Rosa roxburghii tratt juice low-temperature freezing astringency removal technical method and application

Abstract

The invention discloses a rosa roxburghii juice low-temperature freezing deastringency technical method and application, the method utilizes the characteristic that tannin substances are easily dissolved in ethanol to form precipitates under a low-temperature condition, the rosa roxburghii juice is pre-cooled, edible alcohol is added, the mixture is stirred for 15-20 minutes under the low-temperature condition, silica gel or diatomite is adopted for filtering after reaction, and the rosa roxburghii juice is obtained. According to the rosa roxburghii tratt juice obtained by the method, the content of tannin is 6-10 mg / mL and is reduced by 30% or above, the loss rate of vitamin C can be controlled within 10%, the inherent flavor characteristics of rosa roxburghii tratt are reserved to the maximum extent, and the rosa roxburghii tratt juice is rich in flavor and rich in flavor. Meanwhile, operation is simple, and industrial application is facilitated.

Description

Technical Field

[0001] The invention belongs to the field of fruit and vegetable food processing, and particularly relates to a technology for removing astringency from roxburghii juice and its application. Background Art

[0002] Rosa roxburghii Tratt., also known as Sending Spring Back and Ci Li, is the fruit of the deciduous shrub Rosaceae. A large number of studies have shown that Rosa roxburghii fruit is rich in vitamin C, tannins, polyphenols, flavonoids, superoxide dismutase (SOD), rosa roxburghii polysaccharides, organic acids and other functional nutrients, among which the VC content can reach 841.58-3541.13 mg per 100 grams of fresh fruit, which is several times or even dozens of times that of tomatoes, kiwis, citrus, etc., and is known as the "King of VC" among fruits. According to modern pharmacological research, Rosa roxburghii has the effects of preventing arteriosclerosis, anti-tumor, detoxification, alcohol detoxification, liver protection, and anti-oxidation. Because the juice contains a lot of vitamin C, tannins and triterpenoid flavonoids, the typical taste is "sour and bitter". As a food and beverage, taste is the first priority. Bitterness greatly limits consumers' desire to consume sea buckthorn juice and affects the development of the entire industry. Therefore, it is the key task of researchers currently conducting sea buckthorn research to carry out research on improving the taste of sea buckthorn while ensuring that the loss of sea buckthorn's effective substances is small. Among them, removing the bitterness of sea buckthorn is the main task. The traditional methods for removing bitterness from juice mainly include physical removal, chemical removal and biological removal. Among them, the main methods used in the sea buckthorn field include adsorption removal, gelatin sedimentation, chitosan, β-cyclodextrin or α-cyclodextrin encapsulation, etc. The adsorption removal method has a relatively long processing time, and after the removal of tannic acid, the loss of other effective ingredients is very high, which greatly reduces the nutritional value; the gelatin sedimentation method has a long processing time and often requires the use of a large amount of gelatin, resulting in a large amount of gelatin residue, and there is also a risk of microbial growth; in the chitosan method, the chitosan itself has a heavy astringent taste and is not easy to remove cleanly under steps such as centrifugal filtration; the cyclodextrin encapsulation method is to add materials to the juice liquid to encapsulate tannins, and the actual effect is not significant. Guangdong Ocean University has disclosed a patent technology (CN202211666549.5) that combines gelatin sedimentation and enzymolysis technology. Aspergillus oryzae crude protease solution is added to the gelatin aqueous solution, and gelatin is used for sedimentation during enzymolysis, which has the effect of removing astringency. However, the enzymolysis needs to be kept at 40°C for 30-60 minutes. Because the antioxidant property of sea buckthorn is particularly strong, keeping the enzymolysis at 40°C for 1 hour will seriously affect the taste and flavor of sea buckthorn. Patent application CN202011499020.X discloses "a method for removing astringency from sea buckthorn juice", in which the astringent is at least one of sodium caseinate, whey protein isolate and soy protein isolate. This method requires a large amount of water to dissolve the protein, and it is inevitable that the concentration of the sea buckthorn juice will become thinner during the de-astringency process. The sea buckthorn juice after de-astringency can only be used for sea buckthorn drinks with lower concentrations, and the application is limited.

[0003] Therefore, only by understanding the composition and properties of sea buckthorn, based on its specific antioxidant reduction properties, it is best to remove or reduce the tannin content in sea buckthorn without or with less addition of chemical substances so that consumers can better accept sea buckthorn juice. This is a technical problem that sea buckthorn processing companies are currently working to overcome. Summary of the invention

[0004] The object of the present invention is to provide a technical method and application of low-temperature freezing and de-astringency of roxburghii juice. Based on its specific antioxidant reduction properties, it is best to remove or reduce the tannin content in roxburghii without or with less addition of chemical substances so that consumers can better accept the roxburghii juice.

[0005] To achieve the above purpose, the technical solution adopted is:

[0006] 1. A technical method for removing astringency from roxburghii juice by low-temperature freezing, the method comprising the following steps:

[0007] A. Precooling of the roxburghii juice: Put the roxburghii juice into the cold storage, adjust the temperature of the cold storage to -10-0°C, and wait until the center temperature of the roxburghii juice drops below 0°C to complete the precooling of the roxburghii juice;

[0008] B. Sedimentation and stratification: Add edible alcohol to the pre-cooled roxburghii juice in step A, control the ambient temperature to -5-0°C and stir for 15-20 minutes, and filter with silica gel or diatomaceous earth after the reaction to obtain edible alcohol-containing roxburghii juice after de-astringency;

[0009] C. Vacuum distillation: The rosa roxburghii juice containing edible alcohol obtained in step B is subjected to vacuum distillation equipment to remove alcohol to obtain the final de-astringent rosa roxburghii juice.

[0010] In the technical method for removing astringency from roxburghii juice by low-temperature freezing, the amount of edible alcohol added in step B is 0.1-2% by weight of the total weight of the roxburghii juice.

[0011] In the technical method for low-temperature freezing and removing astringency of roxburghii juice, the temperature of reduced-pressure distillation in step C is 65-75° C., the vacuum degree of vacuum drying is -0.45-0.65 Mpa, and the distillation time is 3-5 minutes.

[0012] The technical method for low-temperature freezing and de-astringency of sea buckthorn juice, the specific method of using silica gel or diatomaceous earth for filtration in step B is: the silica gel or diatomaceous earth is loaded into a stainless steel chromatography column, and an ice-water mixture is circulated in the interlayer of the chromatography column, so that the temperature of the silica gel or diatomaceous earth is maintained at 0-5°C during the filtration process.

[0013] The invention discloses an application of the low-temperature freezing and astringency-removing technical method for roxburghii juice in preparing astringent roxburghii juice or roxburghii beverage.

[0014] The invention discloses an application of the low-temperature freezing and astringency removal technical method for roxburghii juice in the preparation of roxburghii tannin extract.

[0015] A de-astringent roxburghii juice is obtained by adopting the technical method for de-astringenting of roxburghii juice by low-temperature freezing.

[0016] The de-astringent roxburghii juice has a tannin content of 6-10 mg / mL and a vitamin C content of 800-1500 mg / 100 mL.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] (1) During the implementation of the technical solution of the present invention, the temperature is controlled to be as low as possible, that is, below 0°C, so as to retain the loss of active substances and flavor components of the roxburghii to the greatest extent.

[0019] (2) By introducing edible alcohol to precipitate the tannins and then filtering them out, the alcohol was removed by vacuum distillation, which had little effect on the quality of the sea buckthorn juice.

[0020] (3) The experimental data show that the tannin content of the roxburghii juice obtained by the method is 6-10 mg / mL, which is reduced by more than 30%, and the vitamin C loss rate can be controlled within 10%. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Tannin determination standard curve Specific implementation plan

[0022] Example 1

[0023] 1. A technical method for removing astringency from roxburghii juice by low-temperature freezing, the method comprising the following steps:

[0024] A. Precooling of the roxburghii juice: Put the roxburghii juice into a cold storage, adjust the temperature of the cold storage to -10°C, and wait until the center temperature of the roxburghii juice drops below 0°C to complete the precooling of the roxburghii juice;

[0025] B. Sedimentation and stratification: Add edible alcohol to the pre-cooled roxburghii juice in step A, control the ambient temperature to 0° C. and stir for 15 minutes, and filter with silica gel or diatomaceous earth after the reaction to obtain edible alcohol-containing roxburghii juice after de-astringency;

[0026] C. Vacuum distillation: The rosa roxburghii juice containing edible alcohol obtained in step B is subjected to vacuum distillation equipment to remove alcohol to obtain the final de-astringent rosa roxburghii juice.

[0027] In the technical method for removing astringency from roxburghii juice by low-temperature freezing, the amount of edible alcohol added in step B is 0.1% by weight of the total weight of the roxburghii juice.

[0028] In the technical method for low-temperature freezing and removing astringency of roxburghii juice, the temperature of reduced-pressure distillation in step C is 75° C., the vacuum degree of vacuum drying is -0.45 Mpa, and the distillation time is 5 minutes.

[0029] The technical method for low-temperature freezing and de-astringency of sea buckthorn juice, the specific method of using silica gel or diatomaceous earth for filtration in step B is: the silica gel or diatomaceous earth is loaded into a stainless steel chromatography column, and an ice-water mixture is circulated in the interlayer of the chromatography column, so that the temperature of the silica gel or diatomaceous earth is maintained at 0°C during the filtration process.

[0030] The invention discloses an application of the low-temperature freezing and astringency-removing technical method for roxburghii juice in preparing astringent roxburghii juice or roxburghii beverage.

[0031] The invention discloses an application of the low-temperature freezing and astringency removal technical method for roxburghii juice in the preparation of roxburghii tannin extract.

[0032] A de-astringent roxburghii juice is obtained by adopting the technical method for de-astringenting of roxburghii juice by low-temperature freezing.

[0033] The de-astringent roxburghii juice has a tannin content of 10.72 mg / mL and a vitamin C content of 1400.45 mg / 100 mL.

[0034] Example 2

[0035] 1. A technical method for removing astringency from roxburghii juice by low-temperature freezing, the method comprising the following steps:

[0036] A. Precooling of the roxburghii juice: Put the roxburghii juice into a cold storage, adjust the temperature of the cold storage to -5°C, and wait until the center temperature of the roxburghii juice drops below 0°C to complete the precooling of the roxburghii juice;

[0037] B. Sedimentation and stratification: Add edible alcohol to the pre-cooled roxburghii juice in step A, control the ambient temperature to -3°C and stir for 18 minutes, and filter with silica gel or diatomaceous earth after the reaction to obtain edible alcohol-containing roxburghii juice after de-astringency;

[0038] C. Vacuum distillation: The rosa roxburghii juice containing edible alcohol obtained in step B is subjected to vacuum distillation equipment to remove alcohol to obtain the final de-astringent rosa roxburghii juice.

[0039] In the technical method for removing astringency from roxburghii juice by low-temperature freezing, the amount of edible alcohol added in step B is 1.5% by weight of the total weight of the roxburghii juice.

[0040] In the technical method for low-temperature freezing and removing astringency of roxburghii juice, the temperature of reduced-pressure distillation in step C is 70° C., the vacuum degree of vacuum drying is 0.55 MPa, and the distillation time is 4 minutes.

[0041] The technical method for low-temperature freezing and de-astringency of sea buckthorn juice, the specific method of using silica gel or diatomaceous earth for filtration in step B is: the silica gel or diatomaceous earth is loaded into a stainless steel chromatography column, and an ice-water mixture is circulated in the interlayer of the chromatography column, so that the temperature of the silica gel or diatomaceous earth is maintained at -2°C during the filtration process.

[0042] The invention discloses an application of the low-temperature freezing and astringency-removing technical method for roxburghii juice in preparing astringent roxburghii juice or roxburghii beverage.

[0043] The invention discloses an application of the low-temperature freezing and astringency removal technical method for roxburghii juice in the preparation of roxburghii tannin extract.

[0044] A de-astringent roxburghii juice is obtained by adopting the technical method for de-astringenting of roxburghii juice by low-temperature freezing.

[0045] The de-astringent roxburghii juice has a tannin content of 10.42 mg / mL and a vitamin C content of 942.46 mg / 100 mL.

[0046] Example 3

[0047] 1. A technical method for removing astringency from roxburghii juice by low-temperature freezing, the method comprising the following steps:

[0048] A. Precooling of the roxburghii juice: Put the roxburghii juice into a cold storage, adjust the temperature of the cold storage to 0°C, and wait until the center temperature of the roxburghii juice drops below 0°C to complete the precooling of the roxburghii juice;

[0049] B. Sedimentation and stratification: Add edible alcohol to the pre-cooled roxburghii juice in step A, control the ambient temperature to -5°C and stir for 20 minutes, and filter with silica gel or diatomaceous earth after the reaction to obtain edible alcohol-containing roxburghii juice after de-astringency;

[0050] C. Vacuum distillation: The rosa roxburghii juice containing edible alcohol obtained in step B is subjected to vacuum distillation equipment to remove alcohol to obtain the final de-astringent rosa roxburghii juice.

[0051] In the technical method for removing astringency from roxburghii juice by low-temperature freezing, the amount of edible alcohol added in step B is 2% by weight of the total weight of the roxburghii juice.

[0052] In the technical method for low-temperature freezing and removing astringency of roxburghii juice, the temperature of reduced pressure distillation in step C is 65° C., the vacuum degree of vacuum drying is 0.65 Mpa, and the distillation time is 3 minutes.

[0053] The technical method for low-temperature freezing and de-astringency of sea buckthorn juice, the specific method of using silica gel or diatomaceous earth for filtration in step B is: the silica gel or diatomaceous earth is loaded into a stainless steel chromatography column, and an ice-water mixture is circulated in the interlayer of the chromatography column, so that the temperature of the silica gel or diatomaceous earth is maintained at 0°C during the filtration process.

[0054] The invention discloses an application of the technical method for removing astringency of roxburghii juice by low-temperature freezing in preparing astringent roxburghii juice or roxburghii beverage.

[0055] The invention discloses an application of the low-temperature freezing and astringency removal technical method for roxburghii juice in the preparation of roxburghii tannin extract.

[0056] A de-astringent roxburghii juice is obtained by adopting the technical method for de-astringenting of roxburghii juice by low-temperature freezing.

[0057] The de-astringent roxburghii juice has a tannin content of 11.48 mg / mL and a vitamin C content of 1027.48 mg / 100 mL.

[0058] In order to further verify the effect of the technical method of the present invention on the de-astringency of roxburghii juice, the Folin phenol reduction method was used to determine the tannin content. The hot reflux method was used for extraction, and the tannin content of the roxburghii juice that had not been de-astringented and the roxburghii juice that had been de-astringented according to the technical solution of the present invention was determined respectively. 10 mL of roxburghii original juice was used as the substrate, and ethanol was added for hot reflux extraction. The weight was weighed before extraction. After hot reflux for 1 hour, the weight was added, filtered, and the volume was recorded. The tannin content was determined by the Folin phenol reduction method, and the standard curve was

[0059] Y=69.057X-0.0009,R 2 =0.9993, standard curve diagram see Figure 1 The test results are shown in Table 1 and Table 2.

[0060] Table 1. Tannin content in roxburghii juice after de-astringency treatment

[0061]

[0062] Table 2 Tannin content of roxburghii juice without de-astringency treatment From the data in the table, it can be seen that the average tannin content of roxburghii juice before de-astringency is 20.34 mg / mL.

[0063]

[0064] After the astringency removal treatment, the test results of the three embodiments of the present invention were 9.57 mg / mL, 7.84 mg / mL, and 10.67 mg / mL, respectively, which were reduced by 52.94%, 61.45%, and 47.54%, respectively. In addition, from the perspective of sensory evaluation, the sour and astringent taste was significantly improved, achieving the purpose of reducing astringency.

[0065] The above is only a preferred embodiment of the present invention, and does not limit the present invention in other forms. Any technician familiar with the profession may use the above disclosed technical content to change or modify it into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the technical solution of the present invention still belongs to the protection scope of the technical solution of the present invention.

Claims

1. A technical method for removing astringency from roxburghii juice by low-temperature freezing, characterized in that: The method comprises the following steps: A. Precooling of the roxburghii juice: Put the roxburghii juice into the cold storage, adjust the temperature of the cold storage to -10-0°C, and wait until the center temperature of the roxburghii juice drops below 0°C to complete the precooling operation of the roxburghii juice; B. Sedimentation and stratification: Add edible alcohol to the pre-cooled roxburghii juice in step A, control the ambient temperature to -5-0°C and stir for 15-20 minutes, and filter with silica gel or diatomaceous earth after the reaction to obtain edible alcohol-containing roxburghii juice after de-astringency; C. Vacuum distillation: The rosa roxburghii juice containing edible alcohol obtained in step B is subjected to vacuum distillation equipment to remove alcohol to obtain the final de-astringent rosa roxburghii juice.

2. The method for removing astringency from roxburghii juice by low-temperature freezing according to claim 1, characterized in that: The amount of edible alcohol added in step B is 0.1-2% by weight of the total weight of the roxburghii juice.

3. The method for removing astringency from roxburghii juice by low-temperature freezing according to claim 1, characterized in that: The temperature of the reduced pressure distillation in step C is 65-75° C., the vacuum degree of the vacuum drying is -0.45-0.65 Mpa, and the distillation time is 3-5 minutes.

4. The method for removing astringency from roxburghii juice by low-temperature freezing according to claim 1, characterized in that: The specific method of using silica gel or diatomaceous earth for filtration in step B is: the silica gel or diatomaceous earth is loaded into a stainless steel chromatography column, and an ice-water mixture is circulated in the interlayer of the chromatography column to keep the temperature of the silica gel or diatomaceous earth at 0-5°C during the filtration process.

5. Application of a roxburghii juice low-temperature freezing and astringency removal technical method according to claim 1 in preparing astringent roxburghii juice or roxburghii beverage.

6. Application of the low-temperature freezing and astringency-removing technical method for roxburghii juice according to claim 1 in the preparation of roxburghii tannin extract.

7. A de-astringent roxburghii juice, characterized in that: The roxburghii juice is obtained by adopting the roxburghii juice low-temperature freezing and astringency removal technology method described in claim 1.

8. The de-astringent roxburghii juice according to claim 7, characterized in that The tannin content of the roxburghii juice is 6-10 mg / mL, and the vitamin C content is 800-1500 mg / 100 mL.

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