Lactobacillus rhamnosus IMAU13186 and application thereof

Abstract

The invention discloses a lactobacillus rhamnosus IMAU13186 and application thereof, belongs to the technical field of microorganisms, and particularly relates to a lactobacillus rhamnosus IMAU13186 which is preserved in China General Microbiological Culture Collection Center (CGMCC) on July 8, 2024, the preservation address is No. 3, No.1 yard, West Beichen Road, Chaoyang District, Beijing, and the preservation number is CGMCC No.31227. The lactobacillus rhamnosus IMAU13186 can be used for preparing the lactobacillus rhamnosus IMAU13186. The method for preparing the active milk beverage comprises the following steps: mixing the cow milk, the white granulated sugar and the mixed stabilizer, inoculating the lactobacillus rhamnosus IMAU13186, and fermenting to obtain the active milk beverage. The invention provides the lactobacillus rhamnosus IMAU13186 with an excellent probiotic effect, and when the lactobacillus rhamnosus IMAU13186 is used for preparing the probiotic fermented milk beverage, the taste is good and the tissue state is stable.

Description

Technical Field

[0001] The invention belongs to the technical field of microorganisms, and in particular relates to a Lactobacillus rhamnosus IMAU13186 and an application thereof. Background Art

[0002] Probiotic functional products have received widespread attention due to their increasing popularity, so it is crucial to explore probiotics with excellent characteristics. The most important feature of probiotics is their ability to "confer health benefits to the host", and lactic acid bacteria from humans have certain intestinal adaptability and colonization capabilities, and are relatively safe. They can better regulate the body's intestinal environment, promote gastrointestinal digestive health, and may show more active intervention potential for specific intestinal diseases. At the same time, human-derived strains have strong genetic stability, functional reliability, and application safety. Using them as probiotics can reduce the risk of functional changes caused by gene mutations.

[0003] Lactobacillus rhamnosus is a common commercial probiotic, widely distributed in the gastrointestinal and reproductive tracts of mammals, fermented dairy products, and plant rhizomes. As one of the most studied probiotics in clinical trials, it has a strong ability to colonize the intestine and tolerate the digestive environment. It can enter the body with a high survival rate and play a role in enhancing the body's immunity, improving lipid metabolism, and affecting the host's nervous system. Due to its rich probiotic effects, Lactobacillus rhamnosus has attracted much attention both in the research field and in commercial production.

[0004] Based on the above-mentioned problem of lack of excellent bacterial strains in the current probiotics industry, rhamnosus Lactobacillus with potential probiotic properties was screened and applied as a probiotic in dairy beverages using fermented milk as a carrier, laying the foundation for the development of probiotics and excellent fermentation agent strains. Summary of the invention

[0005] In order to solve the above technical problems, the present invention proposes a rhamnosus Lactobacillus IMAU13186 and its application, provides a rhamnosus Lactobacillus IMAU13186 with excellent probiotic effects, and uses the strain to prepare probiotic fermented milk beverages with good taste and stable tissue state.

[0006] To achieve the above object, the present invention provides a rhamnosus Lactobacillus IMAU13186, which is deposited in the General Microbiology Center of China Microorganism Culture Collection Committee on July 8, 2024, with a deposit address of No. 3, Yard No. 1, Beichen West Road, Chaoyang District, Beijing, and a deposit number of CGMCC No. 31227.

[0007] The present invention also provides the use of the Lactobacillus rhamnosus IMAU13186 in preparing a probiotic agent with high hydrophobicity and self-aggregation.

[0008] The present invention also provides a probiotic with high hydrophobicity and self-aggregation, and the probiotic comprises the Lactobacillus rhamnosus IMAU13186.

[0009] The present invention also provides the use of the Lactobacillus rhamnosus IMAU13186 in preparing a probiotic with good antioxidant capacity.

[0010] The present invention also provides a probiotic with good antioxidant ability, wherein the probiotic comprises the Lactobacillus rhamnosus IMAU13186.

[0011] The present invention also provides the use of the Lactobacillus rhamnosus IMAU13186 in preparing an active milk beverage with rich taste and good stability.

[0012] The present invention also provides a method for preparing an active milk beverage using the Lactobacillus rhamnosus IMAU13186, comprising the following steps:

[0013] The milk, white sugar and mixed stabilizer are mixed, inoculated with Lactobacillus rhamnosus IMAU13186 for fermentation, and an active milk beverage is obtained.

[0014] Preferably, the mixing ratio of the milk, white sugar and mixed stabilizer is 100mL:14g:0.5g; the mixed stabilizer is sodium carboxymethyl cellulose and carrageenan mixed in a mass ratio of 4:1.

[0015] Preferably, the inoculation amount of the Lactobacillus rhamnosus IMAU13186 is 5×10 6 CFU / mL, the fermentation temperature was 37°C, and the fermentation time was 19h.

[0016] The present invention also provides the method for preparing the active milk beverage and the obtained active milk beverage.

[0017] Compared with the prior art, the present invention has the following advantages and technical effects:

[0018] The invention provides a lactobacillus rhamnosus IMAU13186 having strong artificial gastrointestinal fluid tolerance, antioxidant ability, antibacterial ability and cell adhesion ability. The survival rate is 81.08% after 3h digestion in artificial gastric fluid, and the survival rate is 48.5% after 8h digestion in artificial intestinal fluid; it has a strong inhibitory effect on pathogenic bacteria; the self-aggregation ability reaches 81.48% after 24h; the DPPH scavenging ability can reach 56.72%, and the hydroxyl free radical scavenging ability reaches 81.69%; and the prepared milk beverage has excellent flavor and stable texture. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 The growth curve and pH value change curve of Lactobacillus rhamnosus IMAU13186;

[0021] Figure 2 is the DPPH scavenging ability of Lactobacillus rhamnosus IMAU13186;

[0022] Figure 3 The hydroxyl radical scavenging ability of Lactobacillus rhamnosus IMAU13186;

[0023] Figure 4 To optimize the inoculation amount of Lactobacillus rhamnosus IMAU13186 fermented milk bacteria;

[0024] Figure 5 To optimize the fermentation temperature of Lactobacillus rhamnosus IMAU13186 fermented milk;

[0025] Figure 6 The amount of added white sugar in the fermented milk beverage of Lactobacillus rhamnosus IMAU13186;

[0026] Figure 7 Optimization of mixed stabilizer for fermented milk beverage with Lactobacillus rhamnosus IMAU13186;

[0027] Figure 8 Changes in titratable acidity during storage of active milk beverages prepared from Lactobacillus rhamnosus IMAU13186;

[0028] Fig. 9 pH changes during storage of active milk beverages prepared with Lactobacillus rhamnosus IMAU13186;

[0029] Fig.10 Changes in the number of viable bacteria during storage of active milk beverages prepared from Lactobacillus rhamnosus IMAU13186;

[0030] Fig.11 Backscattered light during the storage period of active milk beverages prepared by Lactobacillus rhamnosus IMAU13186, a is 1d, b is 7d, c is 14d, d is 21d, and e is 28d;

[0031] Fig.12 Electronic tongue radar image of an active milk drink prepared for Lactobacillus rhamnosus IMAU13186. DETAILED DESCRIPTION

[0032] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0033] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0034] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0035] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to the skilled artisan. The present invention description and examples are exemplary only.

[0036] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0037] Example 1

[0038] 1. Simulated Artificial Gastrointestinal Fluid Tolerance Test

[0039] Preparation of artificial gastric juice: Take 20mL of 1mol / L HCl, adjust the pH to 2.0 with distilled water and 1mol / L NaOH solution, then add 0.3% pepsin to dissolve it, filter with a 0.22μm sterile filter membrane to obtain artificial gastric juice, which can be prepared and used immediately.

[0040] The method is as follows: After preparing the test bacterial solution, centrifuge the bacterial solution to collect the bacteria (4000rmp, 5min), wash it with sterilized saline for 2 to 3 times, mix 5mL of saline with the bacterial solution, take 1mL of the bacterial suspension, inoculate it in 9mL of simulated artificial gastric fluid with a pH of 2.0, and culture it at 37℃. Samples are taken at 0h and 3h, and after gradient dilution, the number of viable bacteria (CFU / mL) is counted by the pouring method to calculate the survival rate. Survival rate (%) = N 1 / N 0 ×100%; where: N 0 Indicates the number of viable bacteria at 0 hours, N 1 Indicates the number of viable bacteria after 3 hours in artificial gastric juice.

[0041] Preparation of artificial intestinal fluid: weigh KH 2 PO 4 0.27g, dissolve in 20mL distilled water, adjust to pH 6.8 with 1mol / L NaOH solution, then add 0.1% trypsin, fully dissolve and mix, filter with 0.22μm sterile filter membrane, and get artificial intestinal fluid, ready for use. The bacterial liquid treated in simulated gastric fluid for 3h is inoculated into the sterilized (pH 6.8) artificial intestinal fluid, and continues to be cultured at 37℃, and the number of viable bacteria is determined at 0h, 4h, and 8h respectively. The calculation formula is as follows: Survival rate (%) = G 1 (G 2 ) / G 0 ×100%; Where: G 0 is the number of viable bacteria after artificial gastric juice treatment at 0h (the number of viable bacteria after artificial gastric juice treatment), G 1 and G 2 It is the number of viable bacteria after 4h and 8h of treatment with artificial intestinal fluid.

[0042] Table 1 Simulated artificial gastrointestinal fluid tolerance test results

[0043]

[0044] The strains described in Table 1 are derived from the National Feed Microbial Germplasm Resource Bank (Inner Mongolia). After the 8 strains were subjected to artificial gastrointestinal fluid tolerance test, it can be seen from Table 1 that rhamnosus lactobacillus IMAU13186 had a survival rate of 81.08% at 3 hours, which was higher than that of other strains, and was better than the control group Bifidobacterium lactis V9, indicating that rhamnosus lactobacillus IMAU13186 had a certain gastric juice resistance, and the survival rate in the intestinal fluid for 4 to 8 hours was 54.56% and 48.5%, which was slightly lower than that of the control group Bifidobacterium lactis V9 and FYF26-1, and significantly higher than that of other strains, indicating that the strain had a certain tolerance in the intestine, and the survival rate of FYF26-1 in gastric juice was low. Rhamnosus lactobacillus IMAU13186 was preferred for subsequent experiments.

[0045] 2. Study on the physiological and biochemical characteristics of Lactobacillus rhamnosus IMAU13186

[0046] 1. Growth curve and acid production curve of Lactobacillus rhamnosus IMAU13186

[0047] The growth curve and pH value change curve of Lactobacillus rhamnosus IMAU13186 are shown in Figure 1 After cultivation, the lag phase of Lactobacillus rhamnosus IMAU13186 was from 0 to 2 hours, and the growth rate reached the maximum after 2 hours, the metabolism was the most vigorous, and it entered the logarithmic growth phase. 600 The value was close to 1.4, and the growth rate decreased after 10 hours, entering the stable period. During the culture process of Lactobacillus rhamnosus IMAU13186, the pH value decreased with the increase of growth rate, and the pH value gradually stabilized after the strain entered the stable period.

[0048] 2. API50 CHL test

[0049] Table 2 API50 CHL test results

[0050]

[0051]

[0052] Note: + means use, - means not use.

[0053] The results of API50 sugar fermentation test of Lactobacillus rhamnosus IMAU13186 and Probio-M9 are shown in Table 2. The strains IMAU13186 and Probio-M9 can utilize 23 common carbohydrates. IMAU13186 can utilize D-arabinose, D-ribose, D-galactose, D-glucose, D-fructose, D-mannose, D-sorbose, L-rhamnose, dulcitol, mannitol, sorbitol, methyl-α-D-pyranoglucoside, N-acetylglucosamine, amygdalin, arbutin, salicin, D-cellobiose, D-maltose, D-lactose, D-sucrose, D-trehalose, D-melezitose, D-gentiobiose, D-toulose, D-tagatose, L-fucose and potassium gluconate. The results of its API50 sugar fermentation test are consistent with the results of sugar utilization by Lactobacillus rhamnosus in "Classification and Identification of Lactic Acid Bacteria and Test Methods".

[0054] 3. Safety evaluation of Lactobacillus rhamnosus IMAU13186

[0055] The test strains were selected and coated on MRS solid culture medium, and the paper diffusion method was used for drug sensitivity test. During the experiment, the drug sensitivity paper was pasted on the MRS solid culture medium that had been coated, and 3 parallels were set for each paper. After the paper was pasted, the plate was placed at 4°C for diffusion for 2 hours, and then cultured at 37°C for 24 hours. The diameter of the transparent circle was measured, referring to the NCCLS standard provided by WHO. The drug sensitivity activity of the strain was determined.

[0056] Table 3 Drug sensitivity test results

[0057]

[0058] Note: The diameter of the inhibition zone ≥20 mm is highly sensitive (S), 11-19 mm is moderately sensitive (I), and ≤10 mm is insensitive (R).

[0059] As shown in Table 3, strain IMAU13186 is sensitive to 14 antibiotics including penicillin, ampicillin, erythromycin, streptomycin, vancomycin, chloramphenicol, carbenicillin, tetracycline and cefoperazone. It is moderately sensitive to cefazolin, oxacillin and cephradine, which confirms that lactic acid bacteria have low resistance to these antibiotics.

[0060] 4. Antibacterial ability of Lactobacillus rhamnosus IMAU13186

[0061] The Oxford cup method was used to carry out antibacterial test on the strains, and the antibacterial ability of IMAU13186 and Probio-M9 against four common foodborne pathogens (Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, and Salmonella typhimurium) was determined.

[0062] Table 4 Antibacterial test results

[0063]

[0064]

[0065] Note: “+” indicates the diameter of the inhibition zone is 12.0-15.9 mm, and “++” indicates the diameter of the inhibition zone is 16.0-19.9 mm.

[0066] As shown in Table 4, both strains have strong inhibitory effects on the above four pathogenic bacteria, proving that IMAU13186 has different degrees of antibacterial effects on the above four bacteria, and has stronger inhibitory effects on Escherichia coli and Staphylococcus aureus, reaching 19.65±0.54mm and 18.63±0.34mm, respectively.

[0067] 5. Evaluation of the probiotic properties of Lactobacillus rhamnosus IMAU13186

[0068] 1. Hydrophobicity and self-aggregation experiments

[0069] Hydrophobicity and self-aggregation

[0070] Self-aggregation ability: The test strain was inoculated into MRS liquid medium at a 2% (v / v) inoculation rate, cultured at 37°C for 24 h, centrifuged at room temperature at 4500 r / min for 10 min to collect the cells, and washed twice with sterile PBS buffer. Subsequently, the obtained cells were resuspended in sterile PBS and the A600 was adjusted to 0.6±0.05 (A 0 ) and incubated at 37°C for 24 h. The upper bacterial suspension was taken at 2, 4 and 24 h, and the absorbance (A) was measured at 600 nm. t ), three replicates were measured each time, and the percentage of bacterial self-aggregation ability was calculated according to the following formula: Percentage of bacterial self-aggregation ability (%) = (1-A t / A 0 )×100%. Among them: A 0 Indicates the initial absorbance value of the bacteria, A t Represents the absorbance value of the upper bacterial suspension at time t.

[0071] Hydrophobicity: Prepare bacterial suspension according to the above method for determining self-aggregation ability, then take 1 mL of xylene and add it to 3 mL of the adjusted bacterial cell suspension. After mixing, pre-incubate at room temperature for 10 minutes, vortex and oscillate for 2 minutes, then incubate at room temperature for 30 minutes to separate the layers, carefully aspirate the aqueous phase, and determine the A600 value (A) using sterile PBS as a blank. Calculate the hydrophobicity of bacteria according to the following formula: Bacterial hydrophobicity (%) = (1-A / A 0 )×100%. Among them: A 0 represents the initial absorbance of the bacteria, and A is the absorbance of the lower aqueous phase after xylene treatment.

[0072] Table 5 Hydrophobicity of IMAU13186 and Probio-M9

[0073] strains Hydrophobicity (%) IMAU13186 <![CDATA[38.71±0.08 a ]]> Probio-M9 <![CDATA[36.42±0.13 b ]]>

[0074] Table 6 Self-aggregation ability of IMAU13186 and Probio-M9

[0075]

[0076]

[0077] Tables 5 and 6 show that the hydrophobicity and self-aggregation of IMAU13186 are significantly higher than those of Lactobacillus rhamnosus Probio-M9 (P < 0.05). The self-aggregation ability of both increased with the passage of time, and the self-aggregation ability became stronger and stronger, reaching 81.48% and 73.23% at 24h. IMAU13186 has good hydrophobicity and self-aggregation ability, and can be used as a potential probiotic.

[0078] 2. Antioxidant test

[0079] Preparation of bacterial suspension: inoculate 2% of the suspension into MRS medium, culture at 37°C for 24 h, centrifuge at 10,000 rpm for 10 min at room temperature, discard the supernatant, and collect the bacteria. Wash the bacteria three times with sterile PBS and resuspend to adjust the concentration of the suspension to 10 9 CFU / mL.

[0080] Preparation of fermentation supernatant: inoculate the culture medium at a rate of 2% into MRS medium, culture at 37°C for 24 h, centrifuge at 10,000 rpm at room temperature for 10 min, and collect the supernatant as the desired fermentation supernatant.

[0081] DPPH free radical scavenging ability: According to the requirements of the kit, prepare a usable working solution. Mix 975 μL of the working solution and 25 μL of the prepared sample evenly, place it in the dark at room temperature for 30 minutes, and measure the absorbance value at a wavelength of 515 nm. Use Vc and deionized water instead of the sample as the positive control and blank control, respectively.

[0082] Hydroxyl free radical scavenging ability: Pipette 1mL of the prepared sample and add 1mL of 0.5mmol / LH 2 O 2 Solution, 1mL0.75mmol / LFeSO 4solution, 1mL 0.75mmol / L 1,10-phenanthroline solution and 1.5mL 0.15mol / L phosphate (pH7.2) buffer solution were mixed and reacted at 37℃ for 30min. The absorbance value was measured at a wavelength of 536nm. Vc and deionized water were used instead of samples as positive control and blank control, respectively.

[0083] Depend on Figure 2 and Figure 3 It can be seen that the DPPH scavenging ability and hydroxyl radical scavenging ability of IMAU13186 are significantly higher than those of Lactobacillus rhamnosus Probio-M9. And the antioxidant capacity of the supernatant of both is higher than that of the bacterial suspension. The DPPH scavenging ability of IMAU13186 can reach 56.72%, which is significantly higher than that of Probio-M9 (P < 0.05). The DPPH scavenging ability of IMAU13186 bacterial suspension is 46.54%, which is also significantly higher than that of Probio-M9 (P < 0.05). The hydroxyl radical scavenging ability of IMAU13186 supernatant is significantly higher than that of Probio-M9 (P < 0.05), reaching 81.69%. The ability of its bacterial suspension to scavenging hydroxyl radicals is also significantly higher than that of Probio-M9 (P < 0.05).

[0084] Example 2

[0085] 1. Preparation of fermented milk by Lactobacillus rhamnosus IMAU13186

[0086] 1. Screening of fermentation conditions

[0087] Fermentation method: 100 mL of milk, white sugar and a mixed stabilizer are mixed, and then inoculated with rhamnosus Lactobacillus IMAU13186 for fermentation to obtain an active milk beverage. The mixed stabilizer is sodium carboxymethyl cellulose and carrageenan mixed in a mass ratio.

[0088] Depend on Figure 4 It can be seen that when the inoculation amount is set as a single variable, the sensory score of the milk beverage shows a trend of first high and then low. 6 CFU / mL, the highest sensory score was 84 points, which was significantly higher than the sensory scores of other inoculation amounts. Under this condition, the fermentation time of the milk beverage was appropriate and the texture was uniform. 6 CFU / mL is the optimal inoculation amount of milk beverage bacteria.

[0089] The choice of fermentation temperature results in Figure 5 As shown in the figure, with the different fermentation temperatures, the sensory score of the milk beverage presents a trend of first high and then low. When the fermentation temperature is 37°C, the sensory score is slightly higher than other temperatures. Therefore, the fermentation temperature of 37°C is the optimal fermentation temperature.

[0090] The amount of sugar added is Figure 6 As shown in the figure, the sensory score of milk beverages shows a trend of first high and then low with different addition amounts of white sugar. When the addition amount of white sugar is 14%, the sensory score is higher than other addition amounts. At this time, the milk beverage retains a unique acidity. The addition of white sugar just meets people's taste needs for sweetness, reduces the acidity, and the taste reaches an acceptable range for people. Increasing the addition amount of white sugar will make the taste too sweet, covering up the sour taste that the milk beverage should have, and reducing the sensory evaluation. Therefore, 14% white sugar addition is the best white sugar addition amount.

[0091] According to the results of the single factor experiment, the optimal inoculation amount of the strain was 5×10 6 CFU / mL, the optimal fermentation temperature was 37°C, and the optimal amount of white sugar added was 14%.

[0092] The optimization of single factor conditions is difficult to meet the sensory requirements of milk beverages. Therefore, based on the results of single factor experiments, three factors A (inoculation amount), B (fermentation temperature), and C (amount of white sugar added) were selected for orthogonal experiments. The inoculation amount was 4×10 6 CFU / mL, 5×10 6 CFU / mL, 6×10 6 CFU / mL, fermentation temperature was 35℃, 37℃, 39℃, and the amount of white sugar added was 12%, 14%, 16% for orthogonal experiments. The sensory score was used as the designated standard to determine the optimal process combination.

[0093] Table 7 Orthogonal experiment results

[0094]

[0095] Note: The inoculum volume "1" is 4×10 6 CFU / mL, the inoculum dose "2" is 5×10 6 CFU / mL, the inoculum dose "3" is 6×10 6 CFU / mL, fermentation temperature "1" is 35°C, fermentation temperature "2" is 37°C, fermentation temperature "3" is 39°C, the amount of white sugar added "1" is 12%, the amount of white sugar added "2" is 14%, and the amount of white sugar added "3" is 16%.

[0096] The experimental results are shown in Table 7. The primary and secondary factors affecting the taste of milk beverages are the amount of white sugar added, the amount of inoculation, and the fermentation temperature. The amount of inoculation, the fermentation temperature, and the second level of white sugar addition are all optimal. Therefore, the best optimization combination is A2B2C2, that is, the inoculation amount is 5×10 6 CFU / mL, fermentation temperature was 37°C, and the amount of white sugar added was 14%.

[0097] 2. Addition of stabilizer

[0098] Firstly, the ratio of stabilizer is determined by centrifugal sedimentation rate. The total amount of stabilizer added is 0.5% by mass, and the mass ratio of composite stabilizer is sodium carboxymethyl cellulose: carrageenan is 1:4, 2:3, 1:1, 3:2, 4:1.

[0099] The results are as follows Figure 7 As shown, the best composite stabilizer ratio is sodium carboxymethyl cellulose: carrageenan at a mass ratio of 4:1. If the proportion of sodium carboxymethyl cellulose is further increased, the milk beverage will become viscous and gel-like, and the state will be unstable. Considering cost savings and tissue state, the initial stabilizer ratio selected is sodium carboxymethyl cellulose: carrageenan at a mass ratio of 4:1.

[0100] 3. Analysis of characteristics of fermented milk beverages and storage period

[0101] According to the production method, IMAU13186 was used to ferment skim milk to prepare an active milk beverage, and the acidity change diagram was titrated during storage at 4°C, 15°C, and 25°C for 28 days.

[0102] Results Figure 8 During storage, the titrated acidity at 4℃, 15℃, and 25℃ all showed an upward trend, proving that acid continued to be produced during storage and had good biological activity. At 4℃, the upward trend was relatively slow, proving that low-temperature storage was particularly critical for the preservation of milk beverages. During storage, the pH values ​​at 4℃, 15℃, and 25℃ all showed a downward trend, and the pH downward trend was slower at 4℃, proving that post-acidification was weaker at 4℃ and had the least effect on taste ( Fig. 9 The important thing is that when stored at 4°C, the number of live bacteria in the milk beverage has the smallest change trend, showing a stable change, and the decline in the number of live bacteria is small. On the 28th day, the number of live bacteria is above 5.5 CFU / mL, while the number of live bacteria stored at 15°C and 25°C has dropped significantly ( Fig.10 ).

[0103] The backscattered light intensity (ΔBS) reflects the variation of the volume fraction and average particle size of particles in the sample system. The smaller the ΔBS, the more stable the emulsified system, and vice versa. Fig.11 Middle a, Fig.11 Middle b, Fig.11 Middle c, Fig.11 Medium D and Fig.11 As shown in Figure e, ΔBS is basically stable. The change of ΔBS measured at the storage time of 1d, 7d, 14d, 21d, and 28d is not large. The backscattered light intensity value does not change significantly over time, indicating that the particle concentration of the sample changes little and the stability is good. The above shows that the stability of the tissue state and other factors does not change much during storage, and the stability of the milk beverage remains good.

[0104] The electronic tongue can reflect the difference in taste between different milk drinks and is an excellent indicator for evaluating the taste of milk drinks. During the storage of milk drinks, the electronic tongue was used to measure 9 different indicators. Fig.12 It can be seen that the saltiness and sweetness of the milk beverage are more prominent in the sensor, and there are also obvious response values ​​in the sensors of richness and umami. The response value of astringency is low. The taste of the milk beverage does not change much during storage, which proves that the taste remains relatively consistent during storage and the taste is stable during the storage period.

[0105] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A Lactobacillus rhamnosus IMAU13186, characterized in that The rhamnosus Lactobacillus IMAU13186 was deposited in the General Microbiology Center of the China Microbiological Culture Collection Administration on July 8, 2024, with the deposit address being No. 3, Yard No. 1, Beichen West Road, Chaoyang District, Beijing, and the deposit number being: CGMCC No. 31227.

2. Use of Lactobacillus rhamnosus IMAU13186 as claimed in claim 1 in preparing a probiotic agent with high hydrophobicity and self-aggregation.

3. A probiotic agent with high hydrophobicity and self-aggregation, characterized in that: The probiotic comprises the Lactobacillus rhamnosus IMAU13186 according to claim 1.

4. Use of Lactobacillus rhamnosus IMAU13186 as claimed in claim 1 in preparing a probiotic with good antioxidant capacity.

5. A probiotic with good antioxidant capacity, characterized in that: The probiotic comprises the Lactobacillus rhamnosus IMAU13186 according to claim 1.

6. Use of the Lactobacillus rhamnosus IMAU13186 as claimed in claim 1 in preparing an active milk beverage with rich taste and good stability.

7. A method for preparing an active milk beverage using the Lactobacillus rhamnosus IMAU13186 as claimed in claim 1, characterized in that: The following steps are involved: The milk, white sugar and mixed stabilizer are mixed, inoculated with Lactobacillus rhamnosus IMAU13186 for fermentation, and an active milk beverage is obtained.

8. The method for preparing an active milk beverage according to claim 7, characterized in that: The mixing ratio of the milk, white sugar and mixed stabilizer is 100mL:14g:0.5g; the mixed stabilizer is sodium carboxymethyl cellulose and carrageenan mixed in a mass ratio of 4:

1.

9. The method for preparing an active milk beverage according to claim 7, characterized in that: The inoculation amount of the Lactobacillus rhamnosus IMAU13186 was calculated based on the number of viable bacteria: 5×10 6 CFU / mL, the fermentation temperature was 37°C, and the fermentation time was 19h.

10. An active milk beverage prepared by the method for preparing an active milk beverage according to any one of claims 7 to 9.

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