Preparation method of apple juice, apple juice and beverage

Abstract

The invention provides an apple juice preparation method, an apple juice and a beverage, and the preparation method comprises the following steps: S1, adding nano cellulose into an apple juice raw material, and uniformly stirring; s2, adding apple polyphenol into the uniformly stirred apple juice raw materials, and uniformly stirring to obtain apple juice; wherein the mass of the nanocellulose is 0.25-0.35% of the mass of the apple juice raw material, and the concentration content of the apple polyphenol in the apple juice raw material is 20-50 mg / L. According to the embodiment of the invention, the apple juice with high stability and excellent aroma quality can be prepared.

Description

Technical Field

[0001] This invention relates to the field of food processing technology, and more particularly to a method for preparing apple juice, apple juice and beverage. Background Technology

[0002] Aroma is a key factor determining the overall quality of apple juice. More than 350 flavor compounds, including esters, aldehydes, ketones, alcohols, and terpenes, have been identified from different apple varieties. Among them, aromatic active ingredients play an important role in the overall aroma of apples. For example, acetates are the main aroma compounds in apple juice. Butyl acetate and hexyl acetate give apple juice a rich fruity and sweet aroma and are characteristic flavor compounds of many apple juices.

[0003] Non-concentrated apple juice is produced through a process of washing, chopping, color preservation, juicing, enzymatic hydrolysis and clarification, ultrafiltration, pasteurization, and bottling. It boasts advantages such as safety, freshness, and excellent flavor, gaining increasing recognition from consumers. However, browning of the juice, enzymatic hydrolysis, and sterilization processes all contribute to the loss of aroma components, leading to a decline in the aroma and quality of the apple juice. Summary of the Invention

[0004] This invention provides a method for preparing apple juice, apple juice, and a beverage, to solve the problem that browning of the juice, enzymatic hydrolysis, and sterilization processes in existing apple juice processing can cause loss of aroma components, leading to a decrease in the aroma and quality of apple juice.

[0005] To solve the above-mentioned technical problems, the present invention is implemented as follows:

[0006] In a first aspect, embodiments of the present invention provide a method for preparing apple juice, comprising:

[0007] Step S1: Add nanocellulose to the apple juice ingredients and stir well;

[0008] Step S2: Add apple polyphenols to the well-stirred apple juice raw materials and stir well to obtain apple juice.

[0009] The nanocellulose has a mass of 0.25-0.35% of the apple juice raw material mass, and the apple polyphenols have a concentration of 20-50 mg / L in the apple juice raw material.

[0010] Optionally, the apple polyphenols include at least one of epicatechin, chlorogenic acid, and phlorizin.

[0011] Optionally, the method may include the following steps before step S1:

[0012] Step S3: Boil the freshly squeezed apple juice to inactivate the enzymes, then cool it. Centrifuge the cooled apple juice and filter it to obtain the supernatant of the apple juice.

[0013] The supernatant of the apple juice is sterilized to obtain the apple juice raw material.

[0014] Optionally, the method may include the following steps before step S1:

[0015] Step S4: Boil the freshly squeezed apple juice to inactivate the enzymes, then cool it. Add pectinase to the cooled apple juice and stir well. After enzymatic hydrolysis, filter it once to obtain apple juice after one filtration.

[0016] Step S5: After centrifugation, the apple juice after the first filtration is filtered a second time to obtain the supernatant of the apple juice. The supernatant of the apple juice is then sterilized to obtain the apple juice raw material.

[0017] Optionally, the temperature for inactivating enzymes by boiling is 85-95℃.

[0018] Optionally, the centrifugation speed is 2500-3500 r / min and the processing time is 8-12 min.

[0019] Optionally, the sterilization temperature is 60-80℃ and the sterilization time is 10-20 minutes.

[0020] Optionally, vitamin C may be added to the apple juice during the fresh juicing process, with the amount of vitamin C being 0.4-0.6% of the apple juice.

[0021] Secondly, embodiments of the present invention provide an apple juice prepared using the apple juice preparation method described in any one of the first aspects.

[0022] Thirdly, embodiments of the present invention provide a beverage, including the apple juice described in the second aspect.

[0023] In this embodiment of the invention, by step S1: adding nanocellulose to apple juice raw material and stirring evenly; and step S2: adding apple polyphenols to the evenly stirred apple juice raw material and stirring evenly, apple juice is obtained; wherein, the mass of the nanocellulose is 0.25-0.35% of the mass of the apple juice raw material, and the concentration of the apple polyphenols in the apple juice raw material is 20-50 mg / L, this embodiment of the invention can prepare apple juice with high stability and excellent aroma quality. Attached Figure Description

[0024] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0025] Figure 1 This is a schematic flowchart of the apple juice preparation method according to an embodiment of the present invention;

[0026] Figure 2 A schematic diagram illustrating the effect of adding different concentrations of epicatechin on the content of the main characteristic aromas of apple juice;

[0027] Figure 3 A schematic diagram illustrating the effect of adding different concentrations of chlorogenic acid on the content of the main characteristic aromas of apple juice;

[0028] Figure 4 A schematic diagram illustrating the effect of adding different concentrations of phlorizin on the content of the main characteristic aromas of apple juice;

[0029] Figure 5 A schematic diagram illustrating the sensory evaluation of apple juice aroma. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] The terms "first," "second," etc., used in this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first" and "second" are generally of the same class, without limiting the number of objects; for example, the first object can be one or more. Furthermore, "or" in this application indicates at least one of the connected objects. For example, "A or B" covers three scenarios: Scenario 1: including A but not B; Scenario 2: including B but not A; Scenario 3: including both A and B. The character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0032] In the technical solutions disclosed herein, terms such as “connection,” “coupling,” or “linking” are not limited to physical or mechanical connections, but may include electrical connections.

[0033] Furthermore, the technical features involved in the different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0034] This invention provides a method for preparing apple juice, see [link to relevant documentation]. Figure 1 As shown, Figure 1This is a schematic flowchart of the apple juice preparation method according to an embodiment of the present invention, including:

[0035] Step S1: Add nanocellulose to the apple juice ingredients and stir well;

[0036] Step S2: Add apple polyphenols to the well-stirred apple juice raw materials and stir well to obtain apple juice.

[0037] The nanocellulose has a mass of 0.25-0.35% of the apple juice raw material mass, and the apple polyphenols have a concentration of 20-50 mg / L in the apple juice raw material.

[0038] In some embodiments of the present invention, optionally, the mass of the nanocellulose is 0.25-0.35% of the mass of the apple juice raw material, for example, 0.25%, 0.3%, or 0.35%.

[0039] In some embodiments of the present invention, optionally, the concentration of apple polyphenols in the apple juice raw material is 20-50 mg / L, for example, 20 mg / L, 30 mg / L, 40 mg / L, or 50 mg / L.

[0040] In this embodiment of the invention, adding nanocellulose to apple juice raw materials can reduce pulp sedimentation and improve the stability of the juice. The following is a specific example. Referring to Table 1, 0.3% nanocellulose (i.e., the mass of added nanocellulose is 0.3% of the mass of the apple juice raw materials) was added to 1L of the obtained apple juice raw materials, with no nanocellulose added serving as a control group. Sedimentation in the apple juice was observed after 1, 3, 5, 10, and 15 days.

[0041] Table 1. Sedimentation of Apple Juice

[0042]

[0043] Among them, "+" indicates almost no precipitation; "++" indicates trace precipitation; "+++" indicates a small amount of precipitation; and "++++" indicates a large amount of precipitation.

[0044] In this embodiment of the invention, the addition of apple polyphenols can promote the release of aroma in apple juice, thereby enhancing the richness and complexity of the aroma of apple juice and improving the aroma quality of apple juice.

[0045] In this embodiment of the invention, by step S1: adding nanocellulose to apple juice raw material and stirring evenly; and step S2: adding apple polyphenols to the evenly stirred apple juice raw material and stirring evenly, apple juice is obtained; wherein, the mass of the nanocellulose is 0.25-0.35% of the mass of the apple juice raw material, and the concentration of the apple polyphenols in the apple juice raw material is 20-50 mg / L, this embodiment of the invention can prepare apple juice with high stability and excellent aroma quality.

[0046] In some embodiments of the present invention, the apple polyphenols optionally include at least one of epicatechin, chlorogenic acid, and phlorizin.

[0047] Epicatechin is a naturally occurring flavonoid, belonging to the polyphenol class of compounds, primarily found in tea, cocoa, certain fruits, and red wine. It possesses various biological activities, including antioxidant, anti-inflammatory, and cardiovascular protective effects. The main health benefits of epicatechin include: antioxidant activity, neutralizing free radicals in the body and thus reducing oxidative stress-induced cell damage; cardiovascular health, with some studies showing that epicatechin helps lower blood pressure, improve blood lipid levels, and promote vascular health; anti-inflammatory activity, helping to reduce chronic inflammation, which is associated with the development of various diseases; and improved metabolism, with some studies showing that epicatechin has a positive impact on metabolic health, helping to control weight and improve glucose metabolism.

[0048] Chlorogenic acid is a natural phenolic acid widely found in various plants, especially coffee beans, certain fruits (such as apples and pears), vegetables (such as potatoes and peppers), and some herbs. Chlorogenic acid has garnered attention for its potential health benefits, particularly in its antioxidant, anti-inflammatory, and metabolic regulation properties. Key health benefits of chlorogenic acid include: antioxidant effects (chlorogenic acid possesses powerful antioxidant properties that help neutralize free radicals in the body, reducing oxidative stress damage to cells); metabolic enhancement (some studies suggest that chlorogenic acid helps improve glucose metabolism, lowering postprandial blood sugar levels, which is beneficial for diabetics); weight loss benefits (chlorogenic acid is believed to aid in weight management by influencing fat metabolism and inhibiting fat absorption); cardiovascular health benefits (chlorogenic acid helps lower blood pressure and improve blood lipid levels, thus benefiting cardiovascular health); and anti-inflammatory effects (studies show that chlorogenic acid has anti-inflammatory properties that help reduce chronic inflammation).

[0049] Rutin is a natural flavonoid compound widely found in many plants, especially certain fruits, vegetables, and herbs. Rutin possesses a variety of biological activities and is noteworthy for its antioxidant, anti-inflammatory, and vascular health-promoting properties. The main health benefits of rutin include: antioxidant effects—rutin neutralizes free radicals and reduces oxidative stress, thereby protecting cells from damage; vascular health promotion—rutin helps strengthen and improve the elasticity of blood vessel walls, benefiting varicose veins and other vascular problems; anti-inflammatory effects—rutin has anti-inflammatory properties that help reduce chronic inflammation, which is associated with the development of various diseases; improved circulation—some studies suggest that rutin helps improve blood circulation and reduce the risk of thrombosis; and hypoglycemic effects—preliminary studies indicate that rutin has a certain regulatory effect on blood glucose levels.

[0050] In this embodiment of the invention, by adding apple polyphenols to the uniformly stirred apple juice raw material, wherein the apple polyphenols include at least one of epicatechin, chlorogenic acid, and phlorizin, this embodiment of the invention can improve the aroma quality and nutritional value of apple juice.

[0051] In some embodiments of the present invention, optionally, the method further includes the following step before step S1:

[0052] Step S3: Boil the freshly squeezed apple juice to inactivate the enzymes, then cool it. Centrifuge the cooled apple juice and filter it to obtain the supernatant of the apple juice. Sterilize the supernatant of the apple juice to obtain the apple juice raw material.

[0053] In this embodiment of the invention, the freshly squeezed apple juice is boiled to inactivate enzymes, cooled, centrifuged, and then filtered to obtain a supernatant. This process removes impurities from the apple juice and improves its purity. Furthermore, sterilizing the supernatant kills bacteria in the apple juice and ensures a high total phenol content in the raw apple juice, guaranteeing the nutritional health of the resulting apple juice.

[0054] In some embodiments of the present invention, optionally, the method further includes the following step before step S1:

[0055] Step S4: Boil the freshly squeezed apple juice to inactivate the enzymes, then cool it. Add pectinase to the cooled apple juice and stir well. After enzymatic hydrolysis, filter it once to obtain apple juice after one filtration.

[0056] Step S5: After centrifugation, the apple juice after the first filtration is filtered a second time to obtain the supernatant of the apple juice. The supernatant of the apple juice is then sterilized to obtain the apple juice raw material.

[0057] In this embodiment of the invention, step S4 involves boiling the freshly squeezed apple juice to inactivate enzymes, then cooling it. Pectinase is added to the cooled apple juice and stirred until homogeneous. After enzymatic hydrolysis, the juice is filtered once to obtain first-filtered apple juice. Step S5 involves centrifuging the first-filtered apple juice and then filtering it a second time to obtain a supernatant. The supernatant is then sterilized to obtain the apple juice raw material. This embodiment of the invention can remove impurities from apple juice and improve its purity. Furthermore, centrifuging the first-filtered apple juice and then filtering it a second time to obtain a supernatant, followed by sterilization of the supernatant, can kill bacteria in the apple juice, ensuring the nutritional health of the obtained apple juice raw material.

[0058] In some embodiments of the present invention, optionally, the temperature for boiling to inactivate the enzyme is 85-95°C. This temperature ensures efficient enzyme inactivation.

[0059] In some embodiments of the present invention, optionally, the centrifugation speed is 2500-3500 r / min and the processing time is 8-12 min. The centrifugation speed of 2500-3500 r / min and the processing time of 8-12 min ensure efficient separation of impurities.

[0060] In some embodiments of the present invention, optionally, the sterilization temperature is 60-80°C and the sterilization time is 10-20 minutes. Sterilization within the above temperature range and for the specified time ensures that bacteria are eliminated while preserving the nutritional components of the apple juice.

[0061] In some embodiments of the present invention, vitamin C may optionally be added to the apple juice during the fresh-pressing process, wherein the mass of vitamin C is 0.4-0.6% of the apple juice. By adding vitamin C to the apple juice during the fresh-pressing process, wherein the mass of vitamin C is 0.4-0.6% of the apple juice, oxidation and discoloration of the apple juice can be avoided during the fresh-pressing process, ensuring that the apple juice has an excellent appearance.

[0062] The following description is based on specific embodiments.

[0063] Example 1

[0064] The specific steps for preparing apple juice include: removing damaged or rotten apples, washing them 2-3 times with clean water and juicing them, adding vitamin C to protect the color during juicing (the mass of vitamin C is 0.5% of the apple juice), boiling to inactivate enzymes, filtering through a 400-mesh filter, centrifuging the filtered juice at 3000 r / min for 10 min, taking the supernatant after centrifugation and pasteurizing it for 20 min at 60℃; after cooling, adding 0.3% nanocellulose (i.e., the mass of the added nanocellulose is 0.3% of the mass of the apple juice raw material) and storing it in a refrigerator at 4℃ for later use.

[0065] Add 0 mg / L, 20 mg / L, 30 mg / L, and 50 mg / L of polyphenols such as epicatechin, chlorogenic acid, and phlorizin to apple juice, respectively. (See [reference needed]). Figures 2 to 4 As shown, polyphenols promote the release of most aromas, especially key characteristic aroma compounds such as ethyl butyrate, ethyl 2-methylbutyrate, propyl 2-methylbutyrate, and amyl acetate.

[0066] Furthermore, the addition of chlorogenic acid resulted in the highest content of aroma components in apple juice, leading to the best effect. However, the aroma enhancement effect became minimal with increasing chlorogenic acid concentration. Considering both aroma improvement and cost, a concentration of 20 mg / L of chlorogenic acid was preferred.

[0067] Furthermore, to experimentally measure the beneficial effect of adding 20 mg / L chlorogenic acid on improving the aroma quality of apple juice, the aroma components of apple juice with 0 mg / L chlorogenic acid and apple juice with 20 mg / L chlorogenic acid were determined using gas chromatography-mass spectrometry. The results are shown in Table 2, where "original juice" refers to the juice with 0 mg / L chlorogenic acid added and "added chlorogenic acid" refers to the apple juice with 20 mg / L chlorogenic acid added.

[0068] Table 2. Content of characteristic aroma components in apple juice (μg / L)

[0069]

[0070]

[0071] Table 2 shows that the content of characteristic aroma components in apple juice significantly increased after exogenous addition of 20 mg / L chlorogenic acid, resulting in a significant improvement in apple juice quality. Specifically, compared with the original juice, the apple juice with exogenous addition of 20 mg / L chlorogenic acid exhibited significantly higher yields of characteristic aroma components: ethyl butyrate (22.26 μg / L), ethyl 2-methylbutyrate (29.24 μg / L), propyl 2-methylbutyrate (4.73 μg / L), and amyl hexanoate (0.51 μg / L), effectively improving the problems of weak aroma and lack of distinctive aroma characteristics in the apple juice.

[0072] The specific method for determining the aroma components was as follows: Volatile compounds in apple juice were extracted using headspace solid-phase microextraction (HS-SPME). 5 mL of the wine sample and 50 mg / L 3-octanol (internal standard) were accurately transferred into a 20 mL headspace vial containing 1.5 g NaCl and equilibrated at 50 °C for 30 min. Subsequently, a 50 / 30 μm DVB / CAR from a PDMS fiber was inserted into the headspace vial, and extraction was performed at 50 °C for 30 min. Immediately afterwards, the sample was injected into the gas chromatograph injection port at 250 °C for 3 min to desorb the volatile compounds. GC conditions: A DB-Wax column (30 m × 0.25 mm × 0.25 μm) was used, with helium as the carrier gas at a flow rate of 1.0 mL / min. The sample was introduced into the detector along with the carrier gas. The injection port and detector temperatures were 250 °C, and the ion source temperature was 230 °C. MS conditions: EI was used as the ionization source, with an electron energy of 70 eV and a scan range of 32.0–250.0 m / z. Temperature program: Initial temperature 40℃, hold for 5 min, increase to 220℃ at a rate of 5℃ / min, then increase to 250℃ in 2.5 min and hold for 10 min. Qualitative analysis: Volatile components were qualitatively identified by comparison with the retention times and mass spectra of standard compounds.

[0073] In addition, a descriptive sensory evaluation of the aroma was conducted from six aspects: floral, fruity, sweet, green, overripe, and lingering aromas. The sensory evaluation methods are as follows:

[0074] An evaluation panel of 10 sensory evaluators (5 men and 5 women, aged 20 to 30) conducted descriptive sensory analyses of apple juice (i.e., with 0 mg / L chlorogenic acid added) and apple juice with 20 mg / L chlorogenic acid added. All panel members had extensive sensory experience in evaluating fruit juice flavors. Prior to the evaluation, the panel received training on aroma samples for calibration. Furthermore, the panel members discussed and determined to use fruity, sweet, floral, green, overripe, and lingering notes to describe the apple juice.

[0075] See evaluation results Figure 5 As shown, the "control group" represents the original fruit juice, and "apple juice with 20 mg / L chlorogenic acid" represents apple juice with 20 mg / L chlorogenic acid added. The results show that adding 20 mg / L chlorogenic acid improved the scores for fruity aroma, sweet aroma, and floral aroma in the apple juice. The scores for unripe taste, overripe taste, and lingering aroma decreased after adding 20 mg / L chlorogenic acid. Adding 20 mg / L chlorogenic acid can promote the release of some of the aromas that contribute to the fruity, floral, and sweet aromas of apple juice, and can reduce the overripe taste caused by enzyme inactivation and sterilization processes, thereby increasing the appeal of the apple juice to consumers.

[0076] Example 2

[0077] The difference between Example 2 and Example 1 is that 0.25% nanocellulose was added after pasteurization and cooling (i.e., the mass of the added nanocellulose was 0.25% of the mass of the apple juice raw material).

[0078] As shown in Table 3, 0.25% nanocellulose (i.e., the mass of the added nanocellulose is 0.25% of the mass of the apple juice raw material) was added to 1L of the obtained apple juice raw material, and the precipitation in the apple juice was observed after 1, 3, 5, 10 and 15 days with no nanocellulose added as the control group.

[0079] Table 3. Sedimentation of Apple Juice (Part 2)

[0080]

[0081] Among them, "+" indicates almost no precipitation; "++" indicates trace precipitation; "+++" indicates a small amount of precipitation; and "++++" indicates a large amount of precipitation.

[0082] Example 3

[0083] The difference between Example 3 and Example 1 is that 0.35% nanocellulose was added after pasteurization and cooling (i.e., the mass of the added nanocellulose was 0.35% of the mass of the apple juice raw material).

[0084] As shown in Table 4, 0.35% nanocellulose (i.e., the mass of the added nanocellulose is 0.35% of the mass of the apple juice raw material) was added to 1L of apple juice raw material, and the precipitation in the apple juice was observed after 1, 3, 5, 10 and 15 days with no nanocellulose added as the control group.

[0085] Table 4. Sedimentation of Apple Juice (Part 3)

[0086]

[0087] Among them, "+" indicates almost no precipitation; "++" indicates trace precipitation; "+++" indicates a small amount of precipitation; and "++++" indicates a large amount of precipitation.

[0088] Example 4

[0089] The difference between Example 4 and Example 1 is that the steps for preparing apple juice before adding 0.3% nanocellulose (i.e., the mass of the added nanocellulose is 0.3% of the mass of the apple juice raw material) are as follows:

[0090] Remove damaged or rotten apples, wash them 2-3 times with clean water and juice them. Add vitamin C to the juice during juicing to protect the color. The amount of vitamin C should be 0.5% of the apple juice. Boil the juice to inactivate the enzymes. Filter the juice through a 400-mesh filter. Centrifuge the filtered juice at 3000 rpm for 10 minutes. Take the supernatant after centrifugation and pasteurize it for 20 minutes at 60℃. After cooling, add 0.25% pectinase (i.e., the mass of pectinase is 0.25% of the apple juice mass) and stir well. Perform enzymatic hydrolysis for 8 hours and filter once through a 400-mesh filter to obtain the first-filtered apple juice.

[0091] The juice after the first filtration was centrifuged at 3000 rpm for 10 minutes for a second filtration. The supernatant after centrifugation was then pasteurized for 20 minutes at 60℃.

[0092] The following explanation is based on specific experimental data. See Tables 5 and 6 for the effects of two processing methods on the physicochemical properties and aroma of unconcentrated apple juice: the first processing method (the scheme of Example 1, i.e., "without added pectinase") and the second processing method (the scheme of Example 4, i.e., "with added 0.25% pectinase").

[0093] Table 5. Effects of two processing methods on the physicochemical properties of apple juice.

[0094]

[0095] Table 6. Effects of two processing methods on the aroma compound content of apple juice (ug / L)

[0096]

[0097]

[0098] Table 5 shows that apple juice without added pectinase has higher contents of soluble pectin and total phenols. Table 6 shows that apple juice without added pectinase has higher contents of volatile aroma compounds. There is a hydrophobic interaction between pectin molecules and volatile aroma compounds, and pectin is beneficial for preserving the aroma components of apple juice. The addition of pectinase and cellulase significantly reduced the pectin content in apple juice, affecting the interaction between pectin and aroma compounds and leading to the loss of aroma components. However, the absence of pectinase in the early stages of enzymatic hydrolysis resulted in cloudy and unstable apple juice; the addition of a certain concentration of nanocellulose in the later stages helped maintain the uniformity and stability of the juice.

[0099] This invention provides an apple juice prepared using the apple juice preparation method described in any one of the embodiments of this invention. The apple juice of this invention exhibits high stability and excellent aroma quality.

[0100] This invention provides a beverage, including the apple juice described in this invention.

[0101] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of the present invention.

Claims

1. A method for preparing apple juice, characterized in that, include: Step S1: Add nanocellulose to the apple juice ingredients and stir well; Step S2: Add apple polyphenols to the well-stirred apple juice raw materials and stir well to obtain apple juice. The concentration of apple polyphenols in the apple juice raw material is 20-50 mg / L, and the mass of nanocellulose is 0.25-0.35% of the mass of the apple juice raw material.

2. The method for preparing apple juice according to claim 1, characterized in that, The apple polyphenols include at least one of epicatechin, chlorogenic acid, and phlorizin.

3. The method for preparing apple juice according to claim 1, characterized in that, Step S1 is preceded by: Step S3: Boil the freshly squeezed apple juice to inactivate the enzymes, then cool it. Centrifuge the cooled apple juice and filter it to obtain the supernatant of the apple juice. The supernatant of the apple juice is sterilized to obtain the apple juice raw material.

4. The method for preparing apple juice according to claim 1, characterized in that, Step S1 is preceded by: Step S4: Boil the freshly squeezed apple juice to inactivate the enzymes, then cool it. Add pectinase to the cooled apple juice and stir well. After enzymatic hydrolysis, filter it once to obtain apple juice after one filtration. Step S5: After centrifugation, the apple juice after the first filtration is filtered a second time to obtain the supernatant of the apple juice. The supernatant of the apple juice is then sterilized to obtain the apple juice raw material.

5. The method for preparing apple juice according to claim 3 or 4, characterized in that, The temperature for inactivating enzymes by boiling is 85-95℃.

6. The method for preparing apple juice according to claim 3 or 4, characterized in that, The centrifugation speed is 2500-3500 r / min, and the processing time is 8-12 min.

7. The method for preparing apple juice according to claim 3 or 4, characterized in that, The sterilization temperature is 60-80℃, and the sterilization time is 10-20 minutes.

8. The method for preparing apple juice according to claim 3 or 4, characterized in that, Vitamin C is added to apple juice during the fresh juicing process, with the amount of vitamin C being 0.4-0.6% of the apple juice weight.

9. An apple juice, characterized in that, Prepared using the method for preparing apple juice according to any one of claims 1-8.

10. A beverage, characterized in that, Includes the apple juice as described in claim 9.

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