KR101982288B1 - Microcapsule for pH dependent release of natural antimicrobial extract and preparation method of the same - Google Patents

Abstract

The present invention relates to a pH-dependent release microcapsule comprising a natural antimicrobial substance and a natural polymer chitosan, and to a production method thereof and, more particularly, to a microcapsule which causes pH-dependent release of the natural antimicrobial substance at an appropriate pH using chitosan, a natural polymer, and is capable of adjusting an emission pattern by varying the ratio of an additive, and to a production method thereof. The microcapsule of the present invention is applicable to fermented foods which require release from appropriate acidity, such as fermented fish, and is suitable for mass production on an industrial scale.

Description

[0001] The present invention relates to a pH dependent release type microcapsule containing a natural antimicrobial substance and a preparation method thereof,

The present invention relates to a pH-dependent release microcapsule composed of a natural antimicrobial substance and a natural polymer chitosan, and a method for producing the same. More particularly, the present invention relates to a method for producing a pH- At the same time, the present invention relates to a microcapsule capable of adjusting the emission pattern by varying the proportion of the additive, and a method for producing the microcapsule. The microcapsules of the present invention are applicable to fermented foods requiring release at an appropriate pH such as salted and are suitable for mass production on an industrial scale.

Generally, fermented seaweed is fermented by aerobic microorganisms and aged. The fermented sea urchin has unique flavor by combining the free amino acid produced by fermentation with nitrogen compounds and nucleic acid degradation products. Excessive growth of microorganisms causes food to lose flavor and lead to corruption.

In the food industry, excessive sodium is added to prevent corruption of these salted seafood. Such high sodium foods are known to be associated with adult diseases such as cardiovascular disease, stroke, stomach cancer, kidney disease, obesity, and osteoporosis.

In order to solve these problems, various natural antimicrobial substances that can replace sodium while preventing food corruption have been studied. For example, natural antimicrobial substances having a natural preservative component such as a rhododendron extract, Techniques have been developed for adding extraction materials.

However, in order to maximize the effect of the natural antimicrobial substances, it is necessary to release the natural antimicrobial substances at an appropriate time in the food. For this purpose, it is necessary to control the timing and pattern of the release of the extract.

On the other hand, chitosan is a deacetyl compound of chitin, a natural substance contained in the shell of shrimp. It is a biodegradable and non-toxic natural polymer that can be used as a preservative in the field of food because of its microbial growth inhibitory effect. Chitosan is also used as a drug delivery system in pharmacy because it has a characteristic of dissolving only at a specific pH. The present invention can be applied to the production of microcapsules which release antimicrobial substances from the appropriate acidity in the fermented fish using the characteristics of chitosan.

As a preservative using chitosan, Korean Patent No. 10-1628263 discloses a fermented food preservative using green tea leaf extract. However, the above patent is characterized in that microparticles of chitosan (15,000-20,000 MW) are acidified to form microspheres and then solidified by neutralization with sodium hydroxide or potassium hydroxide.

However, strongly basic substances such as sodium hydroxide and potassium hydroxide may cause diarrhea and stomach cramps when consumed in large quantities, and may cause chemical reactions with food and produce harmful components. Moreover, the neutralization method is not suitable for mass production because it can not produce homogeneous particles.

In the present invention, the release rate and release rate of chitosan microcapsules are controlled by using chitosan and an additive. In particular, dextrin used as an additive is produced by hydrolysis of starch, which is harmless to the human body as compared with sodium hydroxide or potassium hydroxide, and is suitable for industrial use by spray drying.

Korean Registered Patent No. 10-1628263

The present invention provides a pH-dependent release microcapsule capable of releasing a natural antimicrobial substance at a pH of an appropriate acidity using chitosan and an additive, and controlling the release rate and the release rate, and a method for producing the same.

In addition, the present invention provides a pH-dependent release microcapsule suitable for mass production by spray-drying, which is harmless to the human body even when ingested in large quantities using chitosan and chitosan, which are natural antimicrobial substances, chitosan and additive, .

In order to achieve the above object, the present invention provides a pH-dependent releasing microcapsule comprising a natural antimicrobial substance and chitosan in a content ratio of 1: 2 to 10 (w / w).

At this time, the natural antimicrobial substance is a rhizome extract, and the molecular weight of the chitosan is preferably 310,000 ~ 375,000 Da.

In addition, the microcapsules of the present invention may further contain 0.1 to 100 parts by weight of an additive based on the chitosan content, wherein the additive is preferably dextrin.

The microcapsules have an average particle size of 1 to 2.5 μm.

In order to accomplish the above object, the present invention provides a method for producing a chitosan-containing microorganism, comprising the steps of: dissolving chitosan in an acidic aqueous solution; adding a natural antimicrobial substance while stirring the chitosan solution with a stirrer; Based microcapsules containing the pH-dependent release-type microcapsules. Wherein the step of adding the natural antimicrobial substance may further include the step of mixing the additive.

In addition, the operating conditions of the spray dryer in the spray drying step are as follows: the inlet temperature is 120 to 160 ° C, the outlet temperature is 70 to 90 ° C, the spraying rate of the chitosan aqueous solution containing the natural antibacterial substance is 3 to 7 ml / min, The air pressure is preferably 2.0 to 5.0 bar.

The pH-dependent release microcapsules prepared according to the present invention can release natural antimicrobial materials at a pH of appropriate acidity using chitosan and additives, and control the release rate and release rate of the natural antimicrobial substance by controlling the amount of additives .

In addition, the present invention is harmless to human body even when consuming a large amount of natural antimicrobial substance, such as obova extract and chitosan, as an additive, and is suitable for mass production through a spray dryer.

Figures 1 to 3 are graphs showing the pH dependent release characteristics of Examples 1 to 3.
FIG. 4 is a SEM photograph showing the particle size and particle shape of the chitosan microcapsules containing the natural antimicrobial materials of Examples 1 to 3. FIG.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. Prior to the description, terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms and should be construed in a sense and concept consistent with the technical idea of the present invention.

The chitosan microcapsule containing the natural antimicrobial substance of the present invention can be prepared by allowing the natural antimicrobial substance to be released at a pH of appropriate acidity by using chitosan and an additive and controlling the release rate and release rate of the natural antimicrobial substance .

At this time, the content ratio of the natural antimicrobial substance and chitosan can be variously adjusted, but it is preferably adjusted within the range of 1: 2 to 10 (w / w). If the content ratio is larger or smaller than the above ratio, chitosan microcapsule formation may be difficult or the microcapsule may not sufficiently contain natural antimicrobial substance.

The natural antimicrobial substance is not particularly limited, but may be, for example, a natural antimicrobial extract, a pine needle extract, a green tea extract, a red ginseng extract, a licorice extract, a grapefruit seed extract, a ginkgo leaf extract, a grape seed extract, At least one member selected from the group consisting of Angelica keiskei keisai extract, Angelica keiskei kusatake extract, Ginger extract, Gugija extract, Hwanggi extract, Corn oil extract, Rhus vernicifolia extract, Acanthopanax extract, May be selected, and preferably a rhizome extract may be used.

Meanwhile, the natural antimicrobial materials used in the present invention may be those extracted by various methods. However, in order to extract the antimicrobial component more efficiently and continue the antimicrobial effect for a long time, it is preferred to use an extract obtained by using alkaline ionized water as a solvent desirable. Alkali ionized water has better permeability due to its smaller molecular mass than water, has high thermal conductivity and strong dissolving power so that component elution is efficient even at low temperature.

Generally, when extracting natural products, it is common to extract at a temperature of 90 to 100 ° C. by using a solvent in which a certain amount of purified water or a mixture of purified water and alcohols is used. However, in such an extraction method, heat sensitive components are easily decomposed in the extraction process.

However, in the present invention, the alkaline ionized water is used as a solvent to safely extract the active ingredients of the natural product at a relatively low temperature, so that the extract can fully exhibit the antimicrobial function originally possessed, and the absorption power and the usable output are excellent.

In addition, by adding 1 to 30% by weight of glycerin to the extraction solvent, the osmotic pressure phenomenon between the solute and the solvent can be applied to elute the active ingredient more easily.

In order to improve the antibacterial activity of the extracted natural antimicrobial material and solve the odor problem, 0.1 to 70 g of calcium oxide was added to 100 ml of the filtrate extracted with the alkaline ionized water as a solvent, Lt; 0 > C for 12-24 hours to further filtrate the supernatant.

The compositions before and after treatment of the natural antimicrobial substance with calcium oxide are significantly different in terms of color and smell, and the antibacterial activity is improved by treating the foreign substances.

The chitosan may be a commercially available chitosan. In order to efficiently form microcapsules, a polymer chitosan having an average molecular weight of 310,000 to 375,000 Da is preferably used.

At this time, the chitosan may be used alone as a material forming the shell portion of the microcapsule, but may be used together with other polymer components in one embodiment. In particular, chitosan having multiple cross-linking sites can chemically bond with other polymer components to reinforce the shell or reduce pore size, thereby slowing the release rate.

As the polymer component, amino acid may be used, and preferably lysine, leucine, isoleucine, glutamine, methionine, tyrosine, phenylalanine, tryptophan, cysteine or a combination thereof may be used. Preferably, the amino acid is mixed with the chitosan at a ratio of 1: 5 to 5: 1. If the content ratio is more than or less than the above ratio, the effect of controlling the release of the natural antimicrobial substance may be insufficient.

The microcapsule of the present invention may further contain 0.1 to 100 parts by weight of an additive based on the chitosan content, if necessary, in order to control the release rate and release rate of the natural antimicrobial substance. At this time, as the content of the additive increases, the release rate and release rate at low pH can be controlled to increase.

The additive may be selected from the group consisting of dextrin, maltodextrin, cyclodextrin, hydroxypropyl methylcellulose, xanthan gum, arabic gum, guar gum, carrageenan, pectin, etc. have. Preferably, dextrin suitable for mass production through spray drying can be used.

Meanwhile, the microcapsules of the present invention are prepared by dissolving chitosan in an acidic aqueous solution, stirring the chitosan solution with a stirrer, adding a natural antimicrobial substance, and spray-drying a mixed solution of the additives.

At this time, if necessary, the step of mixing the additive with the chitosan solution to which the natural antimicrobial substance is added may be further added before the spray drying step, and then the chitosan solution mixed with the additive may be spray dried to prepare the microcapsule.

Further, in the step of dissolving the chitosan, as described above, in addition to chitosan, an additional polymer component capable of chemically bonding with the chitosan to reinforce the shell may be dissolved together. As the polymer component, amino acid may be used, and preferably lysine, leucine, isoleucine, glutamine, methionine, tyrosine, phenylalanine, tryptophan, cysteine or a combination thereof may be used.

The stirrer used in the method may be a mixer commonly used in the field of food, for example, a high-speed stirrer, a homogenizer, an ultrasonic vibrator, a microfluidizer, a high-pressure homogenizer, or the like.

In addition, the spray dryer used in the spray drying step may be a manufacturing equipment commonly used in the field of food. For example, a spray dryer, a freeze dryer, a hot melt extruder, or the like may be used.

At this time, it is preferable that the operating conditions of the spray dryer include an inlet temperature of 120 to 160 ° C, an outlet temperature of 70 to 90 ° C, an injection speed of 3 to 7 ml / min, and a process air pressure of 2.0 to 5.0 bar.

Hereinafter, the present invention will be described more specifically by way of examples. However, the scope of the present invention is not limited to these examples.

[Example 1]

Chitosan microcapsules containing the natural antibacterial substance of the present invention were prepared by the following method.

2.5 g of chitosan was dissolved in 250 mL of 1% (v / v) acetic acid aqueous solution, and the resultant solution was mixed using a stirrer. 0.5 g of Rhus verniciflua extract was dissolved in 15 mL of ethyl alcohol and added to the solution. The solution was spray-dried to prepare a natural antimicrobial-chitosan microcapsule. (Spray drying operation conditions: inlet temperature 120 ~ 160 ℃, outlet temperature 70 ~ 90 ℃, injection rate of chitosan aqueous solution containing natural antibacterial substance 3 ~ 7 mL / min, process air pressure 2.0 ~ 5.0 bar)

[Example 2]

2.5 g of chitosan was dissolved in 250 mL of 1% (v / v) acetic acid aqueous solution, and the obtained solution was mixed using a stirrer. 0.5 g of Rhus verniciflua extract was dissolved in 15 mL of ethyl alcohol and added to the solution. 0.5 g of dextrin was added to the solution containing the rhizome extract, and the solution was spray-dried to prepare a natural antimicrobial-chitosan microcapsule. (Spray drying operation conditions: inlet temperature 120 ~ 160 ℃, outlet temperature 70 ~ 90 ℃, injection rate of chitosan aqueous solution containing natural antibacterial substance 3 ~ 7mL / min, process air pressure 2.0 ~ 5.0bar)

[Example 3]

2.5 g of chitosan was dissolved in 250 mL of 1% (v / v) acetic acid aqueous solution, and the obtained solution was mixed using a stirrer. 15 g of ethyl alcohol was dissolved in 0.5 g of Rhus verniciflua extract and added to the solution. 1 g of dextrin was added to the solution containing the rhizome extract, and the solution was spray-dried to prepare a natural antimicrobial-chitosan microcapsule. (Spray drying operation conditions: inlet temperature 120 ~ 160 ℃, outlet temperature 70 ~ 90 ℃, injection rate of chitosan aqueous solution containing natural antibacterial substance 3 ~ 7mL / min, process air pressure 2.0 ~ 5.0bar)

[Experimental Example 1] Evaluation of releasing properties of natural antibacterial substance-chitosan microcapsule according to pH

Evaluation of the release characteristics of the microcapsules of the present invention was carried out using a Franz diffusion cell instrument in the following manner. A 0.45 ㎛ nylon filter is fixed between the donor and the receptor phase, and chitosan microcapsules (10 mg) are then loaded. As a receptor, a buffer solution (pH 4.0 acetate buffer, pH 6.8 phosphate buffer, pH 8.0 phosphate buffer solution) containing 5% sodium chloride was used.

At this time, the volume of the cell was kept at 22 mL and the stirring speed was kept at 180 rpm at room temperature. The concentration of the indicator substance was measured by HPLC using the syringe at a predetermined time, and the respective values were measured. The obtained results are shown in FIGS. 1 to 3.

As can be seen from FIGS. 1 to 3, chitosan microcapsules containing the natural antimicrobial substance prepared according to the present invention do not release any natural antimicrobial substance at pH 8.0. The final release rates of the natural antimicrobial materials of Examples 1 to 3 were 53%, 54%, and 64% at pH 6.8, respectively, and the final release rates of the natural antimicrobial materials of Examples 1 to 3 were 85%, 90%, 100 %. It can be seen that the lower the pH, the higher the release rate of the natural antibacterial substance-chitosan microcapsule prepared through the above process. In addition, it was confirmed that the release rate and release rate at low pH were increased as the ratio of dextrin added increased.

The release of the prepared natural antimicrobial substance-chitosan microcapsule was confirmed for 24 hours. However, when applied to a system in which the pH is changed by fermentation such as salted fish, the release time of the natural antimicrobial substance becomes longer due to the difference in the release rate depending on the pH .

[Experimental Example 2] Evaluation of particle size and particle shape of natural antibacterial substance-chitosan microcapsule

The particle size and particle shape evaluation of the chitosan microcapsules containing the natural antimicrobial materials of Examples 1 to 3 were performed using a scanning electron microscope (SEM, Hitachi S-4300 SE) at a voltage of 10 kV, Respectively. As can be seen from the figure, it can be confirmed that the microcapsules of Examples 1 to 3 have a rough surface having an average size of 2.5 탆.

[Experimental Example 3] Comparison of the elution amount of the extract

Example 3 was prepared by adding 50 ml of a 3% glycerin alkaline ionized water (PH.7.5) solution to 100 g of dicotyledonous extract, heating it at 75 DEG C for 3 hours, and then filtering it. In contrast, in the comparative example, 50 ml of distilled water was added to dumbbells and the mixture was heated at 75 캜 for 3 hours and filtered. The extracts of Example 4 and Comparative Example were taken 3 times by 10 ml of microfibers three times and then subjected to a dissolution test, and the results are shown in Table 1 below.

[Experimental Example 4] Comparison of antibacterial activity before and after calcium oxide treatment

In order to improve the antimicrobial activity of the extract and solve the problem of color and odor, 70 g of calcium oxide was added to 100 ml of the extract solution of Example 4, and the mixture was stirred at 4 to 15 ° C for 12 to 24 hours. To prepare Example 5. It was confirmed that the composition before and after the calcium oxide treatment of the extract was improved in terms of color and smell.

On the other hand, in order to compare the antibacterial activity before and after the treatment with calcium oxide, the following experiment was conducted. After sterilization of the strain on the Luria-Bertani medium, the sterilized disk was added to the liquid medium and the bacterial strain was dispensed at 1 쨉 m. The bacterial growth inhibitory ability around the disk was determined by incubating the experimental medium for one day at 37 캜 in the incubator. Respectively.

As can be seen from the above results, it was found that the antimicrobial activity was increased after calcium oxide treatment.

The present invention is not limited to the above-described specific embodiments and descriptions, and various modifications can be made to those skilled in the art without departing from the gist of the present invention claimed in the claims. And such modifications are within the scope of protection of the present invention.

Claims (6)

And a chitosan having a molecular weight of 310,000 to 375,00 Da, wherein the content ratio of the rhizome extract to chitosan is 1: 2 to 10 (w / w)
And 0.1 to 100 parts by weight of dextrin based on the chitosan content,
The average particle size of the microcapsules is 1 to 2.5 占 퐉,
The active ingredient of the obtusifolium extract is extracted by adding alkaline ionized water containing 1 to 30% by weight of glycerin to the obtusa, 0.1 to 70 g of calcium oxide is added based on 100 ml of the extracted filtrate, Lt; 0 > C for 12 to 24 hours. The pH-dependent release microcapsule containing the natural antimicrobial substance is characterized in that the supernatant is filtered.
delete delete delete delete Dissolving chitosan having a molecular weight of 310,000 to 375,00 Da in an acidic aqueous solution; Adding the rhizome extract while stirring the chitosan solution with a stirrer; Adding dextrin to the solution to which the rhizome extract is added; And spray drying the dextrin-added chitosan solution,
Wherein the content ratio of the rhizome extract to chitosan is 1: 2 to 10 (w / w)
The dextrin is added in an amount of 0.1 to 100 parts by weight based on the chitosan content,
The average particle size of the spray-dried microcapsules is 1 to 2.5 占 퐉,
Extracting the active ingredient of the obovate by adding alkaline ionized water containing 1 to 30% by weight of glycerin to the obovate; Adding 0.1 to 70 g of calcium oxide based on 100 ml of the extracted filtrate and stirring; And a step of filtering the supernatant obtained by adding the calcium oxide and stirring the mixture to a solution obtained by allowing the solution to stand at 15 ° C for 12 to 24 hours, thereby preparing a pH-dependent release microcapsule containing a natural antimicrobial substance Way.

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