JPH0415552A - Method for measuring freshness of animal tissue - Google Patents

Abstract

PURPOSE:To allow rapid and quantitative measurement by measuring plural times the complex reflectivity i.e. electric constant of the animal tissue at the frequency at which the presence of the cell membrane does not affect the electric constant and at the frequency at which the presence thereof affects the electric constant. CONSTITUTION:The electric constant of the animal tissue 5 is measured at a relatively low frequency of <=10KHz and a high frequency of several MHz or above by a probe 1 and an electric constant measuring instrument 3. The results of the measurement are analyzed by a data processor 4 to measure the degree of the destruction of the cell membrane by contrasting the value of the electric constant at the high frequency at which the presence of the cell membrane does not affect the electric constant and the value at the low frequency. Further, the measurement of the electric constant of the tissue 5 is repeated plural times by changing the measuring position by the instrument 3. The fluctuation in the electric constant is larger as the tissue 5 is fresh and the cell membrane is less damaged. The electric constant of the tissue 5 is, however, uniformized in a specified relation and the directivity of the tissue and the difference between the local parts are no longer exhibited when the freshness is successively lost. The result obtd. by determining the statistical characteristic, such as dispersion, of the measured values by the processor 4 is, thereupon, decided as the index of the freshness of the tissue 5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for measuring the freshness of animal tissues, which can quickly and quantitatively evaluate the freshness of animal tissues including fish.

[Conventional technology 1 The freshness of animal tissues mainly served as food, such as fish meat, is evaluated based on human experience and qualitative evaluation, such as visual observation of color and shape, and evaluation of elasticity by pressure with fingers. Or, in rare cases, indirect evaluations have been relied upon, such as evaluations based on acidity using pH sensors. In addition, evaluation of the freshness of special animal tissues, that is, human tissues, that is, the time elapsed after death, etc., is performed using medical examination methods based on the experiential knowledge of experts, such as physiological examinations and histological examinations using microscopes, etc. I have relied on

[Problems to be solved by the invention] By the way, the above-mentioned conventional method for evaluating the freshness of animal tissue is influenced by the subjectivity of the person performing the method, so it lacks objectivity and makes quantitative evaluation impossible. It lacks appropriateness as a quantitative indicator, as it may be affected by additives other than freshness.

In addition, histological examination using a microscope etc. allows for objective evaluation of some items, such as the degree of damage to membrane structures, but quantitative evaluation is difficult because judgments are made by human vision, and animal tissue The drawback was that it took a long time to prepare microscopic specimens.

Therefore, even if one attempts to evaluate the freshness of animal tissue based on the above-mentioned means, short-term measurement is not possible, and it is difficult to develop a quantitative evaluation method that includes shelling. As a result, there is a problem in that objective evaluations of freshness cannot be made due to individual differences in the color, shape, and elasticity of animal tissue, the level of experience and subjectivity of the person making the evaluation, and the influence of additives. Ta.

This invention was made to solve the above problems, and it is possible to objectively and quantitatively evaluate the freshness of animal tissue in a short period of time, regardless of the subjectivity or experience of the person making the evaluation. The purpose is to obtain a method for measuring the freshness of animal tissue to be measured.

[Means for Solving the Problems] A method for measuring the freshness of animal tissue according to the present invention includes measuring the complex reflectance of animal tissue multiple times at frequencies affected by the presence of cell membranes and frequencies not affected by the presence of cell membranes, and then The freshness of animal tissue is quantitatively measured from the statistical properties of the electrical constant obtained by processing the ratio.

[Function] In this invention, the complex reflectance of animal tissue is measured,
Further, the electrical constant obtained from the measured complex reflectance is processed by a data processing device to examine statistical properties such as variations, thereby evaluating the freshness of the animal tissue.

[Embodiment] FIG. 1 is a block diagram showing an example of a measuring device for implementing the present invention. In this figure, 1 is a probe, which is equipped with a pair of detection electrodes 2. 3 is an electrical constant measuring device, 4 is a data processing device, and 5 is an animal tissue mainly used for food such as fish and meat.

Next, the measurement method will be explained.

This invention utilizes the fact that protein denaturation over time after removal of animal tissue 5 and destruction of cell membranes due to freezing and thawing are reflected in electrical constants.

That is, as shown in FIG. 1, the measurement of the electrical constant of the animal tissue 5 by the probe 1 and the electrical constant measuring device 3 is performed at a relatively low frequency of 10 KHz or less, where the presence of cell membranes affects the electrical constant. It is carried out at a relatively high frequency of several MHz or less, at which the presence of cell membranes does not affect the electrical constants. When this measurement result is analyzed by the data processing device 4, the degree of membrane destruction can be determined from the comparison between the electrical constant value at high frequencies where the presence of the cell membrane does not affect the electrical constants and the electrical constant at low frequencies.

Furthermore, in this invention, protein denaturation due to the passage of time after extraction of the animal tissue 5 and destruction of cell membranes due to freezing and thawing are prevented.
The fact that this is reflected as variations in electrical constants is utilized.

In other words, the measurement of the electrical constant of the animal tissue 5 cannot be repeated multiple times by changing the measurement position using the electrical constant measuring device 3. The fresher the animal tissue 5 is and the less damage there is to the cell membrane, the greater the variation in electrical constants due to the direction of tissue composition and local differences due to the way the cells are arranged. However, as the membrane destruction of the animal tissue 5 progresses and its freshness decreases, the animal tissue 5 becomes uniform in terms of electrical constants in a certain relationship with the membrane destruction and no longer exhibits tissue directionality or local differences. Therefore, the statistical properties such as the variance of the animal tissue electrical constants measured by the probe 1 and the electrical constant measuring device 3 are determined by the deku processing device 4, and the results are used as an index of the freshness of the animal tissue 5.

Hereinafter, specific examples of this invention will be explained in detail.

In FIG. 1, a probe 1 for measuring electrical constants and an electric constant measuring device 3 measure the complex reflectance on the surface or inside of an animal tissue 5 multiple times using a plurality of frequencies and measuring devices. Here, as an example, 201 electrical constants of animal tissue 5 are selected within the same wavenumber range from IKHz to IGHz, and the units of relative permittivity and conductivity are A method for measuring the electrical constant of animal tissue 5 will be explained below.

Note that determining the electrical constants is directly performed using probe 1.
However, if the characteristic impedance of the probe 1 is determined, the measured quantity can be converted into impedance by the data processing device 4. Since this impedance corresponds one-to-one to the complex dielectric properties of the animal tissue 5 to be measured, that is, the relative permittivity and conductivity, the probe 1 can ultimately measure the relative permittivity and conductivity. becomes.

At relatively low frequencies of 10 KHz or less, the impedance of the cell membrane is very large, so the current flows only outside the cell membrane, but at relatively high frequencies of several MHz or more, the impedance of the cell membrane decreases, so the current flows through the cell membrane. You will no longer be influenced by it. Therefore, by using the data processing device 4 to compare and analyze the relative permittivity and/or conductivity at low frequencies with the corresponding relative permittivity and conductivity at high frequencies, By obtaining statistical quantities such as the variance of similar electric constants using the data processing device 4, it becomes possible to quantitatively evaluate membrane destruction and protein denaturation of the animal tissue 5, that is, measure the freshness of the animal tissue 5.

Figure 2 shows 201 from I M Hz to 3000 MHz.
The relative permittivity and conductivity obtained from the complex reflectance (impedance) of the animal tissue 5 measured at a point frequency are shown.

FIG. 3 also shows the variation in measured values when measurements were performed multiple times.

The above measurement requires simply contacting or inserting the probe 1 into the animal tissue 5, and the measurement of electrical constants and data processing of the measurement results can be completed almost instantly, making it possible to easily and quickly evaluate freshness. It is possible.

[Effect of the invention 1 As explained above, the present invention measures the complex reflectance of animal tissue multiple times at frequencies affected by the presence of cell membranes and frequencies not affected by the presence of cell membranes, and further processes the measured complex reflectance. The freshness of animal tissues can be measured quantitatively from the statistical properties of the electrical constants obtained by It not only greatly benefits quality control, etc., but also has the advantage of being of great utility value in academic fields such as forensic medicine.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an example of a measuring device for implementing the present invention, and FIGS. 2 and 3 are diagrams showing examples of data obtained by the present invention. In the figure, 1 is a probe, 2 is a detection electrode, 3 is an electrical constant measuring device, 4 is a data processing device, and 5 is an animal tissue.

Claims (1)

[Claims] The freshness of the animal tissue is determined by measuring the complex reflectance of the animal tissue multiple times at frequencies affected by the presence of cell membranes and at frequencies not affected by the presence of cell membranes, and further processing the measured complex reflectance to determine the statistical properties of the electrical constants obtained. A method for measuring the freshness of animal tissue, characterized by quantitatively measuring the freshness of animal tissue.