KR20100059278A - Method for manufacturing fermented tea using lactic acid bacteria strains - Google Patents

Abstract

PURPOSE: A method for manufacturing fermented tea using lactic acid bacteria strains is provided to manufacture the fermented tea safe from the pathogenic bacteria, and to improve flavor of the tea by fermenting green tea. CONSTITUTION: A method for manufacturing fermented tea using lactic acid bacteria strains comprises the following steps: removing a culture medium by washing the culture medium with salty water after centrifuging; culturing the lactic acid bacteria strains in a fermentation liquid without protein powder; and fermenting the lactic acid bacteria strains on leaves. The fermentation liquid includes sugar, fructose, lactose and water. The lactic acid bacteria strains is strain separated fermented food.

Description

Method for manufacturing fermented tea using lactic acid bacteria strains

The present invention relates to a method for producing a fermented tea with improved flavor without contamination of pathogenic bacteria or bacteria.

In general, when tea passes through microbial fermentation, the taste, aroma, and color are changed by the metabolic process of microorganisms, thereby changing the existing flavor. This is because the carbohydrate, protein, catechin, and other minerals of tea are metabolized by unique enzymes of each microorganism, and the composition of tea's organic acids and polyphenols changes. The color will change. The change in the taste of tea after fermentation varies depending on the type of microorganism, the content of tea components, the composition of the fermentation broth, fermentation temperature and time.

Therefore, in order to ferment tea with good taste, it is important to select the appropriate microorganism, the composition of the fermentation broth, and the determination of the fermentation temperature and time. Generally, fermented tea is made by filling and leaving the barrel with heat treated tea leaves. At this time, it is subjected to a lot of action of unspecified anaerobic bacteria or general bacteria, especially fungi, attached to the leaves or tea leaves in the air. Specifically, the risk may be increased by being easily exposed to toxins produced by pathogenic microorganisms such as Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and toxins such as aflatoxins produced by the fungus. In particular, lactic acid bacteria are not easy to control germs by high temperature fermentation due to weak heat, and acid is produced by lactic acid bacteria metabolism, which makes mold growth much easier, and it is difficult to control germs, thus making it difficult to reproduce a certain tea taste. have.

The present invention fermented green tea using lactic acid bacteria isolated from Korean traditional fermented foods such as Chinese cabbage kimchi, radish kimchi, water kimchi, soy sauce, soybean paste, lactose, etc. to provide a fermented tea excellent in flavor by microbial metabolism and safe from pathogenic bacteria It aims to do it.

Fermented tea manufacturing method according to an embodiment of the present invention, (i) preparing a lactic acid bacteria strain; (ii) stabilizing the lactic acid bacteria strain; (iii) treating the stabilized lactic acid bacteria strain to tea leaves, characterized in that it comprises the step of fermentation.

Fermented tea manufacturing method according to another embodiment of the present invention, characterized in that the fermentation using Lactobacillus sp. ( Lactobacillus sp. ) Strain or Leuconostoc sp .

According to one embodiment of the present invention is excellent in flavor, astringent taste and bitter taste is improved to improve the overall palatability, it is possible to manufacture a safe fermented tea without the growth of pathogenic bacteria or bacteria.

As used herein, the term "fermentation broth" means a mixture of a strain and a culture solution for fermentation, which do not include protein powder.

As used herein, the term "fermentation bacteria" refers to a mixture of strain and culture for fermentation, including protein powder.

As used herein, the term "lactic acid bacteria strain isolated from fermented food" refers to a strain of lactic acid bacteria isolated from fermented foods such as soy sauce, soybean paste, milk brown, cabbage kimchi, radish kimchi, and water kimchi. Fermented food is particularly preferably a traditional Korean fermented food.

In one embodiment of the present invention, the lactic acid bacteria strain Lactobacillus acidophilus ( Lactobacillus acidophilus ), Lactobacillus brevis ( Lactobacillus brevis ), Lactobacillus bulgaricus , Lactobacillus pentosus ( Lactobacillus pentosus ), Lactobacillus pentosus Lactobacillus plantarum , Lactobacillus rhamnosus , Leuconostoc citreum , Leuconostoc gelidum , Leuconostoc mecenteroses and Leuconostoc mesenteroides It may be one or more strains selected from the group consisting of stock paramesenteroides ( Leuconostoc paramesenteroides ). Among them, in particular from the viewpoint of palatability, the lactic acid bacteria strain is preferably at least one selected from the group consisting of Lactobacillus acidophilus , Lactobacillus brevis and Leuconostoc citreum . Do.

The strains are strains deposited in Korea Food Research Institute or Korea Microorganism Conservation Center (KCCM), anyone can easily be used for pre-sale from Korea Food Research Institute or Korea Microorganism Conservation Center.

In one embodiment of the present invention, the step (i), it is preferable to remove the medium by washing with brine after centrifuging the medium containing the lactic acid bacteria strain. It is desirable to completely remove the medium since residual medium will affect the tea flavor.

In another embodiment of the present invention, the step (ii) comprises stabilizing the strain by culturing the lactic acid bacteria strain in a fermentation broth that does not contain protein powder. The fermentation broth that does not contain the protein powder preferably contains sugar, fructose, lactose and water. The protein powder is added to the culture solution containing the stabilized strain in this way, and the fermentation broth obtained in this way can be fermented by treating the tea leaves.

Protein powder means that the protein is powdered, and any protein powder may be used. Animal protein powders or vegetable protein powders may be used. Examples of animal proteins include beef powder or milk protein powder. Milk protein powder is most preferred for the lactic acid bacteria strain.

The reason why the protein powder is not added in the stabilization stage of the strain is to solve the problem of microbial decomposition and catching.

In one embodiment of the present invention, the fermentation broth is based on the total weight of the fermentation broth, containing 0.05 to 10.0% by weight sugar, 0.005 to 10.0% by weight fructose, 0.01 to 10.0% by weight lactose and 0.005 to 2.0% by weight protein powder It is preferable. This is because the fermentation of strains occurs most optimally within this range.

In another embodiment of the present invention, the step (iii), the fermentation broth is preferably divided into three to five times at intervals to treat the tea leaves. If you mix it with green tea at once, it is difficult to mix evenly fermented bacteria. On the other hand, it is preferable to continuously stir the tea leaves when the fermentation broth is added to the tea leaves. When moisture is mixed with green tea leaves, an exothermic reaction occurs to prevent the strain from being damaged by rapid temperature increase.

The tea leaves treating the fermentation bacteria solution may be fresh green tea leaves or dried leaves of green tea green leaves. Fermentation is possible even with dry leaves. Dry leaves may be usefully used in view of the availability of dried green tea stock.

In one embodiment of the present invention, the step (iii) is preferably carried out at a temperature of 5 ~ 60 ℃. This is because when the fermentation temperature exceeds 60 ℃, the growth of lactic acid bacteria is inhibited. If it is less than 5 ℃ may also inhibit the growth of lactic acid bacteria. In addition, the step (iii) is to remove the air inside the fermentation tank or packaging material using a vacuum pump, etc., and then perform the fermentation in a state of preventing the inflow of outside air. If the air is not sufficiently removed in the preparation step before fermentation, various bacteria are multiplied, and thus, the fermentation flavor inherent in lactic acid bacteria cannot be maintained.

In one embodiment of the present invention, the fermentation broth of step (iii), it is preferable to include lactic acid bacteria strain of 10 ³ ~ 10 ⁸ CFU / ml. Including the strain within the above range can be carried out smoothly.

Hereinafter, each step of the fermented tea manufacturing method according to an embodiment of the present invention will be described.

<Green tea leaves and inoculation bacteria preparation step>

The dried green tea leaves are applied to a sterile process to prepare as a main substrate. Lactobacillus acidophilus , Lactobacillus brevis , Lactobacillus bulgaricus , Lactobacillus pentosus , Lactobacillus pentosus isolated from traditional fermented foods Lactobacillus plantarum , Lactobacillus rhamnosus , Leuconostoc citreum , Leuconostoc gelidum , Leuconostoc mesenteroides and Leuconose paramethoxetose One or more strains selected from the group consisting of Leuconostoc paramesenteroides were inoculated into an active medium for activating strains contained in an Erlenmeyer flask (eg, 1000 ml), and then subjected to anaerobic or aerobic conditions in a shaking incubator at 5 to 60 ° C. Incubate for 60 to 80 hours.

<Preparation of Inoculation Strains>

Recover the strain incubated under anaerobic or aerobic conditions for 60 to 80 hours in a vibrating incubator to separate the strain and the active medium in a centrifuge first. At this time, centrifugation is performed for 5 to 10 minutes at a speed of 2000-4500 rpm, and the sample of which the separation of the medium and the strain is completed is removed from the supernatant by using a vacuum inhaler. Remaining active medium affects the flavor of green tea during fermentation, washing the strain 2-4 times using 0.8-1.0% physiological saline. In the washing method, physiological saline is added to the strain precipitate from which the active medium is removed, and the mixture is mixed for 30 seconds to 1 minute so that the strain precipitate is well dispersed in physiological saline. The physiological saline bacteria solution in which the strain is dispersed is centrifuged for 5 to 10 minutes at a speed of 2000 to 4500 rpm as in the process of removing the active medium, and the saline solution is removed using a vacuum inhaler. Repeat the above method 2-4 times to completely remove the active medium component.

<Fermentation solution preparation and stabilization of strains>

In addition to green tea, water and energy must be provided for proper microbial metabolism. Food additives that provide energy sources include sugars and proteins. The taste of fermented tea will vary depending on the type and concentration of the additives. Specifically, the fermentation broth is prepared by mixing sugar 0.05-10.0%, fructose 0.005-10.0%, lactose 0.01-10.0% by weight and protein powder 0.005-2.0%. The specific manufacturing method is dissolved in purified water to 0.05 to 10.0% sugar, 0.005 to 10.0% fructose and 0.01 to 10.0% by weight lactose, and then autoclaved at 100 to 140 degrees for 10 to 20 minutes. The sterilized fermentation broth is cooled at room temperature and then mixed with 0.005% to 2.0% protein powder.

Stabilization of the strain in the fermentation broth is required for smooth fermentation metabolism of the damaged strain in the washing process. Mix the strain washed 2-4 times with saline to 100 ~ 500mL of the fermentation broth before adding the protein powder and stabilize while incubating at a temperature of 5 ~ 60 ℃ in aerobic or anaerobic incubator for 12 to 36 hours.

<Fermentation and drying method of green tea>

A protein powder is added to the strain stabilized in the fermentation broth except for the protein powder to prepare the fermentation bacteria. The fermentation broth is mixed with the sterilized reaction tank and the green tea main substrate prepared for each small packaging unit. Prepare so that the number of fermentation strains 10 ³ ~ 10 ⁸ CFU / mL in the mixed fermentation bacteria. If the moisture ratio is greater than 60% of the weight of the green tea leaves (less than 5% water content), the color of the final product may deteriorate. If less than 30% it may be difficult to uniformly ferment the green tea leaves by bacteria. Therefore, the ratio of fermentation broth to the weight of green tea leaves gives 30 to 60% of the mixture. If fermentation broth is mixed with green tea at once, it is difficult to mix evenly with fermentation broth, so mix green tea 3 ~ 5 times by mixing 20 ~ 30% of the whole fermentation broth. When water is mixed with green tea leaves, an exothermic reaction occurs, and after mixing the fermentation bacteria solution so that the strain is not damaged by rapid temperature increase, the tea leaves are continuously stirred to prevent the temperature inside the tea from rising rapidly. After 5 ~ 30 minutes, the exothermic reaction is completed and the temperature is lowered. The mixture of green tea fermentation broth is taken out of the fermenter or the packing material by using a vacuum pump, and the inlet is blocked to prevent the inflow of outside air and the anaerobic constant temperature condition is 5 ~ 60 ℃. Fermentation process at When the fermentation temperature exceeds 60 ℃ it is preferable that the fermentation temperature does not exceed 60 ℃ because the growth of lactic acid bacteria is inhibited. In addition, if the air is not sufficiently removed in the preparatory step before fermentation, various bacteria are multiplied, it is not possible to maintain the fermentation flavor inherent in lactic acid bacteria. The fermentation time should be at least 24 hours for up to 28 days and dried for 3-7 hours at hot air drying 80 ~ 120 ℃.

As a result of the embodiment of the present invention, the total microbial account in the fermented green tea final product manufactured can be obtained in a standard range of 10 ^{2 to 8} CFU / g or less, and pathogenic microorganisms are not detected.

Hereinafter, the present invention will be described in more detail with reference to a preferred embodiment of the present invention. However, the embodiments described below are merely illustrative of the present invention, and the scope of the present invention is not limited to the embodiments.

Fermented green tea manufacturing method according to an embodiment of the present invention is as follows.

Examples 1 to 10 Preparation of Fermented Tea

<Green tea leaves and inoculation bacteria preparation step>

The dried green tea leaves were applied to a sterile process to prepare as a main substrate. And the active medium for strain activation in each of the strains of Table 1 isolated from the traditional fermented food in an Erlenmeyer flask (1000 ml) [MRS Broth (Oxoid Company; composition: Peptone 1%, Lab-Ramco powder 0.8%, yeast extract 0.4%) , Glucose 2%, sorbitan monooleate 0.1% (v / v), dipotassium hydrogen phosphate 0.2%, sodium acetate hydrate 0.5%, triammonium citrate 0.2%, magnesium sulfate hydrate (7H ₂ O) 0.02% , Magnesium sulfate hydrate (4H ₂ O) 0.005%; composition of lab-ramco powder: total nitrogen 13.3% (w / w), amino nitrogen 2.5% (w / w), sodium chloride 1.1% (w / w)) ] And then incubated under anaerobic conditions at 32 ℃ for 72 hours.

The strains selected in this example are strains that have been distributed from the "Food Microbial Gene Bank" of the Korea Food Research Institute or the Korea Microorganism Conservation Center. In this example, the strains described in Table 1 below were used.

Strain name Strain accession number Depositary Institution Example 1 Lactobacillus acidophilus 40265 Korea Microbial Conservation Center Example 2 Lactobacillus brevis 61605 Korea Food Research Institute Example 3 Lactobacillus bulgaricus 40266 Korea Microbial Conservation Center Example 4 Lactobacillus pentosus 40997 Korea Microbial Conservation Center Example 5 Lactobacillus plantarum 60805 Korea Food Research Institute Example 6 Lactobacillus rhamnosus 40069 Korea Microbial Conservation Center Example 7 Leuconostoc citreum 60702 Korea Food Research Institute Example 8 Leuconostoc gelidum 40460 Korea Microbial Conservation Center Example 9 Leuconostoc mesenteroides 60104 Korea Food Research Institute Example 10 Leuconostoc paramesenteroides 40114 Korea Microbial Conservation Center

<Preparation of Inoculation Strains>

Each strain was incubated for 72 hours in a vibrating incubator was first centrifuged at 3000rpm for 10 minutes in a centrifuge to isolate the strain and the active medium. After the separation of the medium and strain was completed, the supernatant was removed from the active medium using a vacuum inhaler. Since the remaining active medium affects the flavor of green tea during fermentation, the strain was washed four times using 0.9% physiological saline. In the washing method, physiological saline was added to the strain precipitate from which the active medium was removed, and the mixture was mixed for 1 minute so that the strain precipitate was well dispersed in physiological saline. The physiological saline bacteria solution in which the strain was dispersed was centrifuged for 10 minutes at a speed of 3000 rpm as in the process of removing the active medium, and the saline was removed using a vacuum inhaler. The same procedure was repeated four times to completely remove the active medium component.

<Fermentation solution preparation and stabilization of strains>

Based on the total weight of the fermentation broth, the strain was added to the fermentation broth containing 5.0 wt% of sugar, 5.0 wt% of fructose, and 5.0 wt% of lactose. Specifically, 5.0 wt% of sugar, 5.0 wt% of fructose and 5.0 wt% of lactose were dissolved in purified water, followed by autoclaving at 120 ° C. for 15 minutes. The sterilized fermentation broth was cooled to 25 ° C. at room temperature. The strain was added to 250 mL of the cooled fermentation broth and incubated at 40 ° C. for 24 hours in an anaerobic incubator.

<Fermentation and drying method of green tea>

Whey protein powder (WPC, Whey Protein Concentrate, Brewster Company, USA) was added 1.0 wt% to the stabilized fermentation broth to prepare a fermentation broth. The fermentation broth was mixed in a sterile reaction tank and the green tea main substrate prepared for each small packaging unit. The number of fermentation strains in the fermentation broth was 10 ⁶ CFU / mL. The ratio of the fermentation broth was mixed to 50% of the weight of green tea leaves. At this time, 20 times of the total fermentation broth was divided by a total of 5 times and mixed with time difference. After the fermentation broth was mixed, the tea leaves were continuously stirred to prevent the temperature inside the tea from rising rapidly. After 20 minutes, the exothermic reaction was completed and the temperature drop of the green tea fermentation broth mixture was removed by using a vacuum pump to remove all the air inside the fermenter, blocking the inlet to prevent the inflow of outside air, and fermenting for 10 days under the anaerobic constant temperature condition of 40 ° C. Then, hot air was dried at 100 ° C. for 5 hours.

As a result, the total microbial account in the fermented green tea final product was able to obtain a standard range of 10 ² to 10 ⁸ CFU / g or less.

Experimental Example 1: Microbial Contamination Test

As a result of measuring the number of general bacteria and specific pathogenic bacteria contained in the fermented tea obtained according to Examples 1 to 10, the results of Table 2 were obtained.

Fermentation strain name General bacterial count
(CFU / g *) Certain pathogenic bacteria bacteria mold Escherichia coli Staphylococcus aureus Pseudomonas aeruginosa Example 1 Lactobacillus acidophilus <100 <100 voice voice voice Example 2 Lactobacillus brevis <100 <100 voice voice voice Example 3 Lactobacillus bulgaricus <100 <100 voice voice voice Example 4 Lactobacillus pentosus <100 <100 voice voice voice Example 5 Lactobacillus plantarum <100 <100 voice voice voice Example 6 Lactobacillus rhamnosus <100 <100 voice voice voice Example 7 Leuconostoc citreum <100 <100 voice voice voice Example 8 Leuconostoc gelidum <100 <100 voice voice voice Example 9 Leuconostoc mesenteroides <100 <100 voice voice voice Example 10 Leuconostoc paramesenteroides <100 <100 voice voice voice

* CFU / g: Colony Forming Unit / g, number of microorganisms per 1g of green tea

Experimental Example 2: Sensory Evaluation

In order to investigate how the comprehensive preference including the taste, aroma and search of the fermented green tea prepared according to Examples 1 to 10 was changed according to the fermentation strain, a panel test was conducted. As for the test method, 10 expert evaluators used an evaluation method of multi-voting on a sample which is considered to have high preference for 10 fermented green teas prepared according to Examples 1 to 10, and the evaluation results were as follows.

No Strain name score Example 1 Lactobacillus acidophilus 7 Example 2 Lactobacillus brevis 8 Example 3 Lactobacillus bulgaricus 5 Example 4 Lactobacillus pentosus 5 Example 5 Lactobacillus plantarum 5 Example 6 Lactobacillus rhamnosus 4 Example 7 Leuconostoc citreum 7 Example 8 Leuconostoc gelidum 4 Example 9 Leuconostoc mesenteroides 6 Example 10 Leuconostoc paramesenteroides 3

Claims (15)

(i) preparing a lactic acid bacteria strain; (ii) stabilizing the lactic acid bacteria strain; (iii) the fermented tea manufacturing method comprising the step of fermenting the stabilized lactic acid bacteria strain to the tea leaves. The method of claim 1, wherein the lactic acid bacteria strain is a fermented tea manufacturing method, characterized in that the strain isolated from the fermented food. The method of claim 2, The lactic acid bacteria strain is Lactobacillus sp. ( Lactobacillus sp. ) Strain or Luconostoc sp. ( Leuconostoc sp. ) Strain characterized in that the manufacturing method of fermented tea. The method according to claim 3, wherein the lactic acid bacteria strain is Lactobacillus acidophilus , Lactobacillus brevis , Lactobacillus bulgaricus , Lactobacillus pentosus ( Lactobacillus pentosus ), Lactobacillus pentosus Lactobacillus plantarum , Lactobacillus rhamnosus , Leuconostoc citreum , Leuconostoc gelidum , Leuconostoc mesentroids and Leuconostoc mesenteroides A method for preparing fermented tea, characterized in that it is at least one strain selected from the group consisting of Leuconostoc paramesenteroides . According to claim 4, The lactic acid bacteria strain is fermentation characterized in that at least one selected from the group consisting of Lactobacillus acidophilus , Lactobacillus brevis and Leuconostoc citreum . Tea manufacturing method. The method of claim 1, wherein step (i) comprises: Method for producing a fermented tea, characterized in that to remove the medium by centrifuging the medium containing the lactic acid bacteria strain and then washed with brine. The method of claim 1, wherein step (ii) Fermented tea production method characterized in that the culture of the lactic acid bacteria strain into the fermentation broth not containing protein powder. The method of claim 7, wherein Fermentation broth that does not contain the protein powder is a fermentation tea production method characterized in that it comprises sugar, fructose, lactose and water. The method of claim 7, wherein step (iii), Fermentation tea production method characterized in that the fermentation broth obtained by adding the protein powder to the culture solution obtained in the step (ii) by treating the tea leaves to ferment. 10. The method of claim 9, The fermentation broth is fermented tea production method, characterized in that it comprises 0.05 to 10.0% by weight sugar, 0.005 to 10.0% by weight fructose, 0.01 to 10.0% by weight lactose and 0.005 to 2.0% by weight protein powder . The method according to any one of claims 7 to 10, The protein powder is a fermented tea manufacturing method, characterized in that the milk protein powder. The method of claim 9, wherein step (iii), Fermented tea production method characterized in that the fermentation broth is divided into three to five times at intervals and treated to tea leaves. The method of claim 9, wherein step (iii), Fermented tea manufacturing method characterized in that the tea leaves are stirred when the fermentation broth is treated with the tea leaves and after treatment. According to claim 1, wherein the step (iii), fermented tea manufacturing method characterized in that carried out under anaerobic conditions of 5 to 60 ℃ temperature. 10. The method of claim 9, wherein the fermentation broth of step (iii) comprises lactic acid bacteria strains of 10 ³ to 10 ⁸ CFU / ml.