Fruit and vegetable soaking type fresh-keeping powder based on freeze-dried probiotics and preparation method of fruit and vegetable soaking type fresh-keeping powder

Abstract

The invention provides fruit and vegetable soaking type fresh-keeping powder based on freeze-dried probiotics and a preparation method, and relates to the technical field of fruit and vegetable fresh keeping. The fruit and vegetable soaking type fresh-keeping powder based on freeze-dried probiotics is prepared from the following raw materials in parts by weight: 100-150 parts of microcapsule particles, 2-3 parts of chitosan, 2-4 parts of sodium alginate, 10-15 parts of sodium bicarbonate, 4-6 parts of a dispersing agent, 1-2 parts of an adhesive and 1-1.5 parts of a bacteriostatic agent. According to the invention, microcrystalline cellulose is a natural multifunctional additive and has anti-caking, emulsifying and thickening functions, so that the fresh-keeping powder has better dispersibility when being dissolved in water and ensures that probiotics are more uniformly dispersed in a soaking solution, carbon dioxide is generated after sodium bicarbonate is dissolved in water, and when the content of carbon dioxide in the soaking solution is increased, the fresh-keeping powder can be used as a fresh-keeping agent. When the fruits and the vegetables are soaked, the physical space of dissolved gas in the water body is occupied, so that the dissolved amount of oxygen in the soaking liquid is reduced, the oxygen in the soaking liquid is greatly reduced, the oxygen is prevented from being stored in preservative film layers on the surfaces of the fruits and the vegetables, and the fruit and vegetable preservation effect is further facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of fruit and vegetable preservation, and in particular to a fruit and vegetable soaking type preservation powder based on freeze-dried probiotics and a preparation method thereof. Background Art

[0002] Fruits and vegetables are a major component of the Chinese diet. They are rich in essential vitamins, inorganic salts, and dietary fiber, and contain a variety of nutrients necessary for human life. However, due to their strong seasonality, regional variations, and perishability, insufficient storage capacity and poor preservation techniques can lead to significant losses. Even after harvest, fruits and vegetables remain living organisms, undergoing complex life cycles such as dormancy, evaporation, and respiration. These processes are closely linked to fruit and vegetable preservation, influencing and limiting their storage lifespan.

[0003] Various fruit and vegetable preservation technologies all regulate three key factors that play a key role in maintaining quality: first, controlling the aging process, generally achieved by controlling respiration; second, controlling microorganisms, mainly through controlling spoilage bacteria; and third, controlling internal water evaporation, mainly through controlling the relative humidity of the environment and the structuring of intercellular water. Currently, the two main preservation methods are low-temperature storage and chemical treatment. The main disadvantages of low-temperature storage are high cost, high energy consumption, unstable quality, and ineffectiveness for certain special fruits and vegetables, such as tropical and subtropical fruits and vegetables. While chemical preparations can effectively control the quality of fruits and vegetables, most of them are harmful to human health. Summary of the Invention

[0004] (1) Technical problems solved

[0005] In view of the deficiencies in the prior art, the present invention provides a fruit and vegetable soaking type fresh-keeping powder based on freeze-dried probiotics and a preparation method thereof, which solves the defects and deficiencies in the prior art.

[0006] (2) Technical solution

[0007] To achieve the above objectives, the present invention is implemented through the following technical scheme: a fruit and vegetable soaking type fresh-keeping powder based on freeze-dried probiotics, wherein the fresh-keeping powder comprises the following raw materials in parts by weight: 100-150 parts of microcapsule particles, 2-3 parts of chitosan, 2-4 parts of sodium alginate, 10-15 parts of sodium bicarbonate, 4-6 parts of dispersant, 1-2 parts of binder, and 1-1.5 parts of antibacterial agent.

[0008] Preferably, the dispersant is microcrystalline cellulose, and the particle size of the microcrystalline cellulose is 40-80 μm.

[0009] Preferably, the adhesive is carrageenan, and the particle size of the carrageenan is 30-80 μm.

[0010] Preferably, the antibacterial agent is nano silver ions, and the particle size of the nano silver ions is 10-40 μm.

[0011] Preferably, the fresh-keeping powder comprises the following raw materials in parts by weight: 100 parts of microcapsule particles, 2 parts of chitosan, 2 parts of sodium alginate, 10 parts of sodium bicarbonate, 4 parts of dispersant, 1 part of adhesive, and 1 part of antibacterial agent.

[0012] Preferably, the fresh-keeping powder comprises the following raw materials in parts by weight: 125 parts of microcapsule particles, 2.5 parts of chitosan, 3 parts of sodium alginate, 12.5 parts of sodium bicarbonate, 5 parts of dispersant, 1.5 parts of adhesive, and 1.25 parts of antibacterial agent.

[0013] Preferably, the fresh-keeping powder comprises the following raw materials in parts by weight: 150 parts of microcapsule particles, 3 parts of chitosan, 4 parts of sodium alginate, 15 parts of sodium bicarbonate, 6 parts of dispersant, 2 parts of adhesive, and 1.5 parts of antibacterial agent.

[0014] A method for preparing a fruit and vegetable soaking type fresh-keeping powder based on freeze-dried probiotics, the preparation method comprising the following steps:

[0015] S1. Expanding and culturing the acclimated probiotics to the logarithmic growth phase, collecting the bacteria by centrifugation, suspending them with a protective agent to prepare a bacterial suspension, and preparing the bacterial suspension into microcapsule particles by spray drying or freeze drying technology;

[0016] S2, adding microcapsule particles into chitosan, sodium alginate and sodium bicarbonate and mixing them evenly;

[0017] S3. Add a dispersant, a binder, and an antibacterial agent to the mixture of step 2, mix well, and prepare a powdered fresh-keeping powder, controlling the water content to be ≤5%.

[0018] Preferably, the protective agent is maltodextrin or oligosaccharide, the particle size of the microcapsule particles is controlled at 50-200 μm, and the probiotics are Lactobacillus plantarum or Lactobacillus reuteri.

[0019] (3) Beneficial effects

[0020] The present invention provides a fruit and vegetable soaking type fresh-keeping powder based on freeze-dried probiotics and a preparation method thereof. It has the following beneficial effects:

[0021] 1. The fresh-keeping powder of the present invention contains microcrystalline cellulose in its raw materials. Microcrystalline cellulose is a natural multifunctional additive with anti-caking, emulsifying and thickening functions. It can make the fresh-keeping powder more dispersible in water, ensuring that the probiotics are more evenly dispersed in the soaking liquid. After sodium bicarbonate is dissolved in water, carbon dioxide is generated. When the carbon dioxide content in the soaking liquid increases, it will occupy the physical space of the dissolved gas in the water body, resulting in a decrease in the amount of dissolved oxygen in the soaking liquid, greatly reducing the oxygen in the soaking liquid, and preventing oxygen from being stored in the preservative film layer on the surface of fruits and vegetables, which is further beneficial to the fresh-keeping effect of fruits and vegetables.

[0022] 2. In the present invention, sodium alginate is cross-linked with calcium ions to form a selective breathable membrane, which reduces the respiration intensity of fruits and vegetables and slows down nutrient loss. Chitosan is extracted from the shells of crustaceans and forms a dense membrane through intermolecular hydrogen bonds, which can inhibit microbial growth and reduce water evaporation from fruits and vegetables, extending the shelf life. Carrageenan can increase the viscosity of the membrane formed on the surface of fruits and vegetables, making the membrane less susceptible to damage. DETAILED DESCRIPTION

[0023] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts are within the scope of protection of the present invention.

[0024] Example 1:

[0025] An embodiment of the present invention provides a fruit and vegetable soaking type fresh-keeping powder based on freeze-dried probiotics. The fresh-keeping powder includes the following raw materials in parts by weight: 100 parts of microcapsule particles, 2 parts of chitosan, 2 parts of sodium alginate, 10 parts of sodium bicarbonate, 4 parts of a dispersant, 1 part of a binder, and 1 part of an antibacterial agent. The dispersant is microcrystalline cellulose with a particle size of 40-80 μm, the binder is carrageenan with a particle size of 30-80 μm, and the antibacterial agent is nanosilver ions with a particle size of 10-40 μm.

[0026] The present invention also includes a method for preparing a fruit and vegetable soaking type fresh-keeping powder based on freeze-dried probiotics, which comprises the following steps:

[0027] S1. Expanding and culturing the acclimated probiotics to the logarithmic growth phase, collecting the cells by centrifugation, and suspending them with a protective agent to prepare a bacterial suspension, wherein the protective agent is maltodextrin or oligosaccharide, and the bacterial suspension is prepared into microcapsule particles by spray drying or freeze drying technology, wherein the particle size of the microcapsule particles is controlled to be 50-200 μm, and the probiotics are Lactobacillus plantarum or Lactobacillus reuteri;

[0028] S2, adding microcapsule particles into chitosan, sodium alginate and sodium bicarbonate and mixing them evenly;

[0029] S3. Add a dispersant, a binder, and an antibacterial agent to the mixture of step 2, mix well, and prepare a powdered fresh-keeping powder, controlling the water content to be ≤5%.

[0030] Example 2:

[0031] An embodiment of the present invention provides a fruit and vegetable soaking type fresh-keeping powder based on freeze-dried probiotics. The fresh-keeping powder includes the following raw materials in parts by weight: 125 parts of microcapsule particles, 2.5 parts of chitosan, 3 parts of sodium alginate, 12.5 parts of sodium bicarbonate, 5 parts of a dispersant, 1.5 parts of a binder, and 1.25 parts of an antibacterial agent. The dispersant is microcrystalline cellulose with a particle size of 40-80 μm, the binder is carrageenan with a particle size of 30-80 μm, and the antibacterial agent is nanosilver ions with a particle size of 10-40 μm.

[0032] The present invention also includes a method for preparing a fruit and vegetable soaking type fresh-keeping powder based on freeze-dried probiotics, which comprises the following steps:

[0033] S1. The acclimated probiotic bacteria are cultured to the logarithmic growth phase, the bacteria are collected by centrifugation, and suspended with a protective agent to prepare a bacterial suspension. The protective agent is maltodextrin or oligosaccharide. The bacterial suspension is prepared into microcapsule particles by spray drying or freeze drying technology. The particle size of the microcapsule particles is controlled to be 50-200 μm;

[0034] S2, adding microcapsule particles into chitosan, sodium alginate and sodium bicarbonate and mixing them evenly;

[0035] S3. Add a dispersant, a binder, and an antibacterial agent to the mixture of step 2, mix well, and prepare a powdered fresh-keeping powder, controlling the water content to be ≤5%.

[0036] Example 3:

[0037] An embodiment of the present invention provides a fruit and vegetable soaking type fresh-keeping powder based on freeze-dried probiotics. The fresh-keeping powder includes the following raw materials in parts by weight: 150 parts of microcapsule particles, 3 parts of chitosan, 4 parts of sodium alginate, 15 parts of sodium bicarbonate, 6 parts of a dispersant, 2 parts of a binder, and 1.5 parts of an antibacterial agent. The dispersant is microcrystalline cellulose with a particle size of 40-80 μm, the binder is carrageenan with a particle size of 30-80 μm, and the antibacterial agent is nanosilver ions with a particle size of 10-40 μm.

[0038] The present invention also includes a method for preparing a fruit and vegetable soaking type fresh-keeping powder based on freeze-dried probiotics, which comprises the following steps:

[0039] S1. The acclimated probiotic bacteria are cultured to the logarithmic growth phase, the bacteria are collected by centrifugation, and suspended with a protective agent to prepare a bacterial suspension. The protective agent is maltodextrin or oligosaccharide. The bacterial suspension is prepared into microcapsule particles by spray drying or freeze drying technology. The particle size of the microcapsule particles is controlled to be 50-200 μm;

[0040] S2, adding microcapsule particles into chitosan, sodium alginate and sodium bicarbonate and mixing them evenly;

[0041] S3. Add a dispersant, a binder, and an antibacterial agent to the mixture of step 2, mix well, and prepare a powdered fresh-keeping powder, controlling the water content to be ≤5%.

[0042] In the present invention, apples are taken as an example, and the fresh-keeping powders prepared in the above three embodiments are used to soak the apples for fresh-keeping. At the same time, the results are compared with apples that have not been soaked (comparative example). Refer to the following table:

[0043] The soaking preservation process is as follows:

[0044] Activation of fresh-keeping powder: Before use, dissolve the fresh-keeping powder in sterile water (or light salt water) at a ratio of 1:50-1:100, stir until completely dissolved, and let it stand for 5-10 minutes to allow the microcapsule particles to release probiotics (the number of viable bacteria must reach 10 8 -10 9 CFU / mL);

[0045] Apple pretreatment: Remove dirt and damaged parts from the surface of the apples, rinse with clean water and drain (avoid excessive water to dilute the bacterial solution);

[0046] Soaking treatment: Immerse the apples completely in the activated bacterial solution for 10-15 minutes to ensure that the probiotics are fully attached to the surface;

[0047] Post-processing: Take out the fruits and vegetables, drain them naturally (or wipe off excess liquid on the surface with sterile gauze), and store them directly at room temperature or low temperature without washing.

[0048]

[0049]

[0050] Table 1

[0051] In the above Table 1, the test was carried out 7 days after immersion.

[0052]

[0053] Table 2

[0054] In the above Table 2, the test was carried out 14 days after immersion.

[0055] It can be seen from Tables 1 and 2 above that after soaking the apples, the preservation effect of fruits and vegetables is greatly improved.

[0056] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the statement "comprising a reference structure" does not exclude the presence of additional identical elements in the process, method, article, or device comprising the element.

[0057] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A fruit and vegetable soaking fresh-keeping powder based on freeze-dried probiotics, characterized by: The fresh-keeping powder comprises the following raw materials in parts by weight: 100-150 parts of microcapsule particles, 2-3 parts of chitosan, 2-4 parts of sodium alginate, 10-15 parts of sodium bicarbonate, 4-6 parts of dispersant, 1-2 parts of adhesive, and 1-1.5 parts of antibacterial agent.

2. The freeze-dried probiotics-based fruit and vegetable soaking fresh-keeping powder according to claim 1, characterized in that: The dispersant is microcrystalline cellulose, and the particle size of the microcrystalline cellulose is 40-80 μm.

3. The freeze-dried probiotics-based fruit and vegetable soaking freshness-preserving powder according to claim 2, characterized in that: The adhesive is carrageenan, and the particle size of the carrageenan is 30-80 μm.

4. The freeze-dried probiotics-based fruit and vegetable soaking freshness-preserving powder according to claim 3, characterized in that: The antibacterial agent is nano silver ions, and the particle size of the nano silver ions is 10-40 μm.

5. The freeze-dried probiotics-based fruit and vegetable soaking fresh-keeping powder according to claim 4, characterized in that: The fresh-keeping powder comprises the following raw materials in parts by weight: 100 parts of microcapsule particles, 2 parts of chitosan, 2 parts of sodium alginate, 10 parts of sodium bicarbonate, 4 parts of dispersant, 1 part of adhesive, and 1 part of antibacterial agent.

6. The freeze-dried probiotics-based fruit and vegetable soaking freshness-preserving powder according to claim 5, characterized in that: The fresh-keeping powder comprises the following raw materials in parts by weight: 125 parts of microcapsule particles, 2.5 parts of chitosan, 3 parts of sodium alginate, 12.5 parts of sodium bicarbonate, 5 parts of dispersant, 1.5 parts of adhesive, and 1.25 parts of antibacterial agent.

7. The freeze-dried probiotics-based fruit and vegetable soaking freshness-preserving powder according to claim 6, characterized in that: The fresh-keeping powder comprises the following raw materials in parts by weight: 150 parts of microcapsule particles, 3 parts of chitosan, 4 parts of sodium alginate, 15 parts of sodium bicarbonate, 6 parts of dispersant, 2 parts of adhesive, and 1.5 parts of antibacterial agent.

8. The method for preparing the freeze-dried probiotics-based fruit and vegetable soaking freshness-preserving powder according to claim 7, characterized in that: The preparation method comprises the following steps: S1. Expanding and culturing the acclimated probiotics to the logarithmic growth phase, collecting the bacteria by centrifugation, suspending them with a protective agent to prepare a bacterial suspension, and preparing the bacterial suspension into microcapsule particles by spray drying or freeze drying technology; S2, adding microcapsule particles into chitosan, sodium alginate and sodium bicarbonate and mixing them evenly; S3. Add a dispersant, a binder, and an antibacterial agent to the mixture of step 2, mix well, and prepare a powdered fresh-keeping powder, controlling the water content to be ≤5%.

9. The method for preparing the freeze-dried probiotics-based fruit and vegetable soaking freshness-preserving powder according to claim 8, characterized in that: The protective agent is maltodextrin or oligosaccharide, the particle size of the microcapsule particles is controlled at 50-200 μm, and the probiotics are Lactobacillus plantarum or Lactobacillus reuteri.

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