Plantarum p-6 and application thereof in tea fermentation

Abstract

The application discloses a Lactiplantibacillus plantarum P-6 and application thereof in tea fermentation, and belongs to the field of microbial fermentation and food technology. The Lactiplantibacillus plantarum P-6 has a preservation number of CGMCC No. 26225, a preservation date of December 25, 2022, and a preservation unit of China General Microbiological Culture Collection Center. The strain is obtained by screening in nature, and is verified by fermentation to be capable of significantly increasing the total phenol content and flavor substances of black tea juice and growing in the black tea juice environment. Compared with other lactic acid bacteria, the strain provided by the application can significantly convert macromolecular phenolic substances in the tea juice into soluble small molecular phenolic substances, thereby improving the bioavailability and biological activity of polyphenols, and the flavor substances of the fermented tea juice are richer, and the taste is better, which lays a foundation for the development of a new probiotic beverage and has a wide application prospect.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of microbial fermentation and food technology, and particularly relates to a plant lactobacillus P-6 and its application in tea fermentation. BACKGROUND

[0002] Tea has a long history of medicinal and edible value in China, and its benefits to human health have long been recognized by the Chinese. Nowadays, people pay more and more attention to the field of life and health, especially in terms of diet. Lactic acid bacteria are recognized by consumers for their ability to improve the utilization rate of nutrients, regulate intestinal flora, and comprehensively regulate the immune function of the body. The use of lactic acid bacteria to ferment beverages has become a new trend in the popularity of beverages. At the same time, the trend of refreshing beverages is gradually becoming mainstream in the beverage market. Fermented tea is an important form of tea product processing. Lactic acid bacteria fermented tea juice is favored by the market due to the health functions of tea and the probiotic properties of lactic acid bacteria.

[0003] However, tea juice contains a large amount of antibacterial components, and there are significant interspecific and intraspecific differences among lactic acid bacteria. Therefore, for lactic acid bacteria fermentation of such complex raw materials, comprehensive research is needed from the aspects of strain characteristics, raw material adaptability, and metabolic products, etc. to provide basic information for product development. This provides a new idea for developing fermented tea rich in functional active substances and good flavor.

[0004] Tea juice contains rich polyphenols and flavonoids. There is some relevant research on the flavor substances of tea juice. In theory, whether the bitter and astringent characteristics of tea juice can be reduced to some extent through biological transformation, and whether the flower and fruit aroma substances can be accumulated and enriched through fermentation, also need to be verified through experiments and analyzed through results. These information has a basic role in establishing the quality control system of fermented tea juice products.

[0005] The utilization and transformation of tea juice by lactic acid bacteria are not clear, and there is a lack of relevant research on the changes in flavor quality and health function. Fermented tea juice products are relatively blind, the utilization rate of useful substances in tea juice is not high, and the volatile substances in tea juice cannot be fully fermented. Therefore, the change in total phenol content and flavor substances after lactic acid bacteria fermentation of tea juice can improve the bioavailability of effective substances in tea juice and lay some foundation for the development of probiotic drinks. SUMMARY

[0006] To solve the above technical problems, the present application selects 17 kinds of lactic acid bacteria obtained from fruits and vegetables as the basis, and selects a plant lactobacillus P-6 with good environmental tolerance, high growth activity, good acid production effect, and rich flavor substances through high-concentration tea polyphenol environment, providing a new method for the development of tea beverages.

[0007] The application provides a Lactiplantibacillus plantarum, named Lactiplantibacillus plantarum P-6, with a preservation number of CGMCC No.26225.

[0008] The application takes fermented black tea juice of lactic acid bacteria as a basis, screens lactic acid bacteria which can adapt to the environment of black tea juice, and then proves the material change of the fermented black tea juice of the plant lactic acid bacillus, studies the influence of the environment of the black tea juice on the growth of lactic acid bacteria, and focuses on the change of the total phenol content and flavor substances after the fermentation of the black tea juice. Specifically, first, 17 strains of lactic acid bacteria which can grow vigorously and adapt to the environment of tea juice are screened from 17 strains of lactic acid bacteria, so as to provide a basis for proving the material change of the fermented tea juice of lactic acid bacteria; then, the lactic acid bacteria P-6, D, F and M which can adapt to the fermentation environment of black tea juice are screened out by comparing sugar consumption, total phenol content, sensory evaluation and the like, and the material change of the tea juice before and after fermentation is detected, and the total phenol content and flavor substances before and after fermentation are compared, so as to obtain a plant lactic acid bacillus P-6 which can significantly improve the total phenol content and flavor substances of black tea juice. The strain is screened out from the aspects of acid production, tea juice environment tolerance, phenol production, sugar consumption, tea juice taste after fermentation and flavor substance production, and has multiple advantages compared with other same strains.

[0009] The application provides a culture or a processed product of the Lactiplantibacillus plantarum.

[0010] A food composition contains the Lactiplantibacillus plantarum, the culture or the processed product thereof.

[0011] Further, the food composition can be used for preparing tea beverages or other forms of tea products.

[0012] An additive composition contains the Lactiplantibacillus plantarum, the culture or the processed product thereof.

[0013] A microbial agent contains the Lactiplantibacillus plantarum.

[0014] Further, the microbial agent is a liquid microbial agent.

[0015] Further, the microbial agent is a solid microbial agent.

[0016] A third object of the application is to provide application of the Lactiplantibacillus plantarum in preparation of tea fermentation products.

[0017] Further, the application comprises: fermenting tea-containing products by using the Lactiplantibacillus plantarum.

[0018] Further, the tea includes but is not limited to black tea, green tea, white tea, dark tea, yellow tea, blue tea and the like. Of course, the most preferred is black tea.

[0019] Further, the tea-containing product contains a carbon source (and to make the product low in sugar, the content of the carbon source is preferably not more than 10%), including but not limited to sucrose and the like.

[0020] The above technical solutions of the present application have the following advantages compared with the prior art:

[0021] The present application provides a plant lactiplantibacillus p-6 with high beta-glucosidase activity that can adapt to growth in black tea juice, significantly improve the total phenol content and flavor substances of black tea juice, and its application. The strain can maintain normal life activities in black tea juice, produce lactic acid and organic acid content, enrich the flavor of tea juice, and at the same time, the high beta-glucosidase activity of the strain can release glycoside-bound flavor substances in the tea juice, decompose large molecular phenolic substances into small molecular phenolic substances, improve the utilization of flavor substances in the tea juice and biological activity, and lay a foundation for the development of probiotic tea beverages.

[0022] Biological material preservation

[0023] The plant lactiplantibacillus P-6 has been preserved in the China General Microbiological Culture Collection Center on December 25, 2022, with a preservation number of CGMCC No. 26225 and a preservation address of No. 3, Institute of Microbiology, Chinese Academy of Sciences, Beijing City, Chaoyang District, Beichen West Road 1st Courtyard 3rd. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to make the content of the present application more easily understood, the present application will be further described in detail below according to specific embodiments of the present application and in conjunction with the drawings, in which

[0025] Figure 1 The figure is the change of total acid of the black tea juice fermented by different lactic acid bacteria of the present application.

[0026] Figure 2 The figure is the change of acid production of the black tea juice fermented by different strains of the present application.

[0027] Figure 3 The figure is the change of pH of the black tea juice fermented by different strains of the present application.

[0028] Figure 4 The figure is the comparison of viable cell count before and after fermentation of black tea juice by different lactic acid bacteria of the present application.

[0029] Figure 5 The figure is the change of total phenol content of the black tea juice by different lactic acid bacteria of the present application.

[0030] Figure 6 The figure is the sugar consumption amount of the black tea juice fermented by different lactic acid bacteria of the present application. The figure is the sugar consumption amount of the black tea juice fermented by different lactic acid bacteria of the present application.

[0031] Figure 7 Electronic tongue detection data chart of tea juice before and after fermentation of Lactobacillus plantarum p-6 of the present application.

[0032] Figure 8 Change of volatile substances of black tea juice after fermentation of Lactobacillus plantarum p-6 of the present application.

[0033] Figure 9 New flavor substances and content of black tea juice after fermentation of Lactobacillus plantarum p-6 of the present application.

[0034] Figure 10 Comparison chart of flavor substance content of black tea juice after fermentation of Lactobacillus plantarum p-6 of the present application and after fermentation of D, F and M strains. DETAILED DESCRIPTION

[0035] The present application will be further described in conjunction with the drawings and specific examples so that those skilled in the art can better understand the present application and implement it, but the examples are not intended to limit the present application.

[0036] I. Fermentation index determination:

[0037] Total acid determination method:

[0038] Take 1 mL of sample in a 250 mL conical flask, add 100 mL of distilled water and one drop of phenolphthalein, shake well. Observe the color of the solution while adding sodium hydroxide solution, and when the solution color changes to light pink, add one drop of lye, until the solution becomes stable pink (i.e. 1 min without fading) is the end point of titration, record the volume of lye added (accurate to two decimal places), repeat three times, and take the average value.

[0039]

[0040] In the formula: X - the content of total acid in the fermentation broth, g lactic acid / 100 mL;

[0041] C (NaOH) - concentration of standard sodium hydroxide solution, moL / L;

[0042] V1 - volume of standard NaOH solution required for titration of sample, mL;

[0043] V2 - volume of standard NaOH solution required for titration of blank, mL;

[0044] V - volume of fermentation broth taken, mL;

[0045] 0.09 - 1 mL of 1 moL / L standard sodium hydroxide solution corresponding to the mass of lactic acid

[0046] pH determination method:

[0047] Calibrate the pH meter first, then take 2 mL sample, first flush, wipe the electrode of pH with distilled water, then put the electrode of pH meter into the sample for measurement, record the value.

[0048] Live bacteria colony count after fermentation:

[0049] The plate dilution coating method is used to determine the live bacteria count at the end of fermentation.

[0050] Total phenol determination method:

[0051] In an alkaline solution, tungsten molybdate can quantitatively oxidize polyphenol compounds (gallic acid groups), and itself is reduced (W6+ to W5+) to generate blue compounds, and the depth of blue is proportional to the number of phenolic groups. If the sample contains other classified compounds or other reducing substances, they will also be measured at the same time.

[0052] Centrifuge the sample (4500 rpm, 20 min) to obtain the supernatant. Take 200 microliters of sample, add 1 mL of Folin phenol reagent (diluted 10 times), add 1 mL of 7.5% sodium carbonate solution, and stand at room temperature for 30 min. Measure the absorbance at a wavelength of 765 nm with a 1 cm cuvette. The reagent blank is used as the reference.

[0053] Standard curve equation: y = 11.79x + 0.0658

[0054] y - total phenol concentration, mg / mL

[0055] x - sample absorbance at 765 nm

[0056] Reducing sugar determination method:

[0057] The samples taken before and after fermentation are added to the DNS reagent and heated in a water bath. Measure the absorbance at 540 nm. Each sample is done in triplicate.

[0058] II. Raw material information:

[0059] Black tea juice one raw tea juice: 12 Brix, tea polyphenol 11 g / L;

[0060] Black tea juice two raw tea juice: 25.5 Brix, tea polyphenol 16 g / L;

[0061] The black tea juice one and the black tea juice two used in the following experiments are obtained by diluting ten times the original tea juice (purchased from Fujian Lvquan Food Co., Ltd.).

[0062] The strain required by the present application needs to be thawed and activated in MRS medium at 32°C for 2 generations before being used for fermentation.

[0063] Example 1: Screening and identification of black tea juice adapted Lactobacillus plantarum p-6 and preservation of the strain

[0064] 1. Screening of black tea juice adapted Lactobacillus plantarum p-6

[0065] The tea soup medium used in the present application is: original tea juice diluted by 10%; and 5% of sugar (sucrose) is added to provide sufficient energy substances for lactic acid bacteria. The prepared tea soup medium is divided into food-grade blue cap bottles. High pressure sterilization at 115°C for 20 min, and then cooled for standby.

[0066] The fermentation conditions used in the present application are: the activated strain is inoculated into the tea soup medium at an inoculation amount of 2%, and incubated in a 37°C incubator for 72 h.

[0067] Strain activation: the strain preserved in a glycerol tube is inoculated into MRS medium at an inoculation amount of 2%, and incubated in a 37°C incubator for 24 h for activation. Then, it is inoculated into new MRS medium at an inoculation amount of 2%, and incubated in a 37°C incubator for 18 h for activation of the second generation. After activation, 1 ml of bacterial liquid and 1 ml of 40% glycerol are taken into a bacteria preservation tube for preservation.

[0068] The activated strain is inoculated into the tea soup medium at an inoculation amount of 2%, and incubated in a 37°C incubator for 72 h. Sampling is performed every certain period of time, and total acid, pH, total number of viable bacteria, total phenol and sugar consumption are determined.

[0069] (1) Change of total acid of Lactobacillus plantarum p-6 in black tea juice fermentation

[0070] In the food fermentation process, lactic acid bacteria produce lactic acid, acetic acid and other organic acids as the most typical characteristics, and the acid production capacity of the strain ultimately affects the quality of the product. The total acid content is also a very important index. 17 kinds of lactic acid bacteria pL-3, pL-2, 3, pL-4, pL-5, 1-1, 1260, D, F, M, p-6, R, 5, 15, HE, 3-F, p1-1 (all selected from nature) are inoculated into black tea juice II with a total phenol content of 0.9707 g / L for fermentation. Due to the consumption of sugar and the accumulation of lactic acid and other organic acids in the fermentation process, the total acid of the tea juice shows an overall upward trend. Figure 1 ).

[0071] The total acid of the tea juice after fermentation of the 15 kinds of lactobacillus has different rising degrees, between 0.02-0.43 g / 100 mL Figure 2), and the total acid content of the tea juice fermented by p1-1 bacteria had no change, and the total acid content of the tea juice fermented by HE decreased by 0.04 g / 100 mL. The total acid content of the tea juice before fermentation was 0.17 g / 100 mL, and the total acid content of the tea juice fermented by Lactobacillus plantarum p-6 was 0.43 g / 100 mL, and the total acid content increased by 0.26 g / 100 mL.

[0072] (2) Comparison of pH of different lactic acid bacteria in black tea juice fermentation

[0073] While determining the total acid content of the tea juice, the change of pH of the black tea juice fermented by the above 17 kinds of lactic acid bacteria was determined, and the pH of the black tea juice fermented by the 17 kinds of lactic acid bacteria all decreased, and the decrease interval was between 0.02-1.82. Among them, the pH of the tea juice fermented by p-6 decreased by 1.82, which had the largest decrease amplitude, indicating that p-6 grew well in the black tea juice Figure 3 ).

[0074] (3) Total number of viable bacteria of Lactobacillus plantarum p-6 in black tea juice fermentation

[0075] 100 microliters of sample liquid was sucked by a pipette, slowly injected into a centrifuge tube containing 900 microliters of physiological saline along the wall (note that the tip of the pipette should not touch the diluent), and shaken well. The dilution factor was 10-1, and then another gun head was used to suck 100 microliters of sample liquid from the centrifuge tube of the previous dilution factor into another test tube, and 900 microliters of physiological saline was added, and shaken well. The dilution factor was 10-2. The above operation was repeated until the dilution factor was 10 -4 , 10 -5 , 10 -6 .

[0076] Take the sample liquid with dilution factors of 10 -4 , 10 -5 , 10 -6 , and 100 microliters of each dilution was taken on the solid culture medium, and then coating treatment was carried out, and two culture media were used as controls for each dilution. After coating, the culture medium was placed in a 37℃ constant temperature box and incubated for 24 h.

[0077] The dilution factor and the corresponding number of colonies were observed and recorded by naked eye. The colony count was expressed by colony forming units (CFU). The total number of colonies was counted on the plate with the number of colonies between 30 CFU-300 CFU and no spreading colony growth, the number of colonies on the plate with less than 30 CFU was recorded, and the number of colonies on the plate with more than 300 CFU could be recorded as too many to count. The number of colonies of each dilution should use the average number of two plates.

[0078] When one of the plates has a large patchy colony growth, it is not suitable to use, and the plate without patchy colony growth should be used as the colony count of the dilution; if the patchy colony is less than half of the plate, and the remaining half has a very uniform distribution of colonies, then half of the plate can be calculated and multiplied by 2 to represent the colony count of one plate. When the plate has chain-like growth without obvious boundaries between colonies, each single chain is counted as a colony. If only one dilution plate has a colony count within the suitable counting range, the average of the colony counts of two plates is calculated, and then multiplied by the corresponding dilution factor to obtain the total colony count per gram or per milliliter.

[0079] If the colony counts of two consecutive dilution plates are within the suitable counting range, the formula

[0080] is used to calculate

[0081] wherein N is the colony count in the sample,

[0082] C is the sum of the colony counts of the plates (including the plates with suitable range of colony counts);

[0083] n1 is the number of plates of the first dilution (low dilution factor);

[0084] n2 is the number of plates of the second dilution (high dilution factor);

[0085] d is the dilution factor (first dilution).

[0086] If the colony counts of all dilution plates are greater than 300 CFU, the plate with the highest dilution is counted, and the other plates can be recorded as "not countable". The result is calculated by multiplying the average colony count by the highest dilution factor. If the colony counts of all dilution plates are less than 30 CFU, the result is calculated by multiplying the average colony count of the lowest dilution by the dilution factor. If all dilution plates (including the original liquid sample) have no colony growth, the result is calculated by multiplying less than 1 by the lowest dilution factor. If the colony counts of all dilution plates are not between 30 CFU and 300 CFU, and some are less than 30 CFU or greater than 300 CFU, the result is calculated by multiplying the average colony count closest to 30 CFU or 300 CFU by the dilution factor.

[0087] By determining the total number of viable colonies in the tea fermentation broth, the growth activity of the strains in the fermentation broth can be analyzed. Seventeen lactic acid bacterial strains, pL-3, pL-2, 3, pL-4, pL-5, 1-1, 1260, D, F, M, p-6, R, 1-21, 2-41, etc., were inoculated into black tea with a brix of 7.50 for fermentation. As the fermentation proceeds, the cells reproduce continuously by utilizing the nutrients in the culture medium. By comparing the number of strains at 0 h and the number of strains at 60 h, Figure 4), found that the number of live lactic acid bacteria decreased significantly, and the number of live bacteria decreased from 0.1 to 72.0 (10^5) CFU / mL after fermentation of black tea juice. Among them, the number of live bacteria of p-6 in tea juice after 60h fermentation was 25.5×10^5 CFU / ml. The decrease was not obvious, indicating that the p-6 strain had good tolerance in black tea juice.

[0088] (4) Changes in total phenol content of plant lactobacillus in black tea juice fermentation.

[0089] With the extension of fermentation time, the bacteria grow and reproduce in large numbers. Because phenolic substances can be combined and adsorbed with polysaccharides, proteins and other substances, insoluble substances will be produced, resulting in a decrease in the total phenol content of the fermentation broth. The enzymes produced by lactic acid bacteria can break the bond between phenols and other substituents, thereby releasing soluble conjugated or insoluble bound phenolic compounds from plant cell walls. This results in an increase in the total phenol content of the fermentation broth. The change in total phenol content can to some extent reflect the growth activity of the strain in the fermentation broth and the fermentation degree of the fermentation broth. The large molecular phenolic substances in the tea juice are decomposed into small molecular phenolic substances under the action of lactic acid bacteria β-glucosidase, resulting in an increase in the content of soluble phenolic substances in plant-based beverages, thereby improving the bioavailability and biological activity of polyphenols.

[0090] Seventeen lactic acid bacteria pL-3, pL-2, 3, pL-4, pL-5, 1-1, 1260, D, F, M, p-6, R, 5, 15, HE, 3-F, p1-1 were respectively inoculated into black tea juice with total phenol content of 0.9707g / L for fermentation. The total phenol content of black tea juice fermented by different lactic acid bacteria was different. Among them, ten strains decreased from 0.9707g / L to 0.9049-0.9677g / L, among which p1-1 decreased the most, to 0.9049g / L, and pL-2 decreased the least, to 0.9677g / L. The total phenol content of seven strains increased from 0.9707g / L to 0.9915-1.1739g / L, among which 3-F increased the most, to 1.1739g / L. The total phenol content of black tea juice fermented by p-6 increased from 0.9707g / L to 1.0043g / l, an increase of 0.0336g / L. The total phenol content of black tea juice fermented by p-6 increased significantly Figure 5 )。

[0091] (5) Sugar consumption of different lactic acid bacteria in black tea juice

[0092] 16 kinds of lactic acid bacteria pL-3, pL-2, 3, pL-4, pL-5, 1-1, 1260, D, F, M, p-6, 5, 15, HE, 3-F, p1-1 were inoculated into the second black tea juice with 5.12 g / L reducing sugar respectively for fermentation.

[0093] First, 2 mL of the sample before and after fermentation was taken with a centrifugal tube, centrifuged at 12000 rpm for 2 min, 200 microliters of supernatant was taken, 200 microliters of DNS reagent was added, and it was heated in a boiling water bath for 5 min. Immediately take it out, put it into ice blocks to cool to room temperature, add 600 microliters of pure water, shake well. Take 200 microliters of sample in a 96-well plate, three parallel samples for each sample. Measure the absorbance of the sample at 540 nm, and the reagent blank is the reference.

[0094] Standard curve equation: y = 1.3839x - 0.1153

[0095] y - absorbance of the sample at 540 nm

[0096] x - concentration of reducing sugar, mg / mL

[0097] The reducing sugar content of the second black tea juice fermented by different lactic acid bacteria decreased significantly, with a decrease of 0.16-4.64 g / L. Among them, the reducing sugar content of pL-3 decreased the most, by 4.64 g / L, and the sugar consumption of p1-1 was the least, at 0.16 g / L. The reducing sugar content of the second black tea juice fermented by p-6 decreased by 4.081 g / L, indicating that it could grow and reproduce normally in the fermentation environment of the second black tea juice. Figure 6

[0098] This example mainly carried out the comparison of acid production capacity, growth performance and total phenol metabolism of 17 strains of lactic acid bacteria D, M, F, p-6, pL-2, pL-3, 1260, etc. fermented in the second black tea juice. Through the comprehensive evaluation of the acid production, growth of colonies and sugar consumption of the lactic acid bacteria strains before and after the fermentation of the second black tea juice for 60 h, it was found that:

[0099] In the total phenol metabolism, the total phenol content in the tea juice fermented by 1260, D, p-6, R, 15, HE, 3-F increased, indicating that these seven strains of lactic acid bacteria helped to convert large molecular phenolic substances into soluble small molecular phenolic substances, thereby improving the biological activity of the black tea juice.

[0100] In the experiment of comparing the acid production capacity, it was found that the tea soup environment in the second black tea juice was not suitable for the growth of HE and p1-1, and the remaining 15 strains had certain adaptability and good acid production capacity.

[0101] ​In the process of lactic acid bacteria fermentation of black tea juice two, the detection of different lactic acid sugar consumption found that D, F, M, p-6 has good sugar consumption performance, which shows that in the fermentation process, the physiological activity is vigorous, and the reducing sugar is converted into different chemical substances.

[0102] In the comparison of the growth performance of lactic acid bacteria before and after fermentation, we found that the growth of p-6 type lactic acid bacteria was good, which showed that the strain could adapt to the fermentation environment of black tea juice two.

[0103] In summary, through the screening experiment of lactic acid bacteria suitable for fermented tea juice, after comprehensive consideration of the adaptability of lactic acid bacteria strains to tea juice two, D, F, M, p-6 four plant lactobacillus were finally screened for the following electronic tongue taste analysis.

[0104] Example 2: Electronic tongue taste analysis of tea juice before and after fermentation of D, F, M, p-6

[0105] Electronic tongue determination method:

[0106] After diluting the fermented and unfermented black tea juice by 4 times, the sensor was immersed in each sample for 30 seconds to obtain the potential of the sample. Each sample was repeated 3 times. Four plant lactobacillus D, M, p-6 and F were inoculated in black tea juice one with reducing sugar content of 5.2340 g / L for fermentation.

[0107] Comparing the tea juice before and after fermentation, it was found that the fermented tea juice greatly reduced the original salty, bitter and fresh taste, and greatly increased the sour taste, slightly increased the astringency and richness. The fermented tea juice of p-6 improved the unadapted flavor of the original tea juice, and the bitter and astringent taste of the fermented tea juice was significantly reduced, and the richness was also improved. The results of sensory evaluation of the fermented black tea juice by p-6 were consistent with our results, the taste was rich, the sour taste was clear, and the fruit flavor was good. Figure 7 ).

[0108] Example 3: Analysis of volatile components of black tea juice before and after fermentation of D, F, M, p-6

[0109] In this example, we also detected the content and types of flavor substances before and after fermentation of plant lactobacillus p-6.

[0110] Analysis of the volatile substances of black tea juice one found that there were 20 kinds of substances, including 1 pyrrole, 1 pyrazine, 9 alcohols, 4 aldehydes, 1 acid, 1 ketone, 1 ester, and 2 others. Analysis of the volatile substances of fermented black tea juice one found that there were 49 kinds of substances, including 18 alcohols, 2 aldehydes, 8 acids, 7 ketones, 8 esters, 4 phenols and 2 others Figure 8The total amount of volatile substances in the fermented black tea juice increased from 203 μg / L to 1721.18-2184.81 μg / L.

[0111] (1) Comparison of volatile substances in tea juice after p-6 fermentation and original tea juice

[0112] The total amount of volatile substances in tea juice was greatly increased after fermentation with Lactobacillus plantarum p-6. The total amount of volatile substances in the original tea juice was 220.8316 mg / L, and the total amount of volatile substances in the tea juice after p-6 fermentation was 2174.7517 mg / L, an increase of 1953.9201 mg / L.

[0113] like Figure 9 As shown, after P-6 fermentation, the content of phenolic compounds such as 4-ethylphenol in the tea juice increased by 553.828 mg / L. The content of alcohols such as linalool, geraniol, phenylethyl alcohol, and α-terpineol increased significantly, by 159.7963 mg / L, 139.5688 mg / L, 90.4327 mg / L, and 65.9047 mg / L, respectively. The rose aroma of the tea juice became more intense, as the aroma components within the tea juice were released through fermentation with Lactobacillus plantarum. Furthermore, the fermented tea juice also contained a large number of aroma components not present in the original tea juice, such as nerolidol, isopentanol, and 2-pentanone. These flavor compounds add fruity aromas such as apple, banana, and pineapple to the fermented tea juice, enriching its flavor profile.

[0114] (2) Comparison of volatile substances in tea juice after fermentation with those after fermentation with D, F, and M

[0115] Compared with the tea juice fermented by D, F, and M, the total amount of volatile substances in the tea juice fermented by p-6 was the highest at 2174.7517 mg / L, while the total amount of volatile substances in the tea juice fermented by the other three strains were 1891.2954 mg / L, 2119.3812 mg / L, and 1721.1816 mg / L, respectively. Figure 10 The results show that the contents of 4-ethylphenol, methyl salicylate, linalool, α-terpineol, nerolidol, geraniol, 2-heptanol and isopentanol in the black tea juice after fermentation with p-6 increased most significantly compared with the average contents after fermentation with strains D, F and M, which were 256.0886 mg / L, 22.5562 mg / L, 19.87613333 mg / L, 10.5983 mg / L, 5.7038 mg / L, 4.2969 mg / L, 3.88 mg / L and 3.01 mg / L respectively.

[0116] Among them, linalool, alpha-terpineol, geraniol and nerolidol have obvious plant floral fragrance, isoamyl alcohol is one of the main characteristic aroma components of black tea, 2-heptanol has significant lemon aroma, 4-ethyl phenol has sweet aroma. Compared with D, F and M strains of lactic acid bacteria, the ability of Lactobacillus plantarum p-6 to enhance the floral and fruity aroma of black tea juice is more significant.

[0117] In summary, after comparing the acid production, strain growth, total phenol metabolism, and the quality and flavor of the fermented tea juice of Lactobacillus plantarum p-6, the content of small molecule phenols in the tea juice fermented by Lactobacillus plantarum p-6 is greatly improved, and a large number of original plant floral fragrance of tea juice is released, and a large number of fruit aroma is added to the tea juice, and the flavor of the tea juice is more rich and mellow.

[0118] Obviously, the above examples are only examples for the sake of clarity, and are not limiting of the embodiments. For those skilled in the art, other different forms of changes or variations can be made on the basis of the above description. Here, it is not necessary and impossible to exhaust all the embodiments. The obvious changes or variations derived therefrom are still within the protection scope of the present invention.

Claims

1. A Lactobacillus plantarum strain, characterized in that, Lactobacillus plantarum (Lactobacillus plantarum Lactiplantibacillus plantarum ) P-6, the deposit number is CGMCC No. 26225.

2. A culture or processed product comprising the Lactiplantibacillus plantarum of claim 1.

3. A food composition, characterized by, containing the Lactiplantibacillus plantarum of claim 1, or the culture or processed product of claim 2.

4. The food composition according to claim 3, characterized in that, The food composition is used for preparing a tea product.

5. An additive composition characterized in that, containing the Lactiplantibacillus plantarum of claim 1, or the culture or processed product of claim 2.

6. A microbial inoculant, characterized in that, comprising the Lactiplantibacillus plantarum of claim 1.

7. The microbial inoculant of claim 6, wherein, The microbial agent is a liquid microbial agent or a solid microbial agent.

8. Use of the Lactobacillus plantarum of claim 1, the culture or processed product of claim 2, the food composition of claim 3 or 4, the additive composition of claim 5, the microbial inoculant of claim 6 or 7, in the preparation of a tea fermentation product, characterized in that, The tea is black tea.

9. Use according to claim 8, characterized in that, The application comprises: fermenting a tea-containing product by using a system containing Lactiplantibacillus plantarum.

Images