Method for debitterizing and deacidifying fruit juice with high pulp content and debitterized and deacidified fruit juice

Abstract

The invention belongs to the field of fruit juice preparation, and particularly relates to a method for debitterizing and deacidifying fruit juice with high pulp content and debitterized and deacidified fruit juice. The debitterizing and deacidifying method for the fruit juice with the high pulp content comprises the working procedures of juicing, centrifugal filtration, deacidification, sterilization, filling, oxidation resistance, bottle opening sealing, secondary high-temperature disinfection, packaging, finished product cold storage and the like, bitterness and excessive acidity in the fruit juice can be effectively removed, and meanwhile the nutritional ingredients and the natural flavor of the fruit juice are reserved; and the generated sodium citrate can enhance the roundness of the juice and avoid metal astringent taste, and can be used as a stabilizer and a preservative to ensure the quality of the juice. Verification experiments show that the fruit juice prepared by the method disclosed by the invention is superior to fruit juice prepared by a traditional method in sensory evaluation and nutritional ingredients, and has a wide market application prospect.

Description

Technical Field

[0001] The invention belongs to the field of fruit juice preparation, and particularly relates to a method for debittering and deacidifying fruit juice with a high pulp content and a debittered and deacidified fruit juice. Background Art

[0002] As people's living standards improve, more and more people are paying more attention to the nutrition and convenience of their diet. As a result, the demand for fruit juice is growing. Citrus juice is popular because it is rich in vitamins, minerals and natural pulp fiber, but its processing has two major technical bottlenecks:

[0003] (1) Bitter substances (such as naringin and limonin) are mainly concentrated in seeds and pits. Traditional juicing processes can easily cause seed breakage, leading to the release of bitterness.

[0004] (2) The organic acid content is too high (citric acid accounts for more than 5%), causing the pH value of the juice to be as low as 4-5, and the taste is sharp and irritating.

[0005] While existing technologies can remove bitterness, adsorption resins can result in pulp loss rates as high as 30%. Conventional alkali neutralization can easily cause localized pH fluctuations, resulting in a salty and astringent taste. Especially for highly concentrated juices with pulp content exceeding 15%, existing processes struggle to balance debittering efficiency with nutrient retention. Therefore, a processing method that simultaneously addresses bitterness and acidity while maximizing pulp nutritional retention is urgently needed.

[0006] Therefore, based on this, the technical solution of the present invention is proposed. Summary of the Invention

[0007] In order to solve the problems existing in the prior art, the present invention provides a method for debittering and deacidifying juice with a high pulp content, the method comprising the following steps:

[0008] (1) Juicing: The fresh pulp is first roughly squeezed to separate the seeds and obtain debittered pulp particles; then the debittered pulp particles are juiced again to obtain debittered pulp;

[0009] (2) centrifugal filtration: centrifuging the debittered pulp and filtering the pomace to obtain debittered juice;

[0010] (3) deacidification: adding an alkaline deacidifier to the debittered juice and stirring to obtain a debittered and deacidified juice;

[0011] (4) Sterilization: Sterilize the debittered and deacidified juice by heating.

[0012] Preferably, in step (1), the rotation speed of the rough pressing is 800-1000 r / min, and the rough pressing time is 10-15 s.

[0013] Preferably, in step (1), the rotation speed of the re-juicing is 1200-1500 r / min, and the time of the re-juicing is 20-30 s.

[0014] Preferably, in step (3):

[0015] The alkaline deacidifier is sodium carbonate (Na2CO3), used in an amount of 0.2-0.5 wt% of the debittered juice. Sodium carbonate (Na2CO3) reacts chemically with citric acid (C6H8O7) in the juice while stirring to produce sodium citrate, carbon dioxide, and water. The reaction equation is C6H8O7 + 3Na2CO3 = Na3C6H5O7 + 3CO2↑ + 3H2O. The pH of the juice before the reaction is approximately 4-5, and after the reaction, the pH is approximately 6-8, thereby achieving the purpose of deacidification and ensuring the juice has an ideal taste. Furthermore, the amount of sodium citrate produced is small and is widely used in the food industry.

[0016] And / or, the stirring speed is 50-60 r / min, and the stirring time is 20-30 min.

[0017] Preferably, in step (4), the heating method is: using ultra-high temperature instantaneous sterilization technology (UHT) to heat the debittered and deacidified juice to 135-150° C. and maintain it for 2-8 seconds.

[0018] Preferably, the method for debittering and deacidifying juice with a high pulp content further comprises the steps of filling, anti-oxidation, bottle sealing, secondary high-temperature sterilization, packaging and cold storage of the finished product.

[0019] Preferably, the temperature of the secondary high-temperature disinfection is 80-90° C., and the disinfection time is 60-80 seconds.

[0020] Based on the same technical concept, the present invention further provides a debittered and deacidified juice obtained by the juice debittering and deacidifying method.

[0021] The beneficial effects of the present invention are:

[0022] The present invention provides a method for debittering and deacidifying high-pulp juice. This method uses a sophisticated juicing process to separate the bitter seeds. Sodium carbonate is then used as an alkaline deacidifier to chemically react with the acidic substances in the juice, effectively reducing the acidity of the juice while preserving its natural flavor and nutritional components. Ultra-high temperature instantaneous sterilization technology is used for sterilization, ensuring the microbial safety of the juice while preventing high temperatures from damaging the juice's nutritional components. The beneficial effects of the present invention are primarily reflected in the following aspects:

[0023] (1) Double juicing for synergistic debittering: The first rough pressing (800-1000 r / min) accurately separates the whole kernels to prevent the dissolution of bitter substances; the second fine pressing (1200-1500 r / min) makes the pulp crushing rate reach more than 92%, which is significantly higher than the 70% of single juicing (see verification example for comparative data);

[0024] (2) Directed acid-base balance: Sodium carbonate and citric acid are precisely controlled according to the reaction formula C6H8O7+3Na2CO3=Na3C6H5O7+3CO2↑+3H2O. The final product, sodium citrate, can enhance the roundness of the juice, avoid metallic astringency, and act as a stabilizer and preservative to ensure the quality of the juice.

[0025] (3) High nutrient retention: UHT sterilization (135-150℃ / 2-8s) enables vitamin C retention rate >95%, which is much better than pasteurization’s 80%;

[0026] (4) Improved pulp stability: Filtration combined with nitrogen antioxidants ensures that the pulp particles suspended in the juice are evenly distributed, and there is no stratification during the shelf life. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0029] To make the objectives, technical solutions, and advantages of the present invention more apparent, the technical solutions of the present invention will be described in detail below. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other implementations obtained by those of ordinary skill in the art without inventive effort are within the scope of protection of the present invention.

[0030] Example 1

[0031] This embodiment provides a method for debittering and deacidifying juice with a high pulp content, the method comprising the following steps:

[0032] (1) Juicing: fresh tangerine pulp was placed in a juicer and roughly squeezed at 800 r / min for 15 s to separate the seeds (because the seeds are bitter) and obtain debittered pulp particles; then the debittered pulp particles were placed in a juicer again and juiced again at 1200 r / min for 30 s to obtain debittered pulp;

[0033] (2) centrifugal filtration: centrifuging the debittered pulp, and then filtering the pulp through a sieve to obtain debittered juice;

[0034] (3) Deacidification: The debittered juice is transferred to a reaction tank, and 0.2 wt% sodium carbonate is added and stirred at 50 rpm for 30 min to obtain debittered and deacidified juice. If the mass of the debittered juice is 100 g, 0.2 g of sodium carbonate is added, and after sufficient reaction, about 0.16 g of sodium citrate is obtained, which can enhance the roundness of the juice, avoid metallic astringency, and act as a stabilizer and preservative to ensure the quality of the juice.

[0035] (4) Sterilization: Using ultra-high temperature instantaneous sterilization technology, the debittered and deacidified juice is rapidly heated to 135° C. and maintained for 8 seconds to obtain sterilized juice;

[0036] (5) Filling: Filling the sterilized juice and retaining a certain volume for subsequent nitrogen retention;

[0037] (6) Antioxidation: Add nitrogen to the bottled juice to prevent the juice from oxidation;

[0038] (7) Sealing the bottle: Seal the bottled juice that has been added with nitrogen;

[0039] (8) Secondary high-temperature disinfection: rinse with 80°C hot water for 80 seconds for disinfection;

[0040] (9) Packaging: Packaging, labeling and coding the bottled juice after secondary high-temperature sterilization;

[0041] (10) Storage of finished products in cold storage: The packaged juice is transported to cold storage for storage and sale.

[0042] Example 2

[0043] This embodiment provides a method for debittering and deacidifying juice with a high pulp content, the method comprising the following steps:

[0044] (1) Juicing: fresh tangerine pulp was placed in a juicer and roughly squeezed for 10 seconds at 1000 r / min to separate the seeds (because the seeds contain bitterness) and obtain debittered pulp particles; then the debittered pulp particles were placed in a juicer again and juiced for another 20 seconds at 1500 r / min to obtain debittered pulp;

[0045] (2) centrifugal filtration: centrifuging the debittered pulp, and then filtering the pulp through a sieve to obtain debittered juice;

[0046] (3) Deacidification: The debittered juice is transferred to a reaction tank, and 0.5 wt% sodium carbonate is added and stirred at 60 rpm for 20 min to obtain debittered and deacidified juice. If the mass of the debittered juice is 100 g, 0.5 g of sodium carbonate is added, and after sufficient reaction, about 0.41 g of sodium citrate is obtained, which can enhance the roundness of the juice, avoid metallic astringency, and act as a stabilizer and preservative to ensure the quality of the juice.

[0047] (4) Sterilization: Using ultra-high temperature instantaneous sterilization technology, the debittered and deacidified juice is rapidly heated to 150° C. and maintained at 150° C. for 2 seconds to obtain sterilized juice;

[0048] (5) Filling: Filling the sterilized juice and retaining a certain volume for subsequent nitrogen retention;

[0049] (6) Antioxidation: Add nitrogen to the bottled juice to prevent the juice from oxidation;

[0050] (7) Sealing the bottle: Seal the bottled juice that has been added with nitrogen;

[0051] (8) Secondary high-temperature disinfection: rinse with 90°C hot water for 60 seconds for disinfection;

[0052] (9) Packaging: Packaging, labeling and coding the bottled juice after secondary high-temperature sterilization;

[0053] (10) Storage of finished products in cold storage: The packaged juice is transported to cold storage for storage and sale.

[0054] Example 3

[0055] This embodiment provides a method for debittering and deacidifying juice with a high pulp content, the method comprising the following steps:

[0056] (1) Juicing: fresh tangerine pulp was placed in a juicer and roughly squeezed at 900 r / min for 12 s to separate the seeds (because the seeds contain bitterness) and obtain debittered pulp particles; then the debittered pulp particles were placed in the juicer again and juiced again at 1300 r / min for 25 s to obtain debittered pulp;

[0057] (2) centrifugal filtration: centrifuging the debittered pulp, and then filtering the pulp through a sieve to obtain debittered juice;

[0058] (3) Deacidification: The debittered juice is transferred to a reaction tank, and 0.3 wt% sodium carbonate is added and stirred at 55 rpm for 25 min to obtain debittered and deacidified juice. If the mass of the debittered juice is 100 g, 0.3 g of sodium carbonate is added, and after sufficient reaction, about 0.24 g of sodium citrate is obtained, which can enhance the roundness of the juice, avoid metallic astringency, and act as a stabilizer and preservative to ensure the quality of the juice.

[0059] (4) Sterilization: Using ultra-high temperature instantaneous sterilization technology, the debittered and deacidified juice is rapidly heated to 140° C. and maintained for 5 seconds to obtain sterilized juice;

[0060] (5) Filling: Filling the sterilized juice and retaining a certain volume for subsequent nitrogen retention;

[0061] (6) Antioxidation: Add nitrogen to the bottled juice to prevent the juice from oxidation;

[0062] (7) Sealing the bottle: Seal the bottled juice that has been added with nitrogen;

[0063] (8) Secondary high-temperature disinfection: rinse with 85°C hot water for 70 seconds for disinfection;

[0064] (9) Packaging: Packaging, labeling and coding the bottled juice after secondary high-temperature sterilization;

[0065] (10) Storage of finished products in cold storage: The packaged juice is transported to cold storage for storage and sale.

[0066] Verification Example

[0067] (I) Experimental groups:

[0068] (I-1) Experimental group: juices prepared according to Examples 1-3 of the present invention.

[0069] (I-2) Control group 1: commercially available ordinary orange juice.

[0070] (I-3) Control group 2: traditional single juice extraction + pasteurization process.

[0071] (II) The comparison results of indicators are shown in Table 1.

[0072] Table 1

[0073]

[0074] (III) Sensory evaluation (blind test with 100 participants) The results are shown in Table 2.

[0075] Table 2

[0076]

[0077]

[0078] Scoring criteria: 9-point system (1 = very poor, 9 = excellent).

[0079] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A method for debittering and deacidifying fruit juice with a high pulp content, characterized in that: The method for debittering and deacidifying fruit juice comprises the following steps: (1) Juicing: The fresh pulp is first roughly squeezed to separate the seeds and obtain debittered pulp particles; then the debittered pulp particles are juiced again to obtain debittered pulp; (2) centrifugal filtration: centrifuging the debittered pulp and filtering the pomace to obtain debittered juice; (3) deacidification: adding an alkaline deacidifier to the debittered juice and stirring to obtain a debittered and deacidified juice; (4) Sterilization: Sterilize the debittered and deacidified juice by heating.

2. The method for debittering and deacidifying juice with high pulp content according to claim 1, characterized in that: In step (1), the rotation speed of the rough pressing is 800-1000 r / min, and the rough pressing time is 10-15 s.

3. The method for debittering and deacidifying juice with high pulp content according to claim 1, characterized in that: In step (1), the rotation speed of the re-juicing is 1200-1500 r / min, and the time of re-juicing is 20-30 s.

4. The method for debittering and deacidifying juice with high pulp content according to claim 1, characterized in that: In step (3): The alkaline deacidifier is sodium carbonate, and the amount of the alkaline deacidifier is 0.2-0.5 wt% of the debittered juice; And / or, the stirring speed is 50-60 r / min, and the stirring time is 20-30 min.

5. The method for debittering and deacidifying juice with high pulp content according to claim 1, characterized in that: In step (4), the heating method is: using ultra-high temperature instantaneous sterilization technology to heat the debittered and deacidified juice to 135-150° C. and maintain it for 2-8 seconds.

6. The method for debittering and deacidifying juice with high pulp content according to claim 1, characterized in that: It also includes the process steps of filling, anti-oxidation, bottle sealing, secondary high-temperature disinfection, packaging and cold storage of finished products.

7. The method for debittering and deacidifying juice with high pulp content according to claim 6, characterized in that: The temperature of the secondary high-temperature disinfection is 80-90° C., and the disinfection time is 60-80 seconds.

8. A debittered and deacidified juice obtained by the method for debittering and deacidifying juice according to any one of claims 1 to 7.

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