Storage method for reducing post-acidification degree of Kangpu tea

Abstract

The invention provides a storage method for reducing post-acidification degree of Kangpu tea, and the storage method comprises the following steps: after fermentation of Kangpu tea is completed, adding 0.01-0.1% by mass of fucoidin into a fermentation liquid; and sealing the Kangpu tea added with the fucoidin, and storing the Kangpu tea at normal temperature or at 20-30 DEG C. The preparation method of the Kangpu tea comprises the following steps: sterilizing sugar water containing cane sugar and glucose or only containing glucose, adding tea leaves, and extracting to obtain tea sugar water; inoculating kombucha mother liquor, carrying out aerobic fermentation for 8 days, and separating the mycoderm after fermentation is completed. The method mainly aims at storage of the unsterilized Kangpu tea fermentation system, the post-acidification degree of the Kangpu tea can be reduced, the retention rate of flavone can be increased, and the storage quality of the unsterilized Kangpu tea fermentation system is greatly improved.

Description

Technical field

[0001] The invention relates to the technical field of tea beverage production, and in particular to a storage method for reducing the post-acidification degree of kombucha. [Background Technology]

[0002] Kombucha is a low-alcohol fermented beverage, typically made by fermenting sweetened black tea with a symbiotic bacterial community (such as acetic acid bacteria and yeast, or SCOBY). Kombucha has a sweet and sour taste, and its acidity primarily comes from organic acids produced during the fermentation process, such as acetic acid, gluconic acid, and lactic acid. These acidic components not only give kombucha its unique flavor but also have antibacterial and antioxidant properties.

[0003] During the kombucha storage or bottle sealing stage (especially when it is not sterilized), the residual microorganisms continue to metabolize sugars and ethanol, causing the acidity to further decrease. Post-acidification not only affects the quality, taste and flavor of the kombucha beverage, but may also cause the SCOBY activity to decrease, and excessive gas production poses a risk of bottle explosion. Traditional methods to reduce the post-acidification of fermented foods include low-temperature refrigeration and pasteurization. Low-temperature refrigeration requires continuous refrigeration and has high energy costs; pasteurization may destroy flavor substances or nutrients. Therefore, for the storage of unsterilized kombucha fermentation systems, a method is needed that can both reduce its post-acidification and maintain its storage quality. [Summary of the invention]

[0004] The technical problem to be solved by the present invention is to provide a storage method for reducing the degree of post-acidification of kombucha. The storage method is mainly aimed at the storage of non-sterilized kombucha fermentation systems. It can not only reduce the degree of post-acidification of kombucha but also increase the retention rate of flavonoids, thereby greatly improving the storage quality of the non-sterilized kombucha fermentation system.

[0005] The present invention is achieved in that:

[0006] A storage method for reducing the degree of post-acidification of kombucha tea, the storage method comprising the following steps:

[0007] After the kombucha fermentation is completed, adding 0.01% to 0.1% by mass of fucoidan to the fermentation liquid;

[0008] The kombucha tea with added fucoidan is sealed and stored at room temperature or 20-30°C.

[0009] Furthermore, the added concentration of the fucoidan is 0.05% to 0.1%.

[0010] Furthermore, the added concentration of the fucoidan is 0.1%.

[0011] Furthermore, the preparation of kombucha includes:

[0012] After sterilizing sugar water containing sucrose and glucose or only glucose, tea leaves are added to obtain tea sugar water; wherein the amount of sucrose and glucose added is 1:1;

[0013] The mother liquor of Kombucha was inoculated and aerobic fermentation was carried out for 8 days, and the biofilm was separated after the fermentation was completed.

[0014] Furthermore, the tea is one of green tea, white tea, rock tea, and black tea, or green tea and black tea are mixed together, white tea and black tea are mixed together, and rock tea and black tea are mixed together, and the mixing ratio is 1:1, and the added amount is 2-5g / L.

[0015] Furthermore, the total acid content of the kombucha fermentation broth does not exceed 0.67 g / 100 g after 32 days of storage, and the total flavonoid and polyphenol retention rates are higher than 23.40 mg RE / 100 mL and 16.22 mg GAE / 100 mL, respectively.

[0016] The present invention has the following advantages:

[0017] The present invention adds fucoidan to kombucha, which can effectively delay the increase in acidity of an unsterilized kombucha fermentation system during storage, and the degree of inhibiting post-acidification is better than traditional preservation technologies such as adding Nisin, pasteurization, and low-temperature refrigeration. The addition of fucoidan not only reduces the post-acidification degree of kombucha and increases the retention rate of flavonoids, but also improves the storage quality of kombucha to a certain extent, making it suitable for modern beverage industrial production.

Brief Description of the Drawings

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0019] Figure 1 This is a comparison chart of kombucha fermentation broth with different concentrations of fucoidan added before storage according to an embodiment of the present invention. [Specific implementation method]

[0020] After sterilizing 50g / L sucrose and 50g / L glucose at 121°C for 15 minutes, add 2-5g / L tea leaves and soak at 90-100°C for 9-12 minutes before removing the tea leaves to obtain tea syrup. The tea syrup, cooled to room temperature, is inoculated with 20-30% (v / v) kombucha mother liquor and placed in a 30°C constant-temperature incubator. After 8 days of aerobic fermentation, the biofilm is separated and various concentrations of fucoidan (0.01%-0.1%, w / w) are added. The mixture is then sealed and stored at room temperature or 30°C.

[0021] The following will be combined with the Figure 1The technical solutions of the present invention are clearly and completely described in the following embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention. Specific conditions not specified in the examples are based on conventional conditions. All reagents or instruments used that are not specified are conventional products that can be purchased commercially.

[0022] Example 1

[0023] A syrup containing 50 g / L sucrose and 50 g / L glucose was sterilized at 121°C for 15 minutes, then 2 g / L black tea was added. The mixture was then steeped at 90°C for 10 minutes, and the tea leaves were removed to obtain the tea syrup. The tea syrup, cooled to room temperature, was inoculated with 20% (v / v) kombucha mother liquor. After 8 days of aerobic fermentation, the biofilm of kombucha (KB) was isolated and supplemented with 0.01% fucoidan, labeled S-0.01FU. The blank control group, labeled S-0FU, was stored sealed at 30°C for 16, 24, and 32 days, respectively.

[0024] The total acid content of S-0.01FU-16d, S-0.01FU-24d, and S-0.01FU-32d were 0.59g / 100g, 0.59g / 100g, and 0.67g / 100g, respectively; the total flavonoid content was 25.62mg RE / 100mL, 25.87mg RE / 100mL, and 23.40mg RE / 100mL, respectively; the total polyphenol content was 21.38mg GAE / 100mL, 20.51mg GAE / 100mL, and 16.22mg GAE / 100mL for S-0.01FU-16d, respectively. In the blank control group, the total acid content of S-OFU-16d, S-OFU-24d, and S-OFU-32d was 0.64g / 100g, 0.68g / 100g, and 0.840g / 100g, respectively; the total flavonoid content was 24.39mg RE / 100mL, 20.18mg RE / 100mL, and 23.64mg RE / 100mL, respectively; and the total polyphenol content was 19.85mg GAE / 100mL, 20.50mg GAE / 100mL, and 20.36mg GAE / 100mL, respectively. 0.01% fucoidan significantly delayed post-acidification after storage for 16-32 days, with total acid content reduced by 7.8%-20.5% compared to the control group (S-OFU).

[0025] Example 2

[0026] A syrup containing 50 g / L sucrose and 50 g / L glucose was sterilized at 121°C for 15 minutes, then 2 g / L black tea was added. The mixture was then steeped at 90°C for 10 minutes, and the tea leaves were removed to obtain the tea syrup. The tea syrup, cooled to room temperature, was inoculated with 20% (v / v) kombucha mother liquor. After 8 days of aerobic fermentation, the biofilm was isolated and 0.05% fucoidan was added, labeled S-0.05FU. The absence of fucoidan was labeled S-0FU. The syrup was then sealed and stored at 30°C for 16, 24, and 32 days, respectively.

[0027] The total acid contents of S-0.05FU-16d, S-0.05FU-24d, and S-0.05FU-32d were 0.56 g / 100 g, 0.57 g / 100 g, and 0.62 g / 100 g, respectively; the total flavonoid contents were 25.13 mg RE / 100 mL, 28.33 mg RE / 100 mL, and 26.61 mg RE / 100 mL, respectively; and the total polyphenol contents were 21.81 mg GAE / 100 mL, 21.31 mg GAE / 100 mL, and 16.51 mg GAE / 100 mL, respectively. The 0.05% fucoidan exhibited a stronger acidification inhibition effect during storage for 16-32 days, with total acid content reduced by 9.4%-26.2% compared to the S-OFU control group (same as in Example 1).

[0028] Example 3

[0029] A syrup containing 50g / L sucrose and 50g / L glucose was sterilized at 121°C for 15 minutes, then 2g / L black tea was added. The mixture was then steeped at 90°C for 10 minutes, and the tea leaves were removed to obtain the tea syrup. The tea syrup, cooled to room temperature, was inoculated with 20% (v / v) kombucha mother liquor. After 8 days of aerobic fermentation, the biofilm was isolated and 0.1% fucoidan was added, labeled S-0.1FU. The absence of fucoidan was labeled S-0FU. The mixture was then sealed and stored at 30°C for 16, 24, and 32 days, respectively.

[0030] The total acid contents of S-0.1FU-16d, S-0.1FU-24d, and S-0.1FU-32d were 0.54 g / 100 g, 0.56 g / 100 g, and 0.60 g / 100 g, respectively; the total flavonoid contents were 23.65 mg RE / 100 mL, 25.87 mg RE / 100 mL, and 24.63 mg RE / 100 mL, respectively; and the total polyphenol contents were 22.17 mg GAE / 100 mL, 21.74 mg GAE / 100 mL, and 16.44 mg GAE / 100 mL, respectively. The 0.1% fucoidan exhibited the strongest inhibitory effect on post-acidification, with the total acid content (0.60 g / 100 g) at 32 days of storage reduced by 28.6% compared to the control (0.84 g / 100 g), and the acidification rate was significantly slowed (increasing by only 11.1% from 16 to 32 days).

[0031] In order to highlight the effect of fucoidan addition on delaying the acidification of kombucha, three groups of traditional preservation technology treatments were set up in the above examples. Among them, the Nisin treatment group added 0.02% Nisin and was named SN-OFU; the pasteurization treatment group was pasteurized at 70℃ for 30 minutes and was named SP-OFU; and the low-temperature treatment group was placed in a refrigerated environment at 4℃ and was named SC-OFU. Figure 1 As shown, the storage treatment conditions and sample physical and chemical test results of the embodiment and traditional preservation technology treatment groups are shown in Table 1 and Table 2 respectively.

[0032] Table 1 Kombucha under different storage conditions

[0033]

[0034] Table 2 Physical and chemical test results of kombucha under different storage treatments

[0035]

[0036]

[0037] As shown in Table 2, Example 3 (adding 0.1% fucoidan) achieved the highest post-acidification inhibition efficiency, followed by Example 2 (adding 0.05% fucoidan), and finally Example 1 (adding 0.01% fucoidan). Compared with traditional storage techniques, all examples demonstrated superior total acid inhibition and flavonoid retention compared to the Nisin and pasteurization groups. Although the low-temperature refrigeration group exhibited superior acidification inhibition after 16-24 days, acidity surged to a peak on day 32, and storage quality significantly deteriorated. Example 1 exhibited the best flavonoid and polyphenol retention at 16 days of storage, with 14.5%-50.9% higher active ingredients than the traditional storage group (Nisin / pasteurization). Example 2 achieved the highest flavonoid retention at 24 days (28.33 mg RE / 100 mL), outperforming the group treated with traditional storage techniques. In Example 3, polyphenol content decreased by 25.8% at 32 days, but remained higher than that of the group treated with traditional storage techniques.

[0038] In summary, the storage method provided by the present invention can more effectively alleviate the post-acidification problem of kombucha during long-term storage than traditional preservation technology, and helps maintain the storage quality of kombucha.

[0039] Although the specific embodiments of the present invention are described above, those skilled in the art should understand that the specific embodiments described are merely illustrative and are not intended to limit the scope of the present invention. Equivalent modifications and changes made by those skilled in the art in accordance with the spirit of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for storing kombucha tea to reduce its post-acidification degree, characterized by: The storage method comprises the following steps: After the kombucha fermentation is completed, adding 0.01% to 0.1% by mass of fucoidan to the fermentation liquid; The kombucha tea with added fucoidan is sealed and stored at room temperature or 20-30°C.

2. The storage method according to claim 1, wherein: The added concentration of the fucoidan is 0.05% to 0.1%.

3. The storage method according to claim 1, wherein: The added concentration of the fucoidan is 0.1%.

4. The storage method according to any one of claims 1 to 3, characterized in that: The preparation of the kombucha tea comprises: After sterilizing sugar water containing sucrose and glucose or only glucose, tea leaves are added to obtain tea sugar water; wherein the amount of sucrose and glucose added is 1:1; The mother liquor of Kombucha was inoculated and aerobic fermentation was carried out for 8 days, and the biofilm was separated after the fermentation was completed.

5. The storage method according to claim 4, wherein: The tea is one of green tea, white tea, rock tea, and black tea, or a combination of green tea and black tea, white tea and black tea, or rock tea and black tea, and the mixing ratio is 1:1, and the added amount is 2-5g / L.

6. The storage method according to claim 1, wherein: The total acid content of the kombucha fermentation liquid does not exceed 0.67 g / 100 g after 32 days of storage, and the total flavonoid and polyphenol retention rates are higher than 23.40 mg RE / 100 mL and 16.22 mg GAE / 100 mL, respectively.

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