Healing agent for rhizome fruits and vegetables and preparation method of healing agent

Abstract

The invention belongs to the technical field of fruit and vegetable healing agents, and particularly relates to a healing agent for rhizome fruits and vegetables and a preparation method of the healing agent. According to the healing agent, the tannic acid modified sodium alginate is used as a core film-forming base material and is matched with the natural plant source composition, the plant source active composition and the low-molecular chitosan oligosaccharide to achieve the synergistic antibacterial and anti-inflammatory effects, the differentially compounded compound amino acid provides targeted nutrition, the wound healing time can be remarkably shortened through the synergistic effect of the multiple components, the rotting rate is reduced, and the wound healing effect is improved. The composition is high in safety, capable of remarkably promoting wound healing and effectively inhibiting pathogenic bacteria infection, suitable for various rhizome type fruits and vegetables, simple in preparation process, low in energy consumption and easy for industrial production. Compared with the prior art that a rhizome fruit and vegetable healing agent has the defects of poor safety, low healing efficiency, narrow applicability, complex preparation process and the like, the prepared healing agent is suitable for various rhizome fruits and vegetables, a formed protective film is high in stability and good in air permeability and can be attached for a long time to play a role, and the storage period is effectively prolonged.

Description

Technical Field

[0001] This invention belongs to the technical field of fruit and vegetable healing agents, specifically relating to a healing agent for root and stem fruits and vegetables and its preparation method. Background Technology

[0002] Root vegetables are important food and cash crops in my country, rich in starch, vitamins, minerals, and other nutrients, and occupy an important position in the national diet. During harvesting, grading, packaging, transportation, and storage, these fruits and vegetables are highly susceptible to surface wounds due to unavoidable mechanical collisions and friction. The presence of these wounds leads to a series of problems: firstly, wounds damage the protective barrier of the fruit and vegetable's surface, causing rapid evaporation of internal moisture, resulting in wilting, weight loss, and a decline in quality; secondly, wounds provide a pathway for pathogens (such as Penicillium, Botrytis, and soft rot fungi) to invade, easily leading to rot and significant post-harvest losses. Statistics show that the post-harvest loss rate of root vegetables due to wound rot in my country is as high as 20%-30%, seriously affecting the economic benefits of growers and the sustainable development of the industry.

[0003] To address the aforementioned issues, various agents for wound healing in fruits and vegetables have been developed in existing technologies, mainly categorized into chemically synthesized and naturally extracted types. While chemically synthesized wound healers (such as carbendazim and thiophanate-methyl) can inhibit pathogen growth to some extent, they pose a risk of residue damage to human health, and long-term use can lead to antibiotic resistance in pathogens. Furthermore, their effect on promoting wound healing is limited, failing to fundamentally solve the problem of slow wound healing. Naturally extracted wound healers (such as chitosan and aloe vera extract) offer advantages such as high safety and environmental friendliness, but they generally suffer from low healing efficiency and short-lasting effects. Moreover, most are only effective for a single type of root vegetable, resulting in poor applicability and difficulty in meeting the needs of large-scale production.

[0004] Furthermore, existing methods for preparing healing agents are often complex, with some processes requiring high temperatures and pressures, resulting in high energy consumption. Moreover, the preparation process easily generates byproducts, affecting the purity and effectiveness of the healing agent. Therefore, developing a healing agent for root and tuber fruits and vegetables that is highly safe, has high healing efficiency, wide applicability, and a simple preparation process is of great significance for reducing post-harvest losses, improving product quality, and promoting the development of the root and tuber fruit and vegetable industry. Summary of the Invention

[0005] To address the above problems, the present invention aims to provide a healing agent for root and tuber fruits and vegetables and a method for preparing the same.

[0006] The technical content of this invention is as follows: This invention provides a healing agent for root and tuber fruits and vegetables, the components of which include modified sodium alginate, plant-derived active composition, low molecular weight chitosan oligosaccharide, complex amino acids, trace mineral elements, food-grade additives, vitamins, and deionized water; By mass fraction, the modified sodium alginate accounts for 5-12%, the plant-derived active composition accounts for 4-10%, the low molecular weight chitosan accounts for 1-4%, the complex amino acids account for 1-3%, the mineral trace elements account for 0.5-1.5%, the food additives account for 1-4%, the vitamin C accounts for 0.3-1%, and the deionized water is made up to 100%.

[0007] The modified sodium alginate is prepared as follows: Sodium alginate is dissolved in deionized water to prepare a sodium alginate solution with a mass concentration of 5%-8%. 3%-5% propylene oxide and 1%-2% tannic acid (by mass of sodium alginate) are added, and the mixture is reacted at 45-55℃ and a stirring rate of 200-300 r / min for 2-3 hours. After the reaction, the mixture is cooled to room temperature, and ethanol is added for precipitation (the amount of ethanol added is 2-3 times the volume of the solution). After filtration, the precipitate is dried in a vacuum drying oven at 40-50℃ until constant weight, thus obtaining the modified sodium alginate. Through the synergistic modification treatment of propylene oxide and tannic acid, the water solubility, film-forming properties, and bioactivity of sodium alginate can be further improved, enabling it to form a more stable and dense protective film on the surface of fruit and vegetable wounds, more effectively reducing water loss and pathogen invasion.

[0008] The plant-derived active composition includes Panax notoginseng extract, rosmarinic acid, and tea polyphenols, with a compound mass ratio of (2-5):(1-3):(1-2). Among them, Panax notoginseng extract contains Panax notoginseng saponins and flavonoids, which can promote wound repair, accelerate cell proliferation at the wound site, and shorten the healing cycle. Rosmarinic acid, as a natural antioxidant and antibacterial agent, can inhibit the growth of pathogens (such as Penicillium and soft rot fungi) and reduce oxidative browning of wounds. Tea polyphenols have strong broad-spectrum antibacterial properties, which can enhance the inhibitory effect of the healing agent on a variety of pathogens, and also have antioxidant properties, protecting the wound tissue of fruits and vegetables from oxidative damage.

[0009] The molecular weight of the chitosan oligosaccharide is 500-2000 Da. Low molecular weight chitosan oligosaccharides have better water solubility and biological activity, which can promote the proliferation and differentiation of fruit and vegetable cells, accelerate wound healing, and also have certain antibacterial capabilities.

[0010] The compound amino acid is composed of alanine, glycine, and glutamic acid in a mass ratio of (2-3):(1-2):(1-2). The compound amino acid can provide necessary nutrients for the healing of wounds in fruits and vegetables and promote cell regeneration.

[0011] The mineral trace elements include potassium dihydrogen phosphate and calcium chloride in a mass ratio of (0.2-0.8):(0.1-0.5). Potassium dihydrogen phosphate provides phosphorus and potassium, which participate in the metabolic process of fruit and vegetable cells, enhance the stress resistance of wound tissue, and reduce the risk of decay. Calcium chloride supplements calcium, promotes the synthesis of cell walls in fruits and vegetables, enhances the mechanical strength of wound tissue, and improves the storage resistance after healing.

[0012] The food-grade additives include one or more of glycerin and sorbitol, which act as humectants and film-forming aids. They can reduce the rate of water loss of the healing agent during the drying process, prevent the film from cracking, and improve the flexibility of the film, thus avoiding film damage caused by the shrinkage of vegetable skins.

[0013] This invention also provides a method for preparing the above-mentioned healing agent for root and tuber fruits and vegetables, comprising the following steps: 1) Preparation of modified sodium alginate solution: Dissolve sodium alginate in deionized water to prepare a sodium alginate solution with a mass concentration of 5%-8%. Add 3%-5% propylene oxide and 1%-2% tannic acid by mass of sodium alginate. React at 45-55℃ and a stirring rate of 200-300 r / min for 2-3 hours. After the reaction is completed, cool to room temperature and add ethanol to precipitate (the amount of ethanol added is 2-3 times the volume of the solution). After filtration, place the precipitate in a vacuum drying oven at 40-50℃ and dry to constant weight to obtain modified sodium alginate. Add the modified sodium alginate to deionized water and stir to dissolve at 50-60℃ and a stirring rate of 250-350 r / min to obtain the modified sodium alginate solution. 2) Add the plant-derived active composition to the modified sodium alginate solution from step 1) and stir continuously until the extract is fully dispersed and dissolved. 3) Add low molecular weight chitosan oligosaccharide, complex amino acids, potassium dihydrogen phosphate, and calcium chloride in sequence, and stir at 40-50℃ for 20-30 minutes until well mixed. 4) Then add food-grade additives and vitamin C, and continue stirring at 40-50℃ for 15-20 minutes to ensure the system is homogeneous; 5) Cool the mixture obtained in step 4) to room temperature, filter it through a 100-200 mesh sieve to remove impurities, and obtain a healing agent for root vegetables.

[0014] The beneficial effects of this invention are as follows: This invention relates to a wound healing agent for root and tuber fruits and vegetables. It uses tannic acid-modified sodium alginate as the film-forming substrate, combined with a natural plant-derived active composition and food-grade additives. The entire process is free of harmful chemically synthesized substances, leaving no residue after use, thus meeting the requirements for green agricultural product production. This invention optimizes the film-forming performance of sodium alginate by adjusting the tannic acid modification parameters to match different component ratios. The plant-derived active composition and low-molecular-weight chitosan oligosaccharides synergistically provide antibacterial and anti-inflammatory effects, while the differentiated compound amino acids offer targeted nutrition. The synergistic effect of these multiple components significantly shortens wound healing time and reduces the rate of decay.

[0015] The preparation method of the healing agent of this invention requires no stringent conditions for modification and preparation, is convenient to operate, has low energy consumption, and is easy to scale up for industrial production. Compared with the shortcomings of existing root and tuber fruit and vegetable healing agents, such as poor safety, low healing efficiency, narrow applicability, and complex preparation process, the healing agent prepared by this invention is suitable for a variety of root and tuber fruits and vegetables. The protective film formed has strong stability and good air permeability, can adhere for a long time and play a role, effectively extending the storage period. Detailed Implementation

[0016] The present invention will be further described in detail below through specific implementation examples. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of protection of the present invention. After reading the present invention, any modifications of the present invention in various equivalent forms by those skilled in the art fall within the scope of the appended claims.

[0017] Unless otherwise specified, all raw materials and reagents used in this invention are from the conventional market.

[0018] Example 1 A method for preparing a healing agent for root and tuber fruits and vegetables 1) Preparation of modified sodium alginate solution: Sodium alginate was dissolved in deionized water to prepare a 5% sodium alginate solution. 3% propylene oxide and 1% tannic acid were added to the solution. The mixture was reacted at 45℃ and a stirring rate of 200 r / min for 2 h. After the reaction was completed, the mixture was cooled to room temperature, and ethanol (2 times the volume of the solution) was added to precipitate the product. After filtration, the precipitate was dried in a vacuum drying oven at 40℃ until constant weight, thus obtaining modified sodium alginate. 5% modified sodium alginate was added to 88.2% deionized water and stirred at 50℃ and a stirring rate of 250 r / min to dissolve the product, thus obtaining the modified sodium alginate solution. 2) Add the plant-derived active composition (2% Panax notoginseng extract, 1% rosmarinic acid, and 1% tea polyphenols) to the modified sodium alginate solution in step 1) and stir continuously until the extract is fully dispersed and dissolved. 3) Add 1% low molecular weight chitosan oligosaccharide, 1% complex amino acids, 0.3% potassium dihydrogen phosphate, and 0.2% calcium chloride in sequence, and stir at 40℃ for 30 minutes to mix evenly; The mass ratio of alanine, glycine, and glutamic acid in the composite amino acid is 2:1:1. 4) Then add 0.6% glycerol, 0.4% sorbitol and vitamin C, and continue stirring at 40°C for 20 minutes to ensure the system is homogeneous; 5) Cool the mixture obtained in step 4) to room temperature, filter it through a 100-150 mesh sieve to remove impurities, and obtain a healing agent for root vegetables.

[0019] Example 2 A method for preparing a healing agent for root and tuber fruits and vegetables 1) Preparation of modified sodium alginate solution: Sodium alginate was dissolved in deionized water to prepare a 6% sodium alginate solution. 3.5% propylene oxide and 1.5% tannic acid were added to the solution. The mixture was reacted at 48℃ and a stirring rate of 220 r / min for 2.2 h. After the reaction was completed, the mixture was cooled to room temperature and 2.2 times the volume of the solution was added to precipitate the product. After filtration, the precipitate was dried in a vacuum drying oven at 42℃ to constant weight to obtain modified sodium alginate. 7% of the modified sodium alginate was added to 80.2% deionized water and stirred at 52℃ and a stirring rate of 280 r / min to dissolve the product, thus obtaining the modified sodium alginate solution. 2) Add the plant-derived active composition (3% Panax notoginseng extract, 1.8% rosmarinic acid, and 1.2% tea polyphenols) to the modified sodium alginate solution in step 1), and stir continuously until the extract is fully dispersed and dissolved. 3) Add 2% low molecular weight chitosan, 1.5% complex amino acids, 0.5% potassium dihydrogen phosphate, and 0.3% calcium chloride in sequence, and stir at 43℃ for 24 minutes to mix evenly; The mass ratio of alanine, glycine, and glutamic acid in the composite amino acid is 2:1:1.5. 4) Then add 1.2% glycerol, 0.8% sorbitol and 0.5% vitamin C, and continue stirring at 43°C for 16 minutes to ensure the system is homogeneous; 5) Cool the mixture obtained in step 4) to room temperature, filter it through a 100-150 mesh sieve to remove impurities, and obtain a healing agent for root vegetables.

[0020] Example 3 A method for preparing a healing agent for root and tuber fruits and vegetables 1) Preparation of modified sodium alginate solution: Sodium alginate was dissolved in deionized water to prepare a sodium alginate solution with a mass concentration of 7%. 4.5% propylene oxide and 1.8% tannic acid by mass of sodium alginate were added. The mixture was reacted at 52℃ and a stirring rate of 280 r / min for 2.8 h. After the reaction was completed, the mixture was cooled to room temperature, and 2.8 times the volume of the solution was added to precipitate the product. After filtration, the precipitate was dried in a vacuum drying oven at 48℃ to constant weight to obtain modified sodium alginate. 10% of the modified sodium alginate was added to 73.9% deionized water and stirred at 58℃ and a stirring rate of 320 r / min to dissolve the product, thus obtaining the modified sodium alginate solution. 2) Add the plant-derived active composition (4.5% Panax notoginseng extract, 2.2% rosmarinic acid, and 1.3% tea polyphenols) to the modified sodium alginate solution in step 1), and stir continuously until the extract is fully dispersed and dissolved. 3) Add 3% low molecular weight chitosan, 2.5% complex amino acids, 0.7% potassium dihydrogen phosphate, and 0.6% calcium chloride in sequence, and stir at 48℃ for 28 minutes to mix evenly; The mass ratio of alanine, glycine, and glutamic acid in the composite amino acid is 2.5:1.5:1. 4) Then add 2% glycerol, 1.5% sorbitol and 0.8% vitamin C, and continue stirring at 48°C for 19 minutes to ensure the system is homogeneous; 5) Cool the mixture obtained in step 4) to room temperature, filter it through a 150-200 mesh sieve to remove impurities, and obtain a healing agent for root vegetables.

[0021] Example 4 A method for preparing a healing agent for root and tuber fruits and vegetables 1) Preparation of modified sodium alginate solution: Sodium alginate was dissolved in deionized water to prepare an 8% sodium alginate solution. 5% propylene oxide and 2% tannic acid were added to the solution. The mixture was reacted at 55℃ and a stirring rate of 300 r / min for 3 h. After the reaction was completed, the mixture was cooled to room temperature and 3 times the volume of the solution was added to precipitate the product. After filtration, the precipitate was dried in a vacuum drying oven at 50℃ to constant weight to obtain modified sodium alginate. 12% modified sodium alginate was added to 64.5% deionized water and stirred at 60℃ and a stirring rate of 350 r / min to dissolve the modified sodium alginate solution. 2) Add the plant-derived active composition (5% Panax notoginseng extract, 3% rosmarinic acid, 2% tea polyphenols, in a ratio of 5:3:2) to the modified sodium alginate solution in step 1), and stir continuously until the extract is fully dispersed and dissolved. 3) Add 4% low molecular weight chitosan, 3% complex amino acids, 0.8% potassium dihydrogen phosphate, and 0.7% calcium chloride in sequence, and stir at 50℃ for 30 minutes to mix evenly; The mass ratio of alanine, glycine, and glutamic acid in the composite amino acid is 3:2:2. 4) Then add 2.5% glycerol, 1.5% sorbitol and 1% vitamin C, and continue stirring at 50°C for 20 minutes to ensure the system is homogeneous; 5) Cool the mixture obtained in step 4) to room temperature, filter it through a 150-200 mesh sieve to remove impurities, and obtain a healing agent for root vegetables.

[0022] Comparative Example 1 As a control group for Example 2, Comparative Example 1 did not modify sodium alginate. Instead, 7% sodium alginate was directly added to 80.2% deionized water and stirred at 52°C and a stirring rate of 280 r / min to dissolve it, thus obtaining a modified sodium alginate solution for subsequent preparation. Other steps were the same as in Example 2.

[0023] Comparative Example 2 As a control group for Example 2, tannic acid was removed from the modification of sodium alginate in Comparative Example 2, while the other steps were the same as in Example 2.

[0024] Comparative Example 3 As a control group for Example 2, the plant-derived active composition in Comparative Example 3 used only 6% Panax notoginseng extract, omitting the other two components, while the other steps were the same as in Example 2.

[0025] Comparative Example 4 As a control group for Example 2, the plant-derived active composition in Comparative Example 4 used only 6% Panax notoginseng extract, removing the other two components, and the mass ratio of alanine, glycine, and glutamic acid in the complex amino acids was 1:1:1.

[0026] The healing agents prepared in the above examples and comparative examples were used for the following tests:

[0027] I. Test Materials and Conditions 1) Test subjects: Select fresh potatoes (variety: Atlantic) that are uniform in size (5-6cm in diameter), without mechanical damage, and free from pests and diseases, with 50 potatoes per group.

[0028] 2) Wound preparation: Create a circular wound with a diameter of 1cm and a depth of 0.5cm on the equatorial side of each potato, and wipe the wound surface clean with sterile gauze.

[0029] 3) Treatment method: The healing agents of Examples 1-4 and Comparative Examples 1-5 were applied to the surface of potato wounds in the corresponding groups (application amount: 0.2 mL / wound), and the blank control group was not treated. After treatment, the wounds were air-dried for 30 minutes and stored under the same storage conditions (temperature 10℃, relative humidity 75%) for 30 days.

[0030] II. Test Indicators and Methods 1. Wound healing time: Regularly observe the wound healing process and record the time (in days) when the wound is completely scabbed over and there is no exudate.

[0031] 2. 30-day rot rate: After 30 days of storage, the number of rotten potatoes is counted. Rot rate = (number of rotten potatoes / total number of potatoes) × 100%.

[0032] 3. Weight loss rate: The total weight of potatoes before storage and after 30 days of storage was measured. Weight loss rate = (weight before storage - weight after storage) / weight before storage × 100%.

[0033] 4. Antibacterial properties: The plate inhibition zone method was used, with Penicillium and soft rot bacteria as test strains, to determine the diameter (mm) of the inhibition zone of each healing agent. The larger the diameter, the stronger the antibacterial properties.

[0034] 5. Residue detection: High performance liquid chromatography (HPLC) was used to detect chemical residues on the surface of potatoes after 30 days of storage. The detection limit was 0.01 mg / kg.

[0035] The test results are as follows: Table 1

[0036] As shown in Table 1, the healing agents of Examples 1-4 were significantly superior to those of Comparative Examples 1-4 and the blank control group in terms of wound healing time, decay rate, weight loss rate, and antibacterial properties. Among them, Example 4 showed the best effect, with a wound healing time of only 5.0 days, a decay rate of 1.5% after 30 days, a weight loss rate of 3.5%, and inhibition zone diameters of nearly 20 mm against Penicillium and soft rot fungi. Example 2, as the core control example, also showed excellent performance in various aspects, highlighting the rationality of the formulation and process of this invention.

[0037] Comparative Example 1 (unmodified sodium alginate) showed the worst results, with a wound healing time of up to 12.8 days and a decay rate of 16.5%, indicating that tannic acid modification can significantly improve the film-forming density and bioactivity of sodium alginate, which is the key to ensuring the healing effect. Comparative Example 2 (modified with propylene oxide only without tannic acid) showed better results than Comparative Example 1 but worse results than Example 2, indicating that tannic acid and propylene oxide have a synergistic modification effect, which can further optimize the performance of the substrate.

[0038] Comparative Example 3 (single Panax notoginseng extract) was less effective than Example 2, indicating that the combination of Panax notoginseng extract, rosmarinic acid, and tea polyphenols in the plant-derived active composition has a synergistic effect, which can enhance the antibacterial and healing-promoting effects. Comparative Example 4 (single Panax notoginseng extract + compound amino acids 1:1:1) was even less effective than Comparative Example 3, indicating that the differentiated compound amino acid combination (2:1:1.5 in Example 2) can provide targeted nutritional supply and synergistically enhance the healing effect with the plant-derived active composition.

[0039] No chemical residues were found in any of the embodiments and comparative examples, and the overall performance of the embodiments was significantly better, indicating that the healing agent of the present invention has obvious advantages in both safety and effectiveness.

Claims

1. A healing agent for root and tuber fruits and vegetables, characterized in that, The healing agent comprises modified sodium alginate, plant-derived active composition, low molecular weight chitosan oligosaccharide, complex amino acids, trace mineral elements, food-grade additives, vitamins, and deionized water.

2. The healing agent for root and tuber fruits and vegetables according to claim 1, characterized in that, By mass fraction, the modified sodium alginate accounts for 5-12%, the plant-derived active composition accounts for 4-10%, the low molecular weight chitosan accounts for 1-4%, the complex amino acids account for 1-3%, the mineral trace elements account for 0.5-1.5%, the food additives account for 1-4%, the vitamin C accounts for 0.3-1%, and the deionized water is made up to 100%.

3. The healing agent for root and tuber fruits and vegetables according to claim 1, characterized in that, The modified sodium alginate is prepared by dissolving sodium alginate in deionized water to prepare a sodium alginate solution with a mass concentration of 5%-8%. Then, 3%-5% propylene oxide and 1%-2% tannic acid are added to the sodium alginate solution. The mixture is reacted at 45-55℃ and a stirring rate of 200-300 r / min for 2-3 hours. After the reaction is completed, the mixture is cooled to room temperature, and ethanol is added to precipitate the product. After filtration, the precipitate is dried in a vacuum drying oven at 40-50℃ until constant weight is obtained, thus obtaining the modified sodium alginate.

4. The healing agent for root and tuber fruits and vegetables according to claim 1, characterized in that, The plant-derived active composition includes Panax notoginseng extract, rosmarinic acid and tea polyphenols, with a compound mass ratio of (2-5):(1-3):(1-2).

5. The healing agent for root and tuber fruits and vegetables according to claim 1, characterized in that, The molecular weight of the chitosan oligosaccharide is 500-2000 Da.

6. The healing agent for root and tuber fruits and vegetables according to claim 1, characterized in that, The complex amino acid is composed of alanine, glycine, and glutamic acid in a mass ratio of (2-3):(1-2):(1-2).

7. The healing agent for root and tuber fruits and vegetables according to claim 1, characterized in that, The mineral trace elements include potassium dihydrogen phosphate and calcium chloride, in a mass ratio of (0.2-0.8):(0.1-0.5).

8. The healing agent for root and tuber fruits and vegetables according to claim 1, characterized in that, The food-grade additives include one or more of glycerin and sorbitol.

9. A method for preparing a healing agent for root and tuber fruits and vegetables as described in any one of claims 1-8, characterized in that, Includes the following steps: 1) Preparation of modified sodium alginate solution: Add modified sodium alginate to deionized water and stir to dissolve at 50-60℃ and a stirring rate of 250-350r / min to obtain modified sodium alginate solution. 2) Add the plant-derived active composition to the modified sodium alginate solution from step 1) and stir continuously until the extract is fully dispersed and dissolved. 3) Add low molecular weight chitosan oligosaccharide, complex amino acids, potassium dihydrogen phosphate, and calcium chloride in sequence, and stir at 40-50℃ for 20-30 minutes until well mixed. 4) Then add food-grade additives and vitamin C, and continue stirring at 40-50℃ for 15-20 minutes to ensure the system is homogeneous; 5) Cool the mixture obtained in step 4) to room temperature, filter it through a 100-200 mesh sieve to remove impurities, and obtain a healing agent for root vegetables.

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