KR20140002357A - Food surface sterilization method using non-thermal plasma - Google Patents

Abstract

The present invention relates to a food surface sterilization method using nonthermal plasma. The sterilization method of the present invention selects nonthermal plasma among dielectric barrier discharge plasma (DBDP) or corona discharge plasma jet (CDPJ), which is suitable for the food group and the surface character, and optimizes the treatment condition, so as to increases the sterilization effect to the microorganism on the surface of food materials or food, and to decompose the residual agricultural chemical components on the surface of the food materials or food.

Description

TECHNICAL FIELD [0001] The present invention relates to a method of sterilizing food using a low-temperature plasma,

The present invention relates to a method of sterilizing food surfaces using a low-temperature plasma, and more particularly, to a method of sterilizing food using a low-temperature plasma selected from Dielectric Barrier Discharge Plasma (DBDP) or Corona Discharge Plasma Jet (CDPJ) And a method for sterilizing food using a low-temperature plasma in which the sterilizing effect of a microorganism on the surface of a food or a food is enhanced by optimizing treatment conditions.

Safe and quality food supply is the most realistic way to improve human health and quality of life.

Consumers want high quality food means fresh food, rich in nutrition, high palatability such as taste, flavor and texture, and demand for high quality food is steadily increasing due to economic growth.

In order to meet these demands, the food industry uses sterilization methods from food raw materials to final products, such as heat sterilization using steam or hot water.

However, the heat sterilization method is disadvantageous in that it consumes a large amount of energy and destroys not only nutritional components due to heat but also sensual quality such as incense, taste and color.

Accordingly, in the field of food industry, as an alternative to overcome the above problems, research on non-thermal sterilization methods has been concentrated.

As the non-heat sterilization method, there are radiation, electron beam, ultra high pressure, high electric pulse, ultraviolet ray, low temperature plasma and the like.

At present, radiation technology is used as a representative, but the rejection from consumers due to vague anxiety about radiation is a stumbling block to research and development.

In addition, ultra high pressure technology, which has been studied extensively after irradiation, can be applied to a limited number of products of large corporations because it requires expensive equipments.

As a non-thermal sterilization method for solving these disadvantages, interest in low-temperature plasma and optical pulse technology with low secondary contamination due to a generation material during treatment is minimized while minimizing changes in the quality of food using a relatively low- [ Food Eng. Prog ., 2010 , 14 , 202-207].

Plasma is an electrolytically gaseous state in which cations and electrons are distributed at almost the same density and are electrically neutral. [ J. Food Sci ., 2007 , 72 (2) , M62-M65], and the like, because the plasma contains excited ions, free radicals, electrons, photons and the like, The complex biological action of a substance can kill microorganisms [ Pure Appl. Chem ., 2002 , 74 , 349-358].

Particularly, since the low temperature plasma technology exhibits a biological action to inactivate microorganisms such as bacteria and viruses without causing a serious temperature rise in the object to be treated, it is highly likely to be used in sanitary and environmental fields. In the moment when the switch is turned off after the treatment, Has the advantage of being simple to control and not leaving any residual material [ Plasma Sci ., 2002 , 28 , 41-50; Air plasma chemistry. In: Non-equilibrium Air Plasmas at Atmospheric Pressure. Becker KM, Kogelschartzi, Schoenback KH, Barker RJ (eds.). IOP Publishing Ltd., London, England, 2005 , pp. 124-182.]

Despite these advantages, there are few examples of research that apply low temperature plasma technology to foodstuffs or foods.

The present inventors have searched for conditions suitable for the shape and surface characteristics of the food group in order to establish the method of disinfecting the food or the foodstuff by the low temperature plasma technology. As a result, it was found that the sterilization of the microorganism By demonstrating the effect, the present invention has been completed.

It is an object of the present invention to provide a method of surface sterilization of foodstuffs or foods by low temperature plasma treatment.

Another object of the present invention is to provide a sterilization method by a low-temperature plasma treatment optimized according to the type and properties of a food or a foodstuff.

The present invention provides a method of sterilizing a food surface by using low-temperature plasma which lowers the temperature of the food or the food to the microorganism on the surface of the food or the food.

In the present invention, the low temperature plasma chamber is selected from dielectric barrier discharge plasma (DBDP) or corona discharge plasma jet (CDPJ).

As the sterilizing method of the first preferred embodiment of the present invention, the dielectric barrier discharge plasma is applied at an electrode interval of 0.50 to 50.0 mm It is useful to apply it to surface sterilization of foodstuffs or foods in flat plate form.

Thus, the flat plate type food or food is excellent in the sterilizing effect of the sheet-like steaming or the cereal, such as the press-in.

In addition, the sterilization method by the dielectric barrier discharge plasma treatment of the present invention can increase the sterilization effect by performing the target sample in a single echo or bidirectional movement method during the plasma treatment.

The sterilization method according to the second preferred embodiment of the present invention is performed by a corona discharge plasma jet (CDPJ) treatment and is sprayed under a condition of a distance of 5.0 to 150.0 mm from the plasma discharge port.

Preferably, the corona discharge plasma jet treatment is sterilized in three directions with respect to the surface of the non-planar food material or foods.

Therefore, the sterilization method by the corona discharge plasma jet treatment is suitable for surface sterilization of fruits or vegetables having a high water content.

By using the low-temperature plasma of the present invention, the food material or the microorganisms on the surface of foods can be killed within a short time after the plasma treatment by the food surface sterilizing method.

It is possible to provide a method of sterilizing a food surface using a low-temperature plasma by optimizing the bactericidal effect of a microorganism on the surface of a food material or a food by selecting plasma and processing conditions suitable for the shape and surface characteristics of the food group of the present invention.

By using the low temperature plasma of the present invention it is possible to decompose the residual pesticide components on the surface of food or foodstuffs.

1 is a diagram showing a disinfection pattern for Escherichia coli by the dielectric barrier discharge plasma (DBDP) treatment of the present invention as a Singh-Heldman model,
FIG. 2 shows the sterilizing effect according to the sample transfer method during the dielectric barrier discharge plasma (DBDP) treatment of the present invention,
FIG. 3 is a graph showing bactericidal effects against bacteria and fungi of rice bran and crushed meat according to the dielectric barrier discharge plasma (DBDP) treatment of the present invention,
Figure 4 shows the bactericidal effect of white rice and pressurized bacilli and fungi according to the corona discharge plasma jet (CDPJ) treatment of the present invention,
FIG. 5 is a graph showing the bactericidal effect of kimchi and alfalfa sprouts on bacteria and fungi according to the dielectric barrier discharge plasma (DBDP) treatment of the present invention,
Figure 6 shows the bactericidal effect of germ and alfalfa sprouts on bacteria and fungi according to the corona discharge plasma jet (CDPJ) treatment of the present invention.

The present invention provides a method of sterilizing food surfaces using low temperature plasma.

More specifically, it is a sterilization method in which a low-temperature plasma treatment is applied to a food or a foodstuff, and the microorganism on the surface of the food or food is killed within a short time after the plasma treatment.

The sterilization method of the present invention is carried out by a first-stage two-step reaction. Since the plasma sterilization effect is very effective for the microorganisms on the surface of the object to be sterilized, sterilization by short-time treatment is possible. However, the sterilizing effect by the second-step secondary reaction is insufficient, so that the microorganisms in the inner part have a low permeability to plasma, so that the long-term treatment is required to kill the microorganisms.

In the present invention, dielectric barrier discharge plasma (DBDP) or corona discharge plasma jet (CDPJ) is selectively used.

The sterilization method according to the first preferred embodiment of the present invention is performed by dielectric barrier discharge plasma treatment in a low-temperature plasma, and is exposed vertically under the condition of an electrode interval of 0.50 to 50.0 mm, more preferably 1.85 to 3.33 mm.

Conditions for optimizing the sterilizing effect in the dielectric barrier discharge plasma are performed according to the electrode interval of 0.50 to 50.0 mm, more preferably 1.85 to 3.33 mm, and the current intensity of 0.1 to 5.0 A, and more preferably 0.75 to 1.25 A .

In the case of the dielectric barrier discharge plasma, the plasma generation is performed in the vertical direction, so that the food material or the foodstuff in the form of a flat plate, specifically the food material or the foods, is a sheet-shaped steaming, seaweed, It is advantageous. In the embodiment of the present invention, the pressurized steam is used as the steam and the grain, but the present invention is not limited thereto.

In addition, since the dielectric barrier discharge plasma is spaced apart at regular intervals, and the energy is concentrated at the plasma generating point to have a locally different plasma density, the target sample is processed in a single echo or bidirectional transfer method during processing. By doing so, the sterilization effect can be enhanced.

The sterilization method of the second preferred embodiment of the present invention is by corona discharge plasma jet (CDPJ) treatment.

The condition for optimizing the sterilizing effect in the corona discharge plasma jet (CDPJ) treatment of the present invention is the spray treatment under the condition of a distance of 5.0 to 150.0 mm, more preferably 15 to 35 mm, from the plasma discharge port. The current intensity is 0.1 to 5.0 A, more preferably 1.0 to 1.50 A.

In the case of the corona discharge plasma jet, the non-uniform shape rather than the flat plate shape is more preferable by jetting in three dimensions.

In the examples of the present invention, in case of white rice and pressed rice, the case of white rice is sterilized in three directions to exhibit high germicidal effect, but the form of the food is not limited thereto.

The corona discharge plasma jet which is jetted so as to favor such a nonuniform shape is suitable for surface sterilization of fruits or vegetables having a high water content.

In the embodiments of the present invention, alfalfa sprouts are described as an example, but the present invention is not limited thereto.

Furthermore, the present invention can decompose the residual pesticides on the surface of foodstuffs or foodstuffs using a low temperature plasma selected from a dielectric barrier discharge plasma (DBDP) or a corona discharge plasma jet (CDPJ).

Hereinafter, the present invention will be described in more detail with reference to Examples.

This embodiment is intended to illustrate the present invention in more detail, and the scope of the present invention is not limited to these examples.

Production Example 1 Dielectric Barrier Discharge Plasma (DBDP) Treatment

Plasma was generated at normal pressure by applying a voltage of 10.0 to 50.0 kV to the pulsed square wave of 10.0 to 50.0 kHz through an electrode wrapped with a ceramic dielectric. Escherichia coli ATCC 25922 was used as a model bacterium.

The slurry was placed on a sample plate (ground plate) of the DBDP apparatus, and the DBDP plate was fixed. The DBDP treatment was performed by placing the slide glass on the grounding plate and moving the grounding plate so that the sample was positioned directly under the electrode. Then, the current intensity (0.75 A, 1.00 A, 1.25 A) and the electrode spacing (1.85 mm, 2.65 mm, 3.33 mm) The ground plate was returned to its original position and the sample was recovered.

In DBDP treatment, the bactericidal effect of E. coli according to the electrode interval and current intensity is shown in Table 1 below.

Figure 1 as showing the result of applying the model to Singh-Heldman against sterile pattern by DBDP processing to interpret the second period the first reaction pattern as a single model, shown in a straight line in the coefficient of determination of 0.982 Escherichia coli (E.coli) The DBDP sterilization pattern was found to be well applied to this model.

From the above Singh-Heldman model and the results shown in Table 1, the sterilization pattern of Escherichia coli treated with DBDP according to current intensity and electrode spacing conditions showed the highest sterilizing power at 2.65 mm.

On the other hand, since the temperature rise by DBDP treatment is below 20 ° C and the maximum temperature when treated at room temperature is only 45 to 50 ° C, the biological effect by heat can be neglected, so DBDP of the present invention is useful as a low temperature plasma.

It was identified as a primary pattern in two sections according to the DBDP treatment time for Escherichia coli (1 section) and the latter part (2 sections).

In other words, as a result of calculating the sterilization rate constant (k ₁ ) and the sterilization rate constant (k ₂ ) according to the interval, the DBDP disinfection process is initially constructed with a straight line having a large slope, Respectively. Thus, as can be seen in Table 1, the sterilization rate constant (k ₁ ) increased with the current intensity, but the sterilization rate constant (k ₂ ) was uniform according to the current intensity.

The sterilization rate constant (k ₁ ) at the electrode interval was the highest at 2.65 mm, 3.33 mm and 1.85 mm at the lowest, and the maximum k ₁ was the optimum sterilization effect when the electrode gap was 2.65 mm and the current was 1.25 A Can be predicted.

In order to investigate the effects of sample migration on the bactericidal effect during DBDP treatment, the treatment method was divided into a fixed type and a mobile type based on the movement of the sample during the plasma treatment and a unidirectional treatment and a bidirectional treatment. Were compared.

At this time, the uni-directional treatment was carried out by placing the slide glass on the grounding plate and treating the grounding plate at a speed of 15 mm / s. Bidirectional processing was performed by alternately repeating the process of turning the slide glass horizontally and then changing the direction by 90 °. The procedure of Preparation Example 1 was repeated except for the above.

Table 2 shows the effect of sample migration on the sterilization rate constant during DBDP treatment.

As shown in Table 2 and FIG. 2 , when the DBDP treatment was compared with the disinfecting effect according to the sample transfer method, the mobile treatment showed much better sterilization effect than the fixed treatment, and the two- The sterilization effect was better than the direction treatment.

This difference is due to the fact that the point where the plasma is generated at the electrode is located apart at regular intervals and the energy is concentrated at the plasma generation point and locally has different plasma density. Such nonuniformity can be improved by moving the sample while moving Respectively.

Therefore, it can be seen that the sample migration during the DBDP treatment greatly enhances the sterilizing effect, and in particular, the bi-directional treatment for changing the sample movement direction during the treatment is preferable.

Production Example 2 Corona Discharge Plasma Jet (CDPJ) Treatment

A pair of electrodes is installed in a ceramic shield (shield), and a large amount of air is introduced using a blower while a voltage of 1.0 to 2.0 kV pulsed DC is applied between the electrodes to generate a plasma. The plasma is injected to the lower portion of the electrode. The sample was placed on the processing plate under the electrode, and plasma was treated for a certain period of time by adjusting the electrode-sample gap and the current intensity.

The sterilization powers of the standard strains and food poisoning bacteria were compared using a corona discharge plasma jet generated at current sources of 1.0, 1.25 and 1.50 A at 15, 25 and 35 mm from the plasma discharge outlet.

Escherichia coli ATCC 25922 was used as the standard strain and food poisoning bacteria used, and Saccharomyces cerevisiae ( La Parisienne, SI Lesaffre, Marcq-en-Baroeul, France) was used as the yeast . Staphylococcus aureus ATCC 25923, Salmonella typhimurium ATCC 13311, and Bacillus cereus ATCC 14579 were selected as food poisoning bacteria. Each strain was used in a tryptic soy broth (TSB) medium (Becton, Dickinson and Company, Sparks, MD, USA) at 37 ° C for 20-24 hours.

The CDPJ germicidal effect according to the distance from the plasma discharge port in the corona discharge plasma jet (CDPJ) treatment is shown in Table 3 below.

From the results of Table 3, it is found that the distance from the plasma discharge port when producing the corona discharge plasma jet is 15 to 35 mm, more preferably 15 to 20 mm, in order to obtain the optimum sterilization effect according to the CDPJ treatment.

The results of the CDPJ sterilization effect according to the current intensity during the CDPJ treatment are shown in Table 4 below.

From the results in Table 4, in order to obtain an optimal sterilization effect according to the CDPJ treatment, the sterilizing power was improved as the current intensity increased.

Therefore, the preferable current intensity at the time of CDPJ generation was 1.00 to 1.50 A, and most preferably 1.50 A.

As a result of observing the change of sterilization value according to CDPJ treatment time, the sterilization effect on E. coli was the most excellent, followed by the sterilization effect of Staphylococcus and Salmonella. On the other hand, the bactericidal effect of Saccharomyces cerevisiae and Cereus bacteria was relatively low, but also in this case, the number of microbes decreased to 2 log by CDPJ treatment for 1 minute.

Table 5 below shows the germicidal effect of CDPJ treatment of the target microorganisms.

From the above results, the sterilization by the CDPJ treatment showed a sterilization pattern of the first reaction in two steps. Specifically, the killing rate constant (k ₁ ) of E. coli was the highest at 12.810 min ^-1 , followed by staphylococci and salmonella at 7.510 min ^-1 and 8.325 min ^-1 , respectively.

On the other hand, the late sterilization rate constant (k ₂ ) was not significantly different from 1.479 to 3.449 min ^-1 .

In addition, the sterilization curve shape factor (n) for CDPJ treatment by strain was in the range of 0.490 ~ 0.828 and the yeast was slightly higher than that of bacteria. D 'value was the most sensitive to Escherichia coli (0.063 min) and the other bacteria were 0.228 ~ 0.295 min.

Example 1 Cereal sterilization using dielectric barrier discharge plasma (DBDP)

Dielectric Barrier Discharge Plasma (DBDP) was applied to the cereals of white rice (Okcheon Nonghyup RPC, Haenam) and Korean Red Peppermint Respectively.

≪ Example 2 > A corona discharge plasma jet (CDPJ) Used cereal sterilization

Corona Discharge Plasma Jet (CDPJ) was added to the cereals of white rice (Okinawa Nonghyup RPC, Haenam) and Korean Red Pepper (Okmae Nonghyup RPC, Haenam) Lt; / RTI >

≪ Comparative Example 1 > A low pressure discharge plasma (LPDP) Used cereal sterilization

Reduced pressure discharge plasma (LPDP) was treated with air plasma at 105 W for 10 minutes to the cereals of white rice (Gapjunami rice, Okcheon Nonghyup RPC, Haenam)

≪ Experimental Example 1 > Sterilization effect versus treatment time for each low-temperature plasma type

1. Measurement of sterilization rate constant

The disinfection value (log (N ₀ / N)) versus treatment time for white rice and pressurized meats for each type of low temperature plasma used in Examples 1 and 2 and Comparative Example 1 was monitored.

The results are shown in FIG. 3 and FIG. 4 , and the sterilization rate constants for the cereal foods of the rice white or the crusher were calculated. The results are shown in Table 6 below.

From the results of the sterilization rate constants for each type of rice of the cereals of the rice or paddy field in Table 1, the sterilization pattern for the cereal food was confirmed as a two-stage first-order reaction.

More specifically, when comparing the first sterilization stage speed according to the kind of bacteria plasma constant (k _1), white rice is corona discharge plasma jet (CDPJ)> the dielectric barrier discharge plasma (DBDP) >> pressure discharge plasma (LPDP) Respectively.

In the case of the pressure vessel, the dielectric barrier discharge plasma (DBDP), the dielectric barrier discharge plasma (DBDP), and the reduced pressure discharge plasma (LPDP) were lowered in the order.

On the other hand, the sterilization rate constant (k ₁ ) for each type of fungus was determined by the order of corona discharge plasma jet (CDPJ)> dielectric barrier discharge plasma (DBDP) and decompression discharge plasma (LPDP) Respectively.

At this time, the germicidal rate constant (k ₁ ) of white rice was somewhat higher than that of the pressurized rice according to the cereals. Based on these results, the germicidal power of the corona discharge plasma jet (CDPJ) and the dielectric barrier discharge plasma (DBDP) It was a reasonable level.

On the other hand, the disinfection effect of LPDP on cereal food was remarkably low.

2. Measurement of sterilization curve shape factor (n) and D 'value

The shape coefficient (n) and the D 'value (D'-value) of the sterilization curve for each kind of plasma of rice or pomace are calculated and are shown in Table 7 below.

In the above, D'-value is expressed in minutes in terms of the time required for microbial treatment at a constant temperature to kill 90% of bacteria, which is reduced to 1/10.

From the results shown in Table 7, the shape coefficient (n) of the sterilization curve for the cereal products of rice or pomace bean was 0.314 to 0.930, which was relatively wide, but all of them had a convex curve of 1.0 or less.

The D 'value for white rice bacteria was the smallest 0.518 min in the corona discharge plasma jet (CDPJ), followed by 1.475 min in the dielectric barrier discharge plasma (DBDP), and 27.931 min in the reduced pressure discharge plasma (LPDP) , It took the longest time to kill bacteria.

The DDP values for the bacterium were lower than those for the dielectric barrier discharge plasma (DBDP) and the corona discharge plasma jet (CDPJ) at 0.292 min and 1.693 min, respectively. DBDP was lower than that of decompressed discharge plasma (LPDP) The results are shown in Fig.

The D 'value for fungi showed the smallest value in the corona discharge plasma jet (CDPJ), followed by the dielectric barrier discharge plasma (DBDP).

On the other hand, the decompression discharge plasma (LPDP) is about 10 times larger than the corona discharge plasma jet (CDPJ) or the dielectric barrier discharge plasma (DBDP), and the bactericidal effect on the fungus in the cereal food is CDPJ> DBDP >> LPDP Respectively.

From the above results, it has been confirmed that the corona discharge plasma jet (CDPJ) and the dielectric barrier discharge plasma (DBDP) can be applied as disinfection technology in the field of grain food manufacturing or distribution.

From the above results, plasma can be selectively used depending on the type of the cereal food.

That is, since the contact area with the plasma is different, the plate-like pressure vessel is exposed to DBDP vertically from top to bottom, and the relative area exposed to the DBDP is 50%, which is larger than that of the ellipsoid, Sterilization value.

However, in the case of the corona discharge plasma jet (CDPJ) injected in the three-dimensional direction, one side of the pressure vessel is in contact with the bottom so that only 50% of the total surface area is exposed to the plasma, It has been confirmed that the sterilization effect is realized because more plasma reaches the surface of the white rice because it is exposed.

Example 3 Disinfection of Food Containing Water by Dielectric Barrier Discharge Plasma (DBDP)

The dielectric barrier discharge plasma (DBDP) was applied to the foodstuffs of Kim (Hwang Paejong Kim, Samil Food Co., Yongin) and alfalfa sprouts (Sprout group, 2.65 mm for 2 minutes.

Example 4 Corona Discharge Plasma Jet (CDPJ) Sterilization of foods containing water

Corona Discharge Plasma Jet (CDPJ) was applied to the foodstuffs of Kim (Sunpalgyeong Kim, Samil Food Co., Yongin) and alfalfa sprouts (Sprout group, Lt; / RTI > for 2 minutes.

≪ Comparative Example 2 > A low pressure discharge plasma (LPDP) Sterilization of foods containing water

Reduced pressure discharge plasma (LPDP) was applied to the foods of Kim (Hat Paya Traditional Korean Kim, Samil Food Co., Yongin) and alfalfa sprouts (Sprout group, Respectively.

≪ Experimental Example 2 > Sterilization effect versus treatment time for each kind of low temperature plasma

1. Measurement of sterilization rate constant

As the water-containing foodstuffs for each of the low-temperature plasma types used in Examples 3 to 4 and Comparative Example 2 The total number of bacteria (log (N ₀ / N)) was monitored for the treatment time for the alfalfa sprouts of Kim or vegetable.

The results are shown in Fig. 5 and Fig. 6 , and the sterilizing rate constants for each kind of plasma of the water-containing foods were calculated. The results are shown in Table 8 below.

As a result of the above Table 3, comparing the first-step sterilization rate constant (k ₁ ) to bacteria according to the type of plasma for Kim and alfalfa sprouts, it was found that in both Kim and alfalfa sprouts, the corona discharge plasma jet (CDPJ) (DBDP) and decompression discharge plasma (LPDP). The difference between CDPJ and DBDP was not large, but k ₁ of LPDP was about 1/10 of DBDP.

This tendency was similarly confirmed for fungi, confirming that CDPJ and DBDP have significant sterilizing power, and the low temperature plasma can be applied to actual food production sites.

2. Measurement of sterilization curve shape factor (n) and D 'value

Selected as a moisture-containing food The shape coefficient (n) and the D 'value (D'-value) of the sterilization curve for each kind of plasma of the Kim or vegetable alfalfa sprouts were calculated and described in Table 9 below.

As can be seen from the results of Table 4, the shape coefficient (n) of the sterilization curves for the plasma and the alfalfa sprouts was 0.422-0.858. The D 'value for bacteria was 0.112 min, which is the smallest value in dielectric barrier discharge plasma (DBDP) for Kim, 0.599 min for Corona Discharge Plasma Jet (CDPJ) and 3.384 min for Reduced Pressure Discharge Plasma (LPDP) .

In other words, DBP was the most effective bactericidal effect against germs of Kim, and CDPJ was also found to be considerable.

On the other hand, for fungi, the corona discharge plasma jet (CDPJ) showed a smaller D 'value than the dielectric barrier discharge plasma (DBDP), showing more effective sterilization effect.

The D 'values for the bacteria of alfalfa sprouts were 0.426 minutes and 0.599 minutes for CDPJ and DBDP, respectively, while CDPJ values were lower, while decompression discharge plasma (LPDP) was 5.937 minutes.

The D 'value for the fungi of alfalfa sprouts was 0.699 minutes in the dielectric barrier plasma (DBDP) and 1.227 minutes in the corona discharge plasma jet (CDPJ), confirming that the bactericidal effect of DBDP was better. These results showed that DBDP and CDPJ methods could be applied to surface sterilization of moisture - containing foods such as Kim and alfalfa sprouts.

From the above results, the disinfection method using the dielectric barrier discharge plasma (DBDP) and the corona discharge plasma jet (CDPJ) has a similar level of sterilizing power between the plasma and the plasma, and a suitable plasma can be selected according to the size and shape of the food.

That is, a dielectric barrier discharge plasma (DBDP) is suitable for flat plate type foods such as Kim and Tang Ma, and a corona discharge plasma jet (CDPJ) can be applied to irregular shaped foods such as white rice, alfalfa sprouts and fruit vegetables.

As described above, the present invention provides a method of sterilizing a food surface using a low-temperature plasma by optimizing the bactericidal effect of a microorganism on the surface of a food or a food by selecting plasma and processing conditions suitable for the shape and surface characteristics of a food group.

The present invention provides a sterilization method capable of killing microorganisms on a surface of a food material or a foodstuff in a flat plate shape, that is, a pressurized surface or a kimchi surface, under optimal conditions using a dielectric barrier discharge plasma as a low-temperature plasma.

The present invention also provides a method for surface sterilization of non-flat plate type foodstuffs or foods or fruits or vegetables having high moisture content by corona discharge plasma jet treatment in a low-temperature plasma, As shown in FIG.

Furthermore, it is possible to decompose the residual pesticide component on the surface of food or food using the low temperature plasma of the present invention.

While the invention has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (9)

A food surface sterilization method using a low temperature plasma treatment of food or food by low temperature plasma treatment to kill microorganisms on the surface of the food or food. The method according to claim 1, wherein the low temperature plasma is a dielectric barrier discharge plasma (DBDP) or a corona discharge plasma jet (CDPJ). The method of claim 2, wherein the dielectric barrier discharge plasma is 0.50 ~ 50.0mm electrode spacing The sterilization method characterized in that the vertical treatment under the conditions. The method according to claim 3, wherein the dielectric barrier discharge plasma is applied to the surface sterilization of food materials or foods in the form of a flat plate. According to claim 3, wherein the sterilization method, characterized in that the food material or food in the form of flat plate or laver. The method according to claim 3, wherein the target sample is subjected to a single echo or a bidirectional movement method during the dielectric barrier discharge plasma treatment. The sterilization method according to claim 2, wherein the corona discharge plasma jet (CDPJ) is sprayed at a distance of 5.0 to 150.0 mm from the plasma discharge port. The method according to claim 7, wherein the corona discharge plasma jet is sterilized in three directions with respect to the surface of the non-flat plate or food. The method according to claim 7, wherein the corona discharge plasma jet is applied to the surface sterilization of fruits or vegetables with high moisture content.

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