JP2007170912A - Antioxidant activity measuring method of food and antioxidant activity measuring system of food - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antioxidant activity measuring method of food for efficiently measuring antioxidant activity of food simply, with its cost suppressed, without using any enzyme or special reagent by electrochemically generating active oxygen, and an antioxidant activity measuring system of food therefor. <P>SOLUTION: Antioxidant activity of food is measured by the following processes: (1) a process of impressing a voltage on an electrode for H<SB>2</SB>O<SB>2</SB>measurement; (2) a process of generating O<SB>2</SB><SP>-</SP>by impressing a voltage on the electrode for O<SB>2</SB><SP>-</SP>generation; (3) a process of producing H<SB>2</SB>O<SB>2</SB>by a disproportionation reaction from the generated O<SB>2</SB><SP>-</SP>; (4) a process of measuring the amount of produced H<SB>2</SB>O<SB>2</SB>by an electrode for H<SB>2</SB>O<SB>2</SB>measurement; and (5) a process of calculating antioxidant activity possessed by food, based on the amount of measured H<SB>2</SB>O<SB>2</SB>. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for measuring antioxidant activity of food and a system for measuring antioxidant activity of food.

  In recent years, active oxygen generated by oxygen in cells during breathing process, stress, radiation / ultraviolet irradiation, carcinogen metabolism process, etc. reacts with unsaturated fatty acids to produce lipid peroxides, which adversely affect the human body. It has become clear. This active oxygen is a highly reactive molecular species generated from water or oxygen and having an unstable unpaired electron. Generally, superoxide anion radical, hydroxy radical, hydrogen peroxide, singlet oxygen, etc. It has been known.

  Excessive active oxygen is said to cause oxidative damage to biological components such as lipids, proteins, and nucleic acids, resulting in diseases such as arteriosclerosis, cancer, and diabetes, as well as promoting aging. . Thus, since active oxygen has a bad influence on a living body, an antioxidant substance having an action of capturing and eliminating the active oxygen has recently attracted attention.

  By the way, it is known that many such antioxidant substances are contained in various foods and drinks including wine, chocolate, tea and the like. For example, it is known that wine, chocolate, etc. contain polyphenols, and tea, etc. contain catechins.

  It is important to measure the strength of the antioxidant activity of an antioxidant substance when developing a highly functional food that makes use of such characteristics of foods and drinks and has an excellent antioxidant function.

  Therefore, conventionally, as a method for measuring the antioxidant activity, for example, there are measuring methods using 1,1-diphenyl-2-picrylhydrazyl (DPPH) method, electron spin resonance (ESR) method, enzyme method and the like. It is known (for example, Patent Document 1, Patent Document 2, and Patent Document 3). In the DPPH method, it is said that the antioxidant activity can be easily measured by measuring the absorbance at the rate at which the DPPH radical is eliminated by using the DPPH radical which is a stable radical. In the ESR method, antioxidant activity is measured by utilizing the fact that radicals generated by γ-ray irradiation remain relatively long in bones and cellulose.

However, all of the measurement methods as described in Patent Documents 1 to 3 require an enzyme and a special reagent for the generation of active oxygen, which is expensive and complicated. In addition, the handling of reagents and reagents requires careful attention, and there is a problem that simple measurement is not possible.
JP 2002-350420 A JP 2003-232755 A JP-A-8-228752

  Therefore, from the background as described above, in order to solve the conventional problems, the present invention generates an active oxygen using an electrochemical method, and does not use an enzyme or a special reagent. In addition, it is an object of the present invention to provide a new method for measuring antioxidant activity of food and a system for measuring antioxidant activity of food, which are capable of efficiently measuring the antioxidant activity of food while suppressing cost.

  The present invention has the following features to solve the above-described problems.

First, the following steps:
<1> a step of applying a voltage to the electrode for measuring H ₂ O ₂ ;
<2> a step of applying a voltage to the O ₂ ⁻ generating electrode to generate O ₂ ⁻ ;
<3> A step of generating H ₂ O ₂ by the disproportionation reaction of the generated O ₂ ⁻ ;
<4> a step of measuring the amount of generated H ₂ O ₂ with the electrode for measuring H ₂ O ₂ ; and <5> calculating the antioxidant activity of the food based on the measured amount of H ₂ O _2. Process;
A method for measuring antioxidant activity of foods, comprising:

Secondly, the voltage applied to the electrode for measuring H ₂ O ₂ is in the range of 0.1 to 1.1 V, the measurement method according to 1 above.

The first 3, O ₂ ^- the voltage applied to the electrode for generating, said first or antioxidant activity measuring method of the second food which is a range of -1.2~-0.3V.

The fourth is a three-electrode configuration including at least an H ₂ O ₂ measuring electrode, an O ₂ ⁻ generating electrode, and a counter electrode, and these H ₂ O ₂ measuring electrode, O ₂ ⁻ generating electrode, and a counter electrode. Is a system for measuring the antioxidant activity of foods, which is arranged in contact with an electrolyte, wherein the electrode for measuring H ₂ O ₂ is arranged to face the electrode for generating O ₂ ⁻ a oxidation activity measurement system, H ₂ O ₂ measuring electrode, O ₂ ^- antioxidant activity measurement system food which are arranged facing a generation electrode.

Fifth, the fourth food antioxidant activity measurement system according to claim 4, wherein the distance between the electrode for measuring H ₂ O ₂ and the electrode for generating O ₂ ⁻ is in the range of 1 to 1000 μm.

  Sixth, the system for measuring antioxidant activity of the fourth or fifth food, comprising either the counter electrode and the reference electrode, or both the counter electrode and the reference electrode.

Seventh, the H ₂ O ₂ measurement electrode is modified with a cellulose ester dialysis membrane, and the antioxidant activity measurement system for food according to any one of the fourth to sixth aspects.

The first 8, H ₂ O ₂ measuring electrode and the O ₂ ^- one of either the generating electrode, or the Toko both electrodes are modified with functional film from the fourth, wherein 7 Food antioxidant activity measurement system.

Ninth, an electrode for measuring H ₂ O _{2 and} an electrode for generating O ₂ ⁻ formed on an insulating substrate are arranged facing each other via a spacer, and an electrode for measuring H ₂ O ₂ and O ₂ ^{− are} generated. Any one of the above-mentioned electrodes is provided with at least one of a reference electrode and a counter electrode.

  According to the present invention as described above, the active oxygen is generated electrochemically, so that the antioxidant activity of food is efficiently measured without using enzymes or special reagents, and at a low cost. can do.

In addition, according to the fourth to ninth inventions, since active oxygen can be generated electrochemically, the use of an enzyme or a special reagent is simple, and the cost of food is reduced without using enzymes or special reagents. The activity can be measured efficiently. Further, the first 8 H ₂ O ₂ measuring electrode according to the invention of is operated at a low potential, and O ₂ ^- O ₂ from generating electrode ^- since it is possible to increase the amount of generated high sensitivity antioxidant activity Can be measured. According to a further aspect of the ninth, each PET film insulating H ₂ by screen printing on a substrate of O ₂ measuring electrode and the O ₂ ^- can in structure disposed facing via a spacer to form a generating electrode An inexpensive disposable sensor can be constructed by injecting an electrolyte-containing sample solution into the spacer and measuring the antioxidant activity.

  The present invention has the features as described above, and the embodiment thereof will be described in detail below.

  The present invention is a method and system for measuring the presence or absence of an antioxidant substance in foods and, if an antioxidant substance is present, the strength of its antioxidant activity.

Specifically, first, the method for measuring antioxidant activity of foods of the present invention comprises at least the following steps:
As a first step, a step of applying a voltage to the electrode for measuring H ₂ O ₂ ;
As a second step, O ₂ ^- a voltage is applied to the generating electrode, O ₂ ^- step of generating;
A step of generating H ₂ O ₂ by a disproportionation reaction of the generated O ₂ ⁻ as a third step;
As a fourth step, the H ₂ O ₂ amount was generated, step measured by the H ₂ O ₂ measuring electrode; and as a fifth step, based on the measured H ₂ O ₂ amount, food has Calculating antioxidant activity;
It is characterized by including. Such a measurement method and measurement system of the present invention are based on the measurement principle by the electrochemical method described below.

That is, when a voltage of −0.284 V or less is applied to an electrode of platinum or the like in an aqueous electrolyte solution of KCl or the like with a standard electrode potential of O ₂ , the active oxygen species is represented by the following formula (1) on the electrode. O ₂ ⁻ is generated.

The generated O ₂ ⁻ generates H ₂ O ₂ by the disproportionation reaction as shown in the following formula (2).

And using such a reaction, a negative voltage is applied to one electrode (O ₂ ⁻ generating electrode) to generate O ₂ ^−, and H ₂ O ₂ is generated by a disproportionation reaction. If an antioxidant is present here, it captures O ₂ ^−, and thus the amount of H ₂ O ₂ produced by the disproportionation reaction decreases as shown in the following formula (3).

The H ₂ O ₂ amount, the O ₂ ^- and the presence or absence of the measurement object by detecting the other electrode close to the generating electrode (H ₂ O ₂ measuring electrode), i.e. anti-oxidizing materials for food, Its antioxidant activity is measured. Here, the antioxidant substance in the present invention is not particularly limited as long as it has an activity of capturing and eliminating active oxygen, for example, polyphenols such as catechin, flavonoid, isoflavone, tannin, Xanthophylls, β-carotene, carotenoids such as lycopene, vitamins and minerals such as vitamin C and vitamin E, and anthocyanins can also be targeted. Similarly, the food is not particularly limited. Examples of the beverage include wine and tea, and examples of the food include chocolate, soybean, pumpkin, carrot, tomato, and blueberry.

Here, since the theoretical electrolysis voltage of water is 1.23V, if a voltage of 1.2V or more is applied, the electrolysis of water occurs, which affects the measurement of H ₂ O ₂ , that is, the sensor response. in view of _voltage applied to the _H 2 O ₂ measuring electrode is in a range of from 0.1～1.1V, can be measured more generation of efficient H ₂ O _2. In addition, when the voltage for O ₂ ⁻ generation is lower than −1.5 V, the sensor response becomes unstable. Therefore, considering the shortening of the measurement time and the stability of the sensor response, the voltage applied to the O ₂ ⁻ generating electrode should be in the range of −1.2 to −0.3V, so that O ₂ ⁻ can be generated efficiently. Can be desirable.

Incidentally, FIG. 1 is a graph illustrating the result of verifying the optimum applied voltage, (A) for the H ₂ O ₂ measuring electrode, (B) is O ₂ ^- shows the generation electrode.

And this invention also provides the antioxidant activity measuring system of foodstuffs which can implement such a measuring method simply. Specifically, the measurement system of the present invention includes at least an H ₂ O ₂ measurement electrode, an O ₂ ⁻ generation electrode, and a counter electrode, and these H ₂ O ₂ measurement electrode, O ₂ ⁻ generation electrode, and It is a system for measuring the antioxidant activity of foods arranged in contact with an electrolyte at any counter electrode. Then, H ₂ O ₂ measuring electrode, O ₂ ^- is characterized in that it is arranged facing a generation electrode.

Here, since the distance between the electrode for measuring H ₂ O ₂ and the electrode for generating O ₂ ⁻ is close, H ₂ O ₂ measurement using the electrode for measuring H ₂ O ₂ and for generating O ₂ ⁻ It is possible to achieve both H ₂ O ₂ measurement using an electrode in a well-balanced manner. _That, H 2 _{O 2} measuring electrode and the _{O 2} ^- be to close the generating _electrode, it is possible to reduce the diffusion of H 2 _{O 2,} it is possible to detect the H 2 _{O 2.} Specifically, for example, as shown in FIG. 2, it is preferably in the range of 125 to 750 μm, and particularly preferably 500 μm. In the case of 250 μm or less and 750 μm or more, H ₂ O ₂ cannot be detected with good reproducibility. Also, O ₂ ^- When considering the occurrence, O ₂ ^{- -} O ₂ in generating electrode surface of the generating electrode shape as described above, it is possible to achieve both a balance between the measurement of H ₂ O ₂ If it is, it will not specifically limit, for example, the shape etc. which increased the surface area.

The measurement system of the present invention, for example, H ₂ O ₂ measuring electrode and O ₂ as the working electrode ^- electrode configuration pattern or by a generating electrode, H ₂ O ₂ measuring electrode and the O ₂ ^- generation electrode in addition, three-electrode configuration pattern according to either counter or reference electrode, or,, H ₂ O ₂ measuring electrode, O ₂ ^- generation electrode, an electrochemical measurement system with 4 electrode configuration pattern according to the reference electrode and a counter electrode It only has to be, and it is not defined by the arrangement pattern.

  Further, the embodiment may be of a batch type as exemplified in FIG. 3 or FIG. 4, or may be produced by screen printing a carbon ink as exemplified in FIG. It may be a disposable type measuring chip.

Here, in the examples of FIGS. 3 and 4, 1 is an electrode for measuring H ₂ O ₂ , 2 is an electrode for O ₂ ⁻ generation, 3 is a reference electrode, 4 is a counter electrode, and 5 is an electrolyte solution. Further, the example of FIG. 5 will be described. In the disposable type anti-oxidation capacity measuring chip, the screen printing electrode H ₂ O ₂ measuring electrode 1 and the O ₂ ⁻ generating electrode 2 are overlapped via a spacer 6. And a sample inlet 8 and an air hole 7 for injecting a sample solution containing an electrolyte solution into the spacer. Further, the electrode for measuring H ₂ O ₂ and the electrode for generating O ₂ ⁻ illustrated in FIG. 5 are each provided with a counter electrode and a reference electrode, but from the measurement principle, it is for measuring H ₂ O ₂ . It is obvious that at least one of the reference electrode and the counter electrode may be provided on one of the electrode and the O ₂ ⁻ generating electrode. In the example of FIG. 5, the thickness of the spacer 6 is exemplified as 420 μm, but the thickness is not limited to this thickness as long as it functions as the measurement system of the present invention.

In the measurement system of the present invention, for example, a platinum electrode, a gold electrode, and a carbon electrode can be used as the H ₂ O ₂ measurement electrode and the O ₂ ⁻ generating electrode, but the electrode is not particularly limited thereto. Furthermore, in the measurement system of the present invention, the electrode for measuring H ₂ O ₂ may be modified with a functional membrane such as a cellulose ester dialysis membrane, Prussian blue, or conductive polypyrrole. Thus, by modifying with a cellulose ester dialysis membrane, for example, the influence of reducing substances other than the target substance such as ascorbic acid contained in food can be prevented, and the antioxidant activity of the target substance is efficiently measured. can do. Moreover, O ₂ ⁻ and H ₂ O ₂ generated by modifying the functional film can be efficiently collected and detected. On the other hand, the O ₂ ⁻ generating electrode may be modified with carbon nanotubes or carbon fine particles. Thus, by modifying with carbon nanotubes or carbon fine particles, the electrode surface is made porous, the surface area of the electrode is increased, the amount of O ₂ ⁻ generated can be increased, and high-sensitivity measurement becomes possible.

  The reference electrode uses a silver / silver chloride electrode, but is not particularly limited thereto. Similarly, the counter electrode is not particularly limited, but is preferably a platinum electrode, a gold electrode, and a carbon electrode in consideration of conductivity and the like. Also, the electrolyte is not particularly limited. For example, an aqueous solution in which various electrolytes are dissolved to such an extent that electrical conductivity necessary for electrolytic reduction can be imparted, specifically, for example, an aqueous KCl solution or a buffer solution. Can be used.

  Hereinafter, although this invention is further demonstrated along an Example, this invention is not limited to these Examples.

<Example 1> _{O 2} ^- detection of _H 2 _{O 2} by disproportionation reaction (1) _{O 2} ^- for effectively detecting the _H 2 _{O 2} by disproportionation reaction, _{O 2} ^- for generating platinum electrode _{(O 2} ^- generation electrode hereinafter, W2-pole) platinum electrode for facing the _H 2 _{O 2} measurements _(H 2 _{O 2} measuring electrode hereinafter, W1-pole) were placed. In addition, a four-electrode system using a platinum wire as a counter electrode and a silver / silver chloride electrode as a reference electrode applies a voltage of −0.9 V to the W2 electrode in KCl as an electrolytic aqueous solution to generate O ₂ ^−. It was. On the other hand, a voltage of 1.1 V was applied to the W1 pole, and the sensor response of the W1 pole at this time was measured. Further, the distance between the W1 pole and the W2 pole was set to 500 μm.

And using the measurement method of the present invention, as a sample catechin standard solution of 0.125 mM, the with the O ₂ ^- measuring the scavenging activity, the following equation (4), O ₂ catechin ^- was calculated scavenging activity rate.

_{(I 1} in the formula, _{O 2} ^- _{O 2} generated from the generation electrode ^- generates an _H 2 _{O 2} by disproportionation reaction, the response current when it was measured in _H 2 _{O 2} measuring electrode shows a value when here antioxidant is present, this O ₂ ^-. for capturing, .I ₂ that the amount of H ₂ O ₂ by disproportionation is decreased, when there are antioxidant The response current value of H ₂ O ₂ is shown.

  The results were as shown in FIG. 6 and FIG.

As a result of detecting H ₂ O ₂ by the disproportionation reaction of O ₂ ⁻ , a clear difference was observed in the sensor response at the W1 electrode depending on the presence / absence of voltage application at the W2 electrode. This revealed that H ₂ O ₂ derived from O ₂ ⁻ generated at the W2 electrode can be detected by the W1 electrode. Also, O ₂ ^- result of determining the scavenging activity, the sensor response of the W1-pole is reduced (FIG. 6). This is probably because catechin captures and eliminates O ₂ ⁻ and suppresses the generation of H ₂ O ₂ due to the disproportionation reaction. Furthermore, with increasing catechin concentration _{O 2} ^- scavenging activity rates continue to increase, the contribution rate ^{R 2} was 0.999 (Fig. 7).
(2) Further, in the above condition (1), using a catechin standard solution of 0.125 mM, repeating _{O 2} ^- was measured for scavenging activity, using the coefficient of variation (repeatability), measurement of the present invention It was also examined measurement reproducibility of scavenging activity ^- O ₂ by the method.
As a result, as shown in FIG. 8, a coefficient of variation of 8.5% and a reliable measurement reproducibility were obtained as a measurement result.

  The coefficient of variation (%) is expressed by the following equation (5)

Can be obtained from

Measurement methods of the study present invention <Example 2> Effect of cellulose ester film of ascorbic acid on the platinum electrode (W1-pole) (hereinafter CE) dialysis membrane, H ₂ O ₂ the voltage is 1.1V and the high-potential Therefore, when measuring the antioxidant activity in food, it is considered that reductive substances other than the target substance such as ascorbic acid are decomposed to affect the sensor response. Therefore, for the purpose of preventing the influence of ascorbic acid, a platinum electrode (W1 electrode) was modified using a CE dialysis membrane (MWCO: 100), and ascorbic acid (MW: 176) was added in the measurement method of the present invention. The sensor response at the time was measured.

The result was as shown in FIG. That is, as a result of examining the influence of ascorbic acid on the platinum electrode and the CE dialysis membrane, when the CE dialysis membrane was used, the response current value due to the electrolysis of ascorbic acid was reduced by about 96%. Thereby, it became clear that the influence of ascorbic acid can be significantly suppressed by using a CE dialysis membrane in the electrode method (FIG. 9). It was also revealed that ascorbic acid at a low concentration of 1 mM or less does not affect the sensor response.
<Example 3> of tea beverage O ₂ ^- scavenging activity measurement catechins include ascorbic acid, and common beverage in a tea beverage (commercially available 4 grades: tea beverage A, tea beverage B, tea beverages C, Brown used beverage D) as a sample, the O ₂ by a measurement method of the present invention (electrode method) ^- was measured scavenging activity. In addition, as a control experiment, the same measurement was performed using the conventional DPPH method, and the correlation with the measurement method of the present invention was examined.

From tea beverage A with D to sample the O ₂ ^- result of measurement of scavenging activity, as shown in FIG. 10, as those catechin is to contain a high concentration, it showed high activity . Moreover, the same result as the measurement by the DPPH method was shown, and a good correlation with the contribution ratio R ² = 0.959 was obtained between the measurement method of the present invention and the DPPH method.
<Example 4> fruit, O ₂ vegetables ^- using scavenging activity measurement fruits and vegetables each aqueous extract to the sample, the O ₂ ^- was measured scavenging activity. The fruits and vegetables used were apple peels and flesh, two brands of strawberries A and B, perilla, peppers and carrots.

  At this time, in the DPPH method, a colorimetric analysis method using a tetrazolium salt (WST-1) as a coloring reagent is used as a comparative experimental method in consideration of the effect of anthocyanins contained in fruits on the absorption wavelength of measurement. went.

As a result, as shown in FIG. 11, a good correlation with the contribution ratio R ² = 0.986 was obtained between the measurement method of the present invention (electrode method in the drawing) and the WST-1 method.
<Example 5>
The H ₂ O ₂ measuring electrode is immersed in a mixed solution of 40 mmol / L potassium ferricyanide and 40 mmol / L FeCl ₃ and then energized at a current density of −40 μA / cm 2, and Prussian blue functions on the electrode by electrolytic deposition. A film was formed, and an electrode for measuring H ₂ O ₂ as shown in FIG. 12 was produced. The electrode as H ₂ O ₂ measuring ^{_{electrode, O 2 - -0.9V vs. Ag /}} AgCl in generating electrode, by applying a voltage of -0.5 V vs. Ag / AgCl in H ₂ O ₂ measuring electrode O ₂ ^- O ₂ generated on generating electrode ^- disproportionation was H ₂ O ₂ amount was measured H ₂ O ₂ measurement electrode was applied to the functional film by a conventional method as shown in FIG. 13 Good correlation with DPPH method is obtained. As a result, when the functional film of Prussian blue is modified to an electrode for measuring H ₂ O ₂ , the conventional measurement of H ₂ O ₂ by applying a voltage of 1.1 V vs. Ag / AgCl is −0.5 Since V vs. Ag / AgCl can be measured and H ₂ O ₂ can be measured at a lower potential, measurement can be performed without being disturbed by a reducing substance such as ascorbic acid present in a large amount in the plant.

Is a graph illustrating the result of verifying the optimum voltage applied to the electrodes in the measurement method of the present invention, (A) for the H ₂ O ₂ measuring electrode, (B) is O ₂ ^- shows the generation electrode Yes. ^(- The generating electrode -0.9 V, and a voltage of 1.1V to the _H 2 _{O 2} measuring electrode in (B) (in A) _{O 2.)} H ₂ O ₂ measuring electrode and the O ₂ in the measurement method of the present invention ^- is a graph illustrating the result of verifying the optimum distance between the generating electrode. It is the front view which illustrated the batch type as one embodiment of the measurement system of the present invention. It is the front view which illustrated the batch type as another embodiment of the measuring system of the present invention. As yet another embodiment of the measurement system of the present invention, an exploded schematic view schematically illustrating the configuration before assembly of the screen print electrode type, and a disposable type anti-oxidation capacity measurement chip of the screen print electrode type after assembly. It is the top view typically illustrated. It is the figure which showed the verification result of the catechin sample addition in Example 1, and the behavior of a sensor response. Catechin concentration in Example 1, O ₂ ^- is a diagram showing the verification result of the relationship between the scavenging activity. O ₂ in Example 1 ^- illustrates the verification results of the measurement reproducibility of the scavenging activity. It is the figure which showed the verification result of the relationship between the ascorbic acid density | concentration in Example 2, and an electric current value. In Example 3, it is the figure which showed the result verified about the correlation with the measuring method (electrode method) of this invention, and the conventional DPPH method. It is the figure which showed the result verified about the correlation with the measuring method (electrode method) of this invention in Example 4, and the conventional WST-1 method. 6 is a cross-sectional view of an electrode for measuring H ₂ O ₂ modified with a functional film in Example 5. FIG. It is the figure which showed the result verified about the correlation with the measuring method (electrode method) of this invention in Example 5 and the conventional DPPH method.

Explanation of symbols

1 H ₂ O ₂ measuring electrode 2 O ₂ ⁻ generating electrode 3 reference electrode 4 counter electrode 5 electrolyte solution 6 spacer (420 μm)
7 Air hole 8 Sample inlet 9 Insulating substrate
10 Functional membrane

Claims (9)

The following steps:
<1> a step of applying a voltage to the electrode for measuring H ₂ O ₂ ;
<2> a step of applying a voltage to the O ₂ ⁻ generating electrode to generate O ₂ ⁻ ;
<3> A step of generating H ₂ O ₂ by the disproportionation reaction of the generated O ₂ ⁻ ;
<4> a step of measuring the amount of generated H ₂ O ₂ with the electrode for measuring H ₂ O ₂ ; and <5> calculating the antioxidant activity of the food based on the measured amount of H ₂ O _2. Process;
A method for measuring antioxidant activity of foods, comprising: Voltage applied to the H ₂ O ₂ measurement electrodes, the measurement method according to claim 1, characterized in that in the range of 0.1～1.1V. O ₂ ^- the voltage applied to the electrode for generating the antioxidant activity measuring method of the food according to claim 1 or 2, characterized in that in the range of -1.2~-0.3V. At least _H 2 _{O 2} measuring electrode, _{O 2} ^- is a three-electrode configuration with a generating electrode and the counter electrode, and these _H 2 _{O 2} measuring electrode, _{O 2} ^- is generating electrode and the counter electrode in contact with the electrolyte a antioxidant activity measuring system for food comprising arranged Te to, H ₂ O ₂ measuring electrode, O ₂ ^- antioxidant activity measurement system food which are arranged facing a generation electrode. H ₂ O ₂ measuring electrode and the O ₂ ^- antioxidant activity measuring system for food according to claim 4, wherein the distance between the generating electrode is in the range of 1 to 1000 m. The system for measuring antioxidant activity of foods according to claim 4 or 5, further comprising any one of a counter electrode and a reference electrode, or both a counter electrode and a reference electrode. The system for measuring antioxidant activity of food according to any one of claims 4 to 6, wherein the electrode for measuring H ₂ O ₂ is modified with a cellulose ester dialysis membrane. H ₂ O ₂ measuring electrode and the O ₂ ^- antioxidant in either one or any of the food from the claims 4 to 7, characterized in Toko both electrodes are modified with functional film, the generating electrode Activity measurement system. An electrode for measuring H ₂ O _{2 and} an electrode for O ₂ ⁻ generation formed on an insulating substrate are arranged facing each other via a spacer, and either the electrode for measuring H ₂ O ₂ or the electrode for O ₂ ⁻ generation is used. 9. The system for measuring antioxidant activity of food according to claim 4, wherein at least one of a reference electrode and a counter electrode is provided on one side.