Em of the fruits and vegetables to be selected, compares Em with Er and E0, and sets the above fruits and vegetables Er <Em.
At the time, the taste start period t1 and / or the end season period t2 of the fruits and vegetables are t1 = (1 / B) · log (Em / Er), and / or t2 = (1 / B) · log (Em / E0 ), When E0 ≦ Em ≦ Er, the end-of-life period t of the above-mentioned fruits and vegetables
2 is obtained from t2 = (1 / B) · log (Em / Eo), and when Em <E0, it is determined that the expiration date has expired, and the above-mentioned fruits and vegetables are selected. However,
B is the temperature coefficient of additional ripening defined for the same fruits and vegetables). 20. The ripening temperature coefficient B is a function of the ripening temperature of the fruits and vegetables, and the calculating means sets the ripening temperature coefficient B so as to correspond to the ripening temperature. The fruit and vegetable sorting apparatus according to claim 19. 21. A fruit and vegetable selecting apparatus comprising a calculating means for measuring the elastic modulus of fruits and vegetables, wherein the elastic modulus Er of the same type of fruits and vegetables measured in advance at the start of taste is Er.
And the elastic modulus E0 at the end of the season is stored, the arithmetic means measures the elastic modulus Em of the fruits and vegetables to be selected, compares Em with Er and E0, and sets the above fruits and vegetables Er <E.
When m, the taste start period t1 and / or the end season period t2 of the fruits and vegetables are: t1 = (1 / B ′) · ln (Em / Er), and / or t2 = (1 / B ′) · ln (Em / E0), and when E0 ≦ Em ≦ Er, end-of-life period t2 of fruits and vegetables
Is obtained from t2 = (1 / B ′) · ln (Em / Eo), and when Em <E0, it is determined that the expiration date has expired and the above-mentioned fruits and vegetables are selected. However,
B'is the temperature coefficient of additional ripening defined for the same fruits and vegetables). 22. The ripening temperature coefficient B ′ is a function of the ripening temperature of the fruits and vegetables, and the computing means sets the ripening temperature coefficient B ′ so as to correspond to the ripening temperature. 22. The fruit and vegetable sorting apparatus according to claim 21. 23. The fruit and vegetable selecting device comprises a weighing scale for measuring the weight of the fruit and vegetables, a vibrating means for applying a mechanical vibration of a variable frequency to the fruits and vegetables, and a surface vibration of the fruits and vegetables to which the mechanical vibration is applied. A vibration detecting means for detecting is provided, and the calculating means uses the following expression Em = f ² · m ^N (however, from the secondary resonance peak frequency f (Hz) obtained from the surface vibration and the weight m (g) of fruits and vegetables. N is in the range of 1/3 to 1 and is set for fruits and vegetables of the same kind), and the elastic modulus Em (dyne / cm)
² ) The fruit / fruit selecting apparatus according to any one of claims 13 to 23, wherein: 24. The fruit and vegetable selecting apparatus according to claim 23, wherein the vibration detecting means is a laser Doppler vibrometer.