Method for preparing solid beverage based on citrus peels

Abstract

The invention discloses a method for preparing a solid beverage based on citrus peels, and belongs to the technical field of solid beverages. The method comprises the following steps: firstly, pre-treating collected fresh orange peels, and sequentially carrying out superfine grinding and colloid fine grinding on the pre-treated orange peels to obtain orange peel pulp; performing cell wall enzymolysis modification on the obtained citrus peel pulp; carrying out hot salt alkaline liquid-enzyme synergistic debitterizing treatment on the modified material liquid to obtain main slurry; and blending the obtained main slurry, and carrying out spray drying on the blended slurry to obtain the solid beverage based on the citrus peels. Through a set of innovative and systematic preparation technology, multiple technical bottlenecks of the citrus peel solid beverage in flavor, nutrition, quality and production efficiency are synchronously solved, so that a high-quality product with good taste, rich nutrition and excellent brewing performance is developed.

Description

I. TECHNICAL FIELD

[0001] The application belongs to the technical field of solid beverage, and particularly relates to a method for preparing a solid beverage based on citrus peel. II. BACKGROUND

[0002] Citrus is one of the fruits with the largest global yield, and a large amount of by-products, i.e. citrus peels, are generated in the processing of juice extraction and canning. According to statistics, the citrus peel accounts for 40-50% of the weight of the fruit. At present, except for a small amount of citrus peels being used as traditional Chinese medicinal materials (dried tangerine or orange peel) or simply processed into candied fruits, most of the citrus peels are discarded as waste. On the one hand, the discarded citrus peels are prone to corruption and fermentation in the natural environment, breed molds, and cause environmental pollution; on the other hand, the citrus peels are rich in various high-value functional ingredients, and the discarding of the citrus peels is a great waste of resources. Studies have shown that the citrus peels are rich in dietary fiber (especially functional pectin), flavonoids (such as hesperidin and naringin), natural pigments (such as carotenoids), vitamins, and limonoids, and have various physiological activities such as antioxidant, digestion aid, blood lipid regulation, and immune enhancement. Therefore, how to efficiently and high-value utilize the citrus peels to turn waste into treasure has become an important research direction in the food processing industry.

[0003] At present, there are related technologies for developing the citrus peels into solid beverages, and the methods mainly include the following:

[0004] (1) Direct drying and pulverization method: the citrus peels are washed, then subjected to hot air drying or sun drying, and then subjected to mechanical pulverization or ultra-micro pulverization to obtain citrus whole peel powder.

[0005] (2) Single target extraction method: focusing on obtaining specific components in the citrus peels. For example, pectin extraction method: pectin is extracted by acid method or enzyme method, the residue is discarded, and the extract is concentrated and mixed with excipients for spray drying; or flavonoid extraction method: flavonoid extract is obtained by alcohol extraction, and then a solid beverage is prepared.

[0006] (3) Powder method with preliminary treatment: the method is subjected to simple treatment before drying and pulverization, such as water soaking, alkali solution treatment, and the like for preliminary debittering, and then subjected to drying, pulverization (including ultra-micro pulverization) and spray drying.

[0007] Although the existing methods for developing citrus provide ideas for the utilization of citrus peels, they all have systematic defects, and cannot well balance the retention of nutrients and flavor, production efficiency and product quality.

[0008] (1) Difficulty in simultaneous retention of nutrients and flavor

[0009] Direct drying and pulverizing methods, as well as preliminary powdering methods, while striving to retain all nutritional components, are insufficient in addressing the strong bitterness (mainly from limonenes such as naringin). Simple soaking or single-alkali treatment often fails to completely remove bitterness, or due to excessive processing time or harsh conditions, leads to the significant loss of water-soluble vitamins, aroma components, and some flavonoids, creating a contradiction between "preserving nutrition" and "removing bitterness." The final product is either nutritionally acceptable but bitter and unpleasant to drink, or has acceptable flavor but significantly reduced nutritional value.

[0010] (2) Insufficient extraction and utilization of functional components:

[0011] Single-target extraction methods: Pectin extraction discards the filter residue rich in flavonoids and dietary fiber, resulting in resource waste; flavonoid extraction may lose functional components such as pectin. Neither of these methods achieves efficient and synergistic utilization of all components of citrus peel.

[0012] Furthermore, existing technologies (including the use of ultrafine grinding) have failed to effectively solve the problems of adhesion, clumping, and decreased solubility of macromolecules such as pectin during subsequent processing. Although simple physical grinding reduces the particle size, it does not involve bio-enzymatic modification of pectin, and its high viscosity characteristics remain.

[0013] (3) The debittering process is inefficient:

[0014] Existing debittering techniques, such as prolonged soaking in running water, consume large amounts of water, are inefficient, and are a major source of water-soluble nutrient loss. While using a single alkaline solution for debittering improves efficiency, excessively strong or prolonged alkaline treatment can damage the chemical structure of flavonoids, causing them to degrade and become inactive, and promoting Maillard reactions that lead to darker color and unpleasant flavors.

[0015] (4) Unstable product quality:

[0016] In the spray drying process, due to the lack of effective homogenization and viscosity control of the material system during pretreatment, the spray drying process is prone to sticking to the walls and clogging the tower, resulting in low product yield and poor solubility and flowability of the final powder, leading to unstable quality.

[0017] In summary, existing citrus peel processing technologies lack a synergistic process that can systematically integrate debittering, enzymatic hydrolysis, homogenization, and drying. They cannot efficiently remove bitterness while maximizing the preservation and activation of the various natural nutrients in citrus peel, ultimately resulting in high-value solid beverage products with good solubility, excellent flavor, and stable quality. III. Summary of the Invention:

[0018] The technical problem this invention aims to solve is: addressing the shortcomings of existing citrus peel processing technologies, this invention provides a method for preparing solid beverages based on citrus peel. The technical solution of this invention, through a series of synergistically optimized process steps, particularly the "ultra-micro homogenization integration" process and "enzymatic modification and hot saline-alkaline solution-enzyme synergistic debittering," successfully solves the technical difficulties of poor product quality and the inability to simultaneously achieve both nutritional value and flavor in traditional processes.

[0019] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0020] This invention provides a method for preparing a solid beverage based on citrus peel, the preparation method comprising the following steps:

[0021] a. Pre-treat the collected fresh citrus peels;

[0022] b. The pretreated citrus peel is subjected to ultrafine grinding and colloid milling in sequence to obtain citrus peel pulp;

[0023] c. Modify the obtained citrus peel pulp by enzymatic hydrolysis of cell walls;

[0024] d. The modified liquid is subjected to hot saline-alkali solution-enzyme synergistic debittering treatment to obtain the main slurry;

[0025] e. Blend the main pulp obtained after debittering;

[0026] f. Spray dry the prepared slurry to obtain a solid beverage based on citrus peel.

[0027] According to the above method for preparing solid beverages based on citrus peel, the specific process of pre-treatment of fresh citrus peel in step a is as follows: remove the rotten parts from the collected fresh citrus peel, rinse with running water to remove surface impurities, and then soak in a food-grade citric acid solution with a mass percentage concentration of 0.5-2% for 5-15 minutes (soaking is used to preliminarily soften the tissue and remove some pesticide residues); after soaking, take it out, drain the water, and place it in a forced-air drying oven to dry at 50-70℃ until constant weight.

[0028] According to the above method for preparing solid beverages based on citrus peel, the specific process of ultrafine pulverization and fine grinding in step b is as follows: the pretreated citrus peel is cut into pieces and then put into an ultrafine pulverizer for pulverization for 8-10 minutes, and then passed through a 100-mesh sieve; the sieved citrus peel powder is mixed with water at a weight ratio of 1:12-20 to make a pulp, and after pulping, it is subjected to a cyclic fine treatment through a colloid mill, controlling the gap so that the particle size of the final material reaches ≤20μm, and citrus peel pulp is obtained (this step aims to break the plant cell wall, achieve the ultimate homogenization of the material, greatly increase the specific surface area, create favorable conditions for subsequent efficient debittering and enzymatic hydrolysis reactions, ensure that pectin decomposition products, fiber, flavonoids and other components are evenly dispersed, form a stable emulsion system, thereby giving the final product excellent solubility and smooth taste, without any gritty feeling).

[0029] According to the above method for preparing solid beverages based on citrus peel, the specific process of cell wall enzymatic hydrolysis modification in step c is as follows: the temperature of the obtained citrus peel pulp is adjusted to 40-55℃, and the pH is adjusted to 3.0-4.5 (the optimal pH for pectinase) with citric acid; then, 0.15-0.3% of pectinase by weight of the total citrus peel pulp is added, and the mixture is kept at a constant temperature and stirred for 1.5-3 hours for enzymatic hydrolysis (pectinase can effectively decompose the pectin macromolecules in the pulp, significantly reducing the viscosity of the system, which is not only beneficial for subsequent spray drying and prevents sticking to the wall, but also releases bitter substances such as naringin and limonene encapsulated by pectin and nutrients, improving debittering efficiency, product solubility and bioavailability).

[0030] According to the above method for preparing solid beverages based on citrus peel, the specific process of the hot saline-alkaline solution-enzyme synergistic debittering treatment in step d is as follows: Add 2-5% NaCl (by mass percentage) to the enzymatically modified liquid, control the liquid-to-solid ratio at 10-20:1, heat to 90-100℃, and maintain this temperature for 20-30 minutes; then cool the liquid to room temperature, filter or centrifuge the liquid, and discard the bitter filtrate; wash the resulting filter residue (peel pulp) 1-2 times with clean water (to remove residual salt and bitter substances), and drain or centrifuge the washed material. Obtain a wet peel pulp; then add 2-8% CaCO3 by weight of the obtained wet peel pulp, followed by water, controlling the liquid-to-solid ratio at 10-20:1, and stir the reaction for 60-120 minutes; filter or centrifuge the reaction liquid, discarding the bitter filtrate; wash the obtained filter residue, i.e., peel pulp, with clean water 1-2 times (to remove residual salt and bitter substances), drain or centrifuge to obtain a wet peel pulp again (under the synergistic effect of this mild weak alkalinity and salt ions, bitter substances such as naringin can be efficiently dissolved and destroyed, while avoiding the damage and residue risk of strong alkali to nutrients);

[0031] Enzymatic debittering: Water is added to the obtained citrus wet peel pulp, and the liquid-to-solid ratio is controlled at 10-15:1 (to facilitate stirring and enzymatic hydrolysis). First, the pH value is adjusted to 6.5-7.5 with 0.05-0.1 mol / L NaOH. Then, 0.3-0.5% (w / w) of naringin hydrolysate is added at a liquid-to-solid ratio of 1:10-15. Enzymatic hydrolysis is carried out at 50-55℃ for 60-120 minutes (this step can significantly and efficiently remove bitter substances from citrus peel, giving the product better palatability). After enzymatic hydrolysis, the material is immediately heated to 85-90℃ and kept at 5-10 minutes to inactivate the enzyme.

[0032] According to the above-described method for preparing solid beverages based on citrus peel, the naringin hydrolysate is prepared by mixing naringinase and water, with a mass percentage concentration of 0.3-0.5%.

[0033] According to the above method for preparing solid beverages based on citrus peel, the specific process of preparation in step e is as follows: maltodextrin is added to the main slurry obtained in step d, heated to 60-65°C and continuously stirred until completely dissolved (the system becomes uniform and viscous); then, white sugar, citric acid and vitamin C are added in sequence and stirred evenly until the liquid is completely dissolved to obtain the prepared slurry.

[0034] According to the above method for preparing solid beverages based on citrus peel, the amount of maltodextrin used accounts for 10-20% of the weight of the main slurry; the amount of white sugar used accounts for 15-25% of the weight of the main slurry; the amount of citric acid used accounts for 0.3-0.8% of the weight of the main slurry; and the amount of vitamin C used accounts for 0.1-0.3% of the weight of the main slurry.

[0035] According to the above method for preparing solid beverages based on citrus peel, during the spray drying in step f, the pressure of the spray dryer pressure pump is controlled to be 0.2-0.4 MPa, the feed flow rate of the material during drying is 600-800 mL / h, the inlet air temperature is 150-170℃, and the outlet air temperature is 70-80℃.

[0036] In addition, this invention provides an application of the solid beverage based on citrus peel prepared in this invention in the preparation of functional foods that aid digestion, regulate the intestines, provide antioxidant effects, and soothe the throat.

[0037] In the technical solution of this invention, a two-stage fine processing route of "ultrafine grinding (to 50-150μm) → colloid mill homogenization (to below 20μm)" is adopted: ultrafine grinding creates a sufficient reaction interface for subsequent enzymatic hydrolysis and debittering, while colloid mill homogenization ensures the extreme uniformity and stability of the material system, which is the physical basis for the final product to obtain excellent solubility and smooth taste.

[0038] The technical solution of this invention employs cell wall enzymatic modification and a "hot saline-alkali solution-enzyme synergistic debittering" process: Cell wall enzymatic modification is used as a prerequisite step for hot saline-alkali solution-enzyme synergistic debittering, which not only releases bitter substances (naringin, limonene, etc.) encapsulated in pectin, improving debittering efficiency, but also releases nutrients, which is beneficial for subsequent spray drying, prevents adhesion to the cell walls, and solves processing problems. The integration of these two steps is one of the core concepts of this invention.

[0039] The technical solution of this invention adopts a mild and efficient hot saline-alkali debittering system: a composite aqueous solution of sodium chloride and calcium carbonate is used as the debittering agent. This system utilizes the osmotic effect of salt and the decomposition effect of weak alkali to synergistically debitter. Compared with single strong alkali treatment, it can significantly reduce the damage to nutrients and the risk of chemical residues, and achieve the best balance between debittering efficiency and nutrient retention.

[0040] The positive and beneficial effects of this invention are:

[0041] 1. This invention resolves the contradiction between "bitterness removal" and "nutrient preservation" in existing citrus peel processing technologies: The technical solution of this invention is a highly efficient and gentle bitterness removal process that can completely remove or significantly reduce the bitterness caused by limonene such as naringin in citrus peel, while retaining its heat-sensitive flavonoids, vitamins and natural aroma components to the maximum extent, avoiding excessive loss of these high-value nutrients during the bitterness removal process.

[0042] 2. This invention achieves efficient and high-value utilization of all components of citrus peel: Through process innovation, this invention avoids the defects of discarding filter residue in existing single extraction methods. Instead, it synergistically and completely preserves and utilizes dietary fiber, pectin, flavonoids and other components in citrus peel in the final product, realizing the transformation from "extracting some active substances" to "utilizing the essence of the whole peel", thus improving resource utilization.

[0043] 3. This invention improves the processing performance and final quality of the product: The technical solution of this invention can effectively solve the difficulties in subsequent processing (especially spray drying) caused by high viscosity components such as pectin in citrus peel, such as sticking to the wall, clogging the tower, and low yield; and using the technical solution of this invention, a solid beverage with good solubility, good fluidity, no gritty feeling, and uniform and stable solution after brewing can be prepared.

[0044] 4. This invention improves the efficiency of the debittering process: Through the technical solution of this invention, the debittering conditions are optimized, avoiding long-term soaking with huge water consumption or long-term strong alkali treatment, thereby providing a more efficient debittering solution that is shorter in time and gentler.

[0045] 5. The content of relevant components of the citrus peel solid beverage prepared by this invention is detailed in Table 1.

[0046] Table 1. Contents of relevant ingredients in the citrus peel solid beverage of the present invention.

[0047]

[0048] 6. Brewing performance of the citrus peel solid beverage prepared by this invention: The citrus peel solid beverage of this invention completely dissolves in 200mL of water at 80℃ in ≤30 seconds, with no obvious clumping observed. Thirty trained sensory evaluators were organized to evaluate the texture using a scoring method (1-30 points). The evaluation results are detailed in Table 2.

[0049] Table 2 Evaluation results of the brewing performance of the citrus peel solid beverage of the present invention

[0050]

[0051] Most evaluators considered the product of this invention to have good solubility, clear and uniform color, and no impurities. The average sensory score for this item was ≥23 points (out of 30).

[0052] In summary, this invention employs a gentle "hot saline-alkaline solution-enzyme" synergistic debittering process, effectively removing bitterness while maximizing the retention of flavonoids, vitamins, and aroma components. This successfully resolves the contradiction between "debittering" and "preserving nutrition," resulting in a solid beverage with excellent flavor and nutritional value. The entire process generates no waste, fully utilizing the dietary fiber, pectin, and flavonoids in citrus peels, achieving waste-to-treasure transformation and maximizing resource utilization, ensuring high-value utilization of all components. This invention fundamentally solves the problems of product adhesion, solubility, and mouthfeel through a combination of "ultra-fine pulverization + colloid mill homogenization + cell wall enzymatic modification," resulting in a product with rapid dissolution, a uniform and stable solution, and a smooth taste. Therefore, this invention, through an innovative and systematic preparation process, simultaneously solves multiple technical bottlenecks in the flavor, nutrition, quality, and production efficiency of citrus peel solid beverages, thereby developing a high-quality product with excellent taste, rich nutrition, and superior reconstitution performance. IV. Detailed Implementation Methods:

[0053] The present invention will be further illustrated below with reference to the embodiments, but this does not limit the scope of protection of the technical solution of the present invention.

[0054] Example 1:

[0055] The present invention relates to a method for preparing solid beverages based on citrus peel, the detailed steps of which are as follows:

[0056] a. Remove rotten parts from 1000g of fresh citrus peels (from oranges, tangerines, grapefruits, lemons, etc.), rinse with running water to remove surface dirt and other impurities, and then soak in a 1% food-grade citric acid solution for 10 minutes (soaking is used to initially soften the tissue and remove some pesticide residues); after soaking, take it out, drain the water, and place it in a forced-air drying oven to dry at 65℃ until constant weight;

[0057] b. Cut the pretreated citrus peel into pieces, then put them into an ultra-fine pulverizer and pulverize for 8 minutes, then pass them through a 100-mesh sieve; mix the sieved citrus peel powder with water at a weight ratio of 1:15 to make pulp, and then process it through a colloid mill for fine circulation, controlling the gap so that the particle size of the final material reaches ≤20μm (this step aims to break the plant cell wall, achieve the ultimate homogenization of the material, greatly increase the specific surface area, create favorable conditions for the subsequent efficient debittering and enzymatic hydrolysis reaction, ensure that pectin decomposition products, fiber, flavonoids and other components are evenly dispersed, form a stable emulsion system, thereby giving the final product excellent solubility and smooth taste, without any gritty feeling), to obtain citrus peel pulp;

[0058] c. Adjust the temperature of the obtained citrus peel pulp to 45℃ and adjust the pH to 4.5 (the optimal pH for pectinase) with citric acid; then add 0.2% pectinase by weight of the total citrus peel pulp, maintain constant temperature and stir for 2 hours to obtain the enzymatically modified liquid (adding pectinase can effectively decompose the pectin macromolecules in the pulp and significantly reduce the viscosity of the system, which is not only beneficial for subsequent spray drying and prevents sticking to the wall, but also releases bitter substances such as naringin and limonene encapsulated by pectin and nutrients, improving debittering efficiency, product solubility and bioavailability).

[0059] d. Hot saline-alkali solution debittering: Add a 3% (w / w) NaCl solution to the enzymatically modified solution, controlling the liquid-to-solid ratio at 15:1. Heat to 95°C and maintain at this temperature for 30 minutes. Then cool the solution to room temperature, filter the solution, and discard the bitter filtrate. Wash the resulting filter residue twice with clean water (to remove residual salt and bitter substances), and drain the washed material to obtain wet peel pulp. Then add 5% (w / w) CaCO3 of the obtained wet peel pulp, and then add water and stir for 60 minutes (controlling the liquid-to-solid ratio at 15:1). Filter the reaction solution, discard the bitter filtrate, and wash the resulting filter residue, i.e., peel pulp, twice with clean water (to remove residual salt and bitter substances), and drain to obtain wet peel pulp again (under the synergistic effect of this mild weak alkali and salt ions, bitter substances such as naringin can be efficiently dissolved and destroyed, while avoiding the damage and residue risk of strong alkali to nutrients).

[0060] Enzymatic debittering: Water is added to the obtained citrus wet peel pulp, and the liquid-to-solid ratio is controlled at 12:1 (to facilitate stirring and enzymatic hydrolysis). The pH value is first adjusted to 7 with 0.1 mol / L NaOH, and then 0.5% (w / w) of naringin hydrolysate is added at a liquid-to-solid ratio of 1:15. Enzymatic hydrolysis is carried out at 55℃ for 60 min (this step can significantly and efficiently remove bitter substances from citrus peel, giving the product better palatability). After enzymatic hydrolysis, the material is immediately heated to 90℃ and kept at 10 min to inactivate the enzyme.

[0061] The naringin hydrolysate is prepared by mixing naringinase and water, with a mass percentage concentration of 0.5%.

[0062] e. Add maltodextrin to the main slurry obtained in step d, heat to 65°C and stir continuously until completely dissolved (the system becomes uniform and viscous); then add white sugar, citric acid and vitamin C in sequence, and stir until the liquid is completely dissolved to obtain the prepared slurry;

[0063] The amount of maltodextrin (DE10-20) is 16% of the weight of the main slurry, the amount of white sugar is 20% of the weight of the main slurry, the amount of citric acid is 0.5% of the weight of the main slurry, and the amount of vitamin C is 0.20% of the weight of the main slurry.

[0064] f. Spray dry the prepared slurry, controlling the pressure of the spray dryer pressure pump to be 0.25 MPa, the injection flow rate to be 600 mL / h, the inlet air temperature to be 160℃, and the outlet air temperature to be 75℃. After drying, approximately 350 g of citrus peel solid beverage with a slightly yellow color, natural orange aroma, and excellent solubility is obtained.

[0065] In the preparation process of this invention, the slurry undergoes efficient enzymatic hydrolysis to reduce viscosity and homogenization by colloid milling, resulting in good slurry fluidity. Under these drying conditions, it can quickly form microsphere powder with uniform particle size, good fluidity, and good solubility, effectively solving the problem of wall adhesion and improving product yield.

[0066] The solid beverage based on citrus peel prepared by this invention can be used in the preparation of functional foods that aid digestion, regulate the intestines, provide antioxidant effects, and soothe the throat.

Claims

1. A method for preparing solid beverages based on citrus peel, characterized in that, The preparation method includes the following steps: a. Pre-treat the collected fresh citrus peels; b. The pretreated citrus peel is subjected to ultrafine grinding and colloid milling in sequence to obtain citrus peel pulp; c. Modify the obtained citrus peel pulp by enzymatic hydrolysis of cell walls; d. The modified liquid is subjected to hot saline-alkali solution-enzyme synergistic debittering treatment to obtain the main slurry; e. Blend the main pulp obtained after debittering; f. Spray dry the prepared slurry to obtain a solid beverage based on citrus peel.

2. The method for preparing solid beverages based on citrus peel according to claim 1, characterized in that, The specific process for pre-treating the fresh citrus peels in step a is as follows: remove the rotten parts from the collected fresh citrus peels, rinse them with running water to remove surface impurities, and then soak them in a food-grade citric acid solution with a mass percentage concentration of 0.5-2% for 5-15 minutes; after soaking, remove them, drain the water, and place them in a forced-air drying oven to dry at 50-70℃ until constant weight.

3. The method for preparing solid beverages based on citrus peel according to claim 1, characterized in that, The specific process of ultrafine pulverization and fine grinding in step b is as follows: the pretreated citrus peel is cut into pieces and then put into an ultrafine pulverizer for pulverization for 8-10 minutes, and then passed through a 100-mesh sieve; the sieved citrus peel powder is mixed with water at a weight ratio of 1:12-20 to make pulp, and after pulping, it is circulated and finely processed through a colloid mill, and the gap is controlled so that the particle size of the final material reaches ≤20μm to obtain citrus peel pulp.

4. The method for preparing solid beverages based on citrus peel according to claim 1, characterized in that, The specific process of cell wall enzymatic hydrolysis modification in step c is as follows: the temperature of the obtained citrus peel pulp is adjusted to 40-55℃, and the pH is adjusted to 3.0-4.5 with citric acid; then, 0.15-0.3% of pectinase is added according to the total weight of the citrus peel pulp, and the enzymatic hydrolysis is carried out by stirring at a constant temperature for 1.5-3 hours.

5. The method for preparing solid beverages based on citrus peel according to claim 1, characterized in that, The specific process of the hot saline-alkaline solution-enzyme synergistic debittering treatment described in step d is as follows: Add 2-5% NaCl (by mass) to the enzymatically modified solution, controlling the liquid-to-solid ratio at 10-20:1, heat to 90-100℃, and maintain this temperature for 20-30 minutes; then cool the solution to room temperature, filter or centrifuge the solution, and discard the bitter filtrate; wash the resulting filter residue (peel pulp) 1-2 times with clean water, drain or centrifuge the washed material to obtain wet peel pulp; then add 2-8% CaCO3 (by weight of the obtained wet peel pulp), followed by water, controlling the liquid-to-solid ratio at 10-20:1, and stir the reaction for 60-120 minutes; filter or centrifuge the reacted solution, discarding the bitter filtrate; wash the resulting filter residue (peel pulp) 1-2 times with clean water, drain or centrifuge again to obtain wet peel pulp; Enzymatic debittering: Water is added to the obtained citrus wet peel pulp, and the liquid-to-solid ratio is controlled at 10-15:

1. The pH value is first adjusted to 6.5-7.5 with 0.05-0.1 mol / L NaOH. Then, 0.3-0.5% (w / w) of naringin enzymatic hydrolysate is added at a liquid-to-solid ratio of 1:10-15. Enzymatic hydrolysis is carried out at 50-55℃ for 60-120 min. After enzymatic hydrolysis, the material is immediately heated to 85-90℃ and kept at 5-10 min to inactivate the enzyme.

6. The method for preparing solid beverages based on citrus peel according to claim 5, characterized in that: The naringin hydrolysate is prepared by mixing naringinase and water, with a mass percentage concentration of 0.3-0.5%.

7. The method for preparing solid beverages based on citrus peel according to claim 1, characterized in that, The specific process of preparation in step e is as follows: add maltodextrin to the main slurry obtained in step d, heat to 60-65°C and stir continuously until completely dissolved; then add white sugar, citric acid and vitamin C in sequence, stir evenly until the liquid is completely dissolved, and obtain the prepared slurry.

8. The method for preparing solid beverages based on citrus peel according to claim 7, characterized in that: The amount of maltodextrin used is 10-20% of the weight of the main slurry; the amount of white sugar used is 15-25% of the weight of the main slurry; the amount of citric acid used is 0.3-0.8% of the weight of the main slurry; and the amount of vitamin C used is 0.1-0.3% of the weight of the main slurry.

9. The method for preparing solid beverages based on citrus peel according to claim 1, characterized in that, During the spray drying process described in step f, the pressure of the spray dryer pressure pump is controlled to be 0.2–0.4 MPa, the sample feed rate is 600–800 mL / h, the inlet air temperature is 150–170 °C, and the outlet air temperature is 70–80 °C.

10. The application of the citrus peel-based solid beverage prepared according to claim 1 in the preparation of functional foods that aid digestion, regulate the intestines, provide antioxidant effects, and soothe the throat.

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