Fruit, vegetable and flower fresh-keeping bag

Abstract

The present invention relates to the field of fresh-keeping technology, and in particular to a fruit, vegetable and flower fresh-keeping package. The fruit, vegetable and flower fresh-keeping package is prepared from the following components: sodium chlorite, a modified activator, an ethylene inhibitor and auxiliary materials, wherein the modified activator is obtained by encapsulating an organic acid activator with sulfonated β-cyclodextrin and then encapsulating chitosan. The fruit, vegetable and flower fresh-keeping package provided by the present invention realizes efficient and long-term fresh-keeping of fruits, vegetables and flowers, and has broad market potential and application prospects.

Description

Technical Field

[0001] The invention relates to the technical field of fresh-keeping, and in particular to a fresh-keeping bag for fruits, vegetables and flowers. Background Art

[0002] In recent years, with the rapid development of the fruit, vegetable and flower industries, how to effectively extend the shelf life of these perishable items has become an important research topic. Traditional preservation methods, such as low-temperature storage, chemical preservatives and gas regulation, although effective to a certain extent, also have some limitations and disadvantages. Low-temperature storage requires high power consumption and expensive cold chain equipment, chemical preservatives may cause residue problems, and gas regulation technology has high costs and operational complexity. Therefore, it is imperative to seek an efficient, economical and environmentally friendly preservation technology.

[0003] Fresh-keeping packaging is one of the technologies with great potential in maintaining the freshness of fruits, vegetables and flowers. In recent years, researchers have developed a series of fresh-keeping packages using different chemical components. Among them, fresh-keeping packages based on chlorine dioxide have attracted widespread attention. Chlorine dioxide is an effective bactericide that is highly toxic to a wide range of microorganisms and can inhibit the growth of mold, biofilm and bacteria. However, chlorine dioxide gas is prone to explosion when the concentration in the air is too high, and it is unstable under light and heat conditions, posing a safety hazard.

[0004] Reactive fresh-keeping bags are mainly composed of sodium chlorite and solid acid, and mainly rely on the chemical reaction of sodium chlorite and solid acid to release chlorine dioxide gas. This fresh-keeping bag has the function of quickly releasing chlorine dioxide, providing an immediate sterilization effect, and is suitable for the preservation needs of a variety of fruits, vegetables and flowers. However, its defects significantly limit its wide application. First, poor storage stability is the main problem, and secondly, the shelf life is short, because once the reaction is started, the chlorine dioxide release rate is fast, and it is difficult to achieve long-term continuous release. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a fruit, vegetable and flower fresh-keeping package to solve the problem that the reaction-type fresh-keeping package has poor storage stability and a short fresh-keeping validity period.

[0006] Based on the above purpose, the present invention provides a fruit, vegetable and flower preservation package, which comprises the following components by weight percentage: 8%-12% sodium chlorite, 20%-40% modified activator, 0.2%-0.4% ethylene inhibitor and the remainder auxiliary materials;

[0007] The preparation method of the modified activator is as follows:

[0008] (1) Modifying β-cyclodextrin with chlorosulfonic acid to obtain sulfonated β-cyclodextrin;

[0009] (2) dissolving chitosan in an acetic acid aqueous solution to obtain a chitosan solution;

[0010] (3) Add sulfonated β-cyclodextrin to deionized water, heat to 35-45°C, stir for 20-40 minutes, add an organic acid activator, continue stirring for 2-4 hours, then add chitosan solution, continue stirring for 20-40 minutes, wash with water, and freeze-dry to obtain a modified activator;

[0011] Preferably, the ethylene inhibitor is 1-methylcyclopropene.

[0012] Preferably, the auxiliary material is one or a mixture of talcum powder, diatomaceous earth and glucose.

[0013] Preferably, in step (1), the weight ratio of chlorosulfonic acid to β-cyclodextrin is 0.93-1.41:5.67.

[0014] Preferably, the concentration of the acetic acid aqueous solution in step (2) is 1 wt %.

[0015] Preferably, in step (2), the weight ratio of chitosan to acetic acid aqueous solution is 3:40-60.

[0016] Preferably, in step (3), the weight ratio of sulfonated β-cyclodextrin to the organic acid activator is 1:1.5-2.5.

[0017] Preferably, in step (3), the weight ratio of sulfonated β-cyclodextrin to chitosan in the chitosan solution is 1:1.5-2.

[0018] Preferably, the organic acid activator in step (3) is one of citric acid and tartaric acid or a mixture of the two.

[0019] Preferably, the amount of deionized water added in step (3) is 10-12 times the weight of the sulfonated β-cyclodextrin.

[0020] Furthermore, the preparation method of the fruit, vegetable and flower fresh-keeping package is as follows: sodium chlorite, a modified activator, an ethylene inhibitor and auxiliary materials are evenly mixed, and packaged into fruit, vegetable and flower fresh-keeping packages of 0.5 g each.

[0021] Beneficial effects of the present invention:

[0022] The fruit, vegetable and flower preservation bag of the present invention achieves excellent preservation performance through innovative ingredient combination and design. In a high humidity environment (room temperature, humidity 85%), the preservation bag can continuously release chlorine dioxide within 60 days, effectively extending the shelf life of fruits, vegetables and flowers. At the same time, in a low humidity environment (room temperature, humidity 45%), it shows excellent storage stability, so that the preservation bag can be stored for a long time without failure when not in use. The fruit, vegetable and flower preservation bag of the present invention achieves efficient and long-term preservation of fruits, vegetables and flowers, and has broad market potential and application prospects.

[0023] The sulfonated beta-cyclodextrin prepared by the present invention effectively increases the total release amount of chlorine dioxide, which is mainly because it can react with sodium chlorite as a solid acid and increases the inclusion rate of tartaric acid, thereby increasing the effective content of solid acid. In addition, the addition of chitosan enhances the storage stability of the fresh-keeping bag in a low-humidity environment, prolongs the release time of chlorine dioxide, and thus ensures a long-term fresh-keeping effect. DETAILED DESCRIPTION

[0024] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments.

[0025] Example 1: (1) 5.67 g of β-cyclodextrin was added to 25 g of dichloromethane, the temperature was lowered to 0°C, and 0.93 g of chlorosulfonic acid was slowly added dropwise within 1.5 h. After the addition was completed, the temperature was raised to room temperature, and stirring was continued for 1.5 h. The mixture was then filtered, and the filter cake was washed with methanol 3 times and vacuum dried to obtain sulfonated β-cyclodextrin.

[0026] (2) Add 3 g of chitosan to 40 g of 1 wt% acetic acid aqueous solution, stir for 25 min, and then stand at room temperature for 24 h to obtain a chitosan solution;

[0027] (3) Add 1.75 g of sulfonated β-cyclodextrin to 17.5 g of deionized water, heat to 45 °C, stir for 40 min, add 2.7 g of tartaric acid, continue stirring for 2 h, then add 39 g of chitosan solution, continue stirring for 20 min, wash with water, and freeze-dry to obtain a modified activator.

[0028] (4) Mix 0.8 g of sodium chlorite, 2 g of modified activator, 0.03 g of 1-methylcyclopropene and 7.17 g of diatomaceous earth evenly, and pack them into fruit, vegetable and flower preservation packages of 0.5 g each.

[0029] Example 2: (1) 5.67 g of β-cyclodextrin was added to 25 g of dichloromethane, the temperature was lowered to 0°C, and 1.16 g of chlorosulfonic acid was slowly added dropwise within 2 h. After the addition was completed, the temperature was raised to room temperature, and stirring was continued for 2 h. The mixture was then filtered, and the filter cake was washed with methanol 3 times and vacuum dried to obtain sulfonated β-cyclodextrin.

[0030] (2) Add 3 g of chitosan to 50 g of 1 wt% acetic acid aqueous solution, stir for 30 min, and then stand at room temperature for 24 h to obtain a chitosan solution;

[0031] (3) Add 1.75 g of sulfonated β-cyclodextrin to 20 g of deionized water, heat to 40 °C, stir for 30 min, add 3.5 g of tartaric acid, continue stirring for 3 h, then add 53 g of chitosan solution, continue stirring for 30 min, wash with water, and freeze-dry to obtain a modified activator.

[0032] (4) Mix 1 g of sodium chlorite, 3 g of modified activator, 0.03 g of 1-methylcyclopropene and 5.97 g of talcum powder evenly, and pack them into fruit, vegetable and flower fresh-keeping packages of 0.5 g each.

[0033] Example 3: (1) 5.67 g of β-cyclodextrin was added to 25 g of dichloromethane, the temperature was lowered to 0°C, and 1.41 g of chlorosulfonic acid was slowly added dropwise within 2.5 h. After the addition was completed, the temperature was raised to room temperature, and stirring was continued for 3 h. The mixture was then filtered, and the filter cake was washed with methanol 3 times and vacuum dried to obtain sulfonated β-cyclodextrin.

[0034] (2) adding 3.5 g of chitosan to 70 g of 1 wt% acetic acid aqueous solution, stirring for 35 min, and then standing at room temperature for 24 h to obtain a chitosan solution;

[0035] (3) Add 1.75 g of sulfonated β-cyclodextrin to 21 g of deionized water, heat to 35 °C, stir for 20 min, add 4.3 g of tartaric acid, continue stirring for 4 h, then add 73.5 g of chitosan solution, continue stirring for 40 min, wash with water, and freeze-dry to obtain a modified activator.

[0036] (4) Mix 1.2 g of sodium chlorite, 4 g of modified activator, 0.03 g of 1-methylcyclopropene and 4.77 g of glucose evenly, and pack them into fruit, vegetable and flower fresh-keeping packages of 0.5 g each.

[0037] Example 4: (1) 5.67 g of β-cyclodextrin was added to 25 g of dichloromethane, the temperature was lowered to 0°C, and 1.16 g of chlorosulfonic acid was slowly added dropwise within 2 h. After the addition was completed, the temperature was raised to room temperature, and stirring was continued for 2 h. The mixture was then filtered, and the filter cake was washed with methanol 3 times and dried in vacuo to obtain sulfonated β-cyclodextrin.

[0038] (2) Add 3 g of chitosan to 50 g of 1 wt% acetic acid aqueous solution, stir for 30 min, and then stand at room temperature for 24 h to obtain a chitosan solution;

[0039] (3) Add 1.75 g of sulfonated β-cyclodextrin to 20 g of deionized water, heat to 40 °C, stir for 30 min, add 2.5 g of tartaric acid and 1 g of citric acid, continue stirring for 3 h, then add 53 g of chitosan solution, continue stirring for 30 min, wash with water, and freeze-dry to obtain a modified activator.

[0040] (4) Mix 1 g of sodium chlorite, 3 g of modified activator, 0.03 g of 1-methylcyclopropene, 3.97 g of talcum powder and 2 g of diatomaceous earth evenly, and pack them into fruit, vegetable and flower fresh-keeping packages of 0.5 g each.

[0041] Comparative Example 1:

[0042] The difference between Comparative Example 1 and Example 2 is that: β-cyclodextrin is not sulfonated;

[0043] The specific steps are as follows:

[0044] (1) Add 3 g of chitosan to 50 g of 1 wt% acetic acid aqueous solution, stir for 30 min, and then stand at room temperature for 24 h to obtain a chitosan solution;

[0045] (2) Add 1.75 g of β-cyclodextrin to 20 g of deionized water, heat to 40 °C, stir for 30 min, add 3.5 g of tartaric acid, continue stirring for 3 h, then add 53 g of chitosan solution, continue stirring for 30 min, wash with water, and freeze-dry to obtain a modified activator.

[0046] (3) Mix 1 g of sodium chlorite, 3 g of modified activator, 0.03 g of 1-methylcyclopropene and 5.97 g of talcum powder evenly, and pack them into fruit, vegetable and flower fresh-keeping packages of 0.5 g each.

[0047] Comparative Example 2:

[0048] The difference between Comparative Example 2 and Example 2 is that no chitosan is added;

[0049] (1) Add 5.67 g of β-cyclodextrin to 25 g of dichloromethane, cool to 0°C, slowly drop 1.16 g of chlorosulfonic acid over 2 h, warm to room temperature after the addition is complete, continue stirring for 2 h, then filter, wash the filter cake with methanol 3 times, and vacuum dry to obtain sulfonated β-cyclodextrin;

[0050] (2) Add 3 g of chitosan to 50 g of 1 wt% acetic acid aqueous solution, stir for 30 min, and then stand at room temperature for 24 h to obtain a chitosan solution;

[0051] (3) Add 1.75 g of sulfonated β-cyclodextrin to 20 g of deionized water, heat to 40 °C, stir for 30 min, add 3.5 g of tartaric acid, continue stirring for 3 h, wash with water, and freeze-dry to obtain a modified activator.

[0052] (4) Mix 1 g of sodium chlorite, 3 g of modified activator, 0.03 g of 1-methylcyclopropene and 5.97 g of talcum powder evenly, and pack them into fruit, vegetable and flower fresh-keeping packages of 0.5 g each.

[0053] Comparative Example 3:

[0054] The difference between Comparative Example 3 and Example 2 is that the activator is not modified, and tartaric acid is directly used as the activator;

[0055] The specific steps are as follows:

[0056] Mix 1 g of sodium chlorite, 3 g of tartaric acid, 0.03 g of 1-methylcyclopropene and 5.97 g of talcum powder evenly, and pack them into fruit, vegetable and flower fresh-keeping packages of 0.5 g each.

[0057] Performance Testing:

[0058] Humidity influence test: at room temperature, the fruit, vegetable and flower preservation package was placed on a culture dish, and then placed in a dryer with a hygrometer. Deionized water was placed at the bottom of the dryer. The fruit, vegetable and flower preservation package reacted with the humidity in the dryer to generate chlorine dioxide gas. The chlorine dioxide gas was deposited to the bottom and absorbed by the deionized water. The iodine titration method was used to measure the chlorine dioxide release. The hygrometer was controlled to be stable at 45%, 55%, 65%, 75%, 85% and 95% respectively. The total release rate within 60 days was tested. The results are shown in Table 1.

[0059] Table 1 Humidity effect test results

[0060]

[0061] Data Analysis:

[0062] It can be seen from Examples 1-4 in Table 1 that the fruit, vegetable and flower fresh-keeping bag prepared by the present invention can achieve continuous release of chlorine dioxide within 60 days at room temperature and humidity of 85%, effectively ensuring a long-term fresh-keeping effect, and at room temperature and humidity of 45%, the total release rate within 60 days is less than 1 mg, indicating that it has excellent storage stability at low humidity, so that the fresh-keeping bag can be stored for a long time without failure when not in use.

[0063] It can be seen from Example 2 and Comparative Example 1 in Table 1 that the sulfonation of β-cyclodextrin helps to increase the total release of chlorine dioxide within 60 days. This may be because the sulfonated β-cyclodextrin itself can react with sodium chlorite as a solid acid, and it may also be that the sulfonated β-cyclodextrin has a higher inclusion rate for tartaric acid. In short, the sulfonated β-cyclodextrin can effectively increase the content of solid acid in the modified activator.

[0064] It can be seen from Example 2 and Comparative Example 2 in Table 1 that the addition of chitosan can effectively improve the storage stability of the fruit, vegetable and flower fresh-keeping package under low humidity, and prolong the chlorine dioxide release time of the fruit, vegetable and flower fresh-keeping package, thereby ensuring a long-term fresh-keeping effect.

[0065] It can be seen from Example 2 and Comparative Example 3 in Table 1 that when tartaric acid is directly used as an activator, the release rate of chlorine dioxide is too fast, which is not conducive to storage and preservation.

[0066] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present invention is limited to these examples. Under the concept of the present invention, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity.

Claims

1. A fruit, vegetable and flower preservation package, characterized in that: The composition comprises the following components by weight percentage: 8%-12% sodium chlorite, 20%-40% modified activator, 0.2%-0.4% ethylene inhibitor and the balance auxiliary materials; The preparation method of the modified activator is as follows: (1) Modifying β-cyclodextrin with chlorosulfonic acid to obtain sulfonated β-cyclodextrin; (2) dissolving chitosan in an acetic acid aqueous solution to obtain a chitosan solution; (3) Add sulfonated β-cyclodextrin to deionized water, heat to 35-45°C, stir for 20-40 minutes, add an organic acid activator, continue stirring for 2-4 hours, then add chitosan solution, continue stirring for 20-40 minutes, wash with water, and freeze-dry to obtain a modified activator; In step (3), the weight ratio of sulfonated β-cyclodextrin to organic acid activator is 1:1.5-2.5; In the step (3), the weight ratio of sulfonated β-cyclodextrin to chitosan in the chitosan solution is 1:1.5-2; The ethylene inhibitor is 1-methylcyclopropene; In the step (3), the organic acid activator is one of citric acid and tartaric acid or a mixture of the two.

2. The fruit, vegetable and flower preservation package according to claim 1, characterized in that: The auxiliary material is one or a mixture of talcum powder, diatomaceous earth and glucose.

3. The fruit, vegetable and flower preservation package according to claim 1, characterized in that: In the step (1), the weight ratio of chlorosulfonic acid to β-cyclodextrin is 0.93-1.41:5.

67.

4. The fruit, vegetable and flower fresh-keeping package according to claim 1, characterized in that: The concentration of the acetic acid aqueous solution in step (2) is 1 wt %.

5. The fruit, vegetable and flower preservation package according to claim 1, characterized in that: In the step (2), the weight ratio of chitosan to acetic acid aqueous solution is 3:40-60.

6. The fruit, vegetable and flower preservation package according to claim 1, characterized in that: The amount of deionized water added in step (3) is 10-12 times the weight of the sulfonated β-cyclodextrin.

7. The fruit, vegetable and flower preservation package according to claim 1, characterized in that: The preparation method of the fruit, vegetable and flower fresh-keeping package is as follows: sodium chlorite, a modified activator, an ethylene inhibitor and auxiliary materials are evenly mixed, and the mixture is packaged into fruit, vegetable and flower fresh-keeping packages of 0.5 g each.

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