阅读说明：本技术 一种缓释微胶囊防腐保鲜剂及其制备方法和应用 (Slow-release microcapsule preservative and preparation method and application thereof ) 是由 李永才 董玉鹏 毕阳 龙海涛 牛师民 于 2020-06-22 设计创作，主要内容包括：一种缓释微胶囊防腐保鲜剂及其制备方法和应用,属于食品保鲜技术领域。该方法包括：采用反式-2-己烯醛为芯材,β-环糊精为壁材,通过对壁材溶液与芯材油相混合,搅拌,冷藏,过滤,干燥,得到粉末状缓释微胶囊防腐保鲜剂产品。该产品缓释效果显著,具有安全环保、持久的保鲜防腐作用,有效解决了早酥梨贮藏期间单独使用反式-2-己烯醛液体的不便、作用时间短等问题；该方法制备工艺简单易行,重复性好,设备要求低,原料天然无毒,来源广泛,生产成本低,适宜工业化生产。(A slow-release microcapsule preservative and a preparation method and application thereof, belonging to the technical field of food preservation. The method comprises the following steps: the powdery slow-release microcapsule preservative product is prepared by mixing a wall material solution and a core material oil phase, stirring, refrigerating, filtering and drying by adopting trans-2-hexenal as a core material and beta-cyclodextrin as a wall material. The product has obvious slow release effect, has safe, environment-friendly and lasting fresh-keeping and corrosion-preventing effects, and effectively solves the problems of inconvenience, short action time and the like caused by singly using the trans-2-hexenal liquid during the storage period of the early crisp pears; the method has the advantages of simple and easy preparation process, good repeatability, low equipment requirement, natural and nontoxic raw materials, wide sources and low production cost, and is suitable for industrial production.)

1. The slow-release microcapsule preservative is characterized by comprising a wall material and a core material, wherein the wall material is beta-cyclodextrin; the core material is trans-2-hexenal.

2. The slow-release microcapsule preservative and fresh-keeping agent according to claim 1, characterized in that: the mixing mass ratio of the core material to the wall material is 1: 6-8.

3. The preparation method of the slow-release microcapsule preservative and fresh-keeping agent as claimed in claim 1 or 2, which comprises the following steps:

dissolving beta-cyclodextrin in deionized water to obtain a wall material aqueous solution;

dissolving a core material in an organic solvent to obtain a core material oil phase;

and mixing the wall material aqueous solution and the core material oil phase, stirring, refrigerating, filtering and drying to obtain the clathrate compound powder.

4. The preparation method of the slow-release microcapsule preservative and fresh-keeping agent according to claim 3, characterized by comprising the following steps: dissolving beta-cyclodextrin in deionized water at the temperature of 80 ℃, wherein the mass ratio of the beta-cyclodextrin to the deionized water is 1: 11-13.

5. The preparation method of the slow-release microcapsule preservative and fresh-keeping agent according to claim 3, characterized by comprising the following steps: the organic solvent is ethanol, and the volume ratio of the core material to the ethanol is 1: 20-30.

6. The preparation method of the slow-release microcapsule preservative and fresh-keeping agent according to claim 3, characterized by comprising the following steps: the stirring temperature is 45-65 ℃, and the stirring time is 2.5-3.5 h.

7. The preparation method of the slow-release microcapsule preservative and fresh-keeping agent according to claim 3, characterized by comprising the following steps: the refrigeration temperature is 4 ℃, and the refrigeration time is 24 h.

8. The preparation method of the slow-release microcapsule preservative and fresh-keeping agent according to claim 3, characterized by comprising the following steps: the vacuum drying temperature is 50-60 ℃, and the drying time is 2-3 h.

9. The application method of the slow-release microcapsule preservative and fresh-keeping agent according to claim 3, characterized in that: the preservative is used for storing early crisp pears.

Technical Field

The invention relates to the technical field of food preservation, in particular to a slow-release microcapsule preservative and a preparation method and application thereof.

Background

The early crisp pears are the main variety of pears planted in northwest China, have large and small kernels and emerald peel, and are deeply favored by consumers. However, early crisp pears are usually harvested at high temperature in summer, and the rapid quality deterioration and decay cause serious fruit loss after harvest, thereby restricting the healthy development of the early crisp pear industry. Wherein is prepared from alternaria alternata (Alternaria alternata) Caused black spot diseaseIs one of the main diseases of the early crisp pears after picking,A. alternatacan grow rapidly at room temperature or low temperature to make the fruit go bad. At present, chemical antistaling agent is mainly used for controlling rot of picked fruits and vegetables and delaying senescence of picked fruits and vegetables, but long-term use of the chemical antistaling agent can cause drug resistance of pathogenic bacteria and environmental pollution. In addition, with the improvement of the life quality of people, the problem of chemical preservative residue is more and more paid attention to. Therefore, the biological source preservative is increasingly concerned by people because the problems of environmental pollution, pesticide residue, drug resistance and the like caused by no chemical preservative are solved.

Trans-2-hexenal is one of the Green Leaf Volatiles (GLVs) and is a volatile substance that is rapidly synthesized and released after most green plants are damaged. Trans-2-hexenal is approved by the FDA in the united states for use as a food additive. The trans-2-hexenal has good activities such as bacteriostatic activity and antioxidant activity, and is concerned by researchers at home and abroad. Early-stage research finds that trans-2-hexenal can kill alternaria piricolaA. alternataHas obvious inhibiting effect and better preservative and fresh-keeping effect on early crisp pears. The trans-2-hexenal is colorless oily liquid with green apple smell and has certain volatility, and the preservative treatment is usually carried out on the early crisp pears in a direct fumigation mode in a laboratory. In the actual production and transportation process, however, the trans-2-hexenal liquid is easy to spill, inconvenient to use and short in action time; in addition, the trans-2-hexenal has a certain pungent smell, is easy to generate adverse effects on the flavor of the early crisp pears, and limits the use of the early crisp pears in actual production.

Disclosure of Invention

The invention aims to provide a fresh-keeping preservative taking a green leaf volatile substance trans-2-hexenal as a main component. Aiming at the problems of inconvenient use, larger taste, short action time and the like of trans-2-hexenal liquid in the storage process of the early crisp pears, cyclodextrin is adopted to embed the early crisp pears, the liquid is converted into solid, a slow release effect is achieved, the volatilization time of the trans-2-hexenal is prolonged, the action effect is increased, bad smell is masked, a safe and efficient natural preservative is provided for the storage of the early crisp pears, and the effects of prolonging the storage time of the early crisp pears after picking and reducing the loss after picking are achieved.

In order to solve the problems, the slow-release microcapsule preservative and the preparation method thereof comprise the following steps:

a preparation method of a slow-release microcapsule preservative and fresh-keeping agent comprises a wall material and a core material, wherein the wall material is beta-cyclodextrin; the core material is trans-2-hexenal. The mixing mass ratio of the core material to the wall material is 1: 6-8.

A preparation method of a slow-release microcapsule preservative and fresh-keeping agent comprises the following steps:

dissolving beta-cyclodextrin in deionized water to obtain a wall material aqueous solution;

dissolving a core material in an organic solvent to obtain a core material oil phase;

and mixing the wall material aqueous solution and the core material oil phase, stirring, refrigerating, filtering and drying to obtain the clathrate compound powder.

Dissolving beta-cyclodextrin in deionized water at the temperature of 80 ℃, wherein the mass ratio of the beta-cyclodextrin to the deionized water is 1: 11-13.

The organic solvent is ethanol, and the volume ratio of the core material to the ethanol is 1: 20-30.

The stirring temperature is 45-65 ℃, and the stirring time is 2.5-3.5 h.

The refrigeration temperature is 4 ℃, and the refrigeration time is 24 h.

The vacuum drying temperature is 50-60 ℃, and the drying time is 2-3 h.

The slow release microcapsule preservative is applied to early crisp pears.

The slow-release microcapsule preservative has the following advantages:

1. the slow-release microcapsule preservative adopts the trans-2-hexenal and the beta-cyclodextrin which are natural substances, are safe and non-toxic, do not generate harmful substances to human bodies after contacting with fruits, and have better safety than the currently used chemical preservative.

2. According to the slow-release microcapsule preservative and fresh-keeping agent, the liquid trans-2-hexenal is embedded in the solid beta-cyclodextrin, and the slow-release microcapsule preservative and fresh-keeping agent can be used in a tabletting, packaging and other using modes, so that the operation is convenient. In actual production, liquid trans-2-hexenal cannot be used due to the problems of transportation and the like, so the preservative has better practical value and is suitable for fruit storage of various scales.

3. The embedding rate of the slow-release microcapsule preservative is 65-74%, the microcapsule structure is regular and is in a cubic form, and the dispersibility and uniformity are good.

4. The slow-release microcapsule preservative can delay the volatilization time and the volatilization amount of trans-2-hexenal, reduce the pungent smell of the trans-2-hexenal and have better bacteriostatic slow-release performance.

Drawings

The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.

FIG. 1 is a scanning electron microscope image of the slow-release microcapsule preservative prepared in example 1 of the present invention.

FIG. 2 shows the slow-release microcapsule preservative prepared in example 1 of the present invention.

FIG. 3 is a statistical chart of the effect of different temperatures on the release of trans-2-hexenal in the slow-release microcapsule preservative.

FIG. 4 is a statistical chart of the influence of the prepared slow-release microcapsule preservative on the incidence rate of black spot in the storage period of the early crisp pears.

Detailed Description

The present invention is further illustrated by the following specific examples.

A preparation method of a slow-release microcapsule preservative and fresh-keeping agent comprises a wall material and a core material, wherein the wall material is beta-cyclodextrin; the core material is trans-2-hexenal. The mixing mass ratio of the core material to the wall material is 1: 6-8.

A preparation method of a slow-release microcapsule preservative and fresh-keeping agent comprises the following steps:

dissolving beta-cyclodextrin in deionized water to obtain a wall material aqueous solution;

dissolving a core material in an organic solvent to obtain a core material oil phase;

and mixing the wall material aqueous solution and the core material oil phase, stirring, refrigerating, filtering and drying to obtain the clathrate compound powder. Dissolving beta-cyclodextrin in deionized water at the temperature of 80 ℃, wherein the mass ratio of the beta-cyclodextrin to the deionized water is 1: 11-13. The organic solvent is ethanol, and the volume ratio of the core material to the ethanol is 1: 20-30. The stirring temperature is 45-65 ℃, and the stirring time is 2.5-3.5 h. The refrigeration temperature is 4 ℃, and the refrigeration time is 24 h. The vacuum drying temperature is 50-60 ℃, and the drying time is 2-3 h. The slow release microcapsule preservative is applied to early crisp pears.

Embodiment 1 a method for preparing a slow-release microcapsule preservative and fresh-keeping agent, comprising the following steps:

(1) adding 6.0g of beta-cyclodextrin into 66.0 mL of deionized water according to the mass ratio of 1:11, heating and stirring at 80 ℃ until the beta-cyclodextrin is completely dissolved, and cooling for later use;

(2) adding 1mL of trans-2-hexenal into 20 mL of ethanol solution according to the volume ratio of 1:20, and uniformly stirring to obtain a trans-2-hexenal ethanol solution;

(3) mixing the solution prepared in the step 2 with the solution prepared in the step 1, and uniformly stirring;

(4) placing the mixed solution prepared in the step 3 in a constant-temperature water bath kettle at 45 ℃ and stirring for 2.5 hours;

(5) cooling to room temperature, and refrigerating in a refrigerator at 4 deg.C for 24 hr;

(6) and (3) carrying out suction filtration, washing filter residues with a proper amount of distilled water, and drying the wet material obtained by suction filtration in a vacuum drying oven to constant weight at the drying temperature of 50 ℃ for 2.5 h.

The prepared slow-release microcapsule preservative comprises the following components: 6.0g of beta-cyclodextrin, 1mL of trans-2-hexenal, 66.0 mL of deionized water and 20 mL of ethanol, wherein the embedding rate is 73.64 percent.

Embodiment 2 a method for preparing a slow-release microcapsule preservative and fresh-keeping agent, comprising the following steps:

(1) adding 7.0g of beta-cyclodextrin into 84.0 mL of deionized water according to the mass ratio of 1:12, heating and stirring at 80 ℃ until the beta-cyclodextrin is completely dissolved, and cooling for later use;

(2) adding 1mL of trans-2-hexenal into 25mL of ethanol solution according to the volume ratio of 1:25, and uniformly stirring to obtain a trans-2-hexenal ethanol solution;

(3) mixing the solution prepared in the step 2 with the solution prepared in the step 1, and uniformly stirring;

(4) placing the mixed solution prepared in the step 3 in a constant-temperature water bath kettle at 55 ℃ and stirring for 3 hours;

(5) cooling to room temperature, and refrigerating in a refrigerator at 4 deg.C for 24 hr;

(6) and (3) carrying out suction filtration, washing filter residues with a proper amount of distilled water, and drying the wet material obtained by suction filtration in a vacuum drying oven to constant weight at the drying temperature of 55 ℃ for 2.5 h.

The prepared slow-release microcapsule preservative comprises the following components: 7.0g of beta-cyclodextrin, 1mL of trans-2-hexenal, 84.0 mL of deionized water and 25mL of ethanol, wherein the embedding rate is 69.56%.

Embodiment 3 a method for preparing a slow-release microcapsule preservative and fresh-keeping agent, comprising the following steps:

(1) adding 8.0g of beta-cyclodextrin into 104 mL of deionized water according to the mass ratio of 1:13, heating and stirring at 80 ℃ until the beta-cyclodextrin is completely dissolved, and cooling for later use;

(2) adding 1mL of trans-2-hexenal into 30mL of ethanol solution according to the volume ratio of 1:30, and uniformly stirring to obtain a trans-2-hexenal ethanol solution;

(3) mixing the solution prepared in the step 2 with the solution prepared in the step 1, and uniformly stirring;

(4) placing the mixed solution prepared in the step 3 in a constant-temperature water bath kettle at 65 ℃ and stirring for 3.5 hours;

(5) cooling to room temperature, and refrigerating in a refrigerator at 4 deg.C for 24 hr;

(6) and (4) carrying out suction filtration, washing filter residues with a proper amount of distilled water, and drying the wet material obtained by suction filtration in a vacuum drying oven to constant weight at the drying temperature of 60 ℃ for 3 h.

The prepared slow-release microcapsule preservative comprises the following components: 8.0g of beta-cyclodextrin, 1mL of trans-2-hexenal, 104.0 mL of deionized water and 30mL of ethanol, wherein the embedding rate is 66.78%.

Embodiment 4 a method for preparing a slow-release microcapsule preservative and fresh-keeping agent, comprising the following steps:

(1) adding 8.0g of beta-cyclodextrin into 88mL of deionized water according to the mass ratio of 1:11, heating and stirring at 80 ℃ until the beta-cyclodextrin is completely dissolved, and cooling for later use;

(2) adding 1mL of trans-2-hexenal into 25mL of ethanol solution according to the volume ratio of 1:25, and uniformly stirring to obtain a trans-2-hexenal ethanol solution;

(3) mixing the solution prepared in the step 2 with the solution prepared in the step 1, and uniformly stirring;

(4) placing the mixed solution prepared in the step 3 in a constant-temperature water bath kettle at 65 ℃ and stirring for 3.5 hours;

(5) cooling to room temperature, and refrigerating in a refrigerator at 4 deg.C for 24 hr;

(6) and (4) carrying out suction filtration, washing filter residues with a proper amount of distilled water, and drying the wet material obtained by suction filtration in a vacuum drying oven to constant weight at the drying temperature of 60 ℃ for 3 h.

The prepared slow-release microcapsule preservative comprises the following components: 8.0g of beta-cyclodextrin, 1mL of trans-2-hexenal, 88.0 mL of deionized water and 25mL of ethanol, wherein the embedding rate is 67.92%.

Embodiment 5 a method for preparing a slow-release microcapsule preservative and fresh-keeping agent, comprising the following steps:

(1) adding 7.0g of beta-cyclodextrin into 91.0mL of deionized water according to the mass ratio of 1:13, heating and stirring at 80 ℃ until the beta-cyclodextrin is completely dissolved, and cooling for later use;

(2) adding 1mL of trans-2-hexenal into 30mL of ethanol solution according to the volume ratio of 1:30, and uniformly stirring to obtain a trans-2-hexenal ethanol solution;

(3) mixing the solution prepared in the step 2 with the solution prepared in the step 1, and uniformly stirring;

(4) placing the mixed solution prepared in the step 3 in a constant-temperature water bath kettle at 55 ℃ and stirring for 3 hours;

(5) cooling to room temperature, and refrigerating in a refrigerator at 4 deg.C for 24 hr;

(6) and (3) carrying out suction filtration, washing filter residues with a proper amount of distilled water, and drying the wet material obtained by suction filtration in a vacuum drying oven to constant weight at the drying temperature of 55 ℃ for 2.5 h.

The prepared slow-release microcapsule preservative comprises the following components: 7.0g of beta-cyclodextrin, 1mL of trans-2-hexenal, 91.0mL of deionized water and 30mL of ethanol, wherein the embedding rate is 70.32%.

Embodiment 6 a method for preparing a slow-release microcapsule preservative and fresh-keeping agent, comprising the following steps:

(1) adding 6.0g of beta-cyclodextrin into 78 mL of deionized water according to the mass ratio of 1:13, heating and stirring at 80 ℃ until the beta-cyclodextrin is completely dissolved, and cooling for later use;

(2) adding 1mL of trans-2-hexenal into 20 mL of ethanol solution according to the volume ratio of 1:20, and uniformly stirring to obtain a trans-2-hexenal ethanol solution;

(3) mixing the solution prepared in the step 2 with the solution prepared in the step 1, and uniformly stirring;

(4) placing the mixed solution prepared in the step 3 in a constant-temperature water bath kettle at 45 ℃ and stirring for 2.5 hours;

(5) cooling to room temperature, and refrigerating in a refrigerator at 4 deg.C for 24 hr;

(6) and (3) carrying out suction filtration, washing filter residues with a proper amount of distilled water, and drying the wet material obtained by suction filtration in a vacuum drying oven to constant weight at the drying temperature of 50 ℃ for 2.5 h.

The prepared slow-release microcapsule preservative comprises the following components: 6.0g of beta-cyclodextrin, 1mL of trans-2-hexenal, 78.0 mL of deionized water and 20 mL of ethanol, wherein the embedding rate is 72.67%.

Experiment 1 influence of different temperatures on release of trans-2-hexenal in sustained-release microcapsule preservative

Weighing a certain amount of the slow-release microcapsule preservative, uniformly spreading the slow-release microcapsule preservative on a watch glass, putting the watch glass into a dryer containing a saturated potassium sulfate solution with a certain volume (the relative humidity of the environment is 98%), then respectively putting the dryer in an environment with the temperature of 4 ℃ and the room temperature, ventilating for 5 min every 12 h, sampling at intervals of 24h, and measuring the residual amount of trans-2-hexenal in the slow-release microcapsule preservative to calculate the cumulative release rate of the trans-2-hexenal.

As shown in figure 3, the slow-release microcapsule preservative has remarkable slow-release characteristic. Under the condition of 4 ℃, the accumulative release amount of the trans-2-hexenal after 96 hours is 51.65%, the retention amount is still 48.35%, and the microcapsule release tends to be slow and stable. The result shows that the slow-release microcapsule preservative has a long-time preservative effect.

Experiment 2 influence of the slow-release microcapsule preservative on incidence rate of black spot in storage period of early crisp pears

Treatment group: the pretreated early crisp pears are placed in a 3L plastic sealing box, then the slow-release microcapsule preservative is packaged and fixed on the top of a plastic box cover by a tea bag, the box cover is immediately sealed, the early crisp pears are stored for 35 days at the temperature of 1 +/-4 ℃ and the humidity of 90 percent, and the incidence rate of black spot is observed and determined every 7 days.

Control group: and (3) placing the pretreated early crisp pears in a 3L plastic sealing box, immediately sealing, storing for 35 d at the temperature of 1 +/-4 ℃ and the humidity of 90%, and observing and determining the incidence rate of black spot disease every 7 d.

As shown in figure 4, the slow-release microcapsule preservative can obviously inhibit the occurrence of black spot of early crisp pears in a storage period, and the action effect can last for 35 days.