Dried fruit preservation synergistic preparation based on plant polyphenols and preparation method and application thereof

Abstract

The present application relates to the technical field of dried fruit processing, and particularly to a dried fruit preservation and efficiency enhancing preparation based on plant polyphenols, a preparation method and application thereof, comprising the following components by weight: plant polyphenol compound 30-45%, modified chitosan film forming agent 8-15%, natural organic acid antioxidant synergist 5-12%, composite antibacterial agent 3-7%, multi-element water activity regulator 2-6%, and deionized water 30-60%. The main components of the dried fruit preservation and efficiency enhancing preparation based on plant polyphenols are all natural substances, including plant polyphenol compound, natural organic acid and biological antibacterial agent, and do not contain traditional chemical preservatives, thus avoiding the health risks possibly caused by chemical preservatives, meeting the needs of consumers for green and healthy food, and the plant polyphenol compound has strong antioxidant capacity, can effectively scavenge free radicals, delay the oxidative deterioration of dried fruit, and maintain the color and flavor of dried fruit; and can widely inhibit the spoilage bacteria and pathogenic bacteria on the surface of dried fruit, and reduce microbial contamination.

Description

Technical Field

[0001] This invention relates to the field of dried fruit processing technology, specifically to dried fruit preservation and enhancement agents based on plant polyphenols, their preparation methods, and applications. Background Technology

[0002] Preservation is a crucial step in the processing and storage of dried fruit. Dried fruit is rich in nutrients such as sugar and vitamins, and is highly susceptible to microbial contamination during storage, leading to spoilage and oxidation, which deteriorates its color and flavor, and causes nutrient loss.

[0003] Traditional methods of preserving dried fruit mainly rely on chemical preservatives, such as benzoic acid and its salts, sorbic acid and its salts. While these chemical preservatives can effectively inhibit microbial growth, long-term intake may pose potential risks to human health, such as affecting the balance of intestinal flora and causing allergic reactions. As consumers become increasingly concerned about food safety and health, the demand for chemical-free or natural preservatives is growing. To address these technical issues, we have designed a plant polyphenol-based preservative-enhancing agent for dried fruit, along with its preparation method and application. Summary of the Invention

[0004] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0005] The purpose of this invention is to provide a fruit preservation and enhancement preparation based on plant polyphenols, its preparation method and application. It has the advantages of inhibiting the growth of spoilage bacteria and pathogenic bacteria on the surface of dried fruit and delaying oxidative deterioration, and promoting the proliferation of probiotics by regulating the microbial community structure carried by dried fruit. It solves the problem that traditional fruit preservation methods mainly rely on chemical preservatives, which may pose potential risks to human health if consumed in the long term.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a fruit preservative and enhancement preparation based on plant polyphenols, comprising the following components by weight: The ingredients include 30-45% plant polyphenol complex, 8-15% modified chitosan film-forming agent, 5-12% natural organic acid antioxidant synergist, 3-7% compound antibacterial agent, 2-6% multi-element water activity regulator, and 30-60% deionized water.

[0007] Preferably, the plant polyphenol complex is selected from one or more of apple polyphenols, tea polyphenols, and pomegranate polyphenols, and the natural organic acid antioxidant synergist is selected from one or more of ascorbic acid, citric acid, and malic acid.

[0008] Preferably, the composite antibacterial agent comprises nisin and lysozyme, wherein nisin and lysozyme are mixed in a ratio of 1-3:1.

[0009] Preferably, the multi-component water activity regulator includes glycerol, sorbitol and xylitol, which are mixed in a ratio of 1:2:1.

[0010] Preferably, the modified chitosan film-forming agent is prepared by graft copolymerization of chitosan and olefin monomers containing double bonds under the action of an initiator, with the grafting rate controlled at 20-50%.

[0011] The preparation method of the fruit preservative and enhancement agent based on plant polyphenols includes the following steps: S1. Select plant materials such as apple, tea and pomegranate respectively, and after washing, drying and crushing, extract polyphenols by ultrasonic-assisted solvent extraction. S2, The solvent is an ethanol solution with a volume fraction of 50-70%, the extraction temperature is 50-60℃, the extraction time is 1.5-3 hours, the ultrasonic power is 200-400W, and the frequency is 20-40kHz. S3. After extraction and filtration, the filtrates are concentrated separately, then mixed in proportion, and freeze-dried to obtain a plant polyphenol complex with a purity of not less than 80%. S4. Dissolve chitosan in a 1-3% (v / v) acetic acid solution to prepare a 2-5% chitosan solution. S5. Add the plant polyphenol complex, natural organic acid antioxidant synergist, compound antibacterial agent and multi-element water activity regulator to the remaining deionized water in sequence, and stir at a stirring speed of 400-600 rpm for 20-30 minutes to fully mix the components and obtain a mixed solution. S6; Add the film-forming agent solution to the mixed solution while continuously stirring at a stirring speed of 400-700 rpm. After all the solution has been added, continue stirring for 2-3 hours. Then, perform ultrasonic treatment with an ultrasonic power of 100-300W for 10-20 minutes to ensure that the solution is fully emulsified and homogeneous, thereby obtaining a fruit preservative and enhancement preparation based on plant polyphenols.

[0012] The application of plant polyphenol-based fruit preservation and enhancement agents adopts an intelligent spraying-immersion combined process. Based on the variety, texture and initial moisture content of the dried fruit, the state of the dried fruit is monitored in real time by sensors, and the spraying and immersion parameters are automatically adjusted. For dried fruits with high initial moisture content and soft texture, first pre-spray with 4-8 ml per kilogram of dried fruit, then soak in a formulation solution with a concentration of 1.2-1.5 times that of the original formulation for 5-15 minutes. For dried fruits with low initial moisture content and hard texture, soak them in the original preparation solution for 15-25 minutes before spraying. The amount of spraying is 8-12 ml per kilogram of dried fruit. After spraying and soaking, a segmented drying method is adopted. First, it is dried at a low temperature of 40-50℃ until the moisture content is reduced by 30-50%, and then dried at 55-65℃ until it meets the storage requirements.

[0013] Preferably, in the intelligent spraying-immersion combined process, the spraying equipment uses an adjustable atomizing nozzle that can automatically adjust the spraying angle and flow rate according to the shape and size of the dried fruit surface, and the immersion equipment is equipped with a stirring device and a temperature control system, with adjustable stirring speed.

[0014] Preferably, the formulation can also be used for the pretreatment of dried fruit packaging materials. The packaging materials are soaked in the formulation solution for 10-20 minutes, then taken out and dried. The treated packaging materials have slow-release preservative components, which can continuously release plant polyphenol active ingredients during the storage of dried fruit.

[0015] Preferably, the concentration of the formulation solution used for pretreatment of packaging materials is adjusted according to the material and thickness of the packaging materials. For paper packaging materials, the solution concentration is 0.8-1.2 times the original formulation concentration, and for plastic packaging materials, the solution concentration is 1-1.5 times the original formulation concentration. During the natural drying process of the soaked packaging materials, good ventilation should be maintained and direct sunlight should be avoided.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The main components of the plant polyphenol-based dried fruit preservation and enhancement preparation of this invention are all natural substances, including plant polyphenol complexes, natural organic acids and bio-derived antibacterial agents. It does not contain traditional chemical preservatives, thus avoiding the health risks that chemical preservatives may bring and meeting consumers' demand for green and healthy food.

[0017] 2. The plant polyphenol complex of this invention has a strong antioxidant capacity, which can effectively scavenge free radicals, delay the oxidative deterioration of dried fruit, and maintain the color and flavor of dried fruit. The lactic acid nisin and lysozyme in the compound antibacterial agent can work synergistically to widely inhibit spoilage bacteria and pathogenic bacteria on the surface of dried fruit and reduce microbial contamination. The modified chitosan film-forming agent can form a protective film on the surface of dried fruit, which can not only further prevent microbial invasion, but also reduce the contact between dried fruit and the outside air, and slow down the oxidation rate. The natural organic acid antioxidant synergist and the multi-element water activity regulator play a role in enhancing the antioxidant effect and regulating the water activity of dried fruit, respectively, and together improve the preservation effect of dried fruit and extend its shelf life.

[0018] 3. The dried fruit treated with this preservation and enhancement agent can not only effectively maintain its original nutritional components, but also improve its taste and flavor. Since the ingredients in the agent are natural and odorless, they will not have an adverse effect on the original flavor of the dried fruit, thus helping to improve the overall quality and market competitiveness of the dried fruit.

[0019] 4. The ultrasonic-assisted solvent extraction method of this invention for extracting plant polyphenols can improve extraction efficiency, shorten extraction time, and ensure high purity of plant polyphenols. The addition and stirring steps of each component are reasonably designed to ensure that the components are fully and evenly mixed. The subsequent ultrasonic treatment further emulsifies the solution evenly, ensuring the quality stability and performance consistency of the preparation, which is conducive to large-scale industrial production. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a flowchart of the preparation method of the present invention. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Example 1 A fruit preservative and enhancement agent based on plant polyphenols, comprising the following components by weight: This fruit preservative and enhancement formulation based on plant polyphenols uses a scientifically formulated blend of various natural functional ingredients. The plant polyphenol complex provides strong antioxidant capabilities, effectively delaying the oxidative deterioration of dried fruit. The modified chitosan film-forming agent forms a protective film, blocking microorganisms and oxygen. The natural organic acid antioxidant synergist enhances the antioxidant effect, the compound antibacterial agent inhibits microbial growth, and the multiple water activity regulators regulate the moisture environment of the dried fruit. The synergistic effect of these ingredients ensures the quality of the dried fruit from multiple aspects, extends its shelf life, and is made with natural and safe ingredients, meeting consumers' demand for healthy food.

[0024] The plant polyphenol complex is selected from one or more of apple polyphenols, tea polyphenols, and pomegranate polyphenols. The natural organic acid antioxidant synergist is selected from one or more of ascorbic acid, citric acid, and malic acid. Apple polyphenols, tea polyphenols, and pomegranate polyphenols each have unique antioxidant properties. Ascorbic acid, citric acid, and malic acid, as natural organic acids, can effectively synergistically resist oxidation. This diversity of choices allows the formulation to flexibly adjust the combination of ingredients according to different dried fruit characteristics and preservation needs, so as to achieve a more precise and efficient preservation effect.

[0025] The compound antibacterial agent includes nisin and lysozyme, which are mixed in a 2:1 ratio. In this compound antibacterial agent, nisin and lysozyme work together to exert a synergistic antibacterial effect. Nisin has an inhibitory effect on most Gram-positive bacteria, while lysozyme can hydrolyze bacterial cell walls, enhancing the killing effect on bacteria, broadening the antibacterial spectrum, improving antibacterial efficiency, and more effectively inhibiting the growth of microorganisms on the surface of dried fruit, thus reducing the risk of dried fruit spoilage.

[0026] The multi-component water activity regulator includes glycerin, sorbitol, and xylitol, which are mixed in a 1:2:1 ratio. This proportioned mixture of glycerin, sorbitol, and xylitol in the multi-component water activity regulator can more precisely regulate the water activity of dried fruit. Different components have different characteristics and mechanisms of action in regulating water activity. Through reasonable formulation, it can meet the water activity requirements of different dried fruits, effectively inhibit the growth and reproduction of microorganisms, delay the spoilage of dried fruit, and maintain the taste and quality of dried fruit.

[0027] Modified chitosan film-forming agent is prepared by graft copolymerization of chitosan and olefin monomers containing double bonds under the action of an initiator. The grafting rate is controlled at 30%. The modification significantly improves the film-forming properties of chitosan, resulting in films with better flexibility and air permeability. The flexible film can better adhere to the surface of dried fruit and is not easy to break. The good air permeability helps to regulate the gas environment around the dried fruit, preventing microbial invasion and avoiding anaerobic respiration caused by lack of oxygen, which leads to a decline in quality.

[0028] Example 2 Please see Figure 1 The preparation method of a fruit preservative and enhancement agent based on plant polyphenols includes the following steps: S1. Select plant materials such as apple, tea and pomegranate respectively, and after washing, drying and crushing, extract polyphenols by ultrasonic-assisted solvent extraction. S2, The solvent is a 60% ethanol solution by volume, the extraction temperature is 55℃, the extraction time is 2 hours, the ultrasonic power is 300W, and the frequency is 30kHz. S3. After extraction and filtration, the filtrates are concentrated separately, then mixed in proportion, and freeze-dried to obtain a plant polyphenol complex with a purity of not less than 80%. S4. Dissolve chitosan in a 2% (v / v) acetic acid solution to prepare a 3% chitosan solution. S5. Add the plant polyphenol complex, natural organic acid antioxidant synergist, compound antibacterial agent and multi-element water activity regulator to the remaining deionized water in sequence, and stir at a stirring speed of 500 rpm for 25 minutes to fully mix the components and obtain a mixed solution. S6; Add the film-forming agent solution to the mixed solution while continuously stirring at a stirring speed of 500 rpm. After all the solution has been added, continue stirring for 2.5 hours. Then, perform ultrasonic treatment with an ultrasonic power of 200W for 15 minutes to ensure that the solution is fully emulsified and homogeneous, thereby obtaining a fruit-derived preservative and enhancement preparation based on plant polyphenols.

[0029] Ultrasonic-assisted solvent extraction of plant polyphenols can improve extraction efficiency, shorten extraction time, and ensure high purity of plant polyphenols. The addition and stirring steps of each component are reasonably designed to ensure that the components are fully and evenly mixed. Subsequent ultrasonic treatment further emulsifies the solution evenly, ensuring the quality stability and performance consistency of the preparation, which is conducive to large-scale industrial production.

[0030] Example 3 The application of plant polyphenol-based fruit preservation and enhancement agents adopts an intelligent spraying-immersion combined process. Based on the variety, texture and initial moisture content of the dried fruit, the state of the dried fruit is monitored in real time by sensors, and the spraying and immersion parameters are automatically adjusted. For dried fruits with high initial moisture content and soft texture, pre-spray with 6 ml per kilogram of dried fruit, and then soak in a formulation solution with a concentration 1.3 times that of the original formulation for 10 minutes. For dried fruits with low initial moisture content and hard texture, soak them in the original preparation solution for 20 minutes before spraying. The amount of spraying is 10 ml per kilogram of dried fruit. After spraying and soaking, a segmented drying method is adopted. First, it is dried at a low temperature of 45℃ until the moisture content is reduced by 40%, and then dried at 60℃ until it meets the storage requirements.

[0031] Different pretreatment and soaking / spraying methods can be used for dried fruits with different initial moisture content and texture to ensure that the preparation is evenly distributed and fully penetrates the surface of the dried fruit, achieving the best preservation effect. The segmented drying method can ensure that the moisture content of the dried fruit is reduced reasonably, and avoid damage to the quality of the dried fruit due to excessive temperature or improper drying time.

[0032] In the intelligent spraying-immersion combined process, the spraying equipment uses adjustable atomizing nozzles that can automatically adjust the spray angle and flow rate according to the shape and size of the dried fruit surface. The immersion equipment is equipped with a stirring device and a temperature control system. The stirring speed is adjustable, and the automatic adjustment of the spray angle and flow rate can ensure that the preparation is evenly sprayed on the surface of the dried fruit, improving spraying efficiency and preservation effect. The stirring device and temperature control system of the immersion equipment can ensure that the dried fruit and the preparation are in full contact, ensuring immersion uniformity. At the same time, precise temperature control is conducive to the best performance of each component in the preparation, further improving the preservation quality of the dried fruit.

[0033] The formulation can also be used for the pretreatment of dried fruit packaging materials. The packaging materials are soaked in the formulation solution for 15 minutes, then removed and dried. The treated packaging materials have slow-release preservative components that can continuously release plant polyphenols during the storage of dried fruit. During the storage of dried fruit, the packaging materials continuously release plant polyphenols and other active ingredients, providing long-term preservation protection for the dried fruit, further extending the shelf life of the dried fruit, reducing quality changes during storage and transportation, and improving the market competitiveness of the product.

[0034] The concentration of the formulation solution used for pretreatment of packaging materials is adjusted according to the material and thickness of the packaging material. For paper packaging materials, the solution concentration is 1 times the original formulation concentration, and for plastic packaging materials, the solution concentration is 1.2 times the original formulation concentration. During the natural drying process after soaking, the packaging materials should be well ventilated and protected from direct sunlight. Adjusting the concentration of the formulation solution used for pretreatment according to the different materials and thicknesses of the packaging materials can ensure the effective adsorption and sustained release of the formulation by the packaging materials. Different materials and thicknesses of packaging materials have different adsorption and release capabilities for the formulation. By reasonably adjusting the concentration, the packaging materials can play the best preservation function under different conditions, thereby improving the utilization efficiency and preservation effect of the formulation.

[0035] It should be noted that any content not described in detail in this specification belongs to the prior art known to those skilled in the art. The specific embodiments described herein are merely illustrative examples of the spirit of the invention. Those skilled in the art can make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. A fruit preservative and synergistic agent based on plant polyphenols, characterized in that... Includes the following components by weight: The ingredients include 30-45% plant polyphenol complex, 8-15% modified chitosan film-forming agent, 5-12% natural organic acid antioxidant synergist, 3-7% compound antibacterial agent, 2-6% multi-element water activity regulator, and 30-60% deionized water.

2. The fruit preservative and synergistic agent based on plant polyphenols according to claim 1, characterized in that: The plant polyphenol complex is selected from one or more of apple polyphenols, tea polyphenols and pomegranate polyphenols, and the natural organic acid antioxidant synergist is selected from one or more of ascorbic acid, citric acid and malic acid.

3. The fruit preservative and synergistic agent based on plant polyphenols according to claim 1, characterized in that: The compound antibacterial agent includes nisin and lysozyme, which are mixed in a ratio of 1-3:

1.

4. The fruit preservative and synergistic agent based on plant polyphenols according to claim 1, characterized in that: The multi-component water activity regulator includes glycerol, sorbitol and xylitol, which are mixed in a ratio of 1:2:

1.

5. The fruit preservative and synergistic agent based on plant polyphenols according to claim 1, characterized in that: The modified chitosan film-forming agent is prepared by graft copolymerization of chitosan and olefin monomers containing double bonds under the action of an initiator, with the grafting rate controlled at 20-50%.

6. The method for preparing the fruit preservative and synergistic agent based on plant polyphenols according to any one of claims 1-5, characterized in that: Includes the following steps: S1. Select plant materials such as apple, tea and pomegranate respectively, and after washing, drying and crushing, extract polyphenols by ultrasonic-assisted solvent extraction. S2, The solvent is an ethanol solution with a volume fraction of 50-70%, the extraction temperature is 50-60℃, the extraction time is 1.5-3 hours, the ultrasonic power is 200-400W, and the frequency is 20-40kHz. S3. After extraction and filtration, the filtrates are concentrated separately, then mixed in proportion, and freeze-dried to obtain a plant polyphenol complex with a purity of not less than 80%. S4. Dissolve chitosan in a 1-3% (v / v) acetic acid solution to prepare a 2-5% chitosan solution. S5. Add the plant polyphenol complex, natural organic acid antioxidant synergist, compound antibacterial agent and multi-element water activity regulator to the remaining deionized water in sequence, and stir at a stirring speed of 400-600 rpm for 20-30 minutes to fully mix the components and obtain a mixed solution. S6; Add the film-forming agent solution to the mixed solution while continuously stirring at a stirring speed of 400-700 rpm. After all the solution has been added, continue stirring for 2-3 hours. Then, perform ultrasonic treatment with an ultrasonic power of 100-300W for 10-20 minutes to ensure that the solution is fully emulsified and homogeneous, thereby obtaining a fruit preservative and enhancement preparation based on plant polyphenols.

7. The application of the plant polyphenol-based fruit preservative and synergistic agent according to claim 1, characterized in that: The intelligent spraying-soaking combined process is adopted. Based on the variety, texture and initial moisture content of the dried fruit, the sensor monitors the status of the dried fruit in real time and automatically adjusts the spraying and soaking parameters. For dried fruits with high initial moisture content and soft texture, first pre-spray with 4-8 ml per kilogram of dried fruit, then soak in a formulation solution with a concentration of 1.2-1.5 times that of the original formulation for 5-15 minutes. For dried fruits with low initial moisture content and hard texture, soak them in the original preparation solution for 15-25 minutes before spraying. The amount of spraying is 8-12 ml per kilogram of dried fruit. After spraying and soaking, a segmented drying method is adopted. First, it is dried at a low temperature of 40-50℃ until the moisture content is reduced by 30-50%, and then dried at 55-65℃ until it meets the storage requirements.

8. The application of the plant polyphenol-based fruit preservative and synergistic agent according to claim 7, characterized in that: In the intelligent spraying-immersion combined process, the spraying equipment uses adjustable atomizing nozzles that can automatically adjust the spray angle and flow rate according to the shape and size of the dried fruit surface. The immersion equipment is equipped with a stirring device and a temperature control system, and the stirring speed is adjustable.

9. The application of the plant polyphenol-based fruit preservative and synergistic agent according to claim 8, characterized in that: The formulation can also be used for the pretreatment of dried fruit packaging materials. The packaging materials are soaked in the formulation solution for 10-20 minutes, then taken out and dried. The treated packaging materials have slow-release preservative components, which can continuously release plant polyphenol active ingredients during the storage of dried fruit.

10. The application of the plant polyphenol-based fruit preservative and synergistic agent according to claim 1, characterized in that: The concentration of the formulation solution used for pretreatment of packaging materials is adjusted according to the material and thickness of the packaging material. For paper packaging materials, the solution concentration is 0.8-1.2 times the original formulation concentration, and for plastic packaging materials, the solution concentration is 1-1.5 times the original formulation concentration. After soaking, the packaging materials should be kept well ventilated and protected from direct sunlight during natural drying.

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