阅读说明：本技术 一种兼具吸附溴氰菊酯及抗菌性能的便捷式保鲜卡及其制备方法 (Portable preservation card with deltamethrin adsorption and antibacterial properties and preparation method thereof ) 是由 林德荣 陈奕宏 陈聃聃 方楠心 陈雨竹 王艺菲 钟聪健 黄小双 马惠纹 邱钰婷 于 2021-08-18 设计创作，主要内容包括：本发明属于材料技术领域,公开了一种兼具吸附溴氰菊酯及抗菌性能的便捷式保鲜卡及其制备方法。所述制备方法包括：(1)以豆渣膳食纤维、丙酸钙和抗坏血酸钠为原料,配制保鲜剂溶液,将食品级卡纸浸泡在保鲜剂溶液中,取出、置干；(2)将纳米硅气凝胶溶解在冰乙酸中,加入蒸馏水,再加入纳米壳聚糖和柠檬酸三丁酯,充分溶解并混合均匀,除去溶液中的气泡,将膜液均匀地涂布在玻璃板上,干燥后静置揭膜,置于恒温恒湿箱内平衡24～48h,所制备的薄膜覆于置干的食品级卡纸上。本发明所得保鲜卡可有效抑制常见的食品腐败微生物的生长,制作工艺简单,制造成本低、耗时短,且保鲜卡环保、对环境无害。(The invention belongs to the technical field of materials, and discloses a convenient preservation card with deltamethrin adsorption and antibacterial properties and a preparation method thereof. The preparation method comprises the following steps: (1) taking bean dreg dietary fiber, calcium propionate and sodium ascorbate as raw materials, preparing a preservative solution, soaking the food-grade paperboard in the preservative solution, taking out and drying; (2) dissolving nano-silica aerogel in glacial acetic acid, adding distilled water, adding nano-chitosan and tributyl citrate, fully dissolving and uniformly mixing, removing bubbles in the solution, uniformly coating the membrane liquid on a glass plate, drying, standing, uncovering the membrane, placing in a constant-temperature constant-humidity box for balancing for 24-48 h, and covering the prepared membrane on dried food-grade paperboard. The preservation card obtained by the invention can effectively inhibit the growth of common food spoilage microorganisms, has simple manufacturing process, low manufacturing cost and short time consumption, and is environment-friendly and harmless to the environment.)

1. The preparation method of the convenient preservation card with the deltamethrin adsorption and antibacterial properties is characterized by comprising the following steps:

(1) taking bean dreg dietary fiber, calcium propionate and sodium ascorbate as raw materials, preparing a preservative solution, uniformly mixing the solution, and soaking the food-grade paperboard in the prepared preservative solution;

(2) taking out the food-grade paperboard fully adsorbing the fresh-keeping solution, and drying;

(3) dissolving nano-silica aerogel in glacial acetic acid, adding distilled water, adding nano-chitosan and tributyl citrate, and fully dissolving and uniformly mixing under magnetic stirring;

(4) removing bubbles in the solution prepared in the step (3) by adopting a vacuum reduced pressure filtration and ultrasonic oscillation method, uniformly coating the membrane liquid on a glass plate by a casting method, drying, standing, uncovering the membrane, and placing in a constant temperature and humidity cabinet for balancing for 24-48 h;

(5) covering the film prepared in the step (4) on the dried food-grade paperboard prepared in the step (2);

(6) cutting the coated paper into cards with required specification and size.

2. The preparation method of the convenient preservation card capable of adsorbing deltamethrin and resisting bacteria as claimed in claim 1, wherein the mass ratio of the bean dregs dietary fiber, the calcium propionate and the sodium ascorbate in the step (1) is 75-85: 8-12: 5 to 15.

3. The preparation method of the portable preservation card with deltamethrin adsorption and antibacterial properties according to claim 1, wherein the preparation method of the bean dregs dietary fiber in the step (1) comprises the following steps: drying bean dregs at 95-105 ℃, sieving, soaking the bean dregs in diethyl ether for degreasing, washing with water to remove an organic solvent, drying at 75-85 ℃, and mixing the dried bean dregs: and m is 20-30: 1, preparing a solution, adjusting the pH value of the solution to be 5.5-6.5, adding papain and glucoamylase, and performing synergistic enzymolysis.

4. The preparation method of the portable fresh-keeping card with deltamethrin adsorption and antibacterial properties as claimed in claim 1, wherein the food-grade cardboard in step (1) is activated carbon fiber paper with a thickness of 0.5-1.5 mm; preferably, the soaking time in the step (1) is 10-20 min.

5. The preparation method of the portable preservation card with deltamethrin adsorption and antibacterial properties according to claim 1, wherein the drying conditions in the step (2) are as follows: and (3) drying in vacuum for 3-8 min at the temperature of 55-65 ℃.

6. The preparation method of the portable preservation card with deltamethrin adsorption and antibacterial properties as claimed in claim 1, wherein the mass ratio of the nano-silica aerogel, the nano-chitosan and the tributyl citrate in step (3) is 55-65: 20-30: 10 to 20.

7. The preparation method of the portable preservation card with deltamethrin adsorption and antibacterial properties as claimed in claim 1, wherein the preparation method of the nano chitosan in step (3) is as follows: dissolving chitosan in 0.7-1.3% acetic acid to ensure that the mass concentration of the chitosan is 1-3 mg/mL; stirring the chitosan solution, simultaneously adding 0.5-1.5 mg/mL sodium tripolyphosphate solution, then heating to 85-95 ℃ to evaporate the solvent, standing and cooling, washing with absolute ethyl alcohol, and drying in vacuum to obtain the nano chitosan.

8. The preparation method of the portable preservation card with deltamethrin adsorption and antibacterial properties as claimed in claim 1, wherein the vacuum pressure reduction filtration pressure in step (4) is-0.06 to-0.12 Mpa, the frequency of ultrasonic oscillation treatment is 20KHz to 30KHz, and the time is 25 to 35 min; preferably, the conditions in the constant temperature and humidity chamber in the step (4) are that the relative humidity is 45-55% and the temperature is 20-30 ℃.

9. A portable preservation card with deltamethrin adsorption and antibacterial properties, which is characterized in that the preservation card is prepared according to any one of claims 1 to 8.

10. The portable crisper card with deltamethrin adsorption and antibacterial properties as claimed in claim 9, wherein the crisper card is a laminated crisper card, and in the preparation process, in the step (5), films are coated on two sides of the food-grade cardboard; or the fresh-keeping card is a paper-pasted fresh-keeping card, in the preparation process, the film is covered on one side of the food-grade paperboard in the step (5), and the food-grade adhesive back dry adhesive paper is adhered to the other side of the food-grade paperboard.

Technical Field

The invention relates to the technical field of materials, in particular to a convenient preservation card with deltamethrin adsorption and antibacterial properties and a preparation method thereof.

Background

China is a big country for agricultural production, and fruits and vegetables become two major agricultural planting industries following grains. However, the rot of fruits and vegetables in China is serious, and the preservation technology is relatively lagged, so that the non-negligible economic loss is caused, and meanwhile, the rotten fruits and vegetables are seriously harmful to human bodies when being eaten by mistake. On the other hand, in the planting process of fruits and vegetables, in order to prevent plant diseases and insect pests and realize yield increase of the fruits and vegetables, pesticides are inevitably used, and the pesticide is used in an irregular manner, so that the pesticide residue in the fruits and vegetables is always overproof.

The commonly used fruit and vegetable fresh-keeping materials at present comprise a fresh-keeping agent, a fresh-keeping film, a drying agent or a fresh-keeping card and the like which are placed in a packaging box. The antistaling agent is divided into a chemical antistaling agent and a biological antistaling agent, the application of the chemical antistaling agent is limited due to the harmfulness of the chemical antistaling agent residue, and the biological antistaling agent has high preparation technology and cost and less application. Although the preservative film has a good preservation effect, most of the preservative films on the market at present are not degradable and have great harm to the environment. Most of traditional preservation cards are fully soaked in ethanol and then dried, and then effects of sterilization and preservation prolongation are achieved by releasing ethanol, the sterilization effect of ethanol is positively correlated with the concentration of ethanol, however, too high concentration of ethanol not only causes damage to food, but also causes explosion reaction. Therefore, a material which has antibacterial and fresh-keeping properties and can adsorb the deltamethrin on the surface of fruits and vegetables needs to be developed.

Disclosure of Invention

The invention aims to overcome the defects of the background technology and provides a preparation method of a convenient preservation card with deltamethrin adsorption and antibacterial properties. The preparation method of the invention uses food grade card paper with good water absorption to fully soak preservative solution which takes bean dregs dietary fiber as main raw material as a preservation base layer, takes nano-silica aerogel and nano-chitosan film as an antibacterial adsorption preservation layer, takes tributyl citrate (TBC) as a plasticizer, and prepares the fruit and vegetable preservation card which comprises two styles: the laminated paper can be used in food packaging bags, household refrigerators, fruit and vegetable transport containers, and even refrigerators, and each fruit and vegetable fresh-keeping card covers 0.8 m.

In order to achieve the aim of the invention, the preparation method of the convenient preservation card with deltamethrin adsorption and antibacterial properties comprises the following steps:

(1) taking bean dreg dietary fiber, calcium propionate and sodium ascorbate as raw materials, preparing a preservative solution, uniformly mixing the solution, and soaking the food-grade paperboard in the prepared preservative solution;

(2) taking out the food-grade paperboard fully adsorbing the fresh-keeping solution, and drying;

(3) dissolving nano-silica aerogel in glacial acetic acid, adding distilled water, adding nano-chitosan and tributyl citrate, and fully dissolving and uniformly mixing under magnetic stirring;

(4) removing bubbles in the solution prepared in the step (3) by adopting a vacuum reduced pressure filtration and ultrasonic oscillation method, uniformly coating the membrane liquid on a glass plate by a casting method, drying, standing, uncovering the membrane, and placing in a constant temperature and humidity cabinet for balancing for 24-48 h;

(5) covering the film prepared in the step (4) on the dried food-grade paperboard prepared in the step (2);

(6) cutting the coated paper into cards with required specification and size.

Further, in some embodiments of the invention, in the step (1), the mass ratio of the bean dregs dietary fiber, the calcium propionate and the sodium ascorbate is 75-85: 8-12: 5 to 15.

Further, in some embodiments of the present invention, the preparation method of the okara dietary fiber in the step (1) is: drying bean dregs at 95-105 ℃, sieving, soaking the bean dregs in diethyl ether for degreasing, washing with water to remove an organic solvent, drying at 75-85 ℃, and mixing the dried bean dregs: and m is 20-30: 1, preparing a solution, adjusting the pH value of the solution to be 5.5-6.5, adding papain and glucoamylase, and performing synergistic enzymolysis.

Further, in some embodiments of the present invention, the food grade cardboard in step (1) is activated carbon fiber paper, and the thickness is 0.5-1.5 mm.

Preferably, in some embodiments of the present invention, the soaking time in the step (1) is 10 to 20 min.

Further, in some embodiments of the present invention, the drying condition in step (2) is: and (3) drying in vacuum for 3-8 min at the temperature of 55-65 ℃.

Further, in some embodiments of the present invention, the mass ratio of the nano-silica aerogel, the nano-chitosan and the tributyl citrate in the step (3) is 55-65: 20-30: 10 to 20.

Further, in some embodiments of the present invention, the preparation method of the nano chitosan in step (3) is: dissolving chitosan in 0.7-1.3% (w/v) acetic acid to ensure that the mass concentration of the chitosan is 1-3 mg/mL; stirring the chitosan solution, simultaneously adding 0.5-1.5 mg/mL sodium tripolyphosphate solution, then heating to 85-95 ℃ to evaporate the solvent, standing and cooling, washing with absolute ethyl alcohol, and drying in vacuum to obtain the nano chitosan.

Further, in some embodiments of the present invention, in the step (4), the vacuum pressure reduction and filtration pressure is-0.06 to-0.12 Mpa, the frequency of the ultrasonic oscillation treatment is 20KHz to 30KHz, and the time is 25 to 35 min.

Preferably, in some embodiments of the present invention, the conditions in the constant temperature and humidity chamber in the step (4) are 45-55% of relative humidity and 20-30 ℃.

On the other hand, the invention also provides a convenient preservation card with deltamethrin adsorption and antibacterial properties, and the preservation card is prepared by adopting the method.

Further, in some embodiments of the present invention, the freshness card is a laminated freshness card, and the step (5) of preparing the freshness card is to coat the two sides of the food-grade paperboard with a film.

Further, in some embodiments of the present invention, the freshness card is a sticker-type freshness card, and in the preparation process, in the step (5), a film is coated on one side of the food-grade paperboard, and food-grade adhesive-type back-dry adhesive paper is adhered to the other side of the food-grade paperboard.

Compared with the prior art, the invention has the following advantages:

1. the invention takes the bean dregs as the main raw material of the base layer of the fresh-keeping card, so that the bean dregs can be reused, and the problem of environmental pollution caused by the waste bean dregs is reduced.

2. The chitosan is prepared into the nano chitosan, so that the specific surface area and the charge density of the nano chitosan are increased, the nano chitosan has higher antibacterial activity, and the growth of common food spoilage microorganisms such as escherichia coli and staphylococcus aureus can be effectively inhibited.

3. The fruit and vegetable fresh-keeping card has the advantages of simple manufacturing process, low manufacturing cost, short time consumption, environmental protection and no harm to the environment.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention. It is to be understood that the following description is only illustrative of the present invention and is not to be construed as limiting the present invention.

The terms "comprises," "comprising," "includes," "including," "has," "having," "contains," "containing," or any other variation thereof, as used herein, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

When an amount, concentration, or other value or parameter is expressed as a range, preferred range, or as a range of upper preferable values and lower preferable values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether ranges are separately disclosed. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted to include the ranges "1 to 4", "1 to 3", "1 to 2 and 4 to 5", "1 to 3 and 5", and the like. When a range of values is described herein, unless otherwise stated, the range is intended to include the endpoints thereof and all integers and fractions within the range.

Furthermore, the description below of the terms "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily for the same embodiment or example. Further, the technical features of the embodiments of the present invention may be combined with each other as long as they do not conflict with each other.

Example 1

A preparation method of a portable preservation card with deltamethrin adsorption and antibacterial properties comprises the following specific operations:

(1) oven drying bean dregs at 100 deg.C, sieving with 80 mesh sieve, soaking bean dregs in diethyl ether for 8 hr (V)_{Ether (A)}：V_{Bean dregs}6: 1) defatting, washing with water to remove organic solvent, oven drying at 80 deg.C to obtain powder_{Bean dregs}：m_{Water (W)}25: 1, preparing a solution, adjusting the pH value of the solution to 6, adding papain with the mass percentage of 4% and glucoamylase with the mass percentage of 1% to the dried defatted bean dregs, and performing enzymolysis for 40min in a synergistic manner to obtain the bean dregs dietary fiber;

(2) preparing preservative solution with the concentration of 0.5mg/mL, wherein the preservative solution comprises the following components in parts by weight: 75 parts of bean dreg dietary fiber, 10 parts of calcium propionate and 15 parts of sodium ascorbate; selecting activated carbon fiber paper with the thickness of 0.5mm, and soaking the activated carbon fiber paper in an adsorption preservative solution for 10 minutes;

(3) taking out the paper adsorbing the preservative solution, draining the solution under natural conditions, and vacuum drying at 60 ℃ for 3 min;

(4) 0.2g of Chitosan (CS) was weighed out and dissolved in 100mL of 1% (w/v) acetic acid to a mass concentration of 2 mg/mL; preparing 1mg/mL sodium Tripolyphosphate (TPP) solution, filtering with 0.45 μm filter membrane, magnetically stirring the CS solution at 600r/min, and adding 1mg/mL TPP solution into the CS solution with a constant flow pump (V)_CS:V_TPP4:1), then heating to 90 ℃, evaporating the solvent to dryness, standing and cooling, washing with a proper amount of absolute ethyl alcohol for 3 times, and drying in vacuum at 40 ℃ for 5 hours to obtain nano chitosan (CS NPs);

(5) preparing 1.5mg/mL antibacterial adsorption feed liquid, wherein the antibacterial adsorption feed liquid comprises the following components in parts by weight: 55 parts of nano-silica aerogel, 30 parts of nano-chitosan and 15 parts of tributyl citrate, and fully dissolving and uniformly mixing the components under magnetic stirring;

(6) removing bubbles of the feed liquid in the step (5) by vacuum reduced pressure filtration and ultrasonic oscillation methods, and uniformly coating the membrane liquid on a glass plate (25mm multiplied by 25mm) by a casting method;

(7) drying at 45 deg.C for 10 hr, standing, uncovering, and balancing in a constant temperature and humidity box with temperature of 20 deg.C and humidity of 50% for 48 hr;

(8) covering the film prepared in the step (7) on the paper placed in the step (3); for the laminated version fresh-keeping card, the two sides of the paper which is put dry are covered with films; for the fresh-keeping card of the sticker version, a film is coated on one side of the paper to be dried, and the food-grade adhesive back-dry adhesive paper is adhered to the back surface of the fresh-keeping active base layer through an adhesive on the other side;

(9) and finally cutting the coated paper into cards of 2.5 multiplied by 2.5 cm.

Example 2

A preparation method of a portable preservation card with deltamethrin adsorption and antibacterial properties comprises the following specific operations:

(1) oven drying bean dregs at 100 deg.C, sieving with 80 mesh sieve, soaking bean dregs in diethyl ether for 8 hr (V)_{Ether (A)}：V_{Bean dregs}6: 1) defatting, washing with water to remove organic solvent, oven drying at 80 deg.C to obtain powder_{Bean dregs}：m_{Water (W)}25: 1, preparing a solution, adjusting the pH value of the solution to 6, adding papain with the mass percentage of 4% and glucoamylase with the mass percentage of 1% to the dried defatted bean dregs, and performing enzymolysis for 40min in a synergistic manner to obtain the bean dregs dietary fiber;

(2) preparing a preservative solution with the concentration of 1.0mg/mL, wherein the preservative solution comprises the following components in parts by weight: 80 parts of bean dreg dietary fiber, 10 parts of calcium propionate and 10 parts of sodium ascorbate, selecting activated carbon fiber paper with the thickness of 1.0mm, and soaking the activated carbon fiber paper in an adsorption preservative solution for 15 minutes;

(3) taking out the paper adsorbing the preservative solution, draining the solution under natural conditions, and vacuum drying at 60 ℃ for 3 min;

(4) 0.2g of Chitosan (CS) was weighed out and dissolved in 100mL of 1% (w/v) acetic acid to a mass concentration of 2 mg/mL; preparing 1mg/mL sodium Tripolyphosphate (TPP) solution, filtering with 0.45 μm filter membrane, magnetically stirring CS solution at 600r/min, and simultaneously adding 1mg/mL sodium Tripolyphosphate (TPP) solution with constant flow pumpTPP solution added to CS solution (V)_CS:V_TPP4:1), then heating to 90 ℃, evaporating the solvent to dryness, standing and cooling, washing with a proper amount of absolute ethyl alcohol for 3 times, and drying in vacuum at 40 ℃ for 5 hours to obtain nano chitosan (CS NPs);

(5) preparing antibacterial adsorption feed liquid with the concentration of 2.0mg/mL, wherein the antibacterial adsorption feed liquid comprises the following components in parts by weight: 58 parts of nano-silica aerogel, 27 parts of nano-chitosan and 15 parts of tributyl citrate, and fully dissolving and uniformly mixing the components under magnetic stirring;

(6) removing bubbles of the feed liquid in the step (5) by vacuum reduced pressure filtration and ultrasonic oscillation methods, and uniformly coating the membrane liquid on a glass plate (25mm multiplied by 25mm) by a casting method;

(7) drying at 50 deg.C for 10 hr, standing, uncovering, and balancing in a constant temperature and humidity box at 25 deg.C and 50% humidity for 48 hr;

(8) covering the film prepared in the step (7) on the paper placed in the step (3); for the laminated version fresh-keeping card, the two sides of the paper which is put dry are covered with films; for the fresh-keeping card of the sticker version, a film is coated on one side of the paper to be dried, and the food-grade adhesive back-dry adhesive paper is adhered to the back surface of the fresh-keeping active base layer through an adhesive on the other side;

(9) and finally cutting the coated paper into cards of 2.5 multiplied by 2.5 cm.

Example 3

A preparation method of a portable preservation card with deltamethrin adsorption and antibacterial properties comprises the following specific operations:

(1) oven drying bean dregs at 100 deg.C, sieving with 80 mesh sieve, soaking bean dregs in diethyl ether for 8 hr (V)_{Ether (A)}：V_{Bean dregs}6: 1) defatting, washing with water to remove organic solvent, oven drying at 80 deg.C to obtain powder_{Bean dregs}：m_{Water (W)}25: 1, preparing a solution, adjusting the pH value of the solution to 6, adding papain with the mass percentage of 4% and glucoamylase with the mass percentage of 1% to the dried defatted bean dregs, and performing enzymolysis for 40min in a synergistic manner to obtain the bean dregs dietary fiber;

(2) preparing a preservative solution with the concentration of 1.5mg/mL, wherein the preservative solution comprises the following components in parts by weight: 85 parts of bean dreg dietary fiber, 8 parts of calcium propionate and 7 parts of sodium ascorbate, selecting activated carbon fiber paper with the thickness of 1.5mm, and soaking the activated carbon fiber paper in an adsorption preservative solution for 20 minutes;

(3) taking out the paper adsorbing the preservative solution, draining the solution under natural conditions, and vacuum drying at 60 ℃ for 3 min;

(4) 0.2g of Chitosan (CS) was weighed out and dissolved in 100mL of 1% (w/v) acetic acid to a mass concentration of 2 mg/mL; preparing 1mg/mL sodium Tripolyphosphate (TPP) solution, filtering with 0.45 μm filter membrane, magnetically stirring the CS solution at 600r/min, and adding 1mg/mL TPP solution into the CS solution with a constant flow pump (V)_CS:V_TPP4:1), then heating to 90 ℃, evaporating the solvent to dryness, standing and cooling, washing with a proper amount of absolute ethyl alcohol for 3 times, and drying in vacuum at 40 ℃ for 5 hours to obtain nano chitosan (CS NPs);

(5) preparing antibacterial adsorption feed liquid with the concentration of 2.5mg/mL, wherein the antibacterial adsorption feed liquid comprises the following components in parts by weight: 60 parts of nano-silica aerogel, 25 parts of nano-chitosan and 15 parts of tributyl citrate, and fully dissolving and uniformly mixing the components under magnetic stirring;

(6) removing bubbles of the feed liquid in the step (5) by vacuum reduced pressure filtration and ultrasonic oscillation methods, and uniformly coating the membrane liquid on a glass plate (25mm multiplied by 25mm) by a casting method;

(7) drying at 55 deg.C for 10 hr, standing, uncovering, and balancing in a constant temperature and humidity box with temperature of 30 deg.C and humidity of 50% for 48 hr;

(8) covering the film prepared in the step (7) on the paper placed in the step (3); for the laminated version fresh-keeping card, the two sides of the paper which is put dry are covered with films; for the fresh-keeping card of the sticker version, a film is coated on one side of the paper to be dried, and the food-grade adhesive back-dry adhesive paper is adhered to the back surface of the fresh-keeping active base layer through an adhesive on the other side;

(9) and finally cutting the coated paper into cards of 2.5 multiplied by 2.5 cm.

Comparative example 1

A preparation method of a portable preservation card with deltamethrin adsorption and antibacterial properties comprises the following specific operations:

(1) oven drying bean dregs at 100 deg.C, sieving with 80 mesh sieve, soaking bean dregs in diethyl ether for 8 hr (V)_{Ether (A)}：V_{Bean dregs}6: 1) after degreasing treatment, washing with water to remove the organic solvent, and drying at 80 ℃; in m_{Bean dregs}：m_{Water (W)}25: 1, preparing a solution, adjusting the pH value of the solution to 6, adding papain with the mass percentage of 4% and glucoamylase with the mass percentage of 1% to the dried defatted bean dregs, and performing enzymolysis for 40min in a synergistic manner to obtain the bean dregs dietary fiber;

(2) preparing a preservative solution with the concentration of 1.0mg/mL, wherein the preservative solution comprises the following components in parts by weight: 80 parts of bean dreg dietary fiber, 10 parts of calcium propionate and 10 parts of sodium ascorbate, selecting activated carbon fiber paper with the thickness of 1.0mm, and soaking the activated carbon fiber paper in an adsorption preservative solution for 15 minutes;

(3) taking out the paper adsorbing the preservative solution, draining the solution under natural conditions, and vacuum drying at 60 ℃ for 3 min;

(4) preparing antibacterial adsorption feed liquid with the concentration of 2.0mg/mL, wherein the antibacterial adsorption feed liquid comprises the following components in parts by weight: 58 parts of nano-silica aerogel, 27 parts of chitosan and 15 parts of tributyl citrate, and fully dissolving and uniformly mixing the components under magnetic stirring;

(5) removing bubbles of the feed liquid in the step (4) by vacuum reduced pressure filtration and ultrasonic oscillation methods, and uniformly coating the membrane liquid on a glass plate (25mm multiplied by 25mm) by a casting method;

(6) drying at 50 deg.C for 10 hr, standing, uncovering, and balancing in a constant temperature and humidity box at 25 deg.C and 50% humidity for 48 hr;

(7) covering the film prepared in the step (7) on the paper placed in the step (3); for the laminated version fresh-keeping card, the two sides of the paper which is put dry are covered with films; for the fresh-keeping card of the sticker version, a film is coated on one side of the paper to be dried, and the food-grade adhesive back-dry adhesive paper is adhered to the back surface of the fresh-keeping active base layer through an adhesive on the other side;

(8) and finally cutting the coated paper into cards of 2.5 multiplied by 2.5 cm.

Compared with the example 2, the chitosan which is one of the raw materials of the preservation card is not prepared into the nano chitosan, so as to prove that the nano chitosan can obviously improve the antibacterial performance of the preservation card.

Comparative example 2

A preparation method of a portable preservation card with deltamethrin adsorption and antibacterial properties comprises the following specific operations:

(1) preparing a preservative solution with the concentration of 1.0mg/mL, wherein the preservative solution comprises the following components in parts by weight: 80 parts of cellulose powder, 10 parts of calcium propionate and 10 parts of sodium ascorbate, selecting activated carbon fiber paper with the thickness of 1.0mm, and soaking the activated carbon fiber paper in an adsorption preservative solution for 15 minutes;

(2) taking out the paper adsorbing the preservative solution, draining the solution under natural conditions, and vacuum drying at 60 ℃ for 3 min;

(3) 0.2g of Chitosan (CS) was weighed out and dissolved in 100mL of 1% (w/v) acetic acid to a mass concentration of 2 mg/mL; preparing 1mg/mL sodium Tripolyphosphate (TPP) solution, filtering with 0.45 μm filter membrane, magnetically stirring the CS solution at 600r/min, and adding 1mg/mL TPP solution into the CS solution with a constant flow pump (V)_CS:V_TPP4:1), then heating to 90 ℃, evaporating the solvent to dryness, standing and cooling, washing with a proper amount of absolute ethyl alcohol for 3 times, and drying in vacuum at 40 ℃ for 5 hours to obtain nano chitosan (CS NPs);

(4) preparing antibacterial adsorption feed liquid with the concentration of 2.0mg/mL, wherein the antibacterial adsorption feed liquid comprises the following components in parts by weight: 58 parts of nano-silica aerogel, 27 parts of nano-chitosan and 15 parts of tributyl citrate, and fully dissolving and uniformly mixing the components under magnetic stirring;

(5) removing bubbles of the feed liquid in the step (4) by vacuum reduced pressure filtration and ultrasonic oscillation methods, and uniformly coating the membrane liquid on a glass plate (25mm multiplied by 25mm) by a casting method;

(6) drying at 50 deg.C for 10 hr, standing, uncovering, and balancing in a constant temperature and humidity box at 25 deg.C and 50% humidity for 48 hr;

(7) covering the film prepared in the step (7) on the paper placed in the step (3); for the laminated version fresh-keeping card, the two sides of the paper which is put dry are covered with films; for the fresh-keeping card of the sticker version, a film is coated on one side of the paper to be dried, and the food-grade adhesive back-dry adhesive paper is adhered to the back surface of the fresh-keeping active base layer through an adhesive on the other side;

(8) and finally cutting the coated paper into cards of 2.5 multiplied by 2.5 cm.

Compared with the example 2, the comparison example has the advantages that the bean dreg dietary fiber which is one of the raw materials of the preservation card is replaced by the common cellulose powder so as to prove that the adsorption capacity of the preservation card to the deltamethrin can be obviously improved by the bean dreg dietary fiber.

Effects of the embodiment

The portable preservation card with deltamethrin adsorption and antibacterial properties prepared in examples 1-3, the card prepared in the comparative example and the commercially available common preservation card (both are laminated) were subjected to performance tests in the aspects of adsorption capacity, preservation capacity, bacteriostatic capacity and the like.

1) Measurement of fresh-keeping ability

The fresh strawberries with uniform size, no damage and no toxic or harmful infection are purchased and respectively put into three transparent pockets, the same amount of strawberries are put into each pocket, and the three pockets are respectively divided into a non-card group, a fresh-keeping card group prepared by the invention and a common fresh-keeping card group sold in the market. The three groups are respectively placed under the same environmental conditions, indexes such as the rotting rate, titratable acid, weight loss rate and the like of the fruits are measured every two days, the rotting degree of each group of strawberries is recorded every day, and therefore the fresh-keeping effect is evaluated, and the results are shown in table 1.

TABLE 1 fresh-keeping ability measurement results

The data in the table 1 show that the fresh-keeping card prepared by the invention can obviously prolong the fresh-keeping time of fruits and vegetables, and the fresh-keeping capacity of the fresh-keeping card far exceeds that of a common fresh-keeping card sold in the market.

2) Measurement of adsorption Capacity

The method comprises the steps of purchasing fresh strawberries which are uniform in size, free of damage and toxic and harmful infection, uniformly spraying a deltamethrin solution of 0.5mg/kg on the surface of each strawberry, then respectively placing the strawberries in three paper boxes, filling the strawberries into each paper box in an equal amount, respectively placing the preservation card and the common preservation card (both are laminated) in two paper boxes, placing nothing in the other paper box, sealing after placing, respectively placing three groups of the strawberries in the same environmental condition, and testing pesticide residues on the surfaces of the strawberries in 3 rd, 7 th, 12 th and 16 th days to obtain the following data.

TABLE 2 adsorption Capacity measurement results

As can be seen from the data in table 2, examples 1 to 3 and comparative example 1 according to the present invention have a significant effect on the adsorption capacity of the pesticide residues on the surfaces of fruits and vegetables, which is superior to that of comparative example 2. All the examples and comparative examples of the invention aim at that the adsorption capacity of pesticide residues on the surfaces of fruits and vegetables is higher than that of the common preservation card sold in the market.

3) Determination of bacteriostatic ability

Escherichia coli and staphylococcus aureus are used as strains, three groups of inoculation culture dishes are manufactured under the same environmental condition, and 1% of the preservative card paper sample prepared in the embodiment of the invention, 1% of the common preservative card paper sample (both laminated plates) sold in the market and 1% of distilled water are respectively added into the three groups of inoculation culture dishes. And observing the growth condition of bacteria after 24 hours, and calculating the bacteriostasis rate of the paper sample to obtain the following data.

TABLE 3 measurement results of bacteriostatic ability

The data in the table 3 show that the fruit and vegetable preservative clamps prepared in the embodiments 1 to 3 and the comparative example 2 have good bacteriostatic effect, which is superior to that of the comparative example 1. The bacteriostatic ability of all the examples and comparative examples of the invention on escherichia coli and staphylococcus aureus exceeds that of the common preservative card sold in the market.

It will be understood by those skilled in the art that the foregoing is only exemplary of the present invention, and is not intended to limit the invention, which is intended to cover any variations, equivalents, or improvements therein, which fall within the spirit and scope of the invention.