Preparation method of bangia fusco-purpurea kangpu tea beverage

Abstract

The invention discloses a preparation method of a bangia fusco-purpurea kangpu tea beverage, which comprises the following steps: taking tea leaves as a substrate, adding water and cane sugar to prepare tea sugar water, sterilizing, inoculating kombucha strains, and carrying out primary fermentation to obtain primary fermentation liquor; washing and crushing bangia fusco-purpurea, and adding sugar and boiling water for hot water extraction to obtain a bangia fusco-purpurea extracting solution; and mixing the primary fermentation liquor with the bangia fusco-purpurea extracting solution, performing secondary fermentation, sterilizing, filtering, and adding an acid reducer to obtain the bangia fusco-purpurea kangpu tea beverage. The method overcomes the original acerbity and pungent smell of the Kangpu tea and the original algae smell of the bangia fusco-purpurea in the prior art, and significantly improves the functional value and market competitiveness of the product.

Description

Technical Field

[0001] This invention relates to the technical field of tea beverages, specifically to a method for preparing a red algae kombu tea beverage. Background Technology

[0002] Kombucha is a beverage made from traditional black or green tea as a base, with added sugar and fermented by kombucha bacteria, resulting in a unique, strong aroma or bubbly characteristics. Due to the microbial fermentation process, kombucha produces numerous substances, such as organic acids, ethanol, and various phenolic compounds. These are believed to have beneficial health effects, including antioxidant, antibacterial, anti-inflammatory, anti-diabetic, antihypertensive, and anti-cancer properties. However, traditional kombucha has a sour and astringent taste, which makes it difficult to attract consumers, limiting its consumer base and reducing its competitiveness.

[0003] Red hair algae is a primitive type of red algae widely distributed along the coasts of the East China Sea and South China Sea, with Putian City in Fujian Province being one of the main producing areas. Red hair algae is rich in various nutrients and bioactive components, such as soluble polysaccharides, phycocyanin, phenolic compounds, and vitamins, and possesses antioxidant, hypoglycemic, and hypolipidemic functions. However, its strong fishy odor limits its market acceptance. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a method for preparing a red algae kombucha beverage, which overcomes the original sour and astringent odor of kombucha in the prior art, as well as the original fishy smell of red algae.

[0005] An embodiment of the present invention provides a method for preparing a red algae kombucha beverage, which includes the following steps:

[0006] Step 1: Using tea leaves as a base, add water and sucrose to make tea sugar water. After sterilization, inoculate with kombucha culture for primary fermentation to obtain primary fermentation liquid.

[0007] Step 2: The red algae are washed, crushed, and then extracted with sugar and boiling water to obtain red algae extract.

[0008] Step 3: Mix the primary fermentation liquid with the red algae extract and carry out secondary fermentation. After sterilization and filtration, add an acid-reducing agent to obtain the red algae kombucha beverage.

[0009] According to an embodiment of the present invention, a method for preparing a red algae kombucha beverage involves mixed fermentation of red algae extract and kombucha primary fermentation liquid. Utilizing the metabolic activity of the kombucha symbiotic flora, the algal odor of the red algae is significantly reduced, resulting in a final product with no noticeable fishy smell and exhibiting the unique, mellow flavor of red algae. Furthermore, by adding an acid-reducing agent, the acidity of the kombucha is effectively controlled, resulting in a high balance of sweet and sour flavors, making the taste more acceptable to consumers. During the mixed fermentation process, the soluble polysaccharides and phenolic compounds in the red algae synergistically interact with the fermentation products of the kombucha (organic acids, phenolic substances, etc.), enhancing the antioxidant activity of the product. Thus, while addressing the flavor defects of traditional kombucha and red algae beverages, the method significantly improves the functional value and market competitiveness of the product.

[0010] Optionally, in step one, the volume ratio of kombucha culture stock solution to tea sugar water is 1:10.

[0011] Optionally, in step one, the weight ratio of water, sucrose, and tea leaves is 100:10:1.

[0012] Optionally, in step one, the first fermentation is carried out at 28°C for 7 days.

[0013] Optionally, in step two, the coarse powder of red algae, white sugar and boiling water are mixed in a mass ratio of 1:10:100.

[0014] Optionally, in step two, hot water extraction is performed for 15 minutes.

[0015] Optionally, in step three, the primary fermentation broth and the red algae extract are mixed at a volume ratio of 1:10.

[0016] Optionally, in step three, the secondary fermentation is carried out at 28°C for 7 days.

[0017] Optionally, in step three, the acid-lowering agent is 3 g / L potassium carbonate, 3 g / L potassium bicarbonate, and 12 g / L potassium tartrate.

[0018] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Detailed Implementation

[0019] The technical solution of the present invention is illustrated below through specific examples. It should be understood that the one or more method steps mentioned in the present invention do not preclude the existence of other method steps before or after the combined steps, or the insertion of other method steps between these explicitly mentioned steps; it should also be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. Furthermore, unless otherwise stated, the numbering of each method step is merely a convenient tool for identifying each method step, and not for limiting the order of the method steps or defining the scope of the present invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the present invention.

[0020] To better understand the above technical solutions, exemplary embodiments of the present invention are described in more detail below. While exemplary embodiments of the present invention are shown, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the invention to those skilled in the art.

[0021] All test materials used in this invention are common commercially available products. The kombucha inoculum stock solution was purchased from Jiafan Food Store in Yanzhou District, Jining City. The kombucha inoculum is a symbiotic group containing yeast, acetic acid bacteria, and lactic acid bacteria.

[0022] The detection method involved in this invention is as follows:

[0023] pH and titratable acid determination: The pH value of the red algae kombucha was determined using a pH meter; the titratable acid was determined according to GB 5009.239—2016 "National Food Safety Standard - Determination of Total Acid in Food", and the total acid content in the red algae kombucha sample was determined by acid-base indicator titration.

[0024] Determination of total phenols (TPC): Dilute the fermentation broth to be tested 10 times. Take 0.5 mL of the diluted sample from *Rhododendron molle* kombucha, add 0.5 mL of Folin-Ciocalteu reagent, then add 1.5 mL of 7.5% sodium carbonate solution, and add distilled water to a final volume of 5 mL. Incubate at room temperature (approximately 25 ± 2 °C) for 2 hours. Measure the absorbance at 765 nm using a UV spectrophotometer. Establish a standard curve (0.0077x + 0.0548, R0) using gallic acid as the standard (0-50 μg / mL). 2 =0.9992) to measure the content of phenolic substances.

[0025] DPPH free radical scavenging rate: Prepare a 0.1 mmol / L DPPH ethanol solution. Dilute the kombucha sample to be tested 10 times. Take 0.8 mL of the diluted sample solution and 0.8 mL of the prepared DPPH ethanol solution, mix thoroughly, and store at room temperature in the dark for 0.5 h. Then centrifuge at 12000 r / min for 5 min. Measure the absorbance A1 at a wavelength of 517 nm. Replace the sample solution with ultrapure water and measure the absorbance A0. Calculate the free radical scavenging rate of the red algae-based kombucha. The formula for calculating the ability to scavenge DPPH free radicals is as follows:

[0026]

[0027] Iron reducing power determination: The reducing power was determined using the potassium ferricyanide reduction method. A phosphate buffer solution (pH 6.6), 1% (w / v) potassium ferricyanide solution, 10% (w / v) trichloroacetic acid solution, and 0.1% (w / v) ferric chloride solution were prepared. The fermentation broth was centrifuged, and the supernatant was collected and diluted 10-fold. 0.3 mL of the diluted sample was added to 0.35 mL of the prepared phosphate buffer solution and 0.35 mL of the prepared potassium ferricyanide solution, respectively. After mixing thoroughly, the mixture was incubated in a 50°C water bath for 20 min. After cooling to room temperature, 0.35 mL of the prepared trichloroacetic acid solution and 0.15 mL of the prepared ferric chloride solution were added and mixed thoroughly. The absorbance of the solution was measured at 700 nm (A1). The absorbance measured using distilled water instead of the sample solution was A0. The sample absorbance value reflects the reducing power of the sample. The formula for calculating the reducing power of red algae kombucha is as follows:

[0028] Reducing force = (A1 - A0)

[0029] ABTS free radical scavenging capacity: Prepare 7 mmol / L ABTS, 2.4 mmol / L K2S2O8, and 0.2 mol / L NaH2PO4-Na2HPO4 (pH = 7.0). Mix the prepared ABTS solution and the prepared K2S2O8 solution in equal proportions, and after thorough mixing, place in the dark at room temperature for 12-16 hours to prepare ABTS·+ stock solution.

[0030] Dilute with prepared phosphate buffer until the absorbance at 734 nm is 0.7 ± 0.02. Add 0.1 mL of sample solution and 1 mL of prepared ABTS·+ working solution to a test tube, mix well, and incubate at 37°C for 1 h. Then centrifuge at 12000 r / min for 5 min and measure the absorbance at 734 nm, obtaining A1. Replace the sample with distilled water to measure the absorbance A0, and calculate the free radical scavenging rate of the sample. The formula for calculating the ability to scavenge ABTS free radicals is as follows:

[0031]

[0032] Hydroxyl radical scavenging capacity determination: Prepare 6 mmol / L salicylic acid ethanol solution, 2 mmol / L ferrous sulfate solution, and 1 mmol / L hydrogen peroxide solution. Centrifuge the fermentation broth, collect the supernatant, and dilute it 10 times. Add 0.1 mL of the diluted sample solution, 0.1 mL of the prepared salicylic acid ethanol solution, 0.1 mL of the prepared ferrous sulfate solution, and 0.1 mL of the prepared hydrogen peroxide solution to centrifuge tubes in sequence. Mix thoroughly and react at 37℃ in the dark for 60 min. Measure the absorbance of the solution at a wavelength of 510 nm (A1). Measure the absorbance using distilled water instead of the sample (A0). The formula for calculating the hydroxyl radical scavenging capacity of red algae kombucha is as follows:

[0033]

[0034] The present invention will now be described with reference to specific embodiments. It should be noted that these embodiments are merely descriptive and do not limit the present invention in any way.

[0035] Example 1

[0036] Step 1: Place black tea leaves in a sterilized glass container, add boiling water and steep for 15 minutes. Add sucrose to dissolve, filter, and obtain tea sugar water; the weight ratio of water, sucrose, and tea leaves is 100:10:1. After sterilizing at 65℃ for 30 minutes, add kombucha starter culture to the tea sugar water and ferment at 28℃ for 7 days to obtain primary fermentation liquid. The volume ratio of kombucha starter culture to tea sugar water is 1:10.

[0037] Step 2: Wash and dry the red algae, then pulverize it through a 60-mesh sieve to obtain coarse red algae powder. Mix the coarse red algae powder, white sugar, and boiling water in a mass ratio of 1:10:100. After hot water extraction for 15 minutes, a sugar-containing red algae mixture is obtained. Cool the mixture to room temperature and centrifuge it (4000 r / min, 20 min) to obtain the red algae extract.

[0038] Step 3: Mix the primary fermentation broth and the red algae extract at a volume ratio of 1:10, ferment (at 28℃ for 7 days), then sterilize (at 65℃ for 30 minutes), filter with gauze, and add an acid-reducing agent to obtain red algae kombucha. The acid-reducing agent consists of 3g / L potassium carbonate, 3g / L potassium bicarbonate, and 12g / L potassium tartrate.

[0039] The kombucha obtained in this embodiment has a pH of 5.12, a titratable acid content of 3.7 g / L, a total phenol content of 144.45 μg / mL, a DPPH free radical scavenging rate of 65.56%, an ABTS free radical scavenging rate of 75.51%, an iron reducing power of 0.36, and a hydroxyl free radical scavenging rate of 82.93%. It has the unique flavor of red algae, a moderate aroma, a suitable sweetness, and a pleasant sweet and sour taste. The kombucha is clear and transparent with a uniform color.

[0040] Example 2

[0041] Step 1: Place black tea leaves in a sterilized glass container, add boiling water and steep for 15 minutes. Add sucrose to dissolve, filter, and obtain tea sugar water; the weight ratio of water, sucrose, and tea leaves is 100:10:1. After sterilizing at 65℃ for 30 minutes, add kombucha starter culture to the tea sugar water and ferment at 28℃ for 7 days to obtain primary fermentation liquid. The volume ratio of kombucha starter culture to tea sugar water is 1:10.

[0042] Step 2: Wash and dry the red algae, then pulverize it through a 60-mesh sieve to obtain coarse red algae powder. Mix the coarse red algae powder, white sugar, and boiling water in a mass ratio of 1:10:100. After hot water extraction for 15 minutes, a sugar-containing red algae mixture is obtained. Cool the mixture to room temperature and centrifuge it (4000 r / min, 20 min) to obtain the red algae extract.

[0043] Step 3: Mix the primary fermentation liquid and the red algae extract at a volume ratio of 1:10, ferment (28℃ for 1 day), then sterilize (65℃ for 30 minutes), filter with gauze, and obtain red algae kombucha.

[0044] The kombucha obtained in this embodiment has a pH of 2.78, a titratable acid content of 1.00 g / L, a total phenol content of 38.59 μg / mL, a DPPH free radical scavenging rate of 14.72%, an ABTS free radical scavenging rate of 79.80%, an iron reducing power of 0.035, and a hydroxyl free radical scavenging rate of 1.04%. It has a slight fishy smell, a slightly sweet taste, and the kombucha is clear, transparent, and has a uniform color.

[0045] Comparative Example 1

[0046] Step 1: Place black tea leaves in a sterilized glass container, add boiling water and steep for 15 minutes. Add sucrose to dissolve, filter, and obtain tea sugar water; the weight ratio of water, sucrose, and tea leaves is 100:10:1. After sterilizing at 65℃ for 30 minutes, add kombucha starter culture to the tea sugar water and ferment at 28℃ for 7 days to obtain primary fermentation liquid. The volume ratio of kombucha starter culture to tea sugar water is 1:10.

[0047] Step 2: Wash and dry the red algae, then pulverize it through a 60-mesh sieve to obtain coarse red algae powder. Mix the coarse red algae powder, white sugar, and boiling water in a mass ratio of 1:10:100. After hot water extraction for 15 minutes, a sugar-containing red algae mixture is obtained. Cool the mixture to room temperature and centrifuge it (4000 r / min, 20 min) to obtain the red algae extract.

[0048] Step 3: Mix the primary fermentation liquid and the red algae extract at a volume ratio of 1:10, sterilize (sterilize at 65℃ for 30 minutes), filter with gauze, and obtain red algae kombucha.

[0049] The kombucha obtained in this comparative example had a pH of 2.81, a titratable acid content of 1.20 g / L, a total phenol content of 37.08 μg / mL, a DPPH free radical scavenging rate of 8.75%, an ABTS free radical scavenging rate of 28.25%, an iron reducing power of 0.032, and a hydroxyl free radical scavenging rate of 2.58%. Its sensory characteristics were an overpowering seaweed flavor, a distinct fishy taste, an overly sweet taste, and poor flavor harmony.

[0050] Comparative Example 2

[0051] Step 1: Place black tea leaves in a sterilized glass container, add boiling water and steep for 15 minutes. Add sucrose to dissolve, filter, and obtain tea sugar water; the weight ratio of water, sucrose, and tea leaves is 100:10:1. After sterilizing at 65℃ for 30 minutes, add kombucha starter culture to the tea sugar water and ferment at 28℃ for 7 days to obtain primary fermentation liquid. The volume ratio of kombucha starter culture to tea sugar water is 1:10.

[0052] Step 2: Wash and dry the red algae, then pulverize it through a 60-mesh sieve to obtain coarse red algae powder. Mix the coarse red algae powder, white sugar, and boiling water in a mass ratio of 1:10:100. After hot water extraction for 15 minutes, a sugar-containing red algae mixture is obtained. Cool the mixture to room temperature and centrifuge it (4000 r / min, 20 min) to obtain the red algae extract.

[0053] Step 3: Mix the primary fermentation liquid and the red algae extract at a volume ratio of 1:10, ferment (28℃ for 7 days), then sterilize (65℃ for 30 minutes), filter with gauze, and obtain red algae kombu tea.

[0054] The kombucha obtained in this comparative example had a pH of 2.61, a titratable acid content of 9.72 g / L, a total phenol content of 146.31 μg / mL, a DPPH free radical scavenging rate of 67.92%, an ABTS free radical scavenging rate of 71.31%, an iron reducing power of 0.37, and a hydroxyl free radical scavenging rate of 39.89%. Its sensory characteristics showed excessively high acidity and poor flavor harmony.

[0055] In summary, according to the embodiments of the present invention, compared with the unfermented Comparative Example 1, the embodiments of this application, by co-fermenting the red algae extract with the once-fermented kombucha, can achieve a higher total phenolic content, a higher DPPH and ABTS free radical scavenging rate, and remove the algal odor of the red algae, resulting in better sensory quality. Furthermore, compared with Comparative Example 2 without acidity control, the embodiments of this application, by adding an acid-lowering agent, have a higher pH value and a lower titratable acid content in the red algae kombucha, with no significant difference in total phenolic content, DPPH and ABTS free radical scavenging rate, and better sensory quality. Compared with Example 2, which was fermented for 1 day, Example 1, which was fermented for 7 days, had a higher DPPH and ABTS free radical scavenging rate, and removed the algal odor of the red algae, resulting in better sensory quality.

[0056] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. The illustrative expressions of the above terms in this specification should not be construed as necessarily referring to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0057] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for preparing a red algae kombucha beverage, characterized in that, Includes the following steps: Step 1: Using tea leaves as a base, add water and sucrose to make tea sugar water. After sterilization, inoculate with kombucha culture for primary fermentation to obtain primary fermentation liquid. Step 2: The red algae are washed, crushed, and then extracted with sugar and boiling water to obtain red algae extract. Step 3: Mix the primary fermentation liquid with the red algae extract and carry out secondary fermentation. After sterilization and filtration, add an acid-reducing agent to obtain the red algae kombucha beverage.

2. The preparation method according to claim 1, characterized in that, In step one, the volume ratio of kombucha inoculum to tea sugar water is 1:

10.

3. The preparation method according to claim 1, characterized in that, In step one, the weight ratio of water, sucrose, and tea leaves is 100:10:

1.

4. The preparation method as described in claim 1, characterized in that, In step one, the first fermentation is carried out at 28℃ for 7 days.

5. The preparation method according to claim 1, characterized in that, In step two, coarse powder of red algae, white sugar and boiling water are mixed in a mass ratio of 1:10:

100.

6. The preparation method according to claim 1, characterized in that, In step two, hot water extraction is performed for 15 minutes.

7. The preparation method according to claim 1, characterized in that, In step three, the primary fermentation broth and the red algae extract are mixed at a volume ratio of 1:

10.

8. The preparation method according to claim 1, characterized in that, In step three, the secondary fermentation is carried out at 28℃ for 7 days.

9. The preparation method according to claim 1, characterized in that, In step three, the acid-lowering agents are potassium carbonate 3g / L, potassium bicarbonate 3g / L, and potassium tartrate 12g / L.

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