KR101850629B1 - Composition comprising nanostructure layered double hydroxide with antimicrobial agent for shelf-life extension of fresh-cut produce - Google Patents

Abstract

The present invention relates to a composition for maintaining the freshness of fresh-cut farm produce, containing a nanostructure of a metal bilayer hydroxide including an antibacterial agent. To bring antibacterial properties when packing fresh-cut farm produce, various antibacterial molecules are used, but since anionic molecules among the antibacterial molecules have low volatility, the molecules are not easily released into the atmosphere, and a carrier needs to be used for neutral molecules having a strong scent, but the molecules do not get along with the carrier, so emission control is not easy. Thus, in the present invention, anionic cinnamic acid is first arranged in a nanosubstance of a metal bilayer hydroxide, which is highly familiar with anionic molecules, and then, a cinnamic aldehyde, which is a neutral molecule, is arranged with cinnamic acid-cinnamic aldehyde intermolecular gravitation to make continuous emission possible.

Description

[0001] The present invention relates to a composition for preserving a freshly sliced agricultural product containing a metal double-layer hydroxide nanostructure on which an antimicrobial agent is supported,

The present invention relates to a composition for keeping a fresh edible agricultural product containing a metal double layer hydroxide nanostructure on which an antimicrobial agent is supported.

In general, the purchase tendency of food changes according to the surrounding environment condition. Recently, food consumption trend shows a tendency to change from the previous nutrition consumption to health orientation and convenience pursuit. As a result of these changes, the increase in consumption of agricultural products such as fruits and vegetables is remarkable among food materials. Especially, in the recent well-being era, consumption tendency of agricultural products, which are harvested and supplied directly from the mountain rather than processed products of fruits and vegetables, is rapidly growing.

The fresh-cut agricultural products are agricultural products, such as fruits and vegetables, which are used as raw materials, while keeping their freshness and simplicity in use. Their shapes vary greatly depending on the characteristics and uses of raw materials. It does not have the same processing, so the cells of the tissue are alive and can take in the intrinsic influence components of the product, and it has the characteristic of good texture and flavor.

As consumers are increasingly becoming more and more preferred for ready-to-eat agricultural products, it is necessary to move away from the method of circulating and storing large-scale fruits and vegetables, for example, in the form of boxes, It is necessary to distribute only the parts that can be consumed in the mountainous area like a small scale and deliver it directly to consumers.

On the other hand, when processing the fresh sliced agricultural products, the cell structure of the cut surface is destroyed, so that rapid increase of respiration and enzyme activity are caused and the storage life is shortened. In order to prevent oxidative browning of the cut surface, a method of reducing the amount of oxygen through an antioxidant and MAP method is used.

Layered Double Hydroxide (LDH), also called hydrotalcite-like compound, has a structure similar to that of hydrotalcite composed of a double-layer hydroxide structure of zinc and aluminum, Quot; refers to a compound that can be substituted with an alkali metal. The metal double layer hydroxide is positively charged by the layer itself due to the presence of trivalent metal ions in the layer, and can introduce various anions into the layer.

The inventors of the present invention have been studying various methods of preserving fresh-cut agricultural products, and have found that a composition comprising cinnamic acid and cinnamic aldehyde, which are antimicrobial agents having an anion in the metal double-layer hydroxide layer, And confirmed the present invention.

Korean Patent No. 10-1168106, entitled "Antimicrobial Composition for Coating and Antimicrobial Food Packaging Material Using the Same, Applicant: Korea University Industry-Academic Cooperation Agency, Registered Date: July 17, 2012) Korean Patent Laid-Open No. 10-2016-0120411 (entitled: Multifunctional Carbon Dioxide Absorbent for Packaging Fresh Agricultural Products and Fermented Foods and Method for Preventing Damage Using the Applicant: Hanbat National University Industry & University Cooperation Agency, Publication Date: May 24, 2014)

It is an object of the present invention to provide a composition for keeping a freshly sliced agricultural product containing a metal double layer hydroxide nanostructure on which an antimicrobial agent is supported.

The present invention relates to a composition for keeping a fresh edible agricultural product containing a metal double layer hydroxide nanostructure on which an antimicrobial agent is supported.

The antimicrobial agent may include cinnamic acid and cinnamaldehyde.

The divalent metal constituting the metal double layer hydroxide is selected from the group consisting of magnesium (Mg ²⁺ ), calcium (Ca ²⁺ ), zinc (Zn ²⁺ ), and combinations thereof, The trivalent metal may be selected from the group consisting of aluminum (Al ³⁺ ), iron (Fe ³⁺ ), and combinations thereof.

The fresh sliced agricultural produce may be selected from fruits, vegetables, mushrooms and edible fodder crops harvested directly from the mountain.

The fresh-cut agricultural produce may be a commercialized product after finishing, peeling, or cutting the agricultural produce harvested in the mountain area, followed by washing and packaging treatment.

The composition may be coated with an anionic polymer. The anionic polymer may be polymethacrylic acid. The polymethacrylic acid may be selected from the group consisting of butyl methacrylate- (2-dimethylaminoethyl) methacrylate-methyl methacrylate copolymer, ethyl acrylate-methyl methacrylate copolymer, ethyl acrylate-methyl methacrylate- Acrylate copolymer, and a mixture thereof.

In another aspect, the present invention provides a method for producing a composition for keeping a freshly sliced agricultural product straight. Preferably,

(Step 1) A salt solution containing a divalent metal-containing metal nitrate salt and a nitric acid metal salt having a trivalent metal and a cinnamic acid solution are mixed and dried to obtain a metal double layer hydroxide nanostructure carrying the cinnamic acid step;

(Step 2) drying and crushing the precipitate obtained by dispersing the cinnamic acid-bearing metal double layer hydroxide nanostructure in a cinnamaldehyde solution to obtain cinnamic acid and cinnamic aldehyde-loaded metal double layer hydroxide nanostructure; And

(Step 3) a step of dispersing a metal double layer hydroxide nanostructure carrying cinnamic acid and cinnamic aldehyde in an anionic polymer solution and drying and pulverizing the resulting precipitate to obtain a polymer-coated nanostructure;

. ≪ / RTI >

Hereinafter, the present invention will be described in detail.

The present invention relates to a composition for keeping a fresh edible agricultural product containing a metal double layer hydroxide nanostructure on which an antimicrobial agent is supported. The antimicrobial agent may include cinnamic acid or cinnamic aldehyde, and it is preferable that it contains both cinnamic acid and cinnamic aldehyde.

The divalent metal constituting the metal double layer hydroxide is selected from the group consisting of magnesium (Mg ²⁺ ), calcium (Ca ²⁺ ), zinc (Zn ²⁺ ), and combinations thereof, The trivalent metal may be selected from the group consisting of aluminum (Al ³⁺ ), iron (Fe ³⁺ ), and combinations thereof, wherein the interlayer distance in the metal double layer hydroxide is preferably 1.7 to 2.0 nm. When the interlayer distance is less than 1.7 nm or more than 2.0 nm, it may be difficult to support the antimicrobial agent.

The composition may be coated with an anionic polymer. The anionic polymer may be polymethacrylic acid. The polymethacrylic acid which can be used in the present invention can be selected from the group consisting of butyl methacrylate- (2-dimethylaminoethyl) methacrylate-methyl methacrylate copolymer, ethyl acrylate-methyl methacrylate copolymer, ethyl acrylate-methyl methacrylate -Trimethylaminoethyl methacrylic acid chloride copolymer, and mixtures thereof. The polymethacrylic acid preferably has a weight average molar mass (Mw) of 50,000 to 500,000, preferably 100,000 to 200,000 Mw. When polymethacrylic acid of less than 50,000 Mw and polymethacrylic acid of more than 500,000 Mw are used, the release of the antimicrobial agent may not be well controlled.

The butylmethacrylic acid- (2-dimethylaminoethyl) methacrylic acid-methylmethacrylic acid copolymer preferably has a molar ratio of butyl methacrylic acid, (2-dimethylaminoethyl) methacrylic acid and methyl methacrylic acid of 1: 2 : 1 is more preferable. The trade name may be Eudragit E 100, Eudragit E 12.5, or Eudragit E PO from Evonik Degussa (Germany).

It is more preferable that the ethyl acrylate-methyl methacrylate copolymer has a molar ratio of ethyl acrylate to methyl methacrylate of 2: 1. Examples of the product names include Eudragit NE 30D, Eudragit NE 40D and Eudragit NM 30D from Ebonic Degussa (Germany).

The ethyl acrylate-methylmethacrylate-trimethylaminoethyl methacrylate chloride copolymer preferably has a molar ratio of ethyl acrylate, methyl methacrylate and trimethyl aminoethyl methacrylate chloride of 1: 2: 0.2, Products such as Eudragit RL 100, Eudragit RL PO, Eudragit RL 30D, Eudragit RL 12.5 from Germany can be used. Or a mixture of ethyl acrylic acid, methyl methacrylic acid and trimethylaminoethyl methacrylic acid chloride in a molar ratio of 1: 2: 0.1 may be used, and examples thereof include Eudragit RS 100, Eudragit RS PO, Eudragit RS 30D, You can use products such as RS 12.5.

In the method of producing the composition for keeping the fresh edible agricultural product of the present invention,

(Step 1) A precipitate formed by mixing a nitrate metal salt solution containing a divalent metal and a nitrate metal salt solution containing a metal nitrate having a trivalent metal and cinnamic acid solution was dried and crushed to prepare a metal double layer hydroxide nanostructure carrying cinnamic acid In the obtaining step,

The concentration of the nitrate metal salt having a bivalent metal in the salt solution is preferably 0.005 to 0.1 M. The concentration of the solution of the nitrate metal salt having a trivalent metal is preferably 0.001 to 0.02 M, 0.2M. The mixed volume ratio of the salt solution: cinnamic acid solution is preferably 1: 0.5 to 2. At this time, formation of metal double layer hydroxide and supporting of cinnamic acid may be difficult when the concentration range or the mixing volume range is out of the range. The salt solution or the solvent of cinnamic acid is preferably an alcohol, and it is most preferably an aqueous solution of an alcohol, more preferably an aqueous solution of 50 to 90% (v / v). As the alcohol, ethanol may be used.

After the salt solution and the cinnamic acid solution are mixed in the first step, the metal solution in which the cinnamic acid is dissolved is titrated with an alkali solution until the pH is 7.5, thereby forming a precipitate of the cinnamic acid-supported metal double layer hydroxide nanostructure .

(Step 2) In the step of obtaining a metal double layer hydroxide nanostructure containing cinnamic acid and cinnamic aldehyde by drying and pulverizing a precipitate obtained by dispersing the cinnamic acid-bearing metal double layer hydroxide nanostructure in a cinnamaldehyde solution,

A metal double layer hydroxide nanostructure having 0.5 to 2.0 g of cinnamic acid supported on 300 to 700 mL of 7 to 13 equivalents of a cinnamaldehyde solution (solvent: alcohol, preferably 50 to 90 (v / v)% of alcohol aqueous solution) Can be dispersed. At this time, when the concentration range or the mixing range is out of the range, it may be difficult to carry the cinnamic aldehyde into the metal double layer hydroxide.

(Step 3) In the step of obtaining a nanostructure coated with a polymer by drying and pulverizing a precipitate formed by dispersing a metal double layer hydroxide nanostructure carrying cinnamic acid and cinnamic aldehyde in an anionic polymer solution,

0.1 to 0.5 g of anionic polymer is dissolved in 100 to 500 ml of alcohol, and 0.5 to 2 g of cinnamic acid and cinnamic aldehyde-supported metal double layer hydroxide nanostructures can be dispersed. At this time, if the mixing range, the proper volume and the weight are out of the range, the coating of the anionic polymer may not be performed well.

The precipitates in the first to third steps may be obtained by centrifugation and may be washed with an aqueous 50 to 90% (v / v) alcohol solution. The centrifugation and washing may be repeated several times. Also, a process of stirring for 1 minute to 1 hour may be added before centrifugation so that the precipitate formation in each step is good.

The present invention relates to a composition for keeping a fresh edible agricultural product containing a metal double layer hydroxide nanostructure on which an antimicrobial agent is supported. Although various antimicrobial molecules are used to exhibit antimicrobial activity in the packaging of agricultural products, the anionic molecules in antimicrobial molecules have low volatility and are difficult to release in the air. It is difficult to control the release because of its low affinity for retardation. Accordingly, in the present invention, anionic cinnamic acid is first arranged in a metal double layer hydroxide nanomaterial having a high affinity for an anionic molecule, and the neutral molecule, cinnamic aldehyde, is arranged in an intermolecular attraction between cinnamic acid and cinnamic aldehyde to enable continuous release.

Korean Patent No. 10-1168106 and Korean Patent Laid-Open No. 10-2016-0120411 disclose a technology relating to food packaging materials using cinnamaldehyde, and such food packaging materials can be introduced into layered packaging materials It has not been disclosed that nanostructures of metal double layer hydroxides carrying cinnamic acid and cinnamic aldehyde as described in the present invention can be used as an antimicrobial agent for agricultural products with a shed release.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic view of a metal double layer hydroxide nanostructure carrying cinnamic acid prepared in Example 1-1. FIG.
Fig. 2 shows X-ray diffraction analysis (left) and scanning electron microscope image (right) of the metal double layer hydroxide nanocomposite prepared in Example 1-1.
Fig. 3 is a schematic view of a metal double layer hydroxide nanostructure carrying cinnamic acid and cinnamic aldehyde supported thereon prepared in Example 1-2. Fig.
4 shows X-ray diffraction analysis (left) and scanning electron microscope image (right) of cinnamic acid and cinnamic aldehyde-supported metal double layer hydroxide nanostructures prepared in Example 1-2.
FIG. 5 shows changes in properties of the metal double layer hydroxide nanostructures produced in Examples 1-2 and 1-3 according to whether the polymer treatment is carried out or not.
6 shows the surface charge analysis results of the metal double layer hydroxide nanostructures prepared in Examples 1-2 and 1-3 according to the presence or absence of the polymer treatment.
FIG. 7 shows the results of evaluating the release of antimicrobial molecules according to whether or not the polymer treatment of the metal double layer hydroxide nanostructures prepared in Examples 1-2 and 1-3 was conducted.
FIG. 8 shows changes in the total number of bacteria in the vacuum packed onion slices and fracas after storage of the metal double layer hydroxide nanostructures (CLC) prepared in Example 1-3 at 4 ° C during storage.
FIG. 9 shows changes in the number of E. coli cells stored at 4 ° C. in vacuum packaged onion slices and fracas after sealing the metal double layer hydroxide nanostructure (CLC) prepared in Example 1-3.
Fig. 10 shows the decay rate of the onion slice vacuum-packaged after sealing the metal double layer hydroxide nanostructure (CLC) prepared in Example 1-3 at 4 캜 during the storage period.
FIG. 11 shows the decay rate during storage at 4 ° C. of the vacuum-packed wraps after the metal double layer hydroxide nanostructures (CLC) prepared in Example 1-3.
12 shows the decay rate during storage at 4 캜 of vacuum packaged cabbage dies after sealing the metal double layer hydroxide nanostructure (CLC) prepared in Example 1-3.

Hereinafter, preferred embodiments of the present invention will be described in detail. However, the present invention is not limited to the embodiments described herein but may be embodied in other forms. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art.

≪ Example 1: Synthesis of metal double layer hydroxide nano structure carrying antimicrobial agent >

Cinnamic acid and cinnamaldehyde-loaded metal double layer hydroxide nanostructures (CLC) with antibacterial activity were synthesized according to the following procedure.

Example 1-1. Synthesis of Cinnamic Acid Supported Metal Double Layered Hydroxide Nanostructures

Under a nitrogen atmosphere, a salt solution containing 0.03 M of Zn (NO ₃ ) ₂ .6H ₂ O and 0.0075 M Al (NO ₃ ) ₃ .9H ₂ O and 0.0675 M of cinnamic acid solution was added to a round bottom flask in an equal volume (The solvent of each solution was 70 (v / v)% aqueous solution of ethanol), and the metal solution in which cinnamic acid was dissolved was titrated with 0.625 M NaOH solution until the pH reached 7.5. The resulting metal double layer hydroxide nanostructure suspension was reacted for 24 hours under nitrogen atmosphere, and the precipitate was collected by centrifugation and washed with 70 (v / v)% ethanol aqueous solution 2-3 times. The washed precipitate was lyophilized, and the dried solids were pulverized in the form of powder with agate to obtain a metal double layer hydroxide nanostructure carrying the cinnamic acid having the structure shown in Fig.

The X-ray diffraction analysis and the scanning electron microscopic image of the nanostructure are shown in FIG. 2. In the case of the X-ray diffraction pattern of the synthesized nanostructure, hydrotalcite , JCPDS No. 14-0191) similar compounds. It is also confirmed that the lattice peaks (003) of the two-dimensional layered structure appear at 3.6 degrees with an appropriate interlayer spacing (~ 1.8 nm), so that the cinnamic acid molecules are properly arranged between the metal hydroxide layers. Quantitative analysis of the metal double layer hydroxide nanostructure carrying cinnamic acid (CA) showed that the nanostructure had the following chemical formula [Zn ₄ Al (OH) ₁₀ (CA) _2.08 · 0.1H ₂ O] Is confirmed.

Examples 1-2. Synthesis of Metal Double Layered Hydroxide Nanostructures Containing Cinnamic Acid and Cinnamic Aldehyde

The content of cinnamic acid in the metal double layer hydroxide nanostructure into which cinnamic acid was introduced was quantified by high performance liquid chromatography in order to introduce the volatile antimicrobial molecule cinnamaldehyde into the metal double layer hydroxide nanostructure carrying the cinnamic acid. High performance liquid chromatography was performed by dissolving all of the metal hydroxides using a pH 2.0 phosphate buffer solution, and then quantifying the solution under the following conditions.

Appliances: YL9100 series

Mobile phase and conditions: Acetic acid (0.5% v / v%) / distilled water / acetonitrile, 1.0 mL / min

Columns and conditions: C18 column (ZOBAX Eclipse, 4.6 mm x 150 mm, Agilent)

UV-visible light detector wavelength: 276 nm

The quantitative results obtained by high performance liquid chromatography were used to disperse a metal double layer hydroxide nanostructure carrying 1.0 g of cinnamic acid on 500 mL of a 10-equivalent amount of cinnamic aldehyde solution (70 (v / v)% aqueous solution of ethanol) Respectively. Next, the reaction was carried out under nitrogen condition for 24 hours, and the precipitates were collected by centrifugation and washed 2-3 times with 70 (v / v)% aqueous ethanol solution. The precipitate obtained after washing was lyophilized and the dried solid matter was pulverized in the form of powder with agate to obtain cinnamic acid and cinnamic aldehyde-supported metal double layer hydroxide nanostructure having the structure shown in FIG. 3, and X-ray diffraction analysis and injection An electron microscope image is shown in Fig.

In the case of the metal double layer hydroxide nanostructures bearing the cinnamic acid and cinnamic aldehyde thus obtained, the above pattern is the same as the X-ray diffraction pattern of the metal double layer hydroxide nanostructure carrying cinnamic acid. Therefore, the crystalline structure of the metal double layer hydroxide nanostructure It is confirmed that the structure is maintained. It is also expected that lattice peaks (003) appear at 3.6 degrees with appropriate interlayer spacing (~ 1.8 nm) and that cinnamic acid molecules and cinnamic aldehyde molecules are arranged by pi-pi interactions between benzene rings between cinnamic acid molecules do.

Cinnamic acid (CA) and cinnamon aldehyde (CNA) the formula through a quantitative analysis of the metal hydroxide bilayer nanostructure supported as follows: _{[Zn 4 Al (OH) 10} · (CA) 1.47 (CNA) 0.45 · 0.1H 2 O ]. ≪ / RTI >

Examples 1-3. Polymer coating of metal double layer hydroxide nano structure carrying cinnamic acid and cinnamic aldehyde

Eudragit ( ^R) L100, an anionic polymer used in medicine, was selected as a polymer to be introduced onto the surface of cinnamic acid and cinnamic aldehyde-loaded metal double layer hydroxide nanostructures prepared in Example 1-2. 0.247 g of Eudragit ( ^R) L100 was dissolved in 250 mL of ethanol, and 1 g of cinnamic acid and cinnamic aldehyde-supported metal double layer hydroxide nanostructures were dispersed and then stirred for 10 minutes. After stirring, the precipitates were collected through centrifugation, and then lyophilized. The dried solid was pulverized in the form of powder with agate to obtain an anionic polymer-coated nanostructure.

FIG. 5 is a scanning electron microscope (SEM) photograph showing changes in properties before and after the polymer is coated on the metal double layer hydroxide nanostructure carrying cinnamic acid and cinnamic aldehyde, and the results of the surface charge analysis before and after the polymer coating are shown in FIG. 6 Respectively.

Referring to FIG. 5, the nanostructure of the nanostructure was observed to have a size of about several hundreds of nanometers, and the surface of the nanostructure was covered with a polymer on the surface of the nanostructure after the polymer treatment It was confirmed that the polymer was introduced on the surface of the nanostructure.

The effect of the polymer treatment on the surface positively chargeability can be evaluated by surface charge analysis. Referring to FIG. 6, both of the nanostructures before and after the polymer treatment are about 28 mV and 19 mV, and the positive charge of the original metal double layer hydroxide is well preserved . Therefore, it can be seen that the polymer treatment does not greatly affect the surface charge of the nanostructure.

Examples 1-4. Evaluation of Antibacterial Molecule Emission from Nanostructures with Antimicrobial Molecules

40 mg of the sample before and after the surface treatment of the nanostructure was dispersed in 200 mL of distilled water using an anionic polymer. 1 mL of the supernatant was taken at a fixed time (5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes, 45 minutes, 1 hour, 2 hours, 3 hours, 6 hours, 12 hours, 24 hours) The nanostructures present in the supernatant were removed through a 0.45 μm syringe filter. The amount of cinnamic acid and cinnamaldehyde released from the supernatant from which the nanostructure was removed was evaluated by high performance liquid chromatography (HPLC). The evaluation conditions are as follows.

Appliances: YL9100 series

Mobile phase and conditions: Acetic acid (0.5% v / v%) / distilled water / acetonitrile, 1.0 mL / min

Columns and conditions: C18 column (ZOBAX Eclipse, 4.6 mm x 150 mm, Agilent)

UV-visible light detector wavelength: 276 nm

The result of the emission amount confirmation is shown in FIG. 7. As shown in FIG. 7, the antimicrobial molecular emission in the distilled water over time was evaluated, and in the case of the nanostructure before the polymer treatment, about 100% of the cinnamaldehyde after about 45 minutes and about 60% Is released. On the other hand, in the case of the polymer-introduced nanostructures, about 80% of cinnamic aldehyde was released after about 5 hours, and about 60% of the cinnamic acid was released after about 24 hours.

In addition, kinetic analysis of the antimicrobial molecular emission was performed (see Table 1), and it can be seen that the supported cinnamic acid and cinnamic aldehyde follow the parabolic and Elovich models, which are typical release kinetics, so that emission control is possible .

Solvent sample Emission model Regression equation R ²

Symptom
Flow
Number Before /
Cinnamic acid Parabolic diffusion C _t = 0.0174 t _0.5 + 0.0113 0.9700 R = 0.0174 Before /
Cinnamaldehyde Elovich equation C? _T = 2.609? N (t) - 8.600 0.6156 a = 5431.66, b = 2.609 After the polymer treatment /
Cinnamic acid Parabolic diffusion C _t = 0.0143 t _0.5 + 0.0473 0.9510 R = 0.0143 After the polymer treatment /
Cinnamaldehyde Elovich equation C _t = 0.0768 ln (t) + 0.1433 0.8837 a = 1.154, b = 0.0768

< Example  2. The structure of the nanostructure Fresh side  Applying agricultural products distribution process>

Example 2-1. Antimicrobial effect of fresh edible products containing nanostructures during storage

The following experiment was conducted to confirm the antimicrobial effect of cinnamic acid coated with an anionic polymer and cinnamic aldehyde-loaded metal double layer hydroxide nanostructure (hereinafter referred to as CLC) finally prepared in Example 1-4.

Onion slices, wedges, and cabbage dice with a thickness of 5 mm were used as the fresh slices. In the experimental group, 1 g of CLC packed in a miter pore film was sealed together and vacuum packed. The total number of bacteria (the number of bacteria) in the food during the storage period of 4 ° C, And E. coli. The antimicrobial effect was investigated. The results are shown in FIGS. 8 and 9.

At this time, 100 g of each sample for the microbial analysis was taken into a sterilized pack. 25 g of the sample was taken into a filter bag, and 225 mL of sterilized physiological saline was poured into the stomacher for 2 minutes, The test solution was inoculated into petrifilm (3M, USA) and incubated at 35-37 ° C for 24 hours. The total number of bacteria was counted and the number of colony formed was counted.

Referring to FIG. 8, it was confirmed that the number of total bacteria was decreased in the onion slices and the fracas filled with CLC, and in FIG. 9, the number of E. coli bacteria in the packed treatments enclosed with CLC was also slightly reduced.

10 to 12 show that the decay rate in the CLC-treated group is suppressed. The decay rate is defined as "(number of bacteria at the time of measurement - (Number of bacteria at the start of the experiment) / number of bacteria at the start of the experiment x 100% ", and the measurement points are 3 days, 5 days, and 7 days, respectively.

In addition to these experiments, the nano-structure, cinnamic acid and cinnamic aldehyde prepared in Example 1-1 and Example 1-2 were treated on the onion slices in the same manner as the comparative composition for CLC to confirm the decay rate.

Condition Decay rate of onion slices (%) 3 days 5 days 7 days Control group (untreated group) 27.7 28.4 30.0 Example 1-3 Nanostructure (CLC) 1 g
(Cinnamic acid 0.3 g, cinnamic aldehyde 0.081 g) 6.3 14.3 17.1 Example 1-2 Nanostructure 1 g
(Cinnamic acid 0.3 g, cinnamic aldehyde 0.081 g) 6.7 19.7 23.3 Example 1-1 Nanostructure 1 g
(Cinnamic acid 0.4 g) 22.1 24.2 28.2 Cinnamic acid 0.3 g 21.6 23.7 27.2 0.081 g cinnamaldehyde 4.2 15.4 21.0 Mix cinnamic acid 0.3g + cinnamic aldehyde 0.081g 14.3 18.7 23.1

Referring to the results of FIGS. 10 to 12 and Table 2, it can be seen that each of the fresh-cut agricultural products treated with CLC prepared in Example 1-3 had the best decay delay effect. The initial decay rate of the cinnamaldehyde compound itself or the uncoated nanostructure (Example 1-2) was low, but there was little difference from the control group over time. Thus, it can be seen that CLC alone has excellent sustained release properties and can be used as a fresh composition in which the antimicrobial effect is continuously maintained on the fresh-cut agricultural products.

Example 2-2. Antibacterial effect of freshly sliced agricultural products containing CLC during distribution

The fresh-cut material was prepared and vacuum-packed in the same manner as in Example 2-1. The microbial antibacterial effect on general bacteria and Escherichia coli was investigated by storing the packaged product in refrigerated carts under the conditions used in the distribution process (three times). Table 3 shows the temperature of the top tank in which the foodstuffs are stored during the distribution process, and the number of microorganisms (average of 3 times) is shown in Table 4 below.

time Temperature (℃) 08:00 - 09:00 2.7 ± 0.94 09:00 - 10:00 3.6 ± 2.40 10:00 - 11:00 3.4 ± 0.71 11:00 - 12:00 2.9 ± 1.01 12:00 - 13:00 3.9 ± 1.41 13:00 - 14:00 3.0 ± 0.80 14:00 - 15:00 2.8 ± 0.82 15:00 - 16:00 2.9 ± 0.83 Total average 3.1 ± 1.41

Condition Mean (LogCFU / g) General bacteria in onion slice samples 5.95 Onion slices (CLC enclosed) 4.08 E. coli in an onion slice sample 3.23 Onion slices (CLC encapsulated) E. coli in the sample 2.41 General bacteria in pupae samples 5.77 Fungus (CLC encapsulated) Common bacteria in the sample 4.85 Escherichia coli 3.76 E. coli in the sample (CLC encapsulated) 3.09 General bacteria in cabbage dice samples 4.18 Cabbage dice (CLC enclosed) 3.77 E. coli in a cabbage dice sample 2.67 Cabbage dies (CLC encapsulated) E. coli in the sample 2.14

As shown in Table 4, when the samples were stored in the CLC-sealed chamber without refrigerant circulation, the number of bacteria in the CLC-encapsulated group was small and the antibacterial effect was confirmed. Therefore, it can be seen that the composition of the present invention is excellent in the freshness-controlling effect due to the antibacterial effect.

Claims (7)

And a metal double layer hydroxide nanostructure carrying an antimicrobial agent containing cinnamic acid and cinnamic aldehyde. delete The method according to claim 1,
The divalent metal constituting the metal double layer hydroxide is selected from the group consisting of magnesium (Mg ²⁺ ), calcium (Ca ²⁺ ), zinc (Zn ²⁺ ), and combinations thereof, Wherein the trivalent metal is selected from the group consisting of aluminum (Al ³⁺ ), iron (Fe ³⁺ ), and combinations thereof. The method according to claim 1,
Wherein the freshly sliced agricultural produce is selected from fruits, vegetables, mushrooms and edible fodder crops harvested directly from a mountain area. The method according to claim 1,
Characterized in that the agricultural products harvested at the mountain are trimmed, peeled, or cut, and then washed and packaged to be commercialized. The method according to claim 1,
Wherein the composition is coated with an anionic polymer. (Step 1) A salt solution containing a divalent metal-containing metal nitrate salt and a nitric acid metal salt having a trivalent metal and a cinnamic acid solution are mixed and dried to obtain a metal double layer hydroxide nanostructure carrying the cinnamic acid step;
(Step 2) drying and crushing the precipitate obtained by dispersing the cinnamic acid-bearing metal double layer hydroxide nanostructure in a cinnamaldehyde solution to obtain cinnamic acid and cinnamic aldehyde-loaded metal double layer hydroxide nanostructure; And
(Step 3) a step of dispersing a metal double layer hydroxide nanostructure carrying cinnamic acid and cinnamic aldehyde in an anionic polymer solution and drying and pulverizing the resulting precipitate to obtain a polymer-coated nanostructure;
Wherein the method comprises the steps of:

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