CN117966476B

CN117966476B - Fresh cut China rose preservative paper and preparation method thereof and fresh cut China rose preservation method

Info

Publication number: CN117966476B
Application number: CN202410382213.9A
Authority: CN
Inventors: 段玉权; 刘菊; 廖学智; 吕姣; 赵垚垚; 赵竞伊
Original assignee: Yunnan Construction Investment Logistics Co ltd
Current assignee: Yunnan Construction Investment Logistics Co ltd
Filing date: 2024-04-01
Publication date: 2024-06-28
Anticipated expiration: 2044-04-01

Abstract

The invention relates to the technical field of fresh cut flowers, in particular to fresh cut China rose preservative paper and a preparation method thereof and a fresh cut China rose preservation method. The preparation method comprises the following steps: soaking the melt-blown cloth in a fresh-keeping liquid for soaking and adsorbing treatment, and then drying to obtain pretreated melt-blown cloth; the fresh-keeping liquid comprises the following components: natamycin suspension, 6-benzylaminoadenine, nano SiO ₂ and deionized water; sequentially preparing a chlorine dioxide slow-release layer, a thymol slow-release layer and a 1-MCP slow-release layer on the functional surface of the pretreated melt-blown cloth to obtain the product; the functional surface is the surface which is contacted with the fresh cut China rose after being packaged. The China rose cut flower preservative paper prepared by the method is beneficial to improving the utilization rate of preservative preparations, is convenient to transport, turn around and sell, can continuously play a preservative role, and prolongs the storage period of the fresh cut China rose flowers.

Description

Fresh cut China rose preservative paper and preparation method thereof and fresh cut China rose preservation method

Technical Field

The invention relates to the technical field of fresh cut flowers, in particular to fresh cut China rose preservative paper and a preparation method thereof and a fresh cut China rose preservation method.

Background

China rose is an evergreen, semi-evergreen, short shrub of the genus Rosaceae. The leaves are lupin compound leaves, the surfaces are dark green and glossy, the backs of the leaves are bluish white, and the hairless surfaces are provided with small supporting leaves. Flowers are divided into single petals and heavy petals, and the heavy petals are dark red and slightly like roses. The color mainly includes red, and others include white, yellow, pink, rose red, etc. Rosehip oval or pear-shaped, and red when cooked. The natural flowering period is 4 months to 9 months. China rose is named as being capable of being seen in spring, summer, autumn and winter all the year round, and is named as being "moon red" and "catharanthus roseus" by being nearly flowering once a month, and is deeply favored by consumers. The cut flower rose is a beautiful flower, plays an important role in the flower industry, is a plant with high ornamental value, is widely welcome in the markets at home and abroad, and has very wide prospects as the demands of people on flowers are continuously increased. The rose flowers are ripe and aged quickly after being picked, the flowers are easy to rot and deteriorate, and the shelf life is only 3-5 days at normal temperature, so that the storage, transportation and preservation of the fresh cut rose flowers are all the hot spots and difficulties concerned in the flower preservation industry. At present, most flowers are preserved by adopting a method of soaking preservation solution after picking, but the soaked flowers are easy to waste medicaments after picking, and are inconvenient to transport, turnover and sell. Therefore, developing a fresh-keeping means which is environment-friendly and convenient for storage and transportation is increasingly attracting attention of those skilled in the art.

Disclosure of Invention

In order to solve or partially solve the problems in the related art, the invention provides fresh-cut China rose preservative paper, a preparation method thereof and a fresh-cut China rose preservative method.

The invention provides a preparation method of fresh cut China rose preservative paper, which comprises the following steps:

Step a), soaking the melt-blown cloth in a fresh-keeping liquid for soaking and adsorbing treatment, and then drying to obtain a pretreated melt-blown cloth; the fresh-keeping liquid comprises the following components: natamycin suspension, 6-benzylaminoadenine, nano SiO ₂ and deionized water;

Step b), sequentially preparing a chlorine dioxide slow-release layer, a thymol slow-release layer and a 1-MCP slow-release layer on the functional surface of the pretreated melt-blown cloth to obtain the preparation method; the functional surface is the surface which is contacted with the fresh cut China rose after being packaged.

Further, the preservation solution comprises: natamycin suspension 0.3 wt% -1 wt%, 6-benzylaminoadenine 0.05 wt% -0.1 wt%, nano SiO ₂ 1 wt% -2 wt% and the balance deionized water.

Further, the fresh-keeping liquid is prepared according to the following method: and fully stirring the natamycin suspension with the concentration of 3-6wt%, the nano SiO ₂ aqueous solution with the concentration of 22-30wt% and the 6-benzylaminoadenine aqueous solution with the concentration of 460-520 mg/L with deionized water, and dissolving with the aid of ultrasound to obtain the fresh-keeping liquid.

Further, the thymol slow release layer comprises thymol microcapsules; the 1-MCP slow-release layer comprises 1-MCP microcapsules; the wall material of the microcapsule is beta-cyclodextrin.

Further, the step b) specifically includes:

sequentially spraying a chlorine dioxide slow release agent, a thymol microcapsule solution and a 1-MCP microcapsule solution on the functional surface of the pretreated melt-blown cloth; and (5) airing to obtain the finished product.

Further, in the step a), the soaking time is 4-7 min, and the drying temperature is 40-60 ℃.

Further, the preparation processes are all carried out in a sterile environment.

Further, the method further comprises the step of sterilizing the melt-blown fabric before the step a).

The invention also provides fresh cut China rose preservative paper which is prepared according to any one of the methods.

The invention also provides a fresh-keeping method of the fresh-cut China rose, which comprises the following steps:

Cutting the preservative paper according to the size of the fresh cut China rose, packaging the fresh cut China rose by using the cut preservative paper, and enabling the functional surface of the preservative paper to be in contact with the fresh cut China rose after packaging;

and (5) placing the packaged fresh cut China rose flowers in an environment of 1+/-1 ℃ for storage.

The preparation method of the fresh cut China rose preservative paper provided by the invention can comprise the following beneficial effects:

1) The method takes the melt-blown cloth as a carrier, and utilizes the gap structure of the melt-blown cloth to load active ingredients with fresh-keeping and antibacterial functions on the surface of the melt-blown cloth to prepare the fresh-keeping paper. Therefore, the fresh-keeping paper can be packaged after being cut according to the size of the fresh-cut China rose flowers, and then the fresh-keeping paper is directly stored and transported, so that the utilization rate of the fresh-keeping preparation is improved, and the fresh-keeping preparation is convenient to transport, turnover and sell. And meanwhile, the other application of the melt-blown fabric is realized, and the problem of accumulation of the melt-blown fabric is solved.

2) Firstly, soaking melt-blown cloth in a fresh-keeping liquid, and adding nano silicon dioxide into the fresh-keeping liquid to improve the load of natamycin suspension and 6-benzylaminoadenine in the fresh-keeping liquid on the surface of the melt-blown cloth, so as to prepare the pretreated melt-blown cloth with a relatively flat surface; and then sequentially preparing a chlorine dioxide slow-release layer, a thymol slow-release layer and a 1-MCP slow-release layer on the surface of the pretreated melt-blown cloth. The 1-MCP slow release layer is combined with water vapor released by the cut rose flowers within 24 hours after use to quickly release 1-MCP, the 1-MCP is used as an ethylene blocking agent to quickly play a key role in inhibiting the release of cut rose ethylene, the cut rose flowers are preserved, the second layer of thymol is gradually released in 0-7 days of storage, the third layer of thymol is gradually released to kill microorganisms in the cut rose flowers microenvironment after 7-15 days of storage, and the natamycin suspension and the 6-benzylaminoadenine loaded in the melt blown cloth also play a role continuously during and after the release of the functional coating, so that the cut rose flowers preservative paper with gradient preservation is formed, the preservation effect is continuously played, the storage period of the cut rose flowers is prolonged, and good commodity quality and nutritive value of the cut rose flowers are maintained.

3) The method is safe, efficient, simple and feasible, and low in economic cost.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely, and it is apparent that the described embodiments are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in this specification and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any or all possible combinations of one or more of the associated listed items.

It should be understood that although the terms "first," "second," "third," etc. may be used in this disclosure to describe various information, these information should not be limited to these terms. These terms are only used to distinguish one type of information from another. For example, first information may also be referred to as second information, and similarly, second information may also be referred to as first information, without departing from the scope of the invention. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present invention, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

The melt-blown cloth mainly uses polypropylene as a raw material, the fiber diameter can reach 1-5 mu m, and the melt-blown cloth is an important composition material of the medical protective mask. The superfine fiber with the unique capillary structure increases the number and the surface area of the fiber per unit area, so that the melt-blown cloth has good filterability and shielding property. Although melt-blown cloth is not used in the field of fruit and vegetable storage and transportation fresh-keeping, the inventor discovers that the melt-blown cloth does not have dew condensation phenomenon when being used in the low-temperature storage process of fruits and vegetables and has a certain protection effect, so that the melt-blown cloth is considered to be applied to fresh-cut China rose fresh-keeping.

The embodiment of the invention provides a preparation method of fresh cut China rose preservative paper, which comprises the following steps:

The inventor considers that the preparation of the preservative paper is realized by taking the melt-blown cloth as a carrier and processing and preparing a functional layer with the preservative and antibacterial effects on the surface of the melt-blown cloth (namely, the melt-blown cloth is directly subjected to the step b). The fresh-keeping of the fresh cut China rose is realized by releasing the active ingredients with fresh-keeping and antibacterial effects on the fresh-keeping paper; simultaneously, the physiological activities after the China rose is picked are further combined, and the effective components with different functions are released in sequence, so that the fresh-keeping effect is improved to the greatest extent. The inventors found that: the growth of the fresh cut China rose is inhibited at the initial stage, and the effects of sterilization and bacteriostasis at the middle and later stages are most obvious for prolonging the fresh-keeping period of the fresh cut China rose. Therefore, the functional layer is of a composite layer structure so as to exert different effects in stages, and particularly, the functional layer sequentially comprises a growth inhibition layer and a sterilization and bacteriostasis layer from outside to inside.

Further, 1-methylcyclopropene (1-MCP) was used for the growth-suppressing layer selection for selection of specific active ingredients. 1-MCP is an ethylene inhibitor with the most prominent action effect discovered in scientific research in recent years, is nontoxic, harmless and residue-free, has no environmental pollution, can be preferentially and irreversibly combined with ethylene receptors on cell membranes to prevent ethylene signal transmission, thereby achieving the purpose of delaying maturation and aging, and is widely applied to fruit, vegetable and flower preservation. In order to prolong the time and uniformity of the action of the 1-MCP, the 1-MCP is arranged on the outermost layer of the melt-blown cloth in a mode of a 1-MCP slow release layer. Preferably, the 1-MCP sustained release layer includes: 1-MCP microcapsule, wherein the wall material of the microcapsule is beta-cyclodextrin. The respiration of the fresh cut China rose can generate water, and the beta-cyclodextrin is dissolved in the water, so that the 1-MCP can be slowly released. For the selection of the sterilization and bacteriostasis layer, the application considers two effective components, namely chlorine dioxide and thymol. Chlorine dioxide is an inorganic compound, the chemical formula of the chlorine dioxide is ClO ₂, the chlorine dioxide is yellow-green gas at the temperature of more than 11 ℃, the chlorine dioxide is usually treated in the form of aqueous solution and is widely used as disinfectant, and recent researches find that the chlorine dioxide has better effect in the fresh-keeping of plants such as fruits and vegetables, and the chlorine dioxide has the advantages of high safety, good sterilization fresh-keeping effect and the like. The thymol is a volatile phenolic compound extracted from thyme and oregano essential oil, has excellent antioxidant capacity and antibacterial capacity, and a large number of research results show that the thymol or a plant containing the thymol has remarkable antibacterial activity, has broad spectrum and has inhibition effect on most gram bacteria (gram negative and positive bacteria such as salmonella, pertussis bacillus, chromobacterium violaceum and the like), has wide application prospect in the aspects of storage, transportation and preservation of fruits and vegetables and flowers, is easy to volatilize, and takes chlorine dioxide as an innermost layer in consideration of taking the thymol or the plant containing the thymol as an intermediate layer. Similar to 1-MCP, chlorine dioxide was made into a chlorine dioxide slow-release layer, and thymol was made into a thymol slow-release layer. Further, the thymol slow release layer comprises a thymol microcapsule, the wall material of the microcapsule is beta-cyclodextrin, the chlorine dioxide slow release layer comprises organic matter loaded chlorine dioxide, and the carrier organic matter can be methyl cellulose sodium (CMC) and silica gel.

Further, in order to improve the operation efficiency of the above-mentioned functional layers (chlorine dioxide slow-release layer, thymol slow-release layer and 1-MCP slow-release layer) and to facilitate the realization of industrial production, it is preferable to realize the preparation of the above-mentioned functional layers by spraying. However, the present inventors have found that the functional layer can be attached to the surface of the meltblown fabric after the functional layer is directly formed on the surface of the meltblown fabric, but the functional layer is easily detached and the order of release of the active ingredients is unstable. In view of this problem, the present inventors have found that the above-mentioned reasons may be that the melt blown cloth has excessively large surface gaps and uneven distribution, and uneven surface, resulting in reduced adhesion and coating uniformity. In order to solve this problem, the present inventors considered that a step of gap filling was performed in advance before preparing a functional layer on the surface of the flocked plain cloth. For the selection of the filler, the inventor considers that the filler not only plays a role in improving the surface flatness of the melt-blown cloth, but also can further play a role in preserving and inhibiting bacteria, so that the time for playing the preserving role can be further prolonged, and the filler is selected as a preservative.

For the selection of the preservative, the present application first contemplates the use of a suspension of natamycin and 6-benzylaminoadenine. The natamycin is a high-efficiency broad-spectrum fungus inhibitor, is mainly applied to foods such as meat, beverages, dairy products and the like, can well inhibit the growth of mould and saccharomycetes by a small amount of use, and is a natural food preservative which is high-efficiency, safe, nontoxic and free of side effects and does not influence the mouthfeel, color and flavor of foods and is approved to be used internationally at present. 6-benzylaminoadenine (6-BA) is a first artificially synthesized cytokinin, and can be used for prolonging the fresh-keeping period of vegetables by stimulating cell division to cause plant growth and development, inhibiting respiratory kinase, inhibiting decomposition of chlorophyll, nucleic acid and protein in plant leaves, regulating and transporting amino acid, auxin and inorganic salt. Based on the above, the present inventors firstly carried natamycin suspension and 6-benzylaminoadenine on the surface of the melt-blown cloth to realize filling of gaps while expected to exert antibacterial fresh-keeping effect, specifically by immersing the fresh-keeping liquid containing the above two effective components. However, the inventor further discovers through researches that the adsorption effect of natamycin suspension and 6-benzylaminoadenine on the velvet spraying cloth is not ideal, so that the loading rate of the smelting spraying cloth is low, the effect of improving the surface flatness of the smelting spraying cloth is not obvious, and meanwhile, the expected antibacterial fresh-keeping effect is difficult to exert.

Further, the inventors contemplate that the loading rate of the meltblown to natamycin suspension and 6-benzylaminoadenine can be increased by adding nano silica to the preservative solution. In particular, by utilizing the adsorption effect of the nano silica, on one hand, the nano silica is easier to adsorb on the nap spray cloth, and on the other hand, the nano silica can adsorb a large amount of natamycin and 6-benzylaminoadenine, so that the adsorption amount of natamycin and 6-benzylaminoadenine by the melt spray cloth can be improved. In addition, the adsorption sites of the vacancies on the surface of the nano silicon dioxide can also improve the adsorption effect on the functional layer and improve the firmness of the functional layer. And the nano silicon dioxide also has a certain antibacterial effect. Thus, the application firstly carries out the step a), the melt-blown cloth is soaked in the fresh-keeping liquid containing natamycin suspension, 6-benzylaminoadenine and nano SiO ₂ for carrying out soaking adsorption treatment, and then the melt-blown cloth is dried to obtain the pretreated melt-blown cloth, and then the functional layer of the step b) is prepared.

As a preferable aspect of this embodiment, the fresh-keeping solution includes: natamycin suspension 0.3 wt% -1 wt%, 6-benzylaminoadenine 0.05 wt% -0.1 wt%, nano SiO ₂ 1 wt% -2 wt% and the balance deionized water. The loading amount of natamycin, 6-benzylaminoadenine and nano SiO ₂ on the surface of the melt-blown cloth in the proportion is most suitable, and the flatness of the surface of the melt-blown cloth soaked by the fresh-keeping liquid is most suitable for processing and preparing the functional layer. Preferably, the fresh-keeping solution includes: natamycin suspension 0.5-0.5 wt.9 wt%, 6-benzylaminoadenine 0.06-wt-0.08-wt wt%, nano SiO ₂ 1.5.5-wt-2-wt wt% and deionized water for the rest. Most preferably, the preservative solution comprises: natamycin suspension 0.8 wt%, 6-benzylaminoadenine 0.08 wt%, nano SiO ₂ 1.5.5 wt% and the rest deionized water.

Further, the fresh-keeping liquid is prepared according to the following method: and fully stirring the natamycin suspension with the concentration of 3-6wt%, the nano SiO ₂ aqueous solution with the concentration of 22-30wt% and the 6-benzylaminoadenine aqueous solution with the concentration of 460-520 mg/L with deionized water, and dissolving with the aid of ultrasound to obtain the fresh-keeping liquid. The power of the ultrasonic wave is preferably 400-600W, and the ultrasonic wave time is preferably 8-12 min. Most preferably, the preservative solution is prepared according to the following method: and fully stirring the natamycin suspension with the concentration of 5 wt%, the nano SiO ₂ aqueous solution with the concentration of 25: 25 wt% and the 6-benzylaminoadenine aqueous solution with the concentration of 500: 500 mg/L with deionized water, and carrying out ultrasonic auxiliary dissolution to obtain the fresh-keeping liquid.

The time for soaking the fresh-keeping liquid is preferably 4-7 min, and the fresh-keeping liquid is dried after soaking to remove redundant water; the drying is preferably low-temperature drying so as to avoid the loss of active ingredients of the fresh-keeping liquid, and the drying temperature is preferably 40-60 ℃. In addition, as a preferable mode of the present application, the method further comprises a step of sterilizing the meltblown cloth before the step a). The steps of sterilization and disinfection specifically can be as follows: and spraying and sterilizing the melt-blown cloth by using 95% alcohol for 10-30 minutes. The step of processing and manufacturing the functional layer can be carried out after the pretreatment melt-blown cloth is obtained according to the step a).

Preferably, step b) may specifically be: sequentially spraying a chlorine dioxide slow release agent, a thymol microcapsule solution and a 1-MCP microcapsule solution on the functional surface of the pretreated melt-blown cloth; and (5) airing to obtain the finished product. The concentration of chlorine dioxide in the chlorine dioxide slow release agent is preferably 0.8-1.5 mg/mL, and most preferably 1 mg/mL; the concentration of thymol in the thymol microcapsule solution is preferably 0.5-1 mg/mL, and most preferably 0.8 mg/mL; the concentration of 1-MCP in the 1-MCP microcapsule solution is preferably 0.08-0.12 mg/mL, and most preferably 0.1 mg/mL.

The slow-release chlorine dioxide preservative can be prepared according to the following method: adding water into sodium chlorite and silica gel, mixing, and stirring to obtain suspension A. Sodium carboxymethylcellulose (CMC) and sodium chloride are added with water and evenly stirred to obtain a mixture B. A, B, mixing and stirring to obtain a first agent for standby; uniformly stirring ethylenediamine tetraacetic acid (EDTA) and silica gel with water to obtain an agent B; finally, mixing the agent B with the agent A to obtain a slow-release chlorine dioxide preservative; wherein the mass ratio of the sodium carboxymethyl cellulose to the ethylene diamine tetraacetic acid to the sodium chloride is preferably 14:1:5.

Thymol microcapsules can be prepared as follows: preparing thymol microcapsule by saturated aqueous solution method, adding beta-cyclodextrin into distilled water, ultrasonically dissolving to clear solution by using ultrasonic cleaner, dissolving thymol into absolute ethanol to prepare absolute ethanol solution of thymol, dropwise adding absolute ethanol solution of thymol into clear and transparent beta-cyclodextrin solution, transferring the mixed solution into water bath constant temperature oscillator for reaction, and cooling the obtained product to room temperature after the reaction is finished to obtain thymol microcapsule slow release agent.

The 1-MCP microcapsules may be prepared as follows: reacting metallic lithium with anhydrous tetrahydrofuran and diisopropylamine to generate lithium diisopropylamide; slowly dropwise adding 3-chloro-2-methyl propylene into lithium diisopropylamide to generate 1-MCP gas, and introducing the generated 1-MCP gas into beta-cyclodextrin absorption liquid to obtain the 1-MCP liquid microcapsule.

The preparation process of the preparation method of the fresh cut China rose preservative paper provided by the embodiment is preferably carried out in a sterile environment.

The fresh-keeping process of the fresh-cut China rose preservative paper prepared by the method is approximately as follows: the 1-MCP slow release layer is combined with water vapor released by the cut rose flowers within 24 hours after use to quickly release 1-MCP, the 1-MCP is used as an ethylene blocking agent to quickly play a key role in inhibiting the release of cut rose ethylene, the cut rose flowers are preserved, the second layer of thymol is gradually released in 0-7 days of storage, the third layer of thymol is gradually released to kill microorganisms in the cut rose flowers microenvironment after 7-15 days of storage, and the natamycin suspension and the 6-benzylaminoadenine loaded in the melt blown cloth also play a role continuously during and after the release of the functional coating, so that the cut rose flowers preservative paper with gradient preservation is formed, the preservation effect is continuously played, the storage period of the cut rose flowers is prolonged, and good commodity quality and nutritive value of the cut rose flowers are maintained.

From the above, the preparation method of the fresh cut China rose preservative paper provided by the embodiment of the invention has the following advantages:

The invention also provides fresh-cut China rose preservative paper, which is prepared according to the method of the embodiment. The specific implementation and the beneficial effects are the same as those of the above embodiment, and are not repeated.

The invention also provides a fresh-keeping method of the fresh-cut China rose, which comprises the following steps: cutting the preservative paper according to the size of the fresh cut China rose, packaging the fresh cut China rose by using the cut preservative paper, and enabling the functional surface of the packaged preservative paper to be in contact with the fresh cut China rose;

The method for preserving the fresh cut China rose flowers can reduce the convenience of storage and transportation and has lower cost.

The technical scheme of the invention is further described below with reference to specific examples:

The slow-release chlorine dioxide preservative, thymol microcapsule and 1-MCP microcapsule in the following examples were prepared as follows:

(1) The slow-release chlorine dioxide preservative is prepared by the following steps: weighing a proper amount of sodium chlorite and silica gel, adding water, mixing and uniformly stirring to obtain suspension A for later use. Weighing a proper amount of sodium carboxymethylcellulose (CMC) and sodium chloride, adding water, mixing, and uniformly stirring to obtain a mixture B. A, B, mixing and stirring to obtain a first agent for standby; weighing a proper amount of ethylenediamine tetraacetic acid (EDTA) and silica gel, adding water, and uniformly stirring to obtain an agent B; finally, mixing the agent B with the agent A to obtain a slow-release chlorine dioxide preservative; wherein the mass ratio of the sodium carboxymethyl cellulose to the ethylenediamine tetraacetic acid to the sodium chloride is 14:1:5.

(2) Preparation of thymol microcapsules: preparing thymol microcapsule by adopting a saturated aqueous solution method, weighing 4g beta-cyclodextrin, adding distilled water with 15 times of mass, using an ultrasonic cleaner to carry out ultrasonic wave at 45 ℃ (power 180W) to promote dissolution to a clear solution, dissolving 1g thymol in 20 mL absolute ethyl alcohol to prepare a thymol absolute ethyl alcohol solution, dropwise adding the thymol absolute ethyl alcohol solution into the clear and transparent beta-cyclodextrin solution, transferring the mixed solution into a water bath constant temperature oscillator, reacting for 2.0 h under the conditions of 50 ℃ and 150 r/min, and cooling the obtained product to room temperature after the reaction is finished, thus obtaining the thymol microcapsule slow release agent.

(3) Preparation of 1-MCP microcapsules: 659 mg metal lithium and 50 mL anhydrous tetrahydrofuran are added into a 150 mL dry three-necked bottle provided with a dry condensing tube and a dropping funnel under the protection of nitrogen, and 13 mL diisopropylamine is slowly added dropwise until the metal lithium completely disappears; when the reaction is complete, the reaction product is lithium diisopropylamide; then 3-chloro-2-methylpropene of about 8 mL is slowly added dropwise. And introducing the gas generated by the reaction into beta-cyclodextrin absorption liquid under the protection of nitrogen to obtain the 1-MCP liquid microcapsule.

Example 1

The natamycin suspension with the concentration of 5 percent (W), the nano SiO ₂ aqueous solution with the concentration of 25 percent (W) and the 6-benzylaminoadenine aqueous solution with the concentration of 500 mg/L are mixed according to the raw materials with the mass percentage of the fresh-keeping liquid: after 0.8 percent of natamycin, 0.08 percent of 6-benzylaminoadenine, 1.5 percent of nano SiO ₂ and distilled water, fully stirring, and using ultrasonic to assist dissolution to prepare the antibacterial fresh-keeping liquid of the fresh cut China rose; the ultrasonic power was 500W and the ultrasonic time was 10 min.

Comparative example 1

The natamycin suspension with the concentration of 5 percent (W) and the 6-benzylaminoadenine water solution with the concentration of 500 mg/L are mixed according to the raw materials of the fresh-keeping liquid in percentage by mass: after distilled water with the concentration of natamycin being 0.8 percent and 6-benzylaminoadenine being 0.08 percent, fully stirring, and using ultrasonic to assist dissolution to prepare a fresh cut China rose antibacterial fresh-keeping solution; the ultrasonic power was 500W and the ultrasonic time was 10 min.

The same melt-blown cloth is respectively soaked in the fresh-keeping liquid prepared in the example 1 and the comparative example 1 for 5min, and is dried at a low temperature of 40-50 ℃ after soaking and leaching, the adsorption rate and the antibacterial rate of natamycin and 6-benzylaminoadenine are tested (by using botrytis cinerea for inoculation test), and the test results are shown in table 1:

As can be seen from Table 1, the adsorption effect of the meltblown fabric on natamycin 0.8% and 6-benzylaminoadenine can be improved and the antibacterial rate can be improved by adding nano silicon dioxide.

Example 2

1. Spraying 95% alcohol to sterilize the melt-blown cloth for 20 minutes, soaking the preservative paper in the preservative solution prepared in the example 1 for 5 minutes, leaching, and drying at a low temperature of 40-50 ℃;

2. Spraying 1 mg/mL of chlorine dioxide slow-release preservative, 0.8 mg/mL (calculated by thymol) of thymol microcapsule solution and 0.1 mg/mL (calculated by 1-MCP) of 1-MCP microcapsule solution in sequence, and airing to obtain the fresh-cut China rose preservative paper.

Comparative example 2

And (3) sterilizing the melt-blown cloth by using 95% alcohol spray for 20 minutes, and airing to obtain the fresh-cut China rose preservative paper.

Comparative example 3

1. The meltblown was sterilized using a 95% alcohol spray for 20 minutes.

2. The same as in example 2.

Comparative example 4

The difference from example 2 is that: there is no step 2.

Comparative example 5

Preparing a fresh-keeping liquid: the method comprises the steps of (1) suspending natamycin with the concentration of 5% (W), a nano SiO ₂ aqueous solution with the concentration of 25% (W), a 6-benzylaminoadenine aqueous solution with the concentration of 500 mg/L and a thymol solution with the concentration of 20% (W) (ethanol and water are used as solvents), and the raw materials comprise the following components in percentage by mass: after natamycin 0.8%, 6-benzylaminoadenine 0.08%, nano SiO ₂ 1.5.5%, 0.8% thymol and distilled water are fully stirred, and ultrasonic-assisted dissolution is used to prepare fresh cut China rose antibacterial fresh-keeping liquid; the ultrasonic power was 500W and the ultrasonic time was 10 min.

1. Spraying 95% alcohol to sterilize the melt-blown cloth for 20 minutes, soaking the preservative paper in the prepared preservative solution for 5 minutes, leaching, and drying at a low temperature of 40-50 ℃;

2. Spraying with 1 mg/mL chlorine dioxide slow-release preservative and 0.1 mg/mL (calculated by 1-MCP) 1-MCP microcapsule solution in sequence, and air drying to obtain the fresh cut China rose preservative paper.

Comparative example 6

1. The same as in example 2.

2. Mixing 1 mg/mL of chlorine dioxide slow-release preservative, 0.8 mg/mL (calculated by thymol) of thymol microcapsule solution and 0.1 mg/mL (calculated by 1-MCP) of 1-MCP microcapsule solution in equal volume, fully uniformly mixing and stirring for 5min, spraying, and airing to obtain the fresh cut China rose preservative paper.

3. And (3) packaging: cutting the prepared preservative paper according to the size of the fresh cut China rose, and packaging the fresh cut China rose;

4. and (3) storage: and (5) placing the packaged China rose flowers in an environment of 1+/-1 ℃ for storage.

Comparative example 7

Commercial common fresh cut flower packaging paper

[ Shelf-life Effect assessment test ]

Fresh cut China rose flowers are subjected to fresh-keeping treatment by using the fresh-keeping papers prepared in the example 2 and the comparative examples 2-7 respectively in the following manner:

and (3) packaging: cutting the prepared preservative paper according to the size of the fresh cut China rose, and packaging the fresh cut China rose;

and (3) storage: and (5) placing the packaged China rose flowers in an environment of 1+/-1 ℃ for storage.

Quality measurements were made on refrigerated item 20 d. Fresh flowers were taken out of the freezer and the fresh paper was removed, the stems were trimmed under water at 45 ° to a total stem length of about 40 cm, the trimmed flowers were inserted into glass bottles containing 150 ml distilled water, and weight loss, decay rate, sensory evaluation were measured every 2d for a duration of 8 d.

1) Weight loss ratio: the fresh cut China rose flowers subjected to different treatments are numbered and then stored in an environment of 1+/-1 ℃, and are weighed one by one every 7 days, and the weight loss rate= (mass before storage-mass after storage)/mass before storage is 100%. The weight loss rate evaluation results are shown in table 2.

2) Decay rate: the fruits are divided into 4 grades according to the rotten area of the flowers: grade 0, no decay; 1 grade, the rotten area is less than 10% of the area of the flower; 2, the rotting area accounts for 10% -30% of the area of the flower; grade 3, the rotten area is more than 30% of the area of the flower; decay rate = Σ [ (decay level x the level of flowers)/(highest decay level x total flowers) ]x100%. The evaluation results of the decay rate are shown in Table 3.

3) Wilting index:

flower wilting degree is classified into 6 grades:

grade 0-the flowers are naturally stretched, the color is bright and glossy, and the stems are firm;

grade 1-the flowers begin to undergo a dehydration reaction, the flowers are matt, and the leaves of the flower stem part slightly droop;

2-stage flower continuously loses water, and the shrinkage and sagging amplitude of the leaf part is increased;

Grade 3-partial flower dry and hard, curly;

Grade 4-all flowers drooping, shrinking and yellowing of leaves;

stage 5-complete dehydration and drying of leaves and death of plants;

if the degree of wilting is between two stages, the wilting index is = Σ (wilting stage number is the stage flower/total flower) as a half-stage treatment

The wilting index results are shown in table 4.

As can be seen from table 2: the weight loss rate of the fresh cut China rose is gradually increased from 0 to 8 d, and when the bottle is inserted into 8 th d after 20: 20d of the fresh cut China rose is stored, the treatment group of the embodiment 2 is obviously superior to the treatment group of the comparative example. The preservative paper prepared by the invention can protect the water loss of the fresh cut China rose to a certain extent.

As can be seen from table 3: the decay rate of fresh flowers increased continuously during the bottle-inserting experiment, and the decay rate of the treatment group of comparative example 7 was as high as 89% when the bottle was inserted into the bottle 8 d after 20 d storage, and the treatment group of example 2 of the present invention was superior to the comparative group. The preservative paper prepared by the invention can effectively alleviate the decay of the fresh cut China rose, thereby prolonging the preservation period of the fresh cut China rose.

As can be seen from Table 4, the fresh flowers continuously wilt during the bottle inserting test, and the wilt index of the treatment group of comparative example 7 reached the highest value of 50 when the bottle was inserted 8 th d after 20 d of storage, and the treatment group of example 2 of the present invention was superior to the comparative group. The cut flower rose wilting index score packaged in the embodiment 2 is obviously lower than that of the comparative example group, and the preservative paper prepared by the invention has obvious preservative effect.

The foregoing description of embodiments of the invention has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the various embodiments described. The terminology used herein was chosen in order to best explain the principles of the embodiments, the practical application, or the improvement of technology in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. The preparation method of the fresh cut China rose preservative paper is characterized by comprising the following steps of:

Step a), soaking the melt-blown cloth in a fresh-keeping liquid for soaking and adsorbing treatment, and then drying to obtain a pretreated melt-blown cloth; the fresh-keeping liquid comprises the following components: natamycin suspension 0.3-1 wt%, 6-benzylaminoadenine 0.05-0.1 wt%, nano SiO 21 wt-2 wt% and rest deionized water;

2. The preparation method according to claim 1, wherein the preservation solution is prepared according to the following method: and fully stirring the natamycin suspension with the concentration of 3-6wt%, the nano SiO ₂ aqueous solution with the concentration of 22-30wt% and the 6-benzylaminoadenine aqueous solution with the concentration of 460-520 mg/L with deionized water, and dissolving with the aid of ultrasound to obtain the fresh-keeping liquid.

3. The method of preparation of claim 1, wherein the thymol slow release layer comprises thymol microcapsules; the 1-MCP slow-release layer comprises 1-MCP microcapsules; the wall material of the microcapsule is beta-cyclodextrin.

4. A method according to claim 3, wherein step b) is specifically:

5. The method according to claim 1, wherein in the step a), the soaking time is 4-7 min, and the drying temperature is 40-60 ℃.

6. The method of claim 1, wherein the preparation is performed in a sterile environment.

7. The method of claim 1, further comprising the step of sterilizing the meltblown web prior to step a).

8. A cut rose preservative paper, characterized in that it is prepared according to the method of any one of claims 1 to 7.

9. The fresh-keeping method of the fresh cut China rose is characterized by comprising the following steps:

Cutting the preservative paper according to the size of the fresh cut China rose, packaging the fresh cut China rose by using the cut preservative paper, and enabling the functional surface of the packaged preservative paper to be in contact with the fresh cut China rose;