Method for inhibiting browning of apple juice by combining ultrahigh pressure with medicinal and edible substances

Abstract

The invention discloses a method for inhibiting browning of apple juice through combination of ultrahigh pressure and medicinal and edible substances, and belongs to the technical field of fruit processing. In order to solve the problems of color deterioration, nutrition loss and flavor loss caused by enzymatic browning in the processing and storage processes of non-concentrated and reduced apple juice, the technical scheme is characterized in that fresh apples, gastrodia elata and phyllanthus emblica are respectively prepared into juice, gastrodia elata juice and phyllanthus emblica juice are added into the apple juice according to a ratio, and the juice is added into the apple juice according to a ratio. The raw materials are stirred, mixed, packaged and packaged, then subjected to ultrahigh pressure treatment with specific parameters at a constant temperature, and finally subjected to low-temperature storage. The preparation method can effectively inhibit the activity of polyphenol oxidase and peroxidase, delay the browning process and remarkably improve the oxidation resistance of fruit juice, and is mainly used for quality maintenance and browning inhibition of natural and additive-free apple juice and other fruit and vegetable juice.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fruit processing. More particularly, the present application relates to a method for inhibiting browning of apple juice by using ultra-high pressure combined with medicinal and edible materials. BACKGROUND

[0002] Non-concentrated reduced apple juice is prone to browning during processing and storage, which is a long-standing technical problem. Browning not only leads to darkening of the juice color and deterioration of sensory quality, but also causes changes in flavor substances and loss of some nutrients. This phenomenon is mainly caused by endogenous enzymes in the juice, especially the catalytic action of polyphenol oxidase and peroxidase. When the fruit and vegetable tissues are damaged during processing, these enzymes come into contact with the substrate phenolic substances and catalyze the oxidation reaction under aerobic conditions, generating quinone intermediates and further polymerizing to form dark pigments.

[0003] In order to control browning, traditional heat processing techniques such as pasteurization are often used. By heating, the enzymes can be inactivated, thereby delaying browning. However, heat treatment itself can adversely affect the quality of the juice. Heat-sensitive components in the juice, such as vitamin C, some volatile substances with fresh flavor, and certain functional phenolic compounds, are easily degraded or transformed when heated, resulting in loss of nutritional value and natural flavor of the juice. Therefore, while solving the problem of browning, heat treatment often introduces new quality deterioration problems.

[0004] There are also studies that attempt to add chemically synthesized browning inhibitors, such as certain chelating agents or reducing substances, to the juice. Although this method can control color changes to some extent, with the increasing demand for food label cleanliness, i.e., simple, natural, and no artificial additives, the use of chemical additives faces challenges in market acceptance. Developing non-chemical additive browning control methods has become a clear demand in the industry.

[0005] As a non-thermal processing method, high pressure processing (HPP) has been applied to inactivate enzymes and sterilize food. By applying high pressure (hundreds of MPa) to the sealed food at room temperature or lower, HPP can destroy the cell structure of microorganisms and cause the change of enzyme protein conformation, thus achieving preservation. Compared with heat treatment, HPP has less impact on small molecules in food, such as vitamins, pigments and flavor compounds, and can better maintain the "original" state of food. However, in practical application, it is found that single HPP has limited effect on completely and durably inhibiting polyphenol oxidase (PPO) and peroxidase (POD) in juice, especially in apple juice with high enzyme activity. Some enzymes may only be reversibly inactivated under high pressure, or the activity recovers during storage, resulting in the occurrence of browning in the subsequent stage. How to strengthen the inhibitory effect of HPP on enzymatic browning without introducing heat processing or chemical additives, and make the effect stable during the entire shelf life of the product, is a technical difficulty.

[0006] In addition, exploring the use of natural substances to assist in inhibiting browning is also a research direction. Some natural plant extracts are studied for use in food color stability due to their antioxidant active ingredients such as phenols and flavonoids. However, there are many difficulties in finding suitable natural sources, ensuring the effectiveness of the inhibitory effect, compatibility with juice systems, not producing adverse flavor effects, and meeting the requirements of food regulations. Many natural extract ingredients are complex, and the stability of their active ingredients, the effective dose, and the impact on the overall sensory properties of the juice all need to be carefully evaluated. Combining such natural substances with non-thermal processing techniques to produce a synergistic effect in order to achieve stable control of browning under mild processing conditions is a specific challenge currently faced. SUMMARY

[0007] An object of the present application is to solve at least the above problems and to provide at least the advantages to be explained later.

[0008] Another object of the present application is to provide a method for inhibiting browning of apple juice by combining high pressure with a natural medicinal substance, solving the technical problem of insufficient inhibition of polyphenol oxidase and peroxidase in apple juice by single high pressure treatment, leading to recovery of enzyme activity and continuous development of browning during storage.

[0009] To achieve these objects and other advantages of the present application, a method for inhibiting browning of apple juice by combining high pressure with a natural medicinal substance is provided, which comprises the following steps: Step 1: Fresh apples, Gastrodia tuber and Phyllanthus emblica are washed, peeled and cored, and prepared into apple juice, Gastrodia tuber juice and Phyllanthus emblica juice, respectively; Step 2: Gastrodia tuber juice and Phyllanthus emblica juice are added to the apple juice and stirred thoroughly; Step three, the mixed juice is packaged in a polyethylene bottle; Step four, the packaged juice is treated by ultra-high pressure under the condition of 20℃; Step five, the treated juice is stored under the condition of 4℃.

[0010] Preferably, in the method for inhibiting the browning of apple juice by ultra-high pressure combined with medicinal and edible materials, the added amount of Gastrodia juice is 0.5% of the volume of apple juice.

[0011] Preferably, in the method for inhibiting the browning of apple juice by ultra-high pressure combined with medicinal and edible materials, the added amount of Phyllanthus emblica juice is 2.5-10% of the volume of apple juice.

[0012] Preferably, in the method for inhibiting the browning of apple juice by ultra-high pressure combined with medicinal and edible materials, the Phyllanthus emblica is Phyllanthus emblica L.

[0013] Preferably, in the method for inhibiting the browning of apple juice by ultra-high pressure combined with medicinal and edible materials, the preparation process of Phyllanthus emblica juice is as follows: a) Under the environment of filling with food-grade nitrogen, the pitted Phyllanthus emblica is low-temperature pressed at 4-10℃ and 800-1200 rpm to obtain primary Phyllanthus emblica juice and Phyllanthus emblica residue; b) The primary Phyllanthus emblica juice is treated by microfiltration membrane with a pore size of 0.1-0.5μm and ultrafiltration membrane with a molecular weight cut-off of 5000-10000 Da successively under the condition of 4-6℃, and the ultrafiltration retentate is collected as the first Phyllanthus emblica extract; c) The Phyllanthus emblica residue obtained in step a) is mixed with 2-3 times the mass of pure water, and extracted under ultrasonic power of 200-300 W for 10-15 min at 35-45℃, and then solid-liquid separation is performed to obtain the second Phyllanthus emblica extract; d) The first Phyllanthus emblica extract and the second Phyllanthus emblica extract are combined to obtain the Phyllanthus emblica juice.

[0014] Preferably, in the method for inhibiting the browning of apple juice by ultra-high pressure combined with medicinal and edible materials, the ultra-high pressure treatment conditions are as follows: pressurized to 250-350 MPa at a rate of 10-15 MPa / s, pressure maintained for 1-2 min, then rapidly pressurized to 550-650 MPa within 30 seconds, pressure maintained for 3-6 min, then depressurized to normal pressure, and the cycle is repeated for 2-3 times.

[0015] Preferably, in the method for inhibiting the browning of apple juice by ultra-high pressure combined with medicinal and edible materials, the preparation process of apple juice is as follows: ) The peeled and cored apple pieces are immersed in an ice water mixture filled with food-grade nitrogen at 0-4°C for 5-10 minutes; then they are taken out and subjected to staged low-temperature pressing in an environment continuously filled with food-grade nitrogen: first, pre-pressing at 2-4°C and 200-400 rpm to obtain the first apple juice accounting for 30-40% of the total juice, and then pressing the residue at 4-6°C and 800-1000 rpm to obtain the remaining apple juice; ) The first apple juice obtained in step ) The first apple juice obtained in step

[0016] The present application provides an apple juice prepared by the method for inhibiting browning of apple juice by ultra-high pressure combined with medicinal and edible substances.

[0017] The present application at least includes the following beneficial effects: 1. The present application provides a method for inhibiting browning of apple juice by ultra-high pressure combined with medicinal and edible substances, which effectively inhibits the activity of polyphenol oxidase and peroxidase by adding Gastrodia elata juice and Phyllanthus emblica juice to apple juice and combining with ultra-high pressure treatment, thereby delaying the enzymatic browning process. This method takes advantage of the antioxidant properties of natural plant ingredients, avoiding the use of chemical additives, meeting the clean label trend and meeting the needs of consumers for healthy food. As a non-thermal processing technology, ultra-high pressure treatment minimizes the destruction of heat-sensitive nutrients such as vitamin C and flavonoids, maintaining the natural color, flavor and nutritional value of the juice. At the same time, this method is simple to operate and easy to industrialize, significantly prolonging the shelf life of apple juice and improving the market competitiveness of the product. Overall, this method ensures the quality of the juice while providing an environmentally friendly and low-cost browning inhibition solution.

[0018] 2. The present application specifies that the addition amount of Gastrodia elata juice is 0.5% of the volume of apple juice, which can optimize the anti-browning effect without introducing too much foreign flavor. Gastrodia elata juice is rich in phenolic compounds such as p-hydroxybenzyl alcohol, which can effectively inhibit the activity of polyphenol oxidase and peroxidase, reduce the formation of quinone substances, and thus delay browning. This addition amount ensures the inhibition of browning while avoiding changes in the flavor of the juice, ensuring the sensory quality of the final product. In addition, this proportion is reasonable in terms of cost-effectiveness, facilitating large-scale production and application, while enhancing the antioxidant capacity of the juice and improving the overall nutritional value. By precisely controlling the amount of Gastrodia elata juice, the method achieves a balance between efficiency and practicality.

[0019] 3. This invention adds amla juice at a rate of 2.5% to 10% of the apple juice volume. This range provides flexibility, allowing for adjustments to the anti-browning strength as needed. Amla juice is rich in polyphenols and flavonoids (such as gallic acid and ellagic acid), which possess strong antioxidant capabilities, scavenging free radicals and inhibiting enzymatic reactions. Lower addition amounts can be used for mild browning inhibition, while higher addition amounts significantly increase the total phenol and flavonoid content, enhancing the antioxidant activity of the juice. This dose-dependent effect ensures the applicability of the method under different quality requirements while avoiding the flavor impact that may result from excessive addition. Overall, this range optimizes browning inhibition and resource utilization.

[0020] 4. Glassy oleifera is rich in specific phenolic compounds and vitamin C. These components can more effectively competitively bind to the active sites of polyphenol oxidase, reducing quinone intermediates and thus slowing down the browning process. This ensures the consistency and efficiency of the method while enhancing the nutritional value of the juice, such as increasing the content of total phenols and total flavonoids. Furthermore, the flavor characteristics of glassy oleifera are highly compatible with apple juice, avoiding the introduction of undesirable flavors and enhancing the sensory appeal of the product.

[0021] 5. This invention discloses a process for preparing amla juice, including low-temperature pressing, membrane filtration, and ultrasonic extraction. These steps maximize the extraction of active ingredients (such as polyphenols and polysaccharides) from amla while minimizing oxidation and degradation. Operating under nitrogen prevents the oxidation of phenolic substances, membrane filtration removes large molecular impurities, and ultrasonic extraction improves extraction efficiency. The resulting amla juice is highly pure and active, effectively inhibiting browning and enhancing the juice's antioxidant capacity. This method also improves resource efficiency and reduces costs through the secondary utilization of residues, ensuring the quality stability and reproducibility of the amla juice.

[0022] 6. This invention defines specific parameters for ultra-high pressure (UHPP) treatment, including multi-stage pressurization and cyclic processing, which more effectively disrupts the spatial structure of enzyme proteins, leading to irreversible inactivation of polyphenol oxidase and peroxidase. The application of cyclic pressure enhances processing uniformity, ensuring sustained inhibition of enzyme activity and thus prolonging the color stability of the juice. Compared to single high-pressure treatment, this method better maintains the nutritional components and sensory quality of the juice while reducing the potential impact of high pressure on the juice's texture. These parameter settings optimize the efficiency and effectiveness of UHPP treatment, improving the overall reliability of the method.

[0023] 7. This invention further discloses a process for preparing apple juice, including nitrogen protection, staged pressing, and pulsed electric field treatment. This minimizes oxidation of the apple juice during processing. The nitrogen environment reduces oxygen contact, staged pressing increases juice yield and reduces enzymatic reactions, and the pulsed electric field further inhibits enzyme activity. The resulting apple juice base is of high quality, providing a good foundation for subsequent anti-browning treatment. This method also preserves the natural flavor and nutrients of the apple juice, such as vitamins and phenolic compounds, ensuring the superior properties of the final product.

[0024] 8. The apple juice prepared by this invention exhibits excellent color stability, high antioxidant activity, and rich nutritional components. By avoiding heat processing and chemical additives, the juice retains its natural flavor and health-promoting components, such as polyphenols and flavonoids. The product meets clean label requirements, has a longer shelf life, and enjoys higher consumer acceptance. Furthermore, this apple juice maintains stable sensory and nutritional quality during storage, meeting market demand for healthy, natural beverages and enhancing the product's commercial value. Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0025] Figure 1 This is a graph showing the apparent color change of apple juice treated with HPP after adding Gastrodia elata juice and different varieties of Phyllanthus emblica juice to Experiment 1 of the present invention. Figure 2 The graph shows the changes in PPO (a) and POD (b) of apple juice treated with HPP after adding Gastrodia elata juice and different varieties of Phyllanthus emblica juice in Experiment Example 1 of this invention. Figure 3 The graph shows the changes in total phenols (a) and total flavonoids (b) of apple juice treated with HPP after adding Gastrodia elata juice and different varieties of Phyllanthus emblica juice in Experiment Example 1 of the present invention. Figure 4 This is a graph showing the changes in the antioxidant activity of HPP-treated apple juice after adding Gastrodia elata juice and different varieties of Phyllanthus emblica juice to Experiment 1 of the present invention. Figure 5 The image shows the apparent color changes of apple juice treated with HPP after adding 0.5% (v / v) Gastrodia elata juice and different proportions of Phyllanthus emblica juice to Experiment Example 2 of the present invention. Figure 6 The graph shows the changes in PPO (a) and POD (b) of apple juice treated with HPP after adding 0.5% (v / v) Gastrodia elata juice and different proportions of Phyllanthus emblica juice in Experiment Example 2 of the present invention. Figure 7 The graph shows the changes in total phenols (a) and total flavonoids (b) of apple juice treated with HPP after adding 0.5% (v / v) Gastrodia elata juice and different proportions of Phyllanthus emblica juice in Experiment Example 2 of the present invention. Figure 8 The graph shows the changes in antioxidant activity of apple juice treated with HPP after adding 0.5% (v / v) Gastrodia elata juice and different proportions of Phyllanthus emblica juice to Experiment Example 2 of the present invention. Detailed Implementation

[0026] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments, so that those skilled in the art can implement it based on the description.

[0027] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0028] It should be noted that, unless otherwise specified, the experimental methods described in the following implementation plan are all conventional methods, and the reagents and materials described are all commercially available unless otherwise specified.

[0029] In the description of this invention, the terms "lateral", "longitudinal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0030] Example 1 This invention provides a method for inhibiting browning of apple juice using ultra-high pressure combined with food-grade medicinal substances, comprising the following steps: Step 1: Select fresh apples, amla (Buddhist gooseberries), and medium-sized gastrodia tubers that are 80% ripe, uniform in shape and color, and free from disease spots and mechanical damage. Remove surface impurities, wash with clean water, and drain. Peel and core the washed apples, then slice them. Core the washed amla and set aside. Peel and slice the washed gastrodia. Juice the apples and gastrodia separately in a juicer filled with food-grade nitrogen. Immediately filter the juice through a layer of gauze to remove particulate impurities, obtaining apple juice and gastrodia juice. Juice the cored amla, let it stand for a period of time, and then collect the supernatant to obtain amla juice. Step 2: Add Gastrodia elata juice and Phyllanthus emblica juice to the apple juice, then blend quickly with a blender to fully mix the Gastrodia elata juice and Phyllanthus emblica juice with the apple juice; the amount of Gastrodia elata juice added is 0.5% of the volume of apple juice; the amount of Phyllanthus emblica juice added is 10% of the volume of apple juice. Step 3: Seal the mixed juice into polyethylene bottles; Step 4: The packaged juice is subjected to high pressure treatment (HPP) at 20°C. The conditions for HPP treatment are: pressurization rate of about 15 MPa / s, pressure reaching 600 MPa in about 1 minute, pressure held for 5 minutes, and pressure released immediately. Step 5: Store the treated juice at 4°C for 35 days.

[0031] Example 2 The difference from Example 1 is that the preparation process of Phyllanthus emblica juice is as follows: a) Under an environment filled with food-grade nitrogen, the pitted amla seeds are pressed at a low temperature of 4-10℃ and 800-1200rpm to obtain primary amla juice and amla residue. b) The primary amla juice was processed at 4-6℃ by passing it through a microfiltration membrane with a pore size of 0.1-0.5μm and an ultrafiltration membrane with a molecular weight cutoff of 5000-10000 Da, and the ultrafiltration retentate was collected as the primary amla extract. c) Mix the Phyllanthus emblica residue obtained in step a) with 2-3 times its weight of purified water, and extract it at 35-45℃ and 200-300W ultrasonic power for 10-15 minutes. After extraction, perform solid-liquid separation to obtain Phyllanthus emblica secondary extract. d) Combine the initial extract of Phyllanthus emblica with the secondary extract of Phyllanthus emblica to obtain Phyllanthus emblica juice.

[0032] The amount of Gastrodia elata juice added was 0.5% v / v, and the amount of Phyllanthus emblica juice added was 10% v / v. The Phyllanthus emblica juice used was of the glassy variety. The remaining preparation process and parameters were the same as in Example 1.

[0033] Example 3 The difference from Example 1 is that the ultra-high pressure treatment conditions are as follows: pressurize to 250-350 MPa at a rate of 10-15 MPa / s, hold the pressure for 1-2 minutes, then rapidly pressurize to 550-650 MPa within 30 seconds, hold the pressure for 3-6 minutes, and then depressurize to atmospheric pressure. Repeat the cycle 2-3 times.

[0034] The amount of Gastrodia elata juice added is 0.5% v / v, and the amount of Phyllanthus emblica juice added is 10% v / v. The Phyllanthus emblica juice is made from the glassy variety of Phyllanthus emblica.

[0035] The remaining preparation processes and parameters are the same as in Example 1.

[0036] Example 4 The difference from Example 1 is that the preparation process of the apple juice is as follows: Immerse peeled and cored apple pieces in an ice-water mixture filled with food-grade nitrogen at 0-4°C for 5-10 minutes; then remove them and perform staged low-temperature pressing under continuous feeding of food-grade nitrogen: first, pre-press at 2-4°C and 200-400 rpm to obtain the first-press apple juice, which accounts for 30-40% of the total juice; then press the residue at 4-6°C and 800-1000 rpm to obtain the remaining apple juice. ) steps The first apple juice obtained is combined with the remaining apple juice to obtain apple juice solution. Under the conditions of 4-6℃, it is treated with a pulse electric field strength of 15-25 kV / cm, a pulse width of 20-40μs, and a frequency of 100-200 Hz for 50-100 pulses. The treated apple juice solution is then passed through a microfiltration membrane with a pore size of 0.1-0.5μm, and the filtrate is collected to obtain apple juice.

[0037] The addition amount of Gastrodia elata juice is 0.5% v / v, and the addition amount of Phyllanthus emblica juice is 10% v / v. The Phyllanthus emblica juice selected is the "glassy variety" Phyllanthus emblica. "Glassy variety" Phyllanthus emblica is a specific cultivated variety of Phyllanthus emblica, with transparent pulp, rich in polyphenols and vitamin C, and significant antioxidant activity, meeting the relevant regulations of the Chinese Catalogue of Food and Medicine Homologous Substances (such as the "Catalogue of Substances That are Traditionally Both Food and Traditional Chinese Medicine"). The "food and medicine homologous substances" mentioned refer to Gastrodia elata and Phyllanthus emblica, both of which are recognized as edible traditional Chinese medicines by the National Health Commission.

[0038] The remaining preparation processes and parameters are the same as in Example 1.

[0039] Comparative Example 1 Prepare pure apple juice (without adding any gastrodia elata juice or amla juice).

[0040] Pasteurize the apple juice by heating it in an 85°C water bath for 2 minutes.

[0041] After rapid cooling, seal and store at 4°C for 35 days.

[0042] Comparative Example 2 Prepare pure apple juice (without adding any gastrodia elata juice or amla juice).

[0043] Perform the same encapsulation and ultra-high pressure treatment (600MPa, 20℃, pressure holding for 5min) as in steps three and four of Example 1.

[0044] Store at 4℃ for 35 days.

[0045] Comparative Example 3 Add only 0.5% (v / v) of Gastrodia elata juice to apple juice.

[0046] Perform the same encapsulation and ultra-high voltage processing as in steps three and four of Example 1.

[0047] Store at 4℃ for 35 days.

[0048] Comparative Example 4 Add only 10% (v / v) of Phyllanthus emblica juice to the apple juice.

[0049] Perform the same encapsulation and ultra-high voltage processing as in steps three and four of Example 1.

[0050] Store at 4℃ for 35 days.

[0051] Comparative Example 5 Add 0.05% (w / v) vitamin C (VC) to the apple juice. (Do not add gastrodia elata juice or amla juice.) Perform the same encapsulation ultra-high voltage treatment as steps three and four of Example 1.

[0052] Store at 4℃ for 35 days.

[0053] The prepared apple juice was subjected to performance testing, and the testing method is as follows: PPO and POD activity assays: Equal volumes of apple juice were thoroughly mixed with pre-cooled phosphate buffer (0.2 mol / L, pH 6.5). 4% PVPP, 1% Triton X-100, and 1 mol / L NaCl were added sequentially. After shaking and mixing, the mixture was incubated at 4°C for 10 min, followed by centrifugation at 11000×g for 20 min at the same temperature. The collected supernatant was used for PPO and POD activity assays. For PPO assays, 0.05 mol / L, pH 6.5 phosphate buffer (containing 0.07 mol / L catechol) was prepared. 2 mL of phosphate buffer was mixed with 200 μL of the extract in a cuvette and quickly mixed. The absorbance of the reaction system was scanned at 420 nm using a UV spectrophotometer at room temperature, and the change in absorbance over 1 min was recorded. POD was determined by adding 200 μL of extraction buffer, 200 μL of 1% p-phenylenediamine (dissolved in the same concentration buffer), and 200 μL of 1.5% hydrogen peroxide to 1.5 mL of phosphate buffer (0.05 mol / L). After shaking well, the absorbance was immediately scanned at 485 nm, and the change in absorbance was monitored in real time over 1 min. The blank control was replaced with an equal volume of buffer solution. The enzyme activity units of PPO and POD were defined as the amount of absorbance change (U / mL·min) caused by each mL of enzyme solution within 0.001 units per min.

[0054] Determination of total phenols and total flavonoids: After shaking the fruit juice sample thoroughly, 1 mL of apple juice was mixed with 3 mL of 80% methanol. The mixture was vortexed for 1 min and then sonicated for 30 min to ensure homogeneity. Subsequently, the mixture was centrifuged at 8000 × g for 15 min at 4 °C, and the supernatant was collected. The reaction system was prepared in an ELISA strip by adding 100 µL of Folin-Ciocalteu solution (diluted with distilled water at a ratio of 1:9), 10 µL of supernatant, and 90 µL of 7.5% sodium carbonate solution. The mixture was shaken for 5 s to ensure thorough mixing, and then incubated at room temperature in the dark for 1 h. The absorbance at 765 nm was then measured using an ELISA reader. A standard curve was prepared using serial dilutions with 1 mg / mL gallic acid in 80% methanol. The total phenol content was expressed as gallic acid equivalent (GAE) mg / mL. Sample pretreatment was the same as the total phenol determination method described above. The reaction system was prepared in centrifuge tubes. 30 µL of 5% sodium nitrite solution was added to 200 µL of supernatant. After reacting in the dark for 5 min, 30 µL of 5% aluminum trichloride solution was added, and the reaction continued in the dark for another 6 min. Then, 200 µL of 1 mol / L sodium hydroxide solution was added, and the mixture was incubated in the dark for 30 min. After the reaction, the reaction mixture was immediately transferred to an enzyme-linked immunosorbent assay (ELISA) strip, and the absorbance at 510 nm was measured using an ELISA reader. A standard curve was prepared using serial dilutions of 1 mg / mL rutin in 80% methanol. Total flavonoid content was expressed as rutin equivalents (RE) mg / mL. Total phenolic content was expressed as gallic acid equivalents (GAE) mg / mL, indicating the number of milligrams of gallic acid equivalent to total phenols per milliliter of juice; total flavonoid content was expressed as rutin equivalents (RE) mg / mL, indicating the number of milligrams of rutin equivalent to total flavonoids per milliliter of juice.

[0055] Determination of antioxidant capacity: After shaking the juice sample thoroughly, 1 mL of apple juice was mixed with 3 mL of 80% methanol. The mixture was vortexed for 1 min and then sonicated for 30 min to ensure homogeneity. Subsequently, the mixture was centrifuged at 8000×g for 15 min at 4℃, and the supernatant was collected. The extract was diluted 10-fold with 80% methanol, mixed thoroughly, and then ready for measurement. A 0.1 mol / L DPPH solution was prepared with 80% methanol, and the concentration was adjusted so that the absorbance at 517 nm was 0.9 (±0.05). 40 μL of the diluted juice was thoroughly mixed with 160 μL of the DPPH reaction solution, and the mixture was reacted at room temperature in the dark for 30 min. The absorbance at 517 nm was then measured using a microplate reader. The DPPH free radical scavenging activity was calculated using a water-soluble vitamin E standard curve. The results were expressed as mmol (TE) equivalents / L juice, indicating antioxidant capacity. The juice sample pretreatment was the same as above, and the extract was diluted 10-fold with 80% methanol, mixed thoroughly, and then ready for measurement. 7 mmol / L ABTS stock solution was mixed with 2.45 mmol / L potassium persulfate in an 80% methanol solution and activated at room temperature in the dark for 12–16 h. Before use, the solution was diluted to an absorbance of 0.7 (±0.02) at 734 nm. 40 μL of diluted fruit juice was thoroughly mixed with 160 μL of ABTS reaction solution and reacted at room temperature in the dark for 6 min. The absorbance at 734 nm was then measured. The ABTS free radical scavenging activity was calculated based on the water-soluble vitamin E standard curve. The results were expressed as mmol (TE) equivalents / L fruit juice, indicating antioxidant capacity.

[0056] Experimental Example 1: Effect of different varieties of Phyllanthus emblica juice combined with Gastrodia elata juice on inhibiting browning of apple juice Apple juice was prepared according to the method in Example 1, and five parallel groups were set up. Four of the groups were given gastrodia elata juice (0.5% v / v) and four different varieties of amla juice were given to these four groups respectively (glassy amla, red-skinned amla, sweet amla, and persimmon amla, 5% v / v). The last group was the original apple juice, that is, without the addition of gastrodia elata juice and amla juice.

[0057] After mixing, the mixture is packaged and subjected to ultra-high pressure treatment at 20°C (600MPa, pressure held for 5 minutes).

[0058] Stored at 4℃ for 35 days, during which time the apparent color of the five groups of apple juice was observed. Figure 1 As shown, the PPO activity, POD activity, total phenols, total flavonoids, ABTS, and DPPH free radical scavenging capacity of the five groups of apple juice were measured periodically, as shown below. Figures 2-4 As shown.

[0059] like Figure 1As shown, the apple juice groups with added Gastrodia elata juice and four different varieties of Phyllanthus emblica juice had better apparent color during storage than the unadded groups. Among them, the color of the Phyllanthus emblica with added Gastrodia elata juice was the best, and its color stability of apple juice was higher than that of the other Phyllanthus emblica juice groups. This may be due to the difference in maturity and variety of Phyllanthus emblica, which leads to different contents of phenolic substances and vitamin C, thus affecting the color stability of apple juice.

[0060] The main mechanism of browning in HPP-treated apple juice during storage is attributed to enzymatic browning. PPO and POD, ubiquitous in fruit and vegetable tissues, are key enzyme systems that trigger browning, and apples are rich in PPO, which is the main reason why apples are prone to enzymatic browning. Figure 2 As shown, on day 0, the treatment with Gastrodia elata and Phyllanthus emblica juice significantly inhibited the initial activities of PPO and POD in apple juice. Specifically, the PPO and POD activities of apple juice treated with Phyllanthus emblica were reduced by 16% and 14%, respectively, compared to the original apple juice. During storage, the PPO and POD activities of apple juice continued to decrease. By day 35, the PPO and POD activities of apple juice treated with Phyllanthus emblica were reduced by 13% and 9%, respectively, compared to the original apple juice. The treatment with Gastrodia elata and Phyllanthus emblica juice significantly inhibited enzymatic browning of apple juice and improved its color. The browning inhibition effect of Gastrodia elata and Phyllanthus emblica juice may be related to its high content of polyphenols (such as gallic acid and ellagic acid). These components can exert their effects by competitively binding to PPO active sites or reducing quinone intermediates, thus giving it a better PPO inhibition effect.

[0061] Changes in total phenol and total flavonoid content, as follows Figure 3 As shown, the total phenolic and total flavonoid contents of the original apple juice were lowest on day 0, at 0.2 mg / mL and 0.1 mg / mL, respectively. Furthermore, the total phenolic and total flavonoid contents of all groups gradually decreased with prolonged storage. In contrast, the initial total phenolic and total flavonoid contents of the apple juice in the Gastrodia elata-Phyllanthus amla juice group were significantly higher than those of the original apple juice, and maintained relative stability during storage. Among them, the apple juice with added Phyllanthus emblica juice had the highest total phenolic (0.95 mg / mL) and total flavonoid (0.36 mg / mL) contents, which were 3.75 times and 2.6 times higher than those of the original apple juice, respectively.

[0062] Changes in antioxidant activity, such as Figure 4As shown, on day 0, the original apple juice exhibited the lowest ABTS and DPPH free radical scavenging abilities, approximately 128 μmol TE / L and 166 μmol TE / L, respectively. In contrast, the apple juice in the Gastrodia elata-Phyllanthus amla juice group showed significantly higher antioxidant activity than the original apple juice, especially the apple juice with added Phyllanthus emblica juice, which achieved the highest ABTS and DPPH free radical scavenging abilities, at 1521 μmol TE / L and 1756 μmol TE / L, respectively, representing increases of 10.9 times and 9.6 times compared to the original apple juice. During the 35-day storage period, although the ABTS and DPPH free radical scavenging abilities of all groups fluctuated slightly, they remained generally stable.

[0063] Therefore, glassy oleoresin was subsequently selected as an anti-browning agent to be added to apple juice.

[0064] Experimental Example 2: Effect of Different Addition Amounts of Phyllanthus emblica Juice on Inhibiting Browning of Apple Juice Following the method in Example 1, 0.5% (v / v) of Gastrodia elata juice and 1%, 2.5%, 5%, and 10% (v / v) of Phyllanthus emblica juice were added to apple juice, designated as PE-1, PE-2.5, PE-5, and PE-10 addition groups, respectively. Changes in the appearance and quality of the apple juice were observed over 35 days. Figure 5 As shown, the PPO activity, POD activity, total phenols, total flavonoids, ABTS, and DPPH free radical scavenging capacity of apple juice were tested, and the results are as follows: Figures 6-8 As shown.

[0065] like Figure 5 As shown, the original apple juice rapidly turned brown on day 0. Due to the addition of Gastrodia elata-Phyllanthus amla juice, the color of the juice on day 0 was significantly better than the original apple juice. The addition of Gastrodia elata-Phyllanthus amla juice greatly slowed down the browning of the apple juice, and its color-protecting effect was positively correlated with the concentration of Phyllanthus amla juice; the higher the Phyllanthus amla juice content in the apple juice, the better the color-protecting effect. Especially when the addition of Phyllanthus amla juice increased to 10%, the color of the apple juice was optimal, appearing as a bright yellow-orange, similar to the initial color of the apple juice. Gastrodia elata-Phyllanthus amla juice effectively inhibited browning in the early stages of storage, but from day 14 onwards, obvious browning began to appear, and the juice color gradually darkened. This may be because the substances in Gastrodia elata-Phyllanthus amla juice that inhibit browning are its high content of phenolic substances. As the storage time increases, the polyphenols in the juice are easily oxidized to generate quinone intermediates, which further polymerize to form melanin, accelerating the browning of the system.

[0066] Depend on Figure 6As shown, on day 0, the addition of Gastrodia elata-Phyllanthus amla juice significantly inhibited the initial activities of PPO and POD in apple juice. Specifically, the PPO and POD activities in the PE-10 group apple juice decreased by 28% and 24%, respectively, compared to the original apple juice. During storage, the PPO and POD activities of the original apple juice continued to decrease. Simultaneously, the PPO and POD activities in the Gastrodia elata-Phyllanthus amla juice treatment group also continued to decrease with prolonged storage time. On day 35 of storage, the PPO and POD activities of the PE-10 group apple juice decreased by 24% and 26.25%, respectively, compared to the original apple juice. This is consistent with the lower degree of browning in this group of juices.

[0067] Changes in total phenol and total flavonoid content, as follows Figure 7 As shown, the total phenols and total flavonoids content of the original apple juice was lowest on day 0 (approximately 0.1 mg / mL), and showed a slow decreasing trend with prolonged storage time. In contrast, the initial total phenols and total flavonoids content of the 10% amla juice addition was significantly higher than that of the original apple juice, at 1.45 mg / mL and 0.43 mg / mL, respectively, and remained relatively stable during storage. The Gastrodia elata-Amla juice contained high levels of polyphenols and flavonoids, and its addition significantly increased the total phenols and total flavonoids content in the system, showing a dose-dependent increase with increasing amla juice addition. On day 35 of storage, the PE-10 group apple juice had the highest total phenols and total flavonoids content, 28.75 times and 6.4 times that of the original apple juice, respectively. Throughout the 35-day storage period, the total phenols and total flavonoids content of all groups remained relatively stable overall, showing only a slight decreasing trend. Overall, the addition of Gastrodia elata-Phyllanthus amla juice can significantly increase the content and stability of total phenols and total flavonoids in apple juice, and its protective effect is enhanced with the increase of Phyllanthus amla juice addition.

[0068] Changes in antioxidant activity, such as Figure 8As shown, on day 0, the original apple juice exhibited the lowest ABTS and DPPH free radical scavenging abilities (approximately 108 μmol TE / L and 166 μmol TE / L), indicating that the antioxidant activity of the apple juice itself is limited. The antioxidant activity of the apple juice with added Gastrodia elata-Phyllanthus amla juice was significantly higher than that of the original apple juice, and increased with increasing amounts of Phyllanthus emblica juice. In particular, the PE-10 group of apple juice achieved the highest ABTS and DPPH free radical scavenging abilities, at 2082 μmol TE / L and 2721 μmol TE / L, respectively, representing increases of 18.3 times and 15.3 times compared to the original apple juice. During the 35-day storage period, the ABTS and DPPH free radical scavenging abilities of all groups fluctuated slightly but remained generally stable. In conclusion, the antioxidants in Gastrodia elata-Phyllanthus amla juice can effectively maintain the antioxidant stability of the juice system, while its phenolic compounds themselves possess strong free radical scavenging capabilities, effectively reducing oxidative losses.

[0069] In summary, the apple juice preparation method provided in Example 1 effectively reduces oxidative loss of apple juice, and the optimal amount of amla juice added for nutritional value is 10%. When the amount of amla juice added exceeds 10% (e.g., reaching 15%), the juice begins to exhibit a noticeable astringent taste, negatively impacting the original flavor of the apple juice, as assessed by a professional sensory evaluation panel. Therefore, an addition amount of 10% achieves the best balance between browning inhibition and sensory acceptability.

[0070] Experimental Example 3 The PPO activity (Table 1), POD activity (Table 2), total phenols (Table 3), total flavonoids (Table 4), ABTS (Table 5), and DPPH free radical scavenging capacity (Table 6) of apple juice prepared in Examples 1, 2, 3, 4 and Comparative Examples 1, 2, 3, 4 and 5 were tested at 0 days, 7 days, 14 days, 21 days, 28 days, and 35 days.

[0071] Table 1. Changes in PPO activity (U / mL·min) of apple juice in different treatment groups during storage. Group 0 days 7 days 14 days 21 days 28 days 35 days Comparative Example 1 100±0.69 90±3.32 85±2.66 80±2.45 77±1.44 75±2.62 Comparative Example 2 100±0.64 88±4.76 83±2.57 80±4.25 72±2.38 63±3.21 Comparative Example 3 95±2.61 84±2.75 79±1.89 75±2.83 67±4.04 62±1.62 Comparative Example 4 84±1.27 78±1.61 72±1.53 70±3.62 62±4.38 59±3.35 Comparative Example 5 90±1.69 82±2.64 78±3.77 75±3.25 70±2.38 66±2.35 Example 1 72±0.68 65±5.77 64±1.41 53±2.08 51±2.21 48±2.37 Example 2 70±1.52 62±3.05 60±1.83 50±2.52 48±2.01 45±1.83 Example 3 68±1.24 60±2.51 58±1.51 48±2.04 46±1.84 43±1.57 Example 4 66±1.08 58±2.07 56±1.25 46±1.55 44±1.56 42±1.23 Table 2: Changes in POD activity (U / mL·min) of apple juice in different treatment groups during storage Group 0 days 7 days 14 days 21 days 28 days 35 days Comparative Example 1 100±1.71 96±8.76 90±7.39 89±1.63 85±3.26 80±5.92 Comparative Example 2 100±0.25 96±4.49 90±2.24 89±6.25 85±4.76 80±4.49 Comparative Example 3 73±2.86 77±2.77 69±3.44 65±1.79 62±1.17 61±1.27 Comparative Example 4 84±8.68 72±3.13 71±4.08 72±1.64 73±2.08 69±1.08 Comparative Example 5 90±2.25 86±3.49 82±2.24 80±4.25 78±3.76 75±3.49 Example 1 76±1.71 76 ± 2.8 65 ± 1.73 60±1.63 61±3.26 59±1.59 Example 2 74±1.53 70±2.54 62±1.51 58±1.23 59±2.01 56±1.05 Example 3 72±1.23 68±2.01 60±1.24 56±1.07 57±1.54 54±0.82 Example 4 70±1.07 66±1.53 58±1.0 54±0.83 55±1.27 52±0.76 Table 3: Changes in total phenolic content (mg / mL) of apple juice from different treatment groups during storage. Table 4: Changes in total flavonoid content (mg / mL) of apple juice from different treatment groups during storage Table 5: Changes in ABTS free radical scavenging capacity of apple juice in different treatment groups during storage (μmol TE / L) Note: The ABTS value of Comparative Example 2 was abnormally low at 28 days (39.09 μmol TE / L), which may be due to uneven ultra-high pressure treatment or local oxidation, but it does not affect the overall conclusion. The data of the Example group showed significant stability.

[0072] Table 6: Changes in DPPH free radical scavenging capacity of apple juice in different treatment groups during storage (μmol TE / L) Based on the experimental data in Tables 1 to 6, the following is a comprehensive analysis of the PPO activity, POD activity, total phenolic content, total flavonoid content, ABTS free radical scavenging capacity, and DPPH free radical scavenging capacity of apple juice from different treatment groups during storage (days 0 to 35). The data analysis focuses on comparing the effects of the embodiments of this invention (Examples 1-4) with the comparative examples (Comparative Examples 1-5) in inhibiting browning, maintaining nutritional components, and enhancing antioxidant capacity.

[0073] Table 1 shows that Comparative Example 1 (pasteurization) and Comparative Example 2 (single ultra-high pressure treatment) had high PPO activity (100 U / mL·min on day 0), which decreased slowly during storage, but remained at 75 U / mL·min and 63 U / mL·min respectively at day 35, indicating that the traditional treatment had limited inhibitory effect on PPO. Comparative Example 3 (only Gastrodia elata juice added) and Comparative Example 4 (only Phyllanthus emblica juice added) had lower PPO activity than Comparative Examples 1 and 2, showing that the natural additives had some inhibitory effect, but the activity still reached 62 U / mL·min and 59 U / mL·min respectively at day 35. Comparative Example 5 (with added Vitamin C) had similar PPO activity to Comparative Example 2, indicating that Vitamin C alone was not effective. The PPO activity of Examples 1-4 was significantly lower than all comparative examples (66-72 U / mL·min on day 0 and 42-48 U / mL·min on day 35). Among them, Example 4 (improved apple juice preparation) showed the lowest PPO activity, at 42 U / mL·min after 35 days, which was 44% lower than that of Comparative Example 1. This indicates that the method of the present invention can more effectively inhibit PPO activity by combining ultra-high pressure with food-medicine homologous substances, and the effect is long-lasting.

[0074] Examples 1-4 of this invention can significantly reduce PPO activity and delay enzymatic browning, with Example 4 showing the best effect.

[0075] Table 2 data analysis shows that Comparative Examples 1 and 2 had high POD activity (100 U / mL·min on day 0), which decreased slowly after storage, but still reached 80 U / mL·min at day 35. Comparative Example 3 (Gastrodia elata juice) had low POD activity (73 U / mL·min on day 0), but the decrease during storage was small, reaching 61 U / mL·min at day 35. Comparative Example 4 (Phyllanthus amla juice) had lower POD activity than Comparative Examples 1-3, but still reached 69 U / mL·min at day 35. The POD activity of Examples 1-4 was significantly reduced (70-76 U / mL·min on day 0, 52-59 U / mL·min at day 35). Example 4 had the lowest POD activity (52 U / mL·min at day 35), a 35% reduction compared to Comparative Example 1, indicating that the method of the present invention has a more comprehensive inhibitory effect on POD. The data in Table 2 show that ultra-high pressure combined with medicinal and edible homologous substances can synergistically inhibit POD activity, and Example 4 further enhanced the effect by optimizing the apple juice preparation process.

[0076] Table 3 shows that the total phenol content of Comparative Examples 1 and 2 was extremely low (0.196 mg / mL and 0.096 mg / mL, respectively, at day 0), and decreased significantly during storage (Comparative Example 1 decreased to 0.036 mg / mL and 0.044 mg / mL at day 35), indicating that conventional treatment led to severe loss of phenolic substances. The total phenol content of Comparative Examples 3 (Gastrodia elata juice) and 5 (VC) was moderate, but decreased significantly after storage. The total phenol content of Comparative Example 4 (Emblica emblica juice) was high (0.952 mg / mL at day 0), indicating that Emblica emblica is rich in phenols. The total phenol content of Examples 1-4 was significantly higher than all comparative examples (1.452-1.60 mg / mL at day 0 and 1.34-1.44 mg / mL at day 35). Example 4 showed the highest total phenol content, at 1.44 mg / mL after 35 days, which was 40 times that of Comparative Example 1. This indicates that the method of the present invention can effectively retain and stabilize phenolic substances. The addition of food-medicine homologous substances and ultra-high pressure treatment synergistically protected the phenolic components. The improved preparation process of Example 4 had the most significant effect.

[0077] Table 4 shows that Comparative Examples 1 and 2 had the lowest total flavonoid content (approximately 0.1 mg / mL on day 0), which further decreased after storage. Comparative Examples 3 and 5 showed some improvement in total flavonoid content, but only reached 0.134-0.234 mg / mL at 35 days. Comparative Example 4 (Phyllanthus amla juice) had a relatively high total flavonoid content (0.356 mg / mL on day 0), indicating that Phyllanthus amla is a good source of flavonoids. Examples 1-4 had the highest total flavonoid content (0.426-0.46 mg / mL on day 0 and 0.39-0.41 mg / mL at 35 days). The 35-day value for Example 4 was 0.41 mg / mL, which is 6.7 times that of Comparative Example 1, indicating that the method of the present invention can significantly improve and stabilize flavonoid content. The combined use of Gastrodia elata and Phyllanthus amla enhanced flavonoid retention, and the ultra-high pressure treatment avoided thermal degradation.

[0078] Table 5 shows that the ABTS values ​​of Comparative Examples 1 and 2 were extremely low (approximately 128 μmol TE / L and 108 μmol TE / L on day 0), and fluctuated greatly during storage, indicating poor stability. The ABTS values ​​of Comparative Examples 3 and 5 were moderate (approximately 360 μmol TE / L on day 0), but decreased after storage. The ABTS value of Comparative Example 4 (Phyllanthus amla juice) was relatively high (1520 μmol TE / L on day 0), indicating that Phyllanthus emblica has strong antioxidant properties. The ABTS values ​​of Examples 1-4 were significantly increased (2082-2250 μmol TE / L on day 0 and 2074-2240 μmol TE / L on day 35). The 35-day value of Example 4 was 2240 μmol TE / L, which is 24.8 times that of Comparative Example 1. The example groups remained stable during storage without significant decrease. The method of this invention significantly enhances antioxidant capacity through synergistic effects, and the optimized treatment in Example 4 resulted in the most durable effect.

[0079] Table 6 shows that Comparative Examples 1 and 2 had low DPPH values ​​(approximately 166 μmol TE / L on day 0), which decreased significantly after storage (approximately 73 μmol TE / L on day 35). Comparative Examples 3 and 5 had moderate DPPH values ​​(approximately 385 μmol TE / L on day 0), but fluctuated considerably after storage. Comparative Example 4 (Phyllanthus amla juice) had a high DPPH value (1756 μmol TE / L on day 0), but decreased to 1604 μmol TE / L after storage. Examples 1-4 had the highest DPPH values ​​(2721-2900 μmol TE / L on day 0 and 2402-2780 μmol TE / L on day 35). The 35-day value of Example 4 was 2780 μmol TE / L, which was 38 times that of Comparative Example 1. Furthermore, the decrease in DPPH values ​​in the example groups was smaller, indicating strong stability. Ultra-high pressure combined with medicinal and edible homologous substances significantly enhanced and maintained the DPPH free radical scavenging ability, with Example 4 showing the best performance.

[0080] The embodiments of this invention (especially Embodiment 4) are significantly superior to all comparative examples in inhibiting enzyme activity (PPO, POD), retaining nutrients (total phenols, total flavonoids), and enhancing antioxidant capacity (ABTS, DPPH). Single treatments (such as pasteurization, ultra-high pressure, or the addition of Gastrodia elata or Phyllanthus emblica alone) have limited effects, while this invention achieves synergistic effects by combining medicinal and edible substances and optimizing ultra-high pressure parameters. Embodiment 4 (improved apple juice preparation process) shows the best performance in most indicators, indicating that nitrogen protection, staged pressing, and pulsed electric field treatment can further reduce oxidative losses and improve product quality. The method of this invention conforms to the clean label trend, requires no chemical additives, and can effectively extend the shelf life of apple juice while maintaining its natural flavor and nutritional value.

[0081] These data fully demonstrate the technological advantages and practicality of ultra-high pressure combined with food-medicine homologous substances in inhibiting browning of apple juice.

[0082] The number of devices and processing scale described herein are for the purpose of simplifying the description of the invention. Applications, modifications, and variations of the invention will be readily apparent to those skilled in the art.

[0083] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A method for inhibiting browning of apple juice using ultra-high pressure combined with medicinal and edible substances, characterized in that, Includes the following steps: Step 1: Wash, peel and core the fresh apples, gastrodia elata and amla, and prepare apple juice, gastrodia elata juice and amla juice respectively; Step 2: Add gastrodia elata juice and amla juice to apple juice and stir thoroughly. Step 3: Seal the mixed juice into polyethylene bottles; Step 4: The packaged juice is subjected to ultra-high pressure treatment at 20℃; Step 5: Store the treated juice at 4°C.

2. The method for inhibiting browning of apple juice using ultra-high pressure combined with food-medicine homologous substances as described in claim 1, characterized in that, The amount of Gastrodia elata juice added is 0.5% of the volume of apple juice.

3. The method for inhibiting browning of apple juice using ultra-high pressure combined with food-medicine homologous substances as described in claim 2, characterized in that, The amount of amla juice added is 2.5 to 10% of the volume of apple juice.

4. The method for inhibiting browning of apple juice using ultra-high pressure combined with food-medicine homologous substances as described in claim 3, characterized in that, Phyllanthus emblica is a type of glassy, ​​oily Phyllanthus emblica.

5. The method for inhibiting browning of apple juice using ultra-high pressure combined with food-medicine homologous substances as described in claim 4, characterized in that, The specific process for preparing amla juice is as follows: a) Under an environment filled with food-grade nitrogen, the pitted amla seeds are pressed at a low temperature of 4-10℃ and 800-1200rpm to obtain primary amla juice and amla residue. b) The primary amla juice was processed at 4-6℃ by passing it through a microfiltration membrane with a pore size of 0.1-0.5μm and an ultrafiltration membrane with a molecular weight cutoff of 5000-10000 Da, and the ultrafiltration retentate was collected as the primary amla extract. c) Mix the Phyllanthus emblica residue obtained in step a) with 2-3 times its weight of purified water, and extract it at 35-45℃ and 200-300W ultrasonic power for 10-15 minutes. After extraction, perform solid-liquid separation to obtain Phyllanthus emblica secondary extract. d) Combine the initial extract of Phyllanthus emblica with the secondary extract of Phyllanthus emblica to obtain Phyllanthus emblica juice.

6. The method for inhibiting browning of apple juice using ultra-high pressure combined with food-medicine homologous substances as described in claim 1, characterized in that, The conditions for ultra-high pressure treatment are as follows: pressurize to 250-350 MPa at a rate of 10-15 MPa / s, hold the pressure for 1-2 minutes, then rapidly pressurize to 550-650 MPa within 30 seconds, hold the pressure for 3-6 minutes, and then depressurize to atmospheric pressure. Repeat this cycle 2-3 times.

7. The method for inhibiting browning of apple juice using ultra-high pressure combined with food-medicine homologous substances as described in claim 1, characterized in that, The specific process for preparing apple juice is as follows: Immerse peeled and cored apple pieces in an ice-water mixture filled with food-grade nitrogen at 0-4°C for 5-10 minutes; then remove them and perform staged low-temperature pressing under continuous food-grade nitrogen: first, pre-press at 2-4°C and 200-400 rpm to obtain the first-press apple juice, which accounts for 30-40% of the total juice; then press the residue at 4-6°C and 800-1000 rpm to obtain the remaining apple juice. ) steps The first apple juice obtained is combined with the remaining apple juice to obtain apple juice solution. Under the conditions of 4-6℃, it is treated with a pulse electric field strength of 15-25 kV / cm, a pulse width of 20-40μs, and a frequency of 100-200 Hz for 50-100 pulses. The treated apple juice solution is then passed through a microfiltration membrane with a pore size of 0.1-0.5μm, and the filtrate is collected to obtain apple juice.

8. An apple juice, characterized in that, Prepared by the method described in any one of claims 1 to 7.

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