Fruit preservative based on Chinese herbal medicines and preparation process thereof

Abstract

The invention relates to the technical field of food preservation, and discloses a fruit preservative based on Chinese herbal medicines and a preparation process thereof, and the preservative is prepared from licorice, netmeg, honeysuckle and polygonatum odoratum according to a specific weight ratio. The preparation method comprises the following steps: mixing the Chinese herbal medicine raw materials, and carrying out pretreatment of low-temperature drying and superfine grinding; carrying out water extraction by adopting a two-section temperature control method of firstly rapidly boiling and then cooling and slowly boiling; and finally, fine filtration is performed through high-mesh filter cloth, and a clear and uniform fresh-keeping agent finished product is obtained. The innovative preparation process, especially low-temperature drying and two-stage decoction, of the fresh-keeping agent retains active ingredients in plants to the greatest extent, and ensures an excellent fresh-keeping effect. The obtained preservative is natural, safe and free of chemical addition, the formula ingeniously coordinates the flavor, the taste of the fruits is not affected, the shelf life of the fruits can be effectively prolonged, browning and microbial spoilage are inhibited, and the preservative has very high market application value.

Description

Technical Field

[0001] The present invention relates to the technical field of food preservation, in particular to a fruit preservative based on Chinese herbal medicine and a preparation process thereof. Background Art

[0002] As fresh produce rich in vitamins, minerals, and dietary fiber, fruits occupy a vital position in the global consumer market. However, during harvesting, storage, transportation, and marketing, fruits are susceptible to oxidative browning, softening, decay, and nutrient loss due to their own respiration, enzymatic reactions, and microbial contamination. This shortens their shelf life and causes significant economic losses. Therefore, effectively extending the shelf life of fruits while maintaining their quality and commercial value has long been a key and challenging research topic in food science and agricultural product processing.

[0003] Currently, fruit preservation technologies primarily rely on chemical preservatives and physical methods. While chemical preservatives such as sulfites and benzoates have some effectiveness, their potential chemical residues and potential risks to human health are increasingly causing consumer concern. Furthermore, with increasing global demands for food safety and clean labels, their use is subject to increasingly stringent restrictions. Physical preservation methods, such as low-temperature refrigeration and controlled atmosphere storage, while safe and pollution-free, often require expensive equipment and high energy consumption. They also cannot completely prevent microbial growth and slow quality deterioration, especially once the product leaves the cold chain and enters the retail stage, where their protective effect is significantly weakened.

[0004] Against this backdrop, the development of natural, safe, and highly effective bio-based preservatives has become a pressing need and a major trend in the industry. Several attempts have been made to utilize plant extracts for fruit preservation, such as tea polyphenols, chitosan, or single plant essential oils. However, the application of these natural preservatives still faces numerous challenges. A significant challenge lies in their limited functionality: many extracts may only excel in one area, such as antioxidant or antibacterial properties, making them difficult to provide comprehensive protection. A more critical bottleneck is that many highly active plant extracts have a strong, unpleasant medicinal or foreign odor. Direct application to fruit can severely mask or destroy the fruit's natural flavor, reducing the product's palatability and market acceptance, presenting an insurmountable obstacle to their commercial application. Furthermore, traditional extraction processes often fail to fully consider the stability and extraction efficiency of the active ingredients, resulting in unstable product results. Furthermore, the resulting liquids often suffer from turbidity and sedimentation, making them difficult to apply using modern methods such as spraying.

[0005] Therefore, there is an urgent need in the art for a new natural fruit preservative and its preparation method that can provide a broad-spectrum preservative effect, be perfectly compatible with the fruit flavor, have a scientific preparation process, and have stable finished product properties. Summary of the Invention

[0006] The present invention aims to provide a natural fruit preservative which has high efficiency, broad spectrum, freshness preservation and good flavor compatibility, and has stable quality and is suitable for application, and a preparation method thereof.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions: A fruit preservative based on Chinese herbal medicine is prepared from the following raw materials in parts by weight: 5-8 parts of liquorice, 2-4 parts of nutmeg, 2-4 parts of honeysuckle, 3-5 parts of polygonatum, and 100-150 parts of purified water.

[0008] In a preferred technical solution, the weight proportions of the raw materials are: 6 parts of licorice; 3 parts of nutmeg; 2 parts of honeysuckle; 4 parts of polygonatum; and 120 parts of purified water.

[0009] The second aspect of the present invention provides a process for preparing the aforementioned Chinese herbal medicine-based fruit preservative.

[0010] This preparation process aims to efficiently and stably extract the active ingredients from Chinese herbal medicines through a standardized process, ensuring the final preservative is clear and uniform, suitable for direct application to fruit surfaces. The invention's innovation lies in its combined process of pretreatment with specific parameters, two-stage decoction, and fine filtration, ensuring maximum dissolution and stable retention of the active ingredients.

[0011] To achieve the above object, the present invention provides a technical solution: a preparation process for a fruit preservative, comprising the following steps: a) pretreating licorice, nutmeg, honeysuckle, and polygonatum to obtain a mixed powder; b) adding the mixed powder obtained in step a to purified water for decocting to obtain a liquid; and c) filtering the liquid obtained in step b to obtain the fruit preservative.

[0012] Furthermore, the pretreatment in step a specifically includes: drying the licorice, nutmeg, honeysuckle, and polygonatum at a temperature of 60 to 70° C. This temperature range is intended to remove excess moisture while maximally retaining the heat-sensitive active ingredients in the raw materials until the moisture content is no more than 8%.

[0013] Preferably, the pretreatment in step a further comprises: pulverizing the dried Chinese herbal medicine raw material so that it passes through an 80-100 mesh sieve. This fine powder increases the contact surface area between the raw material and the solvent, significantly improving the efficiency of component dissolution during the subsequent decoction process.

[0014] Furthermore, the decoction in step b is specifically as follows: after adding the mixed powder to purified water, a two-stage heating method is adopted, first heating to 100°C and maintaining for 5 minutes. This "high heat" stage can quickly break the wall and allow the ingredients to be initially dissolved; then the temperature is lowered to 80-90°C, and decocted for 20-25 minutes at this "low heat" temperature. This stage is conducive to the full leaching of the active ingredients under stable conditions without violent boiling, avoiding their decomposition or failure due to long-term high temperature.

[0015] Furthermore, during the decoction process at 80-90° C., the liquid is stirred at specific time intervals, for example, once every 5 minutes, to prevent the material from sinking to the bottom and coking, and to promote the renewal of the concentration gradient in the system, thereby enhancing the mass transfer effect.

[0016] Furthermore, before performing the filtration operation in step c, the liquid obtained in step b is cooled to 40-50° C. This cooling step is intended to protect the filter material and reduce the effect of high temperature on the stability of certain dissolved components.

[0017] Preferably, the filtration in step c is performed using a 300-mesh filter cloth. This high-mesh filter can effectively remove fine medicinal residue particles, ensuring that the final preservative liquid is clear and transparent, and avoiding adverse effects on the appearance and taste of the fruit during use.

[0018] In a more preferred embodiment, in order to ensure the clarity of the extract, the filtration operation is repeated twice.

[0019] In summary, the present invention includes at least one of the following beneficial technical effects: 1. This invention constructs a multi-target bioprotection system by scientifically combining licorice, nutmeg, honeysuckle, and polygonatum. The components complement each other in their functions, effectively scavenging free radicals and inhibiting polyphenol oxidase activity, thereby effectively preventing oxidative browning of fruits and vegetables. It also broadly inhibits the growth of various molds and bacteria, resolving the technical shortcomings of existing single natural extracts, which suffer from limited functionality and protection, and achieving synergistic antioxidant and anti-corruption effects.

[0020] 2. This invention leverages the natural sweetness and soothing properties of licorice, making it not only a functional component but also a flavor enhancer in the formulation, effectively masking and balancing the subtle off-flavors that may be introduced by other herbs. This design ensures a mild flavor for the preservative, allowing the treated fruit to retain its inherent fragrance and taste to the greatest extent possible. This overcomes the significant problem of some existing natural preservatives, which suffer from a strong "herbal" flavor that detracts from their commercial value.

[0021] 3. By employing low-temperature drying and ultrafine grinding pretreatment, along with a two-stage temperature-controlled decoction process ("hardening first, then softening"), this invention prevents the destruction and degradation of heat-sensitive active substances from the source, significantly improving the dissolution rate of the active ingredients. This non-destructive, gentle extraction process ensures that the resulting preservative contains a higher concentration of naturally active functional components, resulting in a far superior preservation effect compared to products prepared using traditional methods.

[0022] 4. By incorporating a high-mesh fine filtration process at the end of the preparation process, the present invention effectively removes tiny suspended particles and colloidal impurities from the extract, resulting in a clear, translucent, uniform, and stable preservative liquid. This not only significantly improves the product's appearance but, more importantly, avoids instabilities such as sedimentation and stratification during storage, ensuring consistent and reliable product quality.

[0023] 5. The preservative produced by this invention is perfectly compatible with automated spraying and soaking equipment used in modern food processing, preventing nozzle clogging or pipeline contamination. This ensures uniform and efficient fruit processing in large-scale production. This feature overcomes the difficulty of using traditional crude extracts in automated production lines, laying a solid foundation for the industrialization and application of this natural preservative. DETAILED DESCRIPTION

[0024] Example 1 This embodiment provides a method for preparing a fruit preservative based on Chinese herbal medicine.

[0025] 1. Weigh the ingredients: Accurately weigh the following ingredients: 6g licorice, 3g nutmeg, 3g honeysuckle, 4g polygonatum, and 125ml purified water.

[0026] 2. Raw material pretreatment: (1) Mix the weighed licorice, nutmeg, honeysuckle and polygonatum, and rinse with clean water three times to remove impurities.

[0027] (2) Place the cleaned raw materials in an electric blast drying oven and dry them at 65°C until the moisture content is no more than 8%.

[0028] (3) The dried mixed medicinal materials are put into an ultrafine grinder for pulverization, and the mixture is passed through a 90-mesh sieve to obtain a uniform mixed powder.

[0029] 3. Water extraction and decoction: (1) Add all the mixed powder obtained from pretreatment into a stainless steel pot containing 125 ml of purified water and stir evenly.

[0030] (2) Turn on the heating, quickly raise the temperature to 100°C, and maintain boiling for 5 minutes.

[0031] (3) Then, the heating power was lowered to reduce the temperature of the liquid to 85°C and stabilize it. The liquid was boiled at this temperature for 22 minutes. During the boiling period, the liquid was stirred every 5 minutes to prevent the liquid from sticking to the bottom of the pot.

[0032] 4. Filter the liquid: (1) After the decoction is completed, stop heating and let the liquid stand and cool to 45°C.

[0033] (2) Use 300-mesh filter cloth to filter the cooled liquid to remove the drug residue.

[0034] (3) To ensure clarity, the filtrate is filtered again through a clean filter cloth of the same specification to obtain a clear and uniform finished product of the fruit preservative. The product is sealed and refrigerated at 4°C for later use.

[0035] Example 2 This embodiment provides a method for preparing a fruit preservative based on Chinese herbal medicine.

[0036] 1. Weigh the ingredients: Accurately weigh the following ingredients: 5g of licorice, 2g of nutmeg, 2g of honeysuckle, 3g of polygonatum, and 100ml of purified water.

[0037] 2. Raw material pretreatment: (1) Mix the four weighed Chinese herbal medicines and rinse them with clean water three times.

[0038] (2) Dry the cleaned raw materials at 60°C until the moisture content is no more than 8%.

[0039] (3) The dried mixed medicinal materials are crushed and passed through an 80-mesh sieve to obtain a mixed powder.

[0040] 3. Water extraction and decoction: (1) Add the obtained mixed powder into 100 ml of purified water and stir evenly.

[0041] (2) Heat to 100°C and keep boiling for 5 minutes.

[0042] (3) Then lower the temperature to 80°C and continue to cook at this temperature for 20 minutes, stirring every 5 minutes.

[0043] 4. Filter the liquid: (1) After decoction is completed, cool the liquid to 40℃.

[0044] (2) Filter the liquid with a 300-mesh filter cloth, repeat the filtration operation twice, and obtain the finished fruit preservative, which is then sealed and refrigerated.

[0045] Example 3 This embodiment provides a method for preparing a fruit preservative based on Chinese herbal medicine.

[0046] 1. Weigh the ingredients: Accurately weigh the following ingredients: 8g of licorice, 4g of nutmeg, 4g of honeysuckle, 5g of polygonatum, and 150ml of purified water.

[0047] 2. Raw material pretreatment: (1) Mix the four weighed Chinese herbal medicines and rinse them with clean water three times.

[0048] (2) Dry the cleaned raw materials at 70°C until the moisture content is no more than 8%.

[0049] (3) The dried mixed medicinal materials are crushed and passed through a 100-mesh sieve to obtain a mixed powder.

[0050] 3. Water extraction and decoction: (1) Add the obtained mixed powder into 150 ml of purified water and stir evenly.

[0051] (2) Heat to 100°C and keep boiling for 5 minutes.

[0052] (3) Then lower the temperature to 90°C and continue decocting at this temperature for 25 minutes, stirring every 5 minutes.

[0053] 4. Filter the liquid: (1) After decoction is completed, cool the liquid to 50℃.

[0054] (2) Filter the liquid with a 300-mesh filter cloth, repeat the filtration operation twice, and obtain the finished fruit preservative, which is then sealed and refrigerated.

[0055] Comparative Example 1: Compared with Example 1, the difference is that licorice is not added, and the amounts of other raw materials and preparation steps are the same.

[0056] Comparative Example 2: Compared with Example 1, the difference is that only 6g of licorice is used as the Chinese herbal medicine raw material, and nutmeg, honeysuckle and polygonatum are not added. The other preparation steps are the same.

[0057] Comparative Example 3: Compared with Example 1, the difference is that the amount of nutmeg is increased to 10g, which exceeds the upper limit range stated in the claims, and the amounts of other raw materials and preparation steps are the same.

[0058] Comparative Example 4: Compared with Example 1, the difference is that the drying step in the raw material pretreatment does not adopt 65°C drying, but adopts the traditional high temperature (150°C) baking method to treat the raw materials, and the other steps are the same.

[0059] Comparative Example 5: Compared with Example 1, the difference is that the pulverization step in the raw material pretreatment does not use an ultrafine grinder to pulverize to 90 mesh, but the dried raw material is simply cut into tablets of about 2 to 3 mm. The other steps are the same.

[0060] Comparative Example 6: Compared with Example 1, the difference is that the water extraction and decoction step does not adopt the two-stage temperature control method, but the material liquid is continuously boiled at 100°C for 30 minutes, and the other steps are the same.

[0061] Comparative Example 7: Compared with Example 1, the difference is that, in the filtration step, a 300-mesh filter cloth is not used for secondary filtration, but ordinary medical gauze (about 60 mesh) is used for single filtration, and the other steps are the same.

[0062] Test Example 1: Formula synergy verification experiment Experimental Description 1. Experimental Materials and Grouping (1) Experimental subjects: the preservative prepared in Example 1 (experimental group), the preservative prepared in Comparative Example 1 (control group), and sterile purified water (blank control group).

[0063] (2) Fruit: Select "Red Fuji" apples from the same batch, uniform in size, and without mechanical damage. (3) Instruments and equipment: Fruit knife, cutting board, beaker, strainer, timer, white porcelain plate.

[0064] 2. Experimental Procedure (1) Apple pretreatment: Wash the apples with clean water and wipe off the surface moisture. Use a clean fruit knife to cut the apples vertically along the core into uniform slices with a thickness of 1.0 cm.

[0065] (2) Grouping: Randomly divide the sliced ​​apples into three groups, with 20 slices in each group. Immediately immerse the three groups of apple slices completely in a beaker containing the experimental group preservative, the control group preservative, and purified water for the blank control group.

[0066] (3) Soaking and draining: Ensure that all apple slices are completely covered with liquid and soak for 15 minutes. After soaking, remove each group of apple slices with a strainer and place them on the strainer to drain naturally for 5 minutes.

[0067] (4) Display observation: Spread the drained apple slices in groups on a clean white porcelain plate, keeping a certain distance between groups to prevent cross-contamination. Place the porcelain plate in a clean environment at room temperature (25°C) and a relative humidity of 60%, and expose it to the air for observation.

[0068] (5) Data recording: The cross-sectional conditions of each group of apple slices were recorded at three time points: 0 hour, 1 hour, and 3 hours after treatment. The degree of browning was graded (0: no browning; 1: slight browning; 2: obvious browning; 3: severe browning; 4: extremely severe browning, with >75% of the surface area discolored). At the same time, after 3 hours, 10 sensory assessors evaluated the flavor of the treated apple slices, assessing the intensity of the off-flavor (1-5 points, the higher the score, the stronger the off-flavor) and the harmony of the flavor (1-5 points, the higher the score, the better the harmony), and recorded the average score.

[0069] Experimental data Table 1: Comparative data of browning degree and sensory evaluation of apple slices under different treatment methods

[0070] Experimental results analysis The experimental data in Table 1 demonstrates that apple slices treated with the preservative prepared in Example 1 of this technical solution exhibit significant oxidative browning inhibition and excellent flavor harmony. After 3 hours of storage, the browning rating of the experimental group was only 1.4, significantly lower than the 3.9 rating of the blank control group and the 3.2 rating of the control group. In terms of sensory evaluation, the experimental group achieved a flavor harmony rating of 4.5 and exhibited virtually no off-flavor. In contrast, the control group, lacking licorice, not only exhibited poor browning control but also a flavor harmony rating of only 2.1, accompanied by a high off-flavor intensity.

[0071] These results fully demonstrate the key role of licorice in the entire compound system and its irreplaceable synergistic effect. Mechanistically, the glycyrrhizic acid and flavonoids contained in licorice, as powerful natural antioxidants, can form a multi-target antioxidant network with the active ingredients in honeysuckle and polygonatum, jointly scavenging free radicals and effectively inhibiting the activity of polyphenol oxidase, thereby significantly delaying the oxidative browning process of apple slices. The control group, lacking this core antioxidant component of licorice, compromised the integrity and strength of its antioxidant system, resulting in a significant decrease in freshness preservation.

[0072] More importantly, this experiment highlights the innovative design of this solution in flavor synergy. Licorice's natural sweetness and unique mellow taste play a crucial role in flavor harmonization. It effectively masks and balances the subtle medicinal flavors that may be introduced by other herbs such as nutmeg and honeysuckle, allowing the flavor of the entire preservative to blend seamlessly with the fruit itself, ultimately enhancing the product's sensory acceptance. The lack of licorice's "harmony" in the control group resulted in the herbal aromas of the other ingredients becoming more prominent, creating an unpleasant odor. This demonstrates that this specific combination of ingredients achieves a delicate balance between achieving freshness preservation and maintaining excellent flavor.

[0073] Test Example 2: Formula Integrity Verification Experiment Experimental Description 1. Experimental Materials and Grouping (1) Experimental subjects: the preservative prepared in Example 1 (experimental group), the preservative prepared in Comparative Example 2 (containing only licorice) (control group), and sterile purified water (blank control group).

[0074] (2) Fruit: Select fresh strawberries from the same batch, with similar size, maturity and no damage.

[0075] (3) Instruments and equipment: beaker, filter, clean culture dish, timer.

[0076] 2. Experimental Procedure (1) Strawberry pretreatment: Rinse the strawberries with slow-flowing clean water and gently absorb the surface moisture with absorbent paper.

[0077] (2) Grouping treatment: Randomly divide the strawberries into 3 groups, 30 in each group. Immediately immerse the three groups of strawberries completely in beakers containing the experimental group preservative, the control group preservative, and the blank control group purified water.

[0078] (3) Soaking and draining: Make sure all strawberries are completely covered with liquid and soak for 5 minutes. After soaking, remove each group of strawberries with a strainer and place them on the strainer to drain naturally for 10 minutes.

[0079] (4) Display culture: Place the drained strawberries in a single layer in a clean culture dish, with 10 strawberries per dish. Leave the culture dish uncovered and place it in an environment with room temperature (25°C) and a relative humidity of 70% for culture to simulate the microbial infection process during the shelf life.

[0080] (5) Data recording: Starting from 24 hours after treatment, observe and record the number of strawberries with visible mold spots (usually gray mold or penicillium) in each group every 12 hours, and calculate the good fruit rate (good fruit rate = (total number - number of fruits with mold spots or severe rot) / total number × 100%). Record the time when the mold spots were first observed.

[0081] Experimental data Table 2: Comparative data of strawberry preservation effects under different treatment methods

[0082] Experimental results analysis The experimental data in Table 2 clearly demonstrates that the preservative prepared using the complete formula of this technical solution (Example 1) significantly outperformed both the control group and the blank control group, which contained only a single component, in preserving strawberries. After 72 hours, the experimental group still maintained a high 80% good fruit rate, while the control group's good fruit rate had dropped to 37%, and the blank control group was almost completely spoiled. Crucially, the experimental group significantly delayed the appearance of mold to approximately 65 hours, while the control group developed mold spots after approximately 40 hours, demonstrating the comprehensive formula's robust microbial inhibition capabilities.

[0083] The experimental results strongly reveal the synergistic mechanism of the multi-component combination of this regimen. Since the control group contained only licorice, its effects were primarily reflected in certain antioxidant and tissue aging delays. However, its inhibitory ability against the ubiquitous mold spores in the air was very limited, and it was unable to establish an effective microbial defense line. The complete formula of this regimen, through scientific combination, forms a functionally complementary complex system. Among them, volatile oil components such as myristicin contained in nutmeg, and chlorogenic acid in honeysuckle, all have recognized broad-spectrum antibacterial and antifungal activity. Together, they form a natural "antibacterial protective film" on the surface of the fruit.

[0084] Therefore, this experiment fully demonstrates that the innovative nature of this technical solution lies in the comprehensiveness and synergy of its formulation. Rather than relying on the specific function of a single ingredient, it achieves dual protection through "internal antioxidant" to slow the fruit's decay and "external antibacterial" to resist external microbial infection through the ingenious combination of licorice, nutmeg, honeysuckle, and polygonatum. This multi-target, synergistic design is the core of achieving efficient and long-lasting freshness preservation, and is what distinguishes this solution from simple single-ingredient or conventional compound technologies.

[0085] Test Example 3: Scientific Verification Experiment of Formula Ratio Experimental Description 1. Experimental Materials and Grouping (1) Experimental subjects: the preservative prepared in Example 1 (experimental group) and the preservative prepared in Comparative Example 3 (excessive nutmeg content) (comparative group).

[0086] (2) Fruit: Select “Crown” pears from the same batch with moderate firmness and pure flavor.

[0087] (3) Sensory evaluation team: consists of 10 professionally trained sensory assessors.

[0088] 2. Experimental Procedure (1) Sample preparation: Wash the pears with clean water, peel and core them, and cut them into pieces of roughly uniform size and thickness. Randomly divide them into two groups, with 30 pieces in each group.

[0089] (2) Group treatment: The two groups of pear pieces were completely immersed in beakers containing the experimental group preservative and the control group preservative respectively.

[0090] (3) Soaking and draining: Ensure that all pear pieces are completely covered with liquid and soak for 10 minutes. After soaking, remove each group of pear pieces with a strainer and place them on the strainer to drain naturally for 5 minutes.

[0091] (4) Sensory evaluation: The two groups of processed pear pieces were placed on coded white plates and submitted to the sensory evaluation panel for blind evaluation. The assessors were required to rinse their mouths before and after tasting and score the following indicators: Medicinal flavor intensity: scored on a scale of 1 to 9, with 1 being no medicinal flavor and 9 being a very strong medicinal flavor. Flavor harmony: scored on a scale of 1 to 9, with 1 being a very unharmonious flavor and 9 being a very harmonious flavor that blends naturally with the pear's flavor. Overall acceptance: scored on a scale of 1 to 9, with 1 being a very unacceptable flavor and 9 being a very favorable flavor.

[0092] (5) Data processing: Collect the score sheets of all assessors, eliminate invalid data, and calculate the average score of each indicator.

[0093] Experimental data Table 3: Comparative data of sensory evaluation of pear pieces after treatment with different ratios of preservatives

[0094] Experimental results analysis The sensory evaluation data in Table 3 demonstrate that preservatives prepared using different ratios have a decisive influence on the final flavor of the fruit. The pear pieces treated in the experimental group (Example 1) received an extremely low herbal flavor intensity score of only 1.8, indicating a barely perceptible herbal aroma. Meanwhile, flavor harmony and overall acceptability scores reached high scores of 8.4 and 8.1, respectively, demonstrating that the treatment not only did not detract from the original flavor of the fruit but was highly praised by the panel. In contrast, the control group (Comparative Example 3), due to the excessive use of nutmeg, received a herbal flavor intensity score of 8.2, indicating a strong and pungent medicinal flavor. This resulted in extremely low flavor harmony and overall acceptability scores of 2.3 and 1.9, respectively, making it virtually unacceptable.

[0095] This experiment profoundly reveals the scientific and innovative nature of this technical solution's component ratios. As a substance that comes into direct contact with food, the flavor profile of a fruit preservative is a key factor in determining its application value. The success of this solution lies in the fact that, through extensive experimental screening, the "golden ratio" between the various herbal components, particularly the highly aromatic nutmeg, has been determined, allowing it to exert its antibacterial effects without interfering with the main flavor of the fruit. Within this range, the mild aroma of nutmeg strikes a delicate balance with the sweetness of licorice and the smoothness of polygonatum, creating a harmonious, almost unnoticeable background flavor.

[0096] When nutmeg is used significantly beyond this specific range, as shown in the control group, the concentrations of volatile compounds such as myristicin and camphorene increase dramatically. This strong, penetrating medicinal aroma overwhelms the sweetness of the fruit and disrupts the flavor balance established by licorice, resulting in an unpleasant "medicinal" taste. Therefore, this experiment fully demonstrates that the composition of this solution is not a simple stacking of ingredients, but rather a balanced system with precisely calculated and synergistically optimized amounts of each component. This precise control of the ratio is the key to achieving both efficient freshness preservation and excellent sensory quality.

[0097] Test Example 4: Innovative Verification Experiment of Pretreatment Process (Drying Method) Experimental Description 1. Experimental Materials and Grouping (1) Experimental subjects: the preservative prepared in Example 1 (using low-temperature dried raw materials) (experimental group), the preservative prepared in Comparative Example 4 (using high-temperature baked raw materials) (control group), and sterile purified water (blank control group).

[0098] (2) Fruit: Select “Fuji” apples from the same batch, uniform in size, and bright in color.

[0099] (3) Instruments and equipment: fruit knife, chopping board, beaker, filter, high-precision electronic balance (0.01g), timer, white porcelain plate.

[0100] 2. Experimental Procedure (1) Apple pretreatment: Wash the apples with clean water and wipe off the surface moisture. Use a clean fruit knife to cut the apples vertically along the core into uniform slices with a thickness of 1.0 cm.

[0101] (2) Initial weighing: Immediately divide the sliced ​​apples into three groups, with 20 slices in each group. Use an electronic balance to accurately weigh the initial weight (m0) of each apple slice and keep a record.

[0102] (3) Group treatment: The three groups of apple slices were completely immersed in beakers containing the experimental group preservative, the control group preservative, and the blank control group purified water for 15 minutes.

[0103] (4) Display observation: Take out each group of apple slices, place them on a strainer to drain for 5 minutes, and then spread them flat on a clean white porcelain plate. Place the porcelain plate in a clean environment at room temperature (25°C) and a relative humidity of 60% and expose it to the air naturally.

[0104] (5) Data recording: At 3 and 6 hours after treatment, the browning degree of the cut surface of each group of apple slices was graded (0: no browning; 1: slight browning; 2: obvious browning; 3: severe browning; 4: very severe browning). After 6 hours, the final weight (m1) of each apple slice was weighed again, and the weight loss rate was calculated. Weight loss rate (%) = ((m0-m1) / m0) × 100%.

[0105] Experimental data Table 4: Comparative data of the preservation effect of preservatives prepared by different drying processes on apple slices

[0106] Experimental results analysis The experimental data in Table 4 clearly demonstrates that the preservatives prepared using different drying processes exhibit significant differences in their final preservation effectiveness. The experimental group (Example 1) achieved a browning grade of only 1.5 after 6 hours, with a weight loss rate of 4.8%. Its overall preservation performance significantly outperformed both the control group (browning grade 3.6, weight loss 9.7%) and the blank control group. This directly demonstrates that the specific low-temperature drying process employed in this protocol is a key prerequisite for achieving a highly effective preservative.

[0107] The results of this experiment profoundly reveal the decisive influence of the raw material pretreatment process, especially the control of drying temperature, on the activity of the final product. The low-temperature drying process of 60-70°C adopted in this scheme removes moisture under mild conditions, thereby retaining the key active ingredients in Chinese herbal medicines that are unstable to heat, such as flavonoids, polyphenol antioxidants and some volatile oils to the greatest extent. These substances are the core basis for the antioxidant and antibacterial functions of preservatives. In contrast, the high-temperature baking of 150°C used in the control group will inevitably lead to thermal decomposition, oxidation or excessive volatilization of these valuable heat-sensitive substances, resulting in a large loss of their biological activity, and the natural effectiveness of the preservatives produced will be greatly reduced.

[0108] Therefore, the difference in preservation effectiveness is essentially a difference in the retention rate of active ingredients. This innovative design at the source of the preparation process—the refined control of drying parameters—ensures that the subsequent extract contains higher concentrations of effective antioxidant and antibacterial components, thereby forming a more complete and powerful biological protective layer on the fruit surface. This protective layer not only strongly inhibits the enzymatic reactions that cause browning, but also effectively maintains the structural integrity of the fruit's surface cells, thereby slowing water evaporation and allowing the fruit to maintain its fresh appearance and plump state for a longer period of time.

[0109] Test Example 5: Innovative Verification Experiment of Pretreatment Process (Crushing Method) Experimental Description 1. Experimental Materials and Grouping (1) Experimental subjects: the preservative prepared in Example 1 (using ultrafine grinding raw materials) (experimental group), the preservative prepared in Comparative Example 5 (using coarse grinding raw materials) (control group), and sterile purified water (blank control group).

[0110] (2) Fruit: Select bananas from the same batch with basically the same maturity (pure yellow color, no black spots).

[0111] (3) Instruments and equipment: fruit knife, chopping board, beaker, filter, portable colorimeter, timer, white porcelain plate.

[0112] 2. Experimental Procedure (1) Banana pretreatment: Peel the banana and cut it into uniform round slices with a thickness of 1.5 cm using a clean fruit knife.

[0113] (2) Grouping: Randomly divide the sliced ​​bananas into three groups, with 20 slices in each group. Immediately immerse the three groups of banana slices completely in a beaker containing the experimental group preservative, the control group preservative, and the blank control group purified water for 5 minutes.

[0114] (3) Display observation: Take out each group of banana slices, place them on a strainer to drain for 5 minutes, and then spread them flat on a clean white porcelain plate. Place the porcelain plate in a clean environment at room temperature (25°C) and relative humidity of 60% for observation.

[0115] (4) Data recording: Using a portable colorimeter, measure the L value (brightness value; higher L value indicates lighter color and lower browning degree) of the center point of the cross section of each group of banana slices at 0 hours, 2 hours, and 4 hours after treatment. Randomly measure 10 slices per group and calculate the average value. At the same time, manually grade the degree of browning after 4 hours (0 points: no browning; 1 point: slight browning; 2 points: obvious browning; 3 points: severe browning; 4 points: very severe browning).

[0116] Experimental data Table 5: Comparative data of the effects of preservatives prepared by different crushing processes on the preservation of banana slices

[0117] Experimental results analysis The comparative data in Table 5 clearly demonstrates that the fineness of the raw material grinding has a decisive influence on the effectiveness of the resulting preservative. Banana slices treated with the experimental group (using ultrafinely ground raw materials) maintained a high L value of 65.1 after 4 hours, with a browning rating of only 1.2, demonstrating excellent resistance to browning. In contrast, the L value of the control group (using coarsely ground raw materials) dropped to 55.2, with a browning rating of 2.9. While this performance was superior to the blank control group, it still lagged significantly behind the experimental group. This demonstrates that the ultrafine grinding pretreatment process employed in this solution is a crucial technical guarantee for achieving highly effective fresh-keeping results.

[0118] The mechanism behind this experimental result is that the degree of raw material pulverization directly determines the dissolution efficiency of the active ingredients during the subsequent water extraction and decoction process. The 80-100 mesh ultrafine grinding process adopted in this solution physically disrupts the cell structure of the Chinese herbal raw materials to a significant degree, exponentially increasing their specific surface area. This greatly increases the contact area and mass transfer efficiency between the medicinal materials and the solvent (water), allowing the glycyrrhizic acid, flavonoids, chlorogenic acid, and polysaccharides contained in licorice, nutmeg, honeysuckle, and polygonatum to dissolve more quickly and fully into the extract during the subsequent decoction step, thereby producing a high concentration of active preservatives.

[0119] In contrast, the simple slicing process used in the control group only destroyed the surface cells, leaving most of the active ingredients still encapsulated within the intact cell walls. Dissolution was slow and incomplete, resulting in a low concentration of active substances in the final preservative, and its protective effect was naturally greatly reduced. Therefore, this experiment strongly demonstrated that ultrafine grinding is not a routine or dispensable step, but rather a key innovation in this preparation process. It is through the meticulous control of this physical parameter that the maximum utilization of the active ingredients is ensured, thereby giving the final product excellent antioxidant and preservation properties.

[0120] Test Example 6: Decoction Process Innovation Verification Experiment Experimental Description 1. Experimental Materials and Grouping (1) Experimental subjects: the preservative prepared in Example 1 (using two-stage temperature-controlled decoction) (experimental group), the preservative prepared in Comparative Example 6 (using continuous boiling decoction) (control group), and sterile purified water (blank control group).

[0121] (2) Fruit: Select “Holland No. 15” potatoes from the same batch that are uniform in size, firm in texture, and free of sprouts.

[0122] (3) Instruments and equipment: peeler, strip cutter, beaker, filter, high-precision electronic balance (0.01g), timer, tray.

[0123] 2. Experimental Procedure (1) Potato pretreatment: Wash and peel the potatoes, and use a strip cutter to cut them into uniform strips with a length of about 5 cm and a cross-section of 1 cm × 1 cm.

[0124] (2) Initial weighing and grouping: Randomly divide the cut potato strips into 3 groups, with 30 strips in each group. Use an electronic balance to accurately weigh the initial weight (m0) of each potato strip and keep a record.

[0125] (3) Group treatment: The three groups of potato strips were completely immersed in beakers containing the experimental group preservative, the control group preservative, and the blank control group purified water for 10 minutes.

[0126] (4) Display observation: Take out each group of potato strips, place them on a strainer to drain for 5 minutes, and then spread them on a tray in a single layer. Place the tray in a clean environment at room temperature (25°C) and a relative humidity of 60% and expose them to the air naturally.

[0127] (5) Data recording: At 4 and 8 hours after treatment, the browning degree of each group of potato strips was graded (0: no browning; 1: slight browning; 2: obvious browning; 3: severe browning; 4: very severe browning). After 8 hours, the final weight of each potato strip (m1) was weighed again, and the weight loss rate (%) was calculated as ((m0-m1) / m0)×100%). At the same time, the texture was observed and recorded.

[0128] Experimental data Table 6: Comparative data of the preservation effect of preservatives prepared by different cooking processes on potato strips

[0129] Experimental results analysis The data in Table 6 clearly demonstrate that subtle differences in the cooking process lead to significant differences in the final preservation effect. The preservative prepared using the two-stage temperature-controlled cooking method (experimental group) demonstrated excellent performance in both inhibiting browning and maintaining texture. After 8 hours, its browning rating was only 1.6, and its weight loss rate was controlled at 6.1%, while the potato strips maintained a good firmness. In contrast, the preservative prepared using the traditional continuous boiling method (control group) achieved a browning rating of 3.4 and a weight loss rate of 13.5%, resulting in a noticeably softened texture and far inferior preservation performance to the experimental group.

[0130] The essence of this experimental result stems from the different protective effects of different decoction processes on heat-sensitive active ingredients in traditional Chinese medicines. This innovative two-stage temperature-controlled decoction method, "hard boiling first, soft boiling later," has a mechanism: a short period of intense boiling in the first stage aims to rapidly destroy plant cell walls using high temperature and high energy to achieve initial dissolution of the active ingredients; the key lies in the second stage, where the temperature is lowered to a stable, non-boiling high-temperature range for "slow cooking." The core purpose of this is to ensure mass transfer while avoiding damage to the dissolved active substances caused by prolonged intense high temperatures. These active substances, especially flavonoids and some polyphenols, are highly sensitive to temperature, and prolonged boiling can cause them to thermally degrade or oxidatively lose their effectiveness.

[0131] Therefore, although the continuous boiling method used in the control group seems to be able to continuously extract, it actually comes at the expense of a large number of active ingredients, resulting in a low concentration and activity of effective substances in the final extract, and the protection ability is naturally insufficient. The two-stage temperature-controlled decoction process proposed in this plan is a key process innovation. It achieves the unity of "efficient extraction" and "active protection" through precise control of the temperature curve. It is this non-destructive and gentle extraction method that ensures that the final preservative contains a higher concentration of functional components that maintain natural activity, thereby being able to more effectively inhibit enzyme activity and maintain cell integrity, ultimately manifesting as excellent anti-browning and water-retention and shape-preserving effects on a macro scale.

[0132] Test Example 7: Filtration Process Innovation Verification Experiment Experimental Description 1. Experimental Materials and Grouping (1) Experimental subjects: the preservative prepared in Example 1 (secondary filtration using 300-mesh filter cloth) (experimental group), and the preservative prepared in Comparative Example 7 (single filtration using ordinary gauze) (comparative group).

[0133] (2) Instruments and equipment: clean transparent glass beaker, laboratory turbidity meter, standard spray bottle (50ml capacity, 0.3mm nozzle), black background board, timer.

[0134] 2. Experimental Procedure (1) Observation of appearance and clarity: Take 100 ml of the preservative liquid from the experimental group and the control group respectively and pour it into a clean transparent glass beaker. Place it in front of a black background board and observe and record the clarity, color uniformity and presence of visible suspended matter with the naked eye under sufficient natural light.

[0135] (2) Stability test: Cover the beaker containing the two liquids and let it stand at room temperature for 24 hours. After 24 hours, observe the liquid state again, and pay attention to whether there is any sediment at the bottom of the beaker and its characteristics.

[0136] (3) Turbidity determination: Use a calibrated laboratory turbidity meter to take liquid samples from the experimental group and the control group respectively, and measure their turbidity values ​​(unit: NTU). Repeat the measurement three times for each group and record the average value.

[0137] (4) Spray application test: The preservatives for the experimental and control groups were placed in two new standard spray bottles with identical specifications. The spray nozzles were pressed continuously to spray, and the smoothness of the spray and the uniformity of the atomization were observed and recorded. The total number of times the spray could be sprayed normally before the nozzle became significantly blocked was also counted.

[0138] Experimental data Table 7: Comparison of physical properties and application performance of preservatives prepared by different filtration processes

[0139] Experimental results analysis The experimental data in Table 7 intuitively demonstrates the decisive influence of the filtration process on the quality of the finished preservative. The preservative prepared using this solution's specific filtration process (experimental group) exhibited unparalleled advantages in appearance, stability, and applicability. The liquid was clear and transparent, exhibited excellent stability, and exhibited extremely low turbidity, making it ideal for spray applications. In contrast, the product produced using conventional coarse filtration (control group) exhibited a range of quality defects, including turbidity, easy sedimentation, and difficulty in spraying. This demonstrates the necessity and innovative nature of this solution's terminal purification process.

[0140] The mechanism behind this result is that, during the water extraction and decoction process of Chinese herbal medicines, in addition to the dissolution of active ingredients, a large number of water-insoluble fine particles, such as plant fiber debris, denatured proteins, and some colloidal macromolecules, are also produced. The ordinary gauze used in the control group had a pore size that was too large, and could only filter out the coarse medicinal residue visible to the naked eye, but was completely incapable of removing the micron- and submicron-sized suspended particles that cause liquid turbidity and instability. The presence of these particles is the root cause of poor product appearance, sedimentation after standing, and clogging of precision spray devices.

[0141] The terminal filtration process proposed in this proposal, particularly the use of 300-mesh high-precision filter cloth for secondary filtration, is a key quality control innovation. This fine filtration can effectively intercept all of the aforementioned fine insoluble impurities, thereby obtaining a liquid product with pure, uniform, and stable physical properties. This not only greatly enhances the product's commercial value and consumer sensory acceptance, but more importantly, it ensures the product's industrial applicability. The smooth, non-clogging spray capability means that this preservative can be successfully applied to automated spray production lines in modern agriculture and food processing, ensuring uniform and efficient coverage of fruits, thereby exerting its due preservation effect. This is an important prerequisite for its practical application and marketization.

[0142] 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 preservative based on Chinese herbal medicine, characterized in that: Made from the following raw materials in parts by weight: Licorice: 5-8 parts; Nutmeg: 2-4 parts; Honeysuckle: 2-4 parts; Polygonatum odoratum: 3-5 parts; Purified water: 100-150 parts.

2. The preservative according to claim 1, characterized in that The preservative is a water extract prepared by extracting and boiling the liquorice, nutmeg, honeysuckle and polygonatum through a water extraction and boiling process.

3. The preparation process of a fruit preservative based on Chinese herbal medicine according to any one of claims 1 to 2, characterized in that: The following steps are involved: a. The licorice, nutmeg, honeysuckle, and polygonatum were pretreated to obtain a mixed powder; b. The mixed powder obtained in step a was added to purified water and boiled to obtain a liquid; c. Filter the liquid obtained in step b to obtain the fruit preservative.

4. The preparation process according to claim 3, characterized in that The pretreatment in step a specifically includes: drying the liquorice, nutmeg, honeysuckle, and polygonatum at a temperature of 60-70° C. until the moisture content is no more than 8%.

5. The preparation process according to claim 4, characterized in that: The water extraction and decoction in step b specifically includes: the pretreatment in step a further comprising: crushing the dried Chinese herbal medicine raw material to pass through a sieve of 80 to 100 meshes.

6. The preparation process according to claim 3, characterized in that: The decoction in step b specifically includes: adding the mixed powder to purified water, first heating it to 100° C. and maintaining it for 5 minutes; then lowering the temperature to 80-90° C. and continuing to decoct at this temperature for 20-25 minutes.

7. The preparation process according to claim 6, characterized in that: During the decocting process at 80-90° C., the liquid was stirred every 5 minutes.

8. The preparation process according to claim 3, characterized in that: The filtration in step c specifically includes: before filtration, cooling the liquid obtained in step b to 40-50°C.

9. The preparation process according to claim 8, characterized in that: The filtration was performed using a 300-mesh filter cloth.

10. The preparation process according to claim 9, characterized in that: The filtration step was repeated twice.

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