JPH0829338A - Freshness evaluation apparatus for green vegetables - Google Patents

Abstract

PURPOSE:To estimate the number of days in which green vegetables will droop or green vegetables can be stored in a fresh state by measuring the sugar content and moisture content of green vegetables and storing and operating a table or relational expression estimating the limit number of days before generating drooping as the number of days possible to store the green vegetables. CONSTITUTION:The item of green vegetables is specified in an input part 19. Next, a part of green vegetables is placed on the reflecting plate 5 of a measuring sample part 6 and a measuring part 9 is fitted to the measuring sample part 6. When green vegetables are pressed by cover glass 10, detection accuracy can be enhanced. The wavelength within a predetermined near infrared region of the light emitted from a light source 11 is continuously obtained by the inclination of a diffraction lattice 14 and the light passes through an optical fiber 3 to irradiate the measuring sample part 6. The reflected light is detected by light quantity detectors 8, 8 and the signals of the detectors are inputted to a control part 17. A calibration curve is called out at every item in the control part 17 to calculate sugar and moisture contents. The number of days possible to store is derived from the sugar and moisture contents to be displayed on a display part 20 by a control part 17.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for evaluating freshness of leaf vegetables.

[0002]

2. Description of the Related Art Conventionally, the problems to be solved by the invention
The freshness evaluation of leafy vegetables such as cabbage and spinach was judged sensuously by looking at the appearance, especially the degree of wilting. Especially, in the production area, leaf vegetables are pre-cooled and shipped at a predetermined product temperature, but moisture evaporation occurs during pre-cooling, and the shelf life of the pre-cooled products varies.

On the other hand, it is known that the sugar content such as sucrose and glucose contained in leafy vegetables or the water content affects the number of days of wilting (FIGS. 5 and 6). That is, it is expected that sugar content of leaf vegetables will suppress fungal activity and prevent spoilage,
Alternatively, freshness can be maintained if the water content is kept above a certain level, but the present condition is that the number of days of storage is not controlled by such components.

[0004]

Therefore, according to the present invention, means for measuring the sugar content C and the water content M of leaf vegetables are provided.
Means for storing a table or a relational expression for predicting, as the storable days y, the limit number of days at which wilting occurs from the sugar content and the water content of the target item, and the storage means for receiving the measurement signal of the sugar content and the water content. The leaf-freshness evaluation apparatus is composed of a control means for calculating the storable days derived from the above and an output means for outputting the calculation result to a display means or the like.

[0005]

EFFECTS OF THE INVENTION By determining the sugar content C and the water content M of leaf vegetables and knowing the sugar content and the water content of the target leaf vegetables, it is possible to determine how many days (hours) the leaves will be withered. It is possible to predict whether or not it can be stored without shrinking, so it is possible to judge the utility value thereafter.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. The apparatus includes a measurement mechanism unit 1, a spectroscopic analysis mechanism unit 2, and an optical fiber 3 connected between them. Of these, the measurement unit 1 is a dish-shaped measurement sample unit 6 in which an elastic material 4 such as a sponge is fitted and a reflection plate 5 such as ceramic is arranged on the upper surface thereof, and a central portion is formed in a measurement space 7. , One end of the optical fiber 3 is connectable to the upper surface, and the light amount detectors 8 are disposed on the left and right inner surfaces to form a measuring unit 9. A cover glass 10 is provided on the lower surface of the measuring unit 9, and leaf vegetables as a sample are placed on the reflection plate 5 of the measurement sample unit 6, and the measurement unit 9 is fitted and pushed to remove the leaf vegetables. 5 and the cover glass 10 are pressed against each other while being bent by the elastic member 4 to be in a substantially flat state.

The spectroscopic analysis unit 2 includes a light source 11 and a reflecting mirror 1.
2. The diffraction grating 14 and the like which are supported by the shaft of the motor 13 and rotate in a predetermined manner. The other end of the optical fiber 3 is connected to the spectroscopic analysis section 2, and near-infrared light adjusted to a predetermined wavelength is irradiated onto leaf vegetables through the optical fiber 3. The measurement signals of the light quantity detectors 8 and 8 are supplied to the amplifier 15 and A / D.
The configuration is such that it is input to the control unit 17 via the converter 16.
The storage unit 18 connected to the control unit 17 stores a predetermined wavelength λ
A calculation formula (calibration curve) for calculating the water content M and the sugar content C contained in the leaf vegetable to be measured by processing the absorbance of is stored. For example, M = k ₁ + k ₂ OD (λ ₁ ) + k ₃ OD (λ ₂ ) C = k ₄ + k ₅ OD (λ ₃ ) + k ₆ OD (λ ₄ ). OD (λ _j ) is the absorbance at the wavelength λ _j .

Further, the storage unit 18 stores the following contents. That is, for each item to be measured, a relational expression is established using the sugar content C, the water content M, and the storable days y, and this is set and stored. If one example of the relational expression is shown, y = −a (9
2-M) + b. a and b are values determined by the sugar content C. The values of a and b are, for example, a = 5 (C + 1) /
6, b = 10 (C + 1) / 3 (FIGS. 3 and 4).

A graph of the above relational expression is shown in FIG. In a graph in which the horizontal axis is the water content M and the vertical axis is the storable days y, find out how much storage (the number of days at normal temperature until wilting) is possible in relation to the water content M for each different sugar content C. You can Reference numeral 19 is an input unit for inputting items and the like, and 20 is a display unit.

The operation of the above example will be described. With respect to the leaf vegetables after harvest, the item is designated by the input unit 19. Then, a part of the leaf vegetables is placed on the reflection plate 5 of the measurement sample section 6,
The measuring unit 9 is fitted. The cover glass 10 presses the leaf vegetables, so that the measurement target can be adjusted to a substantially flat surface, which contributes to the improvement of the detection accuracy of the irradiation light. The light emitted from the light source has a predetermined wavelength in the near-infrared region continuously obtained due to the inclination of the diffraction grating 14, and these lights pass through the optical fiber 3 and are applied to the leaf vegetables of the measurement sample portion 6. The reflected light with which the measurement sample is irradiated is detected by the light amount detectors 8, 8 and converted into an electric signal and input to the control unit 17. Here, the calibration curve for each item stored in advance is called, and the sugar content C and the water content M in the sample are calculated.

The control unit 17 subsequently derives the storable days y from the sugar content C and the water content M. For example, assuming that the water content is 91% and the sugar content is 4%, the coefficient a = 20.
/ 6, the coefficient b = 50/3, and the number of storable days y≈
It becomes 13.3. Therefore, the control unit 17 outputs to the display unit 20 so as to display "the storage is possible for about 13 days". In this way, the following treatment is carried out by measuring the sugar content C and the water content M which affect the freshness of leaf vegetables. In other words, by sorting by the number of days that can be stored and shipping, the freshness (shelf life) can be stabilized and made uniform. Further, the freshness can be maintained by changing the storage condition for each sorting and controlling the precooling conditions (temperature and humidity, pressure, etc.). Leafy vegetables with high sugar content are high value-added products because they have a long shelf life and good taste. Further, for those having a predetermined value or less, it is possible to suppress the water evaporation without root cutting (depending on the kind of leafy vegetables) and to secure the shelf life.

Although both the sugar content and the water content have been described in the above embodiments, the sugar content alone may be used. In the above case, the relational expression y = −a (92−M) + b
Although the calculation is made in step 1, the form in which the relationship graph of FIG. 2 is directly stored has the same effect.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of a device.

FIG. 2 is a graph showing the relationship between water content-sugar content-storable days.

FIG. 3 is a sugar content-coefficient a relationship graph.

FIG. 4 is a sugar content-coefficient b relationship graph.

FIG. 5 is a graph showing the relationship between sugar content and the number of storage days.

FIG. 6 is a graph showing the relationship between water content and the number of storage days.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Measurement mechanism part, 2 ... Spectral analysis mechanism part, 3 ... Optical fiber, 4 ... Elastic material, 5 ... Reflector plate, 6 ... Measurement sample part, 7 ... Measurement space, 8, 8 ... Optical material detector, 9 ... Measuring unit, 10 ... cover glass, 11 ... light source, 12 ... reflecting mirror, 13 ... motor,
14 ... Diffraction grating, 15 ... Amplifier, 16 ... A / D converter,
17 ... Control unit, 18 ... Storage unit, 19 ... Input unit, 20 ... Display unit

Claims (1)

[Claims] 1. A table or a relational expression for providing a means for measuring a sugar content C and a water content M of leafy vegetables, and predicting, as the storable number of days y, the critical days for withering from the sugar content and the water content of the target item. And a control means for calculating the storable days derived from the storage means in response to the measurement signals of the sugar content and the water content, and an output means for outputting the calculation result to the display means or the like. A freshness evaluation device for leafy vegetables.