JPH03269252A - Judging device for freshness of vegitable and fruit - Google Patents

Abstract

PURPOSE:To judge true freshness even if temperature is different in the same food material by measuring the temperature and the impedance of a vegitable or a fruit, and judging and displaying the freshness based on the measured value. CONSTITUTION:A temperature detecting means 11 is brought into contact with a vegitable or fruit 1 and the temperature is detected. The temperature is measured with a temperature measuring means 16. The measured value is divided into a plurality of temperature judging levels in a temperature judging means 17. An impedance detecting means 10 is brought into contact with the vegitable or fruit 1, and an AC voltage is applied. Thus the impedance is detected. The impedance is measured with an impedance measuring means 7. A freshness judging means 8 judges the freshness based on the values measured with the judging means 17 and the measuring means 7. The freshness is displayed on a freshness display means 9. Even if the freshness of the vegitable or fruit 1 is different, the correct freshness can be automatically judged by measuring the temperature and comparing the value of the impedance which is set in response to the temperature judging level beforehand with the value of the inputted impedance.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a device for non-destructively and easily determining the freshness of fruits and vegetables.

Conventional technology In households, distribution stages, and production areas, the freshness of fruits, vegetables, and fish is judged with emphasis on appearance. Freshness determination devices perform advanced destructive analysis, so there was no room for these devices to enter ordinary households, but recent research has revealed that there is a simple, non-destructive way to determine the freshness of fruits, vegetables, and fish. Methods for determining freshness by measuring these impedance values are being established, and smaller and lighter shapes are also being devised.

- For example, JP-A No. 63-9856 "Method for determining the freshness, ripeness and internal quality of fruits and vegetables" and JP-A No. 63-9856
No. 3-259452 "Contact and non-contact freshness determination method for fruits and vegetables".

The configuration and operation of a conventional freshness determination device for fruits and vegetables will be explained below.

FIG. 8 is a block diagram of a conventional freshness determination device for fruits and vegetables.

Reference numeral 1 designates a fruit or vegetable such as an apple, a pair of electrodes 2a and 2b which contact the fruit or vegetable 1 and apply an alternating current voltage, and a pair of electrode plates 3a and 3b which conduct electricity when in contact with the electrodes 2a and 2b. 4 is a spring arranged between the electrodes 2a and 2b and the electrode plates 8a and 8b, so that when the fruits and vegetables 1 are not in contact with the electrodes 2a and 2b, the electrodes and the electrode plates are not in contact with each other. 5 is a guide for making the electrodes 2a and 2b move easily; 6 is an outer box that encloses the electrodes; 7 is an impedance measuring means for measuring the impedance of the fruits and vegetables 1; and 8 is based on the value measured by the impedance measuring means 7. 9 is a freshness determining means for determining the freshness, and 9 is a freshness display means for displaying the freshness.

The operation of the conventional freshness determination device for fruits and vegetables, etc. having the above-described configuration will be explained.

When the electrodes 2a and 2b are brought into strong contact with the fruit or vegetable 1, the spring 4 is pressed, and the electrodes 2a and 3a, 2b and 3 of the electrode plate are pressed.
b makes contact, and the voltage generated by the impedance measuring means 7 is applied to the fruits and vegetables 1 via the electrodes 2a and 2b, and the impedance measuring means 7 can measure this impedance. The freshness determining means 8 compares the impedance value input in advance with the impedance value measured by the impedance measuring means 7 to determine the freshness. This result is output to the freshness display means 9, and the freshness display means 9 displays a predetermined display to inform the user of the freshness of the fruits and vegetables 1.

Problems to be Solved by the Invention However, in the conventional configuration, the impedance characteristics vary depending on the measurement environment when measuring the fruits and vegetables 1, especially the temperature of the fruits and vegetables 1, and when the impedance is detected from the electrodes 2a and 2b, when the temperature of the fruits and vegetables 1 is high, The impedance value differs when the temperature is low and when the temperature is low, which has the disadvantage that true freshness cannot be determined based on the difference in temperature for the same food such as fruits and vegetables.

This relationship is shown in FIG.

FIG. 4 is an example of temperature-dependent impedance characteristics of fruits and vegetables, with the number of days elapsed on the horizontal axis and the impedance on the vertical axis. From FIG. 4, it can be seen that impedance decreases when freshness decreases, and that the impedance characteristics of the same food material are different when the temperature is high (solid line) and when the temperature is low (broken line).

The present invention solves the conventional problems and aims to provide a freshness determination device for fruits and vegetables that can accurately determine the freshness even if the temperature of the food differs.

Means for Solving the Problems In order to achieve the above object, the fruit and vegetable freshness determination device of the present invention includes a temperature detection means that detects the temperature by contacting the fruits and vegetables;
A temperature measuring means for measuring this temperature, a temperature determining means for dividing the value obtained by the temperature measuring means into a plurality of temperature determination levels, an impedance detecting means for contacting the fruits and vegetables and applying an alternating current voltage to detect impedance; It is composed of an impedance measuring means for measuring this impedance, a freshness determining means for determining freshness based on the values measured by the temperature determining means and the impedance measuring means, and a freshness display means for displaying the freshness. .

Effect of the present invention With the above-described configuration, the temperature judgment level obtained from the middle temperature judgment stage and the impedance value obtained from the impedance measurement means are manually inputted to the freshness judgment means, so that the temperature judgment level can be set in advance according to the temperature judgment level. By comparing the input impedance value with the input impedance value, it is possible to automatically determine the correct freshness corresponding to the temperature of the food.

EXAMPLE An example of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention, in which 1 is fruits and vegetables, 2a and 2b are electrodes, and 3a and 3b are electrode plates. 4 is a spring, 5 is a guide, 6 is an outer box, 7 is an impedance measuring means, and 9 is a freshness display means for displaying freshness. The above is the same name and operation as the conventional configuration diagram. Reference numeral 10 denotes impedance detection means for detecting the impedance of the fruit or vegetable 1, and is composed of electrodes 2a and 2b, electrode plates 3a and 3b, a spring 4, and a guide 5.

11 is a temperature detection means for detecting the temperature of the fruits and vegetables 1 = 6 A thermistor 12 that contacts the fruits and vegetables 1 to detect the temperature, an electrode plate 13 that conducts when it comes into contact with the thermistor 12, and between the thermistor 12 and the electrode plate 18. Spring 14 placed in
and a guide 15 that allows the thermistor 12 to move easily.

When the fruits and vegetables 1 and the thermistor 12 are not in contact with each other, the thermistor and the electrode plate are kept out of contact with each other. 16 is a temperature measuring means for measuring the temperature detected by the temperature detecting means 11; 17 is a temperature determining means for dividing the value obtained by the temperature measuring means 16 into a plurality of temperature determination levels; and 18 is a temperature determining means for determining the temperature at a high temperature determination level. This is an impedance comparison means that compares a preset impedance value and an input impedance value. 19 is an impedance value preset at a determination level where the temperature is low;
This is an impedance comparison means that compares the input impedance value. 20 is a changeover switch for outputting the result of freshness judgment according to the temperature judgment level judged by the temperature judgment means 17; 8 is a changeover switch for outputting the result of freshness judgment according to the temperature judgment level judged by the temperature judgment means 17; Freshness determining means for determining freshness based on the obtained value is comprised of the impedance comparing means 18, the impedance comparing means 19, and the changeover switch 20.

The operation of the freshness determination device for fruits and vegetables with the above configuration is
This will be explained below with reference to the drawings, but here too, the explanation of the same parts as in the conventional example will be omitted.

First, when the thermistor 12 is brought into strong contact with the fruit or vegetable 1, the spring 14 is pressed and the thermistor 12 and the electrode plate 13 come into contact (5 tepl), and the voltage generated by the temperature measuring means 16 is applied to the thermistor 12, and the temperature measuring means 16 Temperature can be measured (step 2). The temperature determining means 17 uses the temperature inputted in advance and the temperature measuring means 16.
The temperature is determined by comparing the temperatures measured at ste.
p3). The value obtained from the temperature determination means 17 and the conventional operation of impedance detection (step 4) and impedance measurement (step 4), which are started at the same time as the temperature detection, are
When the impedance values obtained from step 5) are respectively input to the freshness determining means 8, in the freshness determining means 8, when this temperature determination is high, the changeover switch 20 is turned on to the high side (step 6), and the temperature is low. At this time, the selector switch 20 is turned on to the low side (step). In the impedance comparison means 18 having a high temperature determination level,
The impedance value inputted in advance is compared with the impedance value measured by the impedance measuring means 7 to determine the impedance (step 7). A certain impedance value is compared with the impedance value measured by the impedance measuring means 7 to determine the impedance (step H).

In the freshness display means, when the impedance value determined by the impedance comparison means 18 is high, the freshness display is good (
In step 8), when the impedance value determined by the impedance comparison means 18 is low, the freshness display is bad (step 9), and when the impedance value determined by the impedance comparison means 19 is high, the freshness display is good. (step 12), and when the impedance value similarly determined by the impedance comparison means 19 is low, the freshness display can be displayed as poor (step 13).

As described above, according to this embodiment, the temperature detection means 11 that contacts the fruits and vegetables 1 to detect the temperature, the temperature measurement means 16 that measures this temperature, and the values obtained by the temperature measurement means 16 are Temperature determination means 17 divided into temperature determination levels
, an impedance detection means 10 that contacts the food of the fruits and vegetables 1 and applies an AC voltage to detect the impedance, an impedance measurement means 7 that measures this impedance, the temperature determination means 17 and the impedance measurement means 7. By providing the freshness determination means 8 for determining freshness based on the value determined by the freshness and the freshness display means 9 for displaying the freshness, even if the temperature of the fruits and vegetables 1 differs, the freshness can be determined correctly from the measured impedance value. The practical effects are significant.

0 Effects of the Invention As is clear from the above embodiments, the present invention provides a temperature detection means for detecting temperature by contacting fruits and vegetables, a temperature measurement means for measuring this temperature, and a value obtained by the temperature measurement means. impedance detection means that contacts fruits and vegetables and applies alternating current voltage to detect impedance; impedance measurement means that measures this impedance; the temperature determination means and the impedance measurement means. By providing a freshness determination means that determines freshness based on the value measured by Correct freshness can be automatically determined by comparing the impedance value set in advance according to the determination level and the manually inputted impedance value.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a freshness determination device for fruits and vegetables according to an embodiment of the present invention, FIG. 2 is an illustration for explaining the operation of the freshness determination device for fruits and vegetables, etc. of the present invention, and FIG. 3 is a conventional diagram. FIG. 4 is a block diagram of the freshness determination device for fruits and vegetables in this example, and is a characteristic diagram showing the impedance of fruits and vegetables according to temperature. 1... Fruits and vegetables, 7... Impedance measuring means, 8... Freshness determining means, 9...
・Freshness display means, 10... Impedance detection means, 11... Temperature detection means, 16...
- Temperature measuring means, 17...Temperature determining means.

Claims (1)

[Claims] temperature detection means that contacts fruits and vegetables to detect the temperature; temperature measurement means that measures the temperature; temperature determination means that divides the values obtained by the temperature measurement means into a plurality of temperature determination levels; impedance detection means for applying a voltage and detecting impedance; impedance measurement means for measuring the impedance; and freshness determination means for determining freshness based on the values measured by the temperature determination means and the impedance measurement means. 1. A freshness determination device for fruits and vegetables, comprising: freshness display means for displaying freshness.