CN117448183A

CN117448183A - Kluyveromyces marxianus KM-20 and application thereof in cherry tomato fermented juice

Info

Publication number: CN117448183A
Application number: CN202311525578.4A
Authority: CN
Inventors: 燕国梁; 段长青; 姜敏捷
Original assignee: China Agricultural University
Current assignee: China Agricultural University
Priority date: 2023-11-15
Filing date: 2023-11-15
Publication date: 2024-01-26

Abstract

The invention belongs to the technical field of microorganisms, and particularly relates to Kluyveromyces marxianus KM-20 and application thereof in cherry tomato fermented juice. The invention discloses a microzyme KM-20 suitable for fermenting cherry tomato juice, which is preserved in China general microbiological culture Collection center (CGMCC) with the preservation number of CGMCC No.27835. The strain is separated from the natural fermentation process of grape wine in Ningxia production area. The strain can improve the disadvantages of insufficient aroma and heavy green taste of lactobacillus single fermentation fruit and vegetable juice, such as cherry tomato juice, and a large amount of organic acid is generated after the cherry tomato juice is inoculated with lactobacillus plantarum HY-1 (with the preservation number of CGMCC No. 23619) and fermented for 48 hours, and meanwhile, the antioxidant activity and aroma substances are increased, the green taste is reduced, so that the quality of cherry tomato fermented juice is greatly improved.

Description

Kluyveromyces marxianus KM-20 and application thereof in cherry tomato fermented juice

Technical Field

The invention belongs to the technical field of microorganisms, and relates to Kluyveromyces marxianus KM-20 and application thereof in cherry tomato fermented juice.

Background

Cherry tomato (Lycopersicon esculentum var. Cerasiform A.Gray), is an annual herb, belonging to the genus Lycopersicon of the family Solanaceae. Has effects in promoting salivation, quenching thirst, invigorating stomach, resolving food stagnation, clearing away heat and toxic materials, cooling blood, suppressing hyperactive liver, replenishing blood, nourishing blood, and stimulating appetite. Huang Lihua the cherry tomato fruit nutrient composition is analyzed, and contains about 13 vitamins and 17 minerals, wherein the mass fraction of vitamin C can reach 66mg/g, which is about 1.7 times of that of common tomatoes. The mature cherry tomatoes are rich in glucose and fructose; citric acid, malic acid, and also small amounts of acetic acid, lactic acid and fumaric acid. In addition, cherry tomato also contains lycopene, polyphenols, flavonoids and other functional components, wherein the content of ascorbic acid, lycopene and reduced glutathione is higher than that of common tomato, and the cherry tomato has higher antioxidant activity.

In recent years, along with the improvement of health consciousness of people, green and natural fruit and vegetable products are increasingly favored by consumers, and the fermented fruit and vegetable juice stands out from the unique quality advantages. With intensive research, scholars find that compared with single strain fermented fruit and vegetable juice, the multi-strain collaborative fermentation can lead the flavor of the fermented fruit and vegetable juice to be more rich and the nutrition to be more balanced. Currently, mixed fermentation inoculants are increasingly receiving attention from researchers. The mixed bacteria fermentation fruit and vegetable juice is used for referencing the fermentation mode of fruit and vegetable ferment, one or more fruits and vegetables (fruit and vegetable juice) are used as raw materials, and multi-strain fermentation is utilized, such as: lactic acid bacteria, saccharomycetes, acetic acid bacteria, etc. to produce beverage with rich nutrients and various functions. The fruit and vegetable juice is subjected to multi-strain synergistic fermentation, and the flavor, nutrition and storage quality of the fruit and vegetable juice are improved. The microorganisms in the fermented fruit and vegetable juice can promote the production of various bioactive substances such as organic acids, proteases, polyphenols and the like by utilizing the nutrients in the raw materials to perform self-metabolism, the interactions among the microorganisms and the substrates and various complex metabolic processes, and can improve the performances of the fruit and vegetable juice in various aspects such as flavor, taste, nutritional value, shelf life and the like.

Disclosure of Invention

The invention aims to provide Kluyveromyces marxianus KM-20, (Kluyveromyces marxianus KM-20) which has strong capability of improving fragrance of fermented fruit and vegetable juice.

The invention also aims to provide the application of the Kluyveromyces marxianus KM-20 in mixed fermentation fruit and vegetable juice.

The invention provides Kluyveromyces marxianus KM-20, which is preserved in China general microbiological culture Collection center, address: the preservation number of the North Chen Xili No. 1 and 3 in the Chaoyang area of Beijing city of China is CGMCC No.27835.

The Kluyveromyces marxianus KM-20 (CGMCC No. 27835) is obtained by separating in the natural fermentation process of wine in Ningxia production area, and the Kluyveromyces marxianus is identified by adopting a 16S rDNA genome sequencing method.

The colony of Kluyveromyces marxianus KM-20 (CGMCC No. 27835) has the characteristics of round shape, diameter of 2-4 mm, white color, transparency and smooth surface, and the surface of a solid culture medium is in a protruding state and the edge of the solid culture medium is neat and smooth.

The Kluyveromyces marxianus KM-20 (CGMCC No. 27835) grows well in a high acidity environment, and can reach the maximum OD after growing for 24 hours in YPD liquid culture medium ₆₀₀ 。

The invention also provides a strain combination, which comprises the Kluyveromyces marxianus (Kluyveromyces marxianus) KM-20 and lactobacillus plantarum (Lactobacillus plantarum) HY-1, wherein the preservation number of the lactobacillus plantarum (Lactobacillus plantarum) HY-1 is CGMCCNo.23619.

Based on the research, the invention also provides an application of the Kluyveromyces marxianus (Kluyveromyces marxianus) KM-20 or the strain combination in preparing cherry tomato fermented juice.

In some embodiments of the invention, the activated inoculum is centrifuged and repeatedly washed with sterile water and inoculated into pasteurizedThe Kluyveromyces marxianus (Kluyveromyces marxianus) KM-20 inoculating amount is 1×10 in cherry tomato to be fermented obtained by rapid ice water cooling ⁶ CFU/mL, lactobacillus plantarum (Lactobacillus plantarum) HY-1 inoculum size of 1×10 ⁷ CFU/mL, standing and fermenting for 48h at the constant temperature of 28 ℃;

activation of Kluyveromyces marxianus (Kluyveromyces marxianus) KM-20: streaking the bacterial liquid preserved by 50% glycerol at the temperature of 80 ℃ below zero on YPD agar culture medium, carrying out stationary culture at the temperature of 28 ℃ for 48-72 hours to obtain single bacterial colonies, picking the single bacterial colonies by an inoculating loop on the YPD liquid culture medium, and carrying out stationary culture at the temperature of 28 ℃ for 24 hours to obtain inoculated bacterial liquid. Activation of the Lactobacillus plantarum (Lactobacillus plantarum) HY-1: streaking the bacterial liquid preserved by 50% glycerol at the temperature of 80 ℃ below zero on an MRS agar culture medium, carrying out stationary culture for 48-72 hours at the temperature of 37 ℃ to obtain single bacterial colonies, picking the single bacterial colonies by an inoculating loop on the MRS broth culture medium, and carrying out stationary culture for 24 hours at the temperature of 37 ℃ to obtain the inoculated bacterial liquid.

Compared with the prior art, the invention has the beneficial effects that:

the kluyveromyces marxianus KM-20 (CGMCC No. 27835) has high growth speed and high aroma-producing capability, and can be used for related purposes. The embodiment of the invention particularly provides application of the mixed fermentation of the strain and lactobacillus plantarum HY-1 (with the preservation number of CGMCC No. 23619) in cherry tomato juice.

The kluyveromyces marxianus KM-20 has the advantages of strong acid resistance, high growth and propagation speed, enhanced antioxidation activity of the fermented cherry tomato juice, increased content of volatile aroma compounds, reduced green taste and greatly improved sensory quality.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below.

FIG. 1 is a colony of Kluyveromyces marxianus KM-20 of the present invention;

FIG. 2 shows the viable count of probiotic Lactobacillus plantarum HY-1 during mixed fermentation of Kluyveromyces marxianus KM-20 and Lactobacillus plantarum HY-1 according to the invention;

FIG. 3 shows the pH of Kluyveromyces marxianus KM-20 and Lactobacillus plantarum HY-1 according to the present invention during mixed fermentation;

FIG. 4 shows the total phenol content of the fermented cherry tomato juice after mixed fermentation of Kluyveromyces marxianus KM-20 and lactobacillus plantarum HY-1;

FIG. 5 shows the DPPH free radical scavenging ability of Kluyveromyces marxianus KM-20 and Lactobacillus plantarum HY-1 mixed fermentation cherry tomato juice;

FIG. 6 shows the total antioxidant capacity (TAOC) of the Kluyveromyces marxianus KM-20 and Lactobacillus plantarum HY-1 mixed fermented cherry tomato juice of the present invention;

FIG. 7 is a sensory evaluation of the cherry tomato juice after mixed fermentation of Kluyveromyces marxianus KM-20 and Lactobacillus plantarum HY-1 according to the present invention.

Description of biological preservation

Biological material: KM-20, classified naming: kluyveromyces marxianus (Kluyveromyces marxianus) is preserved in China general microbiological culture Collection center (CGMCC) for the 07 th month 07 of 2023, and the preservation center address is: the collection number of the microbiological institute of China is CGMCC No.27835, and the collection number of the microbiological institute of China is China, national institute of sciences, no. 1, no. 3, north Chen West Lu, the Korean region of Beijing;

biological material: HY-1, classification naming: lactobacillus plantarum (Lactobacillus plantarum) was deposited in China general microbiological culture Collection center (CGMCC) at 10 and 18 months 2021, and the deposit center address is: the collection number of the microbiological institute of China is CGMCC No.23619, and the collection number of the microbiological institute of China is China, national institute of sciences, no. 1, no. 3, north Chen West Lu, the Korean region of Beijing city.

Detailed Description

The invention will be further described with reference to the drawings and examples.

Example 1: separation, purification and identification of Kluyveromyces marxianus KM-20

Wine grape (variety Cabernet Sauvignon) provided by Ningxia Holland foot producing area is diluted and coated on YPD agar medium (100 mg/L chloramphenicol is added) after natural fermentation, culturing for 48-72 h in a constant temperature incubator at 28deg.C, and selecting colony with different forms for streaking pure culture to obtain separated strain. The identification of the saccharomycetes adopts a 16S rDNA genome sequencing method, wherein the extraction method of the genome DNA of the strain is as follows: single colonies obtained by streak pure culture were picked, centrifuged at 12,000r for 1min, the supernatant was discarded, and then strain genomic DNA was extracted using a yeast DNA genomic extraction kit according to instructions. The PCR amplification method of the 16S rDNA gene comprises the following steps: the extracted strain DNA was used as a forward primer NL1 (GCATATCAATAAGCGGAGGAAAA) and a reverse primer NL4

(GGTCCGTGTTTCAAGACGG) the 16S rDNA gene region of the strain DNA was amplified in a PCR amplification apparatus, and the PCR amplification system and the procedure are shown in Table 1. The amplified product was detected by 1% agarose gel electrophoresis and gel imaging, and a band of about 1500bp was observed, indicating that the PCR was successful. And then sent to Shanghai workers for unidirectional sequencing. Logging onto NCBI website to compare the obtained 16S rDNA gene sequence with known bacterial gene sequence in GenBank database by BLAST program, the homology similarity of the isolated strain with Kluyveromyces marxianus is greater than 99%, so that the isolated strain is identified as Kluyveromyces marxianus and named as KM-20. The colony characteristics of Kluyveromyces marxianus KM-20 are shown in figure 1, and are round, 2-4 mm in diameter, white, transparent and smooth in surface, and the surface of the solid culture medium is in a protruding state and the edges of the solid culture medium are neat and smooth.

And (3) successfully identifying Kluyveromyces marxianus KM-20, picking single colonies obtained by streak pure culture of the Kluyveromyces marxianus KM-20, standing and culturing in YPD liquid culture medium for about 24 hours to mid-log phase, taking 50% glycerol as a cryoprotectant, mixing culture solution with 50% glycerol (1:1), adding into a preservation tube, and preserving at-80 ℃.

Kluyveromyces marxianus KM-20 obtained by the invention is delivered to China general microbiological culture Collection center for culture Collection of microorganisms, and the collection date is 2023, 07 and 07, and the collection number is CGMCC No.27835.

TABLE 1PCR amplification System and program

Example 2:

the Kluyveromyces marxianus KM-20 can effectively overcome the defect of insufficient aroma of single fermentation of lactic acid bacteria, has high acid resistance and high growth rate, and can be one or more of cherry tomato, sea buckthorn, lemon, kiwi fruit, green plum and hawthorn.

This example is given as an example of a fruit and vegetable juice "cherry tomato juice".

1. Preparing cherry tomato juice: washing cherry tomatoes with tap water, removing bad fruits and rotten fruits, and removing tomato stems. The boiling water blanching treatment then crushes cherry tomato pulp with a food grade juicer, filters with 80 mesh gauze, and then immediately adds 0.08% ascorbic acid to prevent enzymatic browning. The cherry tomato juice in the conical flask was heated in a water bath at 80 c for 15 seconds to inactivate the polyphenol oxidase in the cherry tomato juice. Cooling at room temperature (25deg.C), and storing at-20deg.C.

2. Activation of Kluyveromyces marxianus KM-20: streaking the bacterial liquid preserved by 50% glycerol at the temperature of 80 ℃ below zero on YPD agar culture medium, carrying out stationary culture at the temperature of 28 ℃ for 48-72 hours to obtain single bacterial colonies, picking the single bacterial colonies by an inoculating loop on the YPD liquid culture medium, and carrying out stationary culture at the temperature of 28 ℃ for 24 hours to obtain inoculated bacterial liquid.

3. Activation of lactobacillus plantarum HY-1: streaking the bacterial liquid preserved by 50% glycerol at the temperature of 80 ℃ below zero on an MRS agar culture medium, carrying out stationary culture for 48-72 hours at the temperature of 37 ℃ to obtain single bacterial colonies, picking the single bacterial colonies by an inoculating loop on the MRS broth culture medium, and carrying out stationary culture for 24 hours at the temperature of 37 ℃ to obtain the inoculated bacterial liquid.

4. Inoculating and fermenting cherry tomato juice: the thawed cherry tomato juice was heat sterilized at 80℃for 15 minutes and cooled to room temperature (25 ℃), and then the bacterial liquid was added to the cherry tomato juice (500 mL), setting three groups in parallel. Yeast KM-20 inoculation amount is 1X 10 ⁶ CFU/mL, lactobacillus plantarum HY-1 inoculum size of 1X 10 ⁷ CFU/mL, lactobacillus and saccharomycete liquid are added into cherry tomato juice at the same time, fermentation bolts are arranged after the mixture is uniformly mixed, and the mixture is stood and fermented for 48 hours under the constant temperature condition of 30 ℃. After fermentation, the mixture was stored in a refrigerator at 4℃for 14 days.

5. Physical and chemical indexes of the fermented cherry tomato juice are measured: two sets of biological replicates were set up including pH, soluble solids (Total soluble solids, TSS), lactobacillus plantarum HY-1 viable count, reducing sugars, total phenols, organic acids, glucose, fructose, and sucrose. The color, antioxidant activity and volatile aroma of the fermented cherry tomato juice were measured and sensory evaluation was performed. Lactobacillus plantarum HY-1 was inoculated alone as a control group and two biological replicates were set.

(1) Physical and chemical index measurement: the number of viable bacteria of Lactobacillus plantarum HY-1 was determined by a plate count method (refer to GB 4789.35-2016) using MRS agar medium (100 mg/L cycloheximide added) to observe the growth of Lactobacillus plantarum HY-1 under the action of yeast, the number of Lactobacillus plantarum HY-1 was changed as shown in FIG. 2, pH was measured using a pH meter, fermented juices fermented for 0, 24, 48h were taken, lactobacillus plantarum HY-1 was inoculated alone as a control group, two sets of biological replicates were set, and the pH was changed as shown in FIG. 3. The TSS values were determined by PAL-1 digital densitometer as shown in Table 2. After the measurement of the indexes is finished, the fermentation broth is centrifuged (12,000r multiplied by 2 min), and the supernatant is taken and stored in a refrigerator at the temperature of minus 20 ℃ for standby. The Fu Lin Fen method is used for measuring the total phenol content in the fermented juice, and is shown in figure 4; the DNS method determines the total reducing sugar content as shown in table 2.

(2) Primary metabolite assay: the fermentation broth was filtered through a 0.22 μm aqueous filter (PES) and the amino acid concentrations of glucose, fructose and organic acids (citric acid, lactic acid, tartaric acid, succinic acid, malic acid and acetic acid) were determined. Using Agilent 1200 high performance liquid chromatograph, the ion exchange column was HPX-87H (Bio-Rad Co., USA). 5mmol/L sulfuric acid was used as the mobile phase and isocratic elution was performed at a flow rate of 0.6 mL/min. The glucose and fructose were measured using a differential refractometer (Agilent, USA), the sample injection amount was 20. Mu.L, the column temperature was 45℃and the measurement time was 30min. Two techniques were set up in parallel for each sample. The organic acid was measured using an ultraviolet detector (Agilent, USA), the sample loading was 20. Mu.L, the column temperature was 60℃and the measurement time was 25min. Two techniques were set up in parallel for each sample. And (3) quantifying according to the standard curve of the main fermentation product standard substance by the peak time qualitative of the main fermentation product.

(3) Determination of antioxidant Activity of cherry tomato juice: the DPPH (2, 2-Diphenyl-1-picryl) radical scavenging ability kit and the Total antioxidant Capacity (T-AOC) detection kit (FRAP method) were used (available from Nanjing institute of biological engineering, inc.), methods are referred to in the specification.

(4) Volatile flavor compound determination: the variety and content of volatile aroma substances in the obtained fermented cherry tomato juice were detected by an Agilent 7890 Gas Chromatograph (GC) and Agilent5975 Mass Spectrometer (MS) combined instrument (Agilent, usa). The specific conditions are as follows: the capillary column HP-INNOWAX Polyethylene Glycol, 60m×0.25mm×0.25 μm (J & W scientific, USA) carrier gas is high purity helium, flow rate 1mL/min; the headspace solid-phase microextraction is automatically injected, a non-split flow mode is adopted, the mixture is inserted into an injection port of gas chromatography, the temperature is 250 ℃, and the thermal desorption is carried out for 25min. The temperature rise program of the column temperature box is as follows: the temperature was kept at 40℃for 5min, and then heated to 200℃at a rate of 3℃per min for 2min. The temperature of the mass spectrum port is 280 ℃, the temperature of the ion source is 230 ℃, the ionization mode EI and the ion energy are 70ev.

(5) Sensory evaluation method: 15 teachers and students panelists with related experience and background knowledge evaluated the color, morphology, aroma, taste and sweetness of cherry tomato juice, and the evaluation results are shown in fig. 7.

Experimental results:

1. physical and chemical indexes of the Kluyveromyces marxianus KM-20 and lactobacillus plantarum HY-1 mixed fermentation cherry tomato juice are shown in Table 2. The number of viable bacteria, the acid production capacity, the polyphenol production and the reducing sugar consumption in cherry tomato juice obtained by mixed fermentation (KM+HY) of Kluyveromyces marxianus KM-20 and lactobacillus plantarum HY-1 are all higher than those of cherry tomato juice obtained by single fermentation of lactobacillus plantarum HY-1 (HY 1).

TABLE 2 physicochemical index of Kluyveromyces marxianus KM-20 and Lactobacillus plantarum HY-1 after mixed fermentation of cherry tomato juice

Note that: HY1 is abbreviation of lactobacillus plantarum HY-1, KM+HY is abbreviation of Kluyveromyces marxianus KM-20 and lactobacillus plantarum HY-1 mixed fermentation. Lower case letters (a-c) are the significance differences in the table (Duncan test, p < 0.05).

2. The antioxidant activity of Kluyveromyces marxianus KM-20 and lactobacillus plantarum HY-1 mixed fermented cherry tomato juice is shown in figures 5 and 6. The DPPH free radical scavenging ability and FRAP antioxidant activity of the fermented cherry tomato juice are increased by 1.24 times and 2.12 times compared with that of cherry tomato juice, and are increased by 1.06 times and 1.89 times compared with that of lactobacillus plantarum HY-1 alone, which is probably that mixed fermentation produces higher phenolic compounds, and the phenolic compounds have proved to be good reducing agents and free radical scavengers mainly related to the hydrogen atom transfer or electron transfer of free radicals. Kluyveromyces marxianus KM-20 and lactobacillus plantarum HY-1 are mixed for fermentation, so that the antioxidation activity of cherry tomato juice can be obviously improved.

3. Volatile compounds of Kluyveromyces marxianus KM-20 and lactobacillus plantarum HY-1 mixed fermented cherry tomato juice are shown in Table 3. The total volatile compound of the fermented cherry tomato juice is 2.90 times of the cherry tomato juice and 1.77 times of the lactobacillus plantarum HY-1 fermented alone. Volatile alcohols, esters, aldehydes, ketones and acids are 5.61 times, 24.32 times, 0.09 times, 5.71 times and 7.32 times, respectively, than the raw juice, and are 12.64 times, 7.53 times, 1.06 times, 1.14 times and 1.42 times of the independent fermentation of lactobacillus plantarum HY-1. The mixed fermentation increases diisopropyl adipate and trimethyl-1, 3-pentanediol diisobutyl which are not possessed by lactobacillus plantarum HY-1 during independent fermentation, and the contents of 3-methyl-1-butanol acetate, L-methyl lactate, ethyl 2-hydroxy propionate, methyl octanoate and ethyl octanoate are obviously increased, and the esters are the main contributors to the aroma of cherry tomato fermented juice and provide rich fruit aroma, flower aroma and wine aroma. Meanwhile, the content of higher alcohols such as hexanol, nonanol, octanol, benzyl alcohol and the like in the mixed fermentation cherry tomato juice is increased, and the fragrance taste such as flower and fruit fragrance, oil fragrance, grass fragrance and the like is endowed to the fermentation cherry tomato juice. Hexanal, heptanal, benzaldehyde, 2-nonenal and 1-cyclohexene-1-formaldehyde are aldehyde characteristic aroma of the fermented cherry tomato juice, and the content of the hexanal, heptanal, benzaldehyde, 2-nonenal and 1-cyclohexene-1-formaldehyde is increased by mixed fermentation, so that the juice is more intense in fruit aroma and green grass aroma. The increase of the content of pentanone, heptanone, nonanone and the like provides the fermented juice with more intense sweet and fruity flavor and the like. In addition, substances such as eugenol, furan, cyclohexene and the like contribute to complex odors such as burnt odor, clove fragrance, citrus fragrance, wooden spice and the like after fermentation. Meanwhile, the contents of substances with pungent odor such as toluene, 1,2, 3-trimethylbenzene and the like are reduced after fermentation, which is an important reason for weakening green taste after mixed fermentation. In summary, kluyveromyces marxianus KM-20 (CGMCC No. 27835) and lactobacillus plantarum HY-1 are fermented cooperatively, so that the conditions of single fragrance and heavy green taste when lactobacillus plantarum HY-1 is fermented singly can be improved, more pleasant fragrance is obtained, and the method is more acceptable to the masses.

TABLE 3 volatile compounds after fermentation of cherry tomato juice by Lactobacillus plantarum HY-1

Note that: results are the average of three independent replicates; standard errors are all less than 10% of the average value; ND: not detected

4. Sensory evaluation of Kluyveromyces marxianus KM-20 and lactobacillus plantarum HY-1 mixed fermentation cherry tomato juice is shown in FIG. 7. The cherry tomato juice prepared by mixing and fermenting the Kluyveromyces marxianus KM-20 and the lactobacillus plantarum HY-1 has improved fragrance, color, tissue morphology and taste compared with cherry tomato juice, and has higher mass acceptance.

In conclusion, kluyveromyces marxianus KM-20 (CGMCC No. 27835) has good fermentation potential, can be used as a potential strain for collaborative fermentation with lactic acid bacteria, and improves the quality of the fermented cherry tomato juice. The mixed fermentation of Kluyveromyces marxianus KM-20 and lactobacillus plantarum HY-1 changes the acid production condition of cherry tomatoes in the fermentation process, generates more lactic acid, and reduces the content of other organic acids with irritation. The total phenol content of cherry tomato juice is increased, the antioxidant activity is enhanced, the viable count of the lactobacillus plantarum HY-1 is increased after the Kluyveromyces marxianus KM-20 and the lactobacillus plantarum HY-1 are mixed and fermented, and the cherry tomato juice has higher nutritional value and health care function and is more easily accepted by consumers and markets. The Kluyveromyces marxianus KM-20 and lactobacillus plantarum HY-1 are mixed for fermentation, so that the original characteristic ester substances of cherry tomato juice are maintained, green taste substances such as benzene, C6 and the like are reduced, a large amount of higher alcohols, aldehydes, ketones, phenols, esters and other terpene aroma substances are added, the flower and fruit aroma and other pleasant aroma of cherry tomato fermentation juice are added, the whole aroma is more intense, the layering is more abundant, and the bad smell of cherry tomato juice and lactobacillus plantarum HY-1 during independent fermentation is covered. Sensory evaluation results also show that the aroma, the tissue morphology, the color and the mass acceptability of the fermented cherry tomato juice are all better than those of cherry tomato juice and lactobacillus plantarum HY-1 fermented juice alone.

The foregoing is merely a preferred embodiment of the present invention and it should be noted that modifications and adaptations to those skilled in the art may be made without departing from the principles of the present invention, which are intended to be comprehended within the scope of the present invention.

Claims

1. Kluyveromyces marxianus (Kluyveromyces marxianus) KM-20 is characterized in that the preservation number is CGMCC No.27835.

2. The strain combination is characterized by comprising Kluyveromyces marxianus (Kluyveromyces marxianus) KM-20 and lactobacillus plantarum (Lactobacillus plantaru m) HY-1 as claimed in claim 1, wherein the preservation number of the lactobacillus plantarum (Lactobacillus plantarum) HY-1 is CGMCC No.23619.

3. Use of kluyveromyces marxianus (Kluyveromyces marxianus) KM-20 as defined in claim 1 or a combination of strains as defined in claim 2 for the preparation of cherry tomato fermented juice.

4. The use according to claim 3, wherein the inoculated bacteria obtained after activation are centrifuged and repeatedly washed with sterile water and inoculated into cherry tomato to be fermented obtained by rapid cooling with ice water after pasteurization, and the Kluyveromyces marxianus (Kluyveromyces marxianus) KM-20 is inoculated in an amount of 1X 10 ⁶ CFU/mL, lactobacillus plantarum (Lactobacillus plantarum) HY-1 inoculum size of 1×10 ⁷ CFU/mL, standing and fermenting for 48h at the constant temperature of 28 ℃;

activation of Kluyveromyces marxianus (Kluyveromyces marxianus) KM-20: streaking the bacterial liquid preserved by 50% glycerol at the temperature of 80 ℃ below zero on a YPD agar medium, carrying out stationary culture for 48-72 hours at the temperature of 28 ℃ to obtain single bacterial colonies, and picking the single bacterial colonies into the YPD liquid medium by an inoculating loop, and carrying out stationary culture for 24 hours at the temperature of 28 ℃ to obtain inoculated bacterial liquid;

activation of the Lactobacillus plantarum (Lactobacillus plantarum) HY-1: streaking the bacterial liquid preserved by 50% glycerol at the temperature of 80 ℃ below zero on an MRS agar culture medium, carrying out stationary culture for 48-72 hours at the temperature of 37 ℃ to obtain single bacterial colonies, picking the single bacterial colonies by an inoculating loop on the MRS broth culture medium, and carrying out stationary culture for 24 hours at the temperature of 37 ℃ to obtain the inoculated bacterial liquid.