Application of plant lactobacillus FMBL L23251 FJX in preparation of fermented apricot and plum products and preparation method of plant lactobacillus FMBL L23251 FJX

Abstract

The invention relates to the technical field of biology, and particularly provides an application of plant lactobacillus FMBL L23251FJX in preparation of a fermented apricot plum product and a preparation method of the plant lactobacillus FMBL L23251FJX, the plant lactobacillus FMBL L23251FJX is preserved in China Center for Type Culture Collection on June 26, 2023, and the preservation number is CCTCC NO: M 20231110; the viable count is obviously increased when the prunus armeniaca is fermented, the total acid content is generally increased, the pH is generally decreased, and the total phenol content is firstly increased and then decreased; the content is increased to 584.504 mg / L to the maximum extent; the ABTS free radical scavenging rate, the DPPH free radical scavenging rate and the alpha-amylase and alpha-glucosidase inhibitory activity of the fermented apricot and plum juice are remarkably increased, and the fermented apricot and plum juice can be widely applied to fermentation of the apricot and plum juice, so that the storage life of apricot and plum is prolonged.

Description

Technical Field

[0001] The invention relates to the field of biotechnology, and in particular to application of Lactobacillus plantarum FMBL L23251 FJX in the preparation of fermented apricot and plum products and a preparation method thereof. Background Art

[0002] Prunus salicina belongs to the genus Prunus in the Rosaceae family. It is a new fruit variety bred by hybridizing apricot and plum. It combines some of the excellent traits of apricot and plum, so it has a unique appearance, taste and flavor characteristics. It is rich in vitamins, minerals and antioxidants. The currently cultivated commercial varieties include Flavor Rose, Wei Di, Dinosaur Egg, Red Velvet and Black Rose. Due to its unique geographical location and sufficient light and heat resources, Xinjiang produces apricots and plums with excellent quality and good taste, which have won the favor of consumers. Prunus salicina is mainly eaten fresh, but apricot plums are seasonal fruits, and the fresh fruit supply period is short. Apricot plums are easy to rot and deteriorate, resulting in a decrease in nutritional quality and difficulty in storage. During ripening and long-term storage, more defective fruits will be formed. Processing into preserved fruits, juices and canned fruits has become an important way to extend the storage time of seasonal fruits and increase their economic value. In the production process of preserved apricot and plum fruit, there are strict requirements on the maturity, fullness and damage of apricot and plum fruit, which makes apricot and plum fruit not fully utilized; and the existing apricot and plum juice is prepared by squeezing, filtering, blending and other processes, which has problems such as single taste, serious loss of nutrients and short shelf life. Therefore, how to maximize the use of apricot and plum fruit and improve its economic value is particularly critical to the development of the apricot and plum industry.

[0003] The research group where the inventor belongs has long been committed to the research in the field of probiotics and has screened out a number of probiotics with good probiotic properties, but the substrates preferred by each strain are inconsistent. For example, Lactobacillus paracasei FMBL L23249 FJX can efficiently utilize chickpea fermentation (CN2023114705670), and Lactobacillus paracasei YL-29 can efficiently utilize Elaeagnus angustifolia to ferment Elaeagnus angustifolia juice (CN2024100950811). The inventor has conducted continuous research and screened out a strain of Lactobacillus plantarum FMBL L23251 FJX from the feces of healthy people. It was found that it can ferment apricots and plums to obtain apricot and plum juice, improve the flavor of apricot and plum juice, significantly increase the polyphenol content in apricot and plum juice, improve antioxidant activity, and improve α-amylase and α-glucosidase inhibitory activity. Summary of the invention

[0004] The primary purpose of the present invention is to provide an application of Lactobacillus plantarum FMBLL23251 FJX in fermenting apricot plums. The Lactobacillus plantarum FMBL L23251 FJX was deposited in the China Center for Type Culture Collection on June 26, 2023, with a deposit number of CCTCC NO: M 20231110.

[0005] The second object of the present invention is to provide an apricot and plum product, which is obtained by fermenting Lactobacillus plantarum FMBLL23251 FJX. The Lactobacillus plantarum FMBL L23251 FJX was deposited in the China Center for Type Culture Collection on June 26, 2023, with a preservation number of CCTCC NO: M 20231110.

[0006] Preferably, the product is one or more of a liquid beverage, a solid beverage, fermented milk or a freeze-dried powder.

[0007] The third object of the present invention is to provide an apricot and plum liquid beverage with significantly improved total phenol content, wherein the apricot and plum liquid beverage is fermented by Lactobacillus plantarum FMBL L23251 FJX, and the Lactobacillus plantarum FMBL L23251FJX was deposited in the China Center for Type Culture Collection on June 26, 2023, with a preservation number of CCTCC NO: M 20231110.

[0008] A fourth object of the present invention is to provide a method for preparing the apricot-plum liquid beverage, characterized in that it comprises the following steps:

[0009] (1) Weigh apricot and plum fruits, wash them, drain them and set aside;

[0010] (2) adding distilled water to the apricot and plum fruits obtained in step (1), beating into pulp, filtering, adding 3% to 7% w / v glucose and 0.3% to 1.5% w / v casein, and stirring evenly to obtain apricot and plum juice;

[0011] (3) placing the apricot and plum juice obtained in step (2) at 95° C. for sterilization for 10 min, cooling to room temperature, and placing in a 4° C. refrigerator for later use;

[0012] (4) placing the bacterial solution of Lactobacillus plantarum FMBL L23251 FJX on MRS solid medium for anaerobically culturing, activating, and picking a single colony for subculture in MRS liquid medium;

[0013] (5) Take the second-generation bacterial solution obtained in step (4), centrifuge it, remove the supernatant, wash the precipitate with 0.9% saline, centrifuge it, and resuspend it with saline to make the bacterial density reach 1.0×107 CFU / mL; inoculate it into the apricot and plum juice obtained in step (3), culture it statically, and obtain a fermented apricot and plum liquid beverage.

[0014] Preferably, in step (2), the amount of glucose added is 4% to 6%, and the amount of casein added is 0.3% to 0.9%.

[0015] Preferably, the filtration in step (2) uses gauze with a mesh size of 100 to 300.

[0016] Preferably, the inoculation amount of the Lactobacillus plantarum FMBL L23251 FJX in step (5) is 1% to 5%.

[0017] Preferably, the fermentation time in step (5) is 0 h to 48 h.

[0018] Preferably, the fermentation time in step (5) is 12h-24h.

[0019] The fifth object of the present invention is to provide an application of fermenting apricot plum with Lactobacillus plantarum FMBLL23251 FJX in the preparation of antioxidant products. The Lactobacillus plantarum FMBL L23251 FJX was deposited in the China Center for Type Culture Collection on June 26, 2023, with a deposit number of CCTCC NO: M 20231110.

[0020] The sixth object of the present invention is to provide an application of Lactobacillus plantarum FMBLL23251 FJX fermenting apricot plum in inhibiting α-glucosidase activity or preparing α-glucosidase inhibitors. The Lactobacillus plantarum FMBL L23251 FJX was deposited in the China Center for Type Culture Collection on June 26, 2023, with a preservation number of CCTCC NO: M 20231110.

[0021] The seventh object of the present invention is to provide an application of Lactobacillus plantarum FMBLL23251 FJX fermenting apricot plum in inhibiting α-amylase activity or preparing α-amylase inhibitors. The Lactobacillus plantarum FMBL L23251 FJX was deposited in the China Center for Type Culture Collection on June 26, 2023, with a preservation number of CCTCC NO: M 20231110.

[0022] The eighth object of the present invention is to provide an application of fermenting apricot plum with Lactobacillus plantarum FMBLL23251 FJX in the preparation of a blood sugar-lowering product. The Lactobacillus plantarum FMBL L23251 FJX was deposited in the China Center for Type Culture Collection on June 26, 2023, with a deposit number of CCTCC NO: M 20231110.

[0023] The beneficial effects of the present invention are as follows: the present invention provides an application of Lactobacillus plantarum FMBL L23251 FJX in fermenting apricot and plum juice. In the process of fermenting apricot and plum juice, the growth of Lactobacillus plantarum FMBL L23251 is good, from the initial 9.3×10 6 The CFU / mL increased to 3.47×10 9 CFU / mL, with the advantage of stable growth; the total acid content of apricot and plum juice showed an overall upward trend during the fermentation process of 0-48h, the pH showed an overall downward trend, and the total phenol content showed a trend of first increasing and then decreasing; at 24h of fermentation, the total phenol content in apricot and plum juice increased from the initial 334.475mg / L to 584.504mg / L, a significant increase of 74.75%; the ABTS and DPPH free radical scavenging rates of fermented apricot and plum juice were increased by 23.46% and 91.33% respectively compared with those before fermentation; the inhibition rates of α-amylase and α-glucosidase were increased by 41.33% and 59.15% respectively; it can be widely used in the fermentation of apricot and plum juice to extend the shelf life of apricot and plum. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Effects of different inoculum amounts on polyphenol content in fermented apricot and plum juice

[0025] Figure 2 Changes of viable cell counts during fermentation of apricot and plum juice by Lactobacillus plantarum FMBL L23251 FJX

[0026] Figure 3 Changes of total acid and pH during fermentation of apricot and plum juice by Lactobacillus plantarum FMBL L23251 FJX

[0027] Figure 4 Changes of total phenolic content in apricot and plum juice fermented by Lactobacillus plantarum FMBL L23251 FJX

[0028] Figure 5 Changes of ABTS and DPPH free radical scavenging rates during fermentation of apricot and plum juice by Lactobacillus plantarum FMBL L23251 FJX DETAILED DESCRIPTION

[0029] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the specific embodiments of the present invention are described in detail below through several examples to clearly and completely describe the present invention, but no limitation is made to the claims of the present invention. Specific conditions are not specified in the embodiments, and the conventional conditions or the conditions recommended by the manufacturer are followed. The reagents or instruments used without indicating the manufacturer are all conventional products that can be purchased commercially.

[0030] In the following examples, the MRS agar medium formula is as follows: peptone 10g, beef extract 10g, yeast extract 5g, glucose 20g, Tween 80 1mL, K2HPO42g, sodium acetate 5g, diammonium citrate 2g, MgSO4·7H2O 0.58g, MnSO4·7H2O 0.25g, L-cysteine ​​hydrochloride 0.5g, vancomycin 20mg, agar 20g, water 1000mL, sterilized at 115°C for 20min.

[0031] The apricots and plums used in the following implementation cases were purchased in Kashgar, Xinjiang. Other experimental materials and instruments can be purchased through commercial channels unless otherwise specified.

[0032] The plant lactobacillus (Lactiplantibacillus plantarum) FMBL L23251FJX described in the present invention was deposited in the China Center for Type Culture Collection on June 26, 2023, with a deposit number of CCTCC NO: M20231110, and a deposit address: Wuhan University, Wuhan, China, telephone: 027-68754052; fax: 027-68754833.

[0033] In the following examples, Lactobacillus plantarum FMBL L23251FJX is abbreviated as Lactobacillus plantarum FMBL L23251 FJX.

[0034] Example 1: Preparation of fermented apricot and plum juice

[0035] The preparation method of apricot and plum juice is as follows:

[0036] (1) Weigh 100 g of apricot and plum fruits, ensure that they are free of pests and mechanical damage, repeatedly rinse with running water to clean the mud and impurities on the surface, and drain for later use;

[0037] (2) adding 300 mL of distilled water to the washed apricot and plum fruits, and beating them into a homogenous slurry using a wall-breaking machine (5 min). After filtering the obtained apricot and plum slurry through a 300-mesh gauze, adding glucose and casein to mix, and stirring evenly to obtain apricot and plum juice;

[0038] (3) Sterilize the apricot and plum juice prepared in (2) at 95°C for 10 min, cool to room temperature, and then place in a refrigerator at 4°C for later use;

[0039] (4) The bacterial solution of Lactobacillus plantarum FMBL L23251 FJX stored in a glycerol tube was streaked on MRS solid medium for activation, and then subcultured twice in liquid medium, each time for 12 hours, with an inoculum size of 2%;

[0040] (5) Take the second generation bacterial solution, centrifuge at 8000 rpm for 3 min, remove the supernatant, wash the precipitate with 0.9% saline, centrifuge, repeat 3 times, and resuspend with saline to make the bacterial density reach 1.0×10 7 CFU / mL, inoculated into the sterilized apricot and plum juice in (3), and cultured at 37°C to obtain fermented apricot and plum juice.

[0041] Example 2: Optimization of substrate ratio for fermented apricot and plum juice

[0042] Glucose and casein were used as supplementary carbon and nitrogen sources, and their supplementation amounts were optimized. A two-factor five-level orthogonal experiment was designed for the addition of carbon and nitrogen sources in the fermentation matrix. 3% (v / v) plant lactobacillus FMBL L23251FJX was inoculated, and the fermentation was stopped by standing at 4°C for 2 hours after fermentation at 37°C for 24 hours. The samples were tested with the number of viable bacteria as an indicator to determine the optimal addition amount of carbon and nitrogen sources.

[0043] As shown in Table 1, from the comparison of live bacteria counts, when the carbon source and nitrogen source supplementation amounts are low, the live bacteria count increases with the increase in supplementation amount, and there are significant differences between the groups (p < 0.05). When the amount of glucose added reaches 5% to 6%, the live bacteria count reaches a peak value. When the carbon source supplementation amount continues to increase to 7%, the live bacteria count remains at a similar level. When the nitrogen source supplementation reaches more than 1.2%, casein can no longer be completely dissolved. After fermentation, the texture of the apricot juice will cause abnormal conditions such as agglomeration and stratification. Therefore, through the live bacteria count results, the optimal ratio was finally confirmed: 5% carbon source supplementation and 0.9% nitrogen source supplementation. At this time, the live bacteria count can reach 3.467×10 9 cfu / mL or above.

[0044] Table 1 Results of viable bacterial count detection by optimizing matrix ratio

[0045]

[0046] Note: a,b,c,d,e Indicates that there is a significant difference between the same groups (p < 0.05). A,B,C,D,E Indicates that there is a significant difference between the same groups (p < 0.05)

[0047] Example 3: Optimization of the inoculum amount of the strain in the fermented apricot and plum juice

[0048] Example 2 The juice samples after matrix optimization prepared were supplemented with 5% (w / v) glucose and 0.9% (w / v) casein, and then inoculated with Lactobacillus plantarum FMBL L23251FJX at inoculum amounts of 1%, 2%, 3%, 4% and 5% (v / v), and then fermented at 37° C. for 24 h. The samples were tested with total phenol content as an indicator to confirm the optimal inoculum amount.

[0049] like Figure 1 As shown in the data, fermentation can significantly increase the content of polyphenols in fermented juice (P<0.05), and with the increase of inoculation size, the total phenol content showed a trend of first increasing and then decreasing, and reached the maximum value under the condition of 3% inoculation size, with the total phenol content of 580.48 mg / L. Therefore, 3% inoculation size was selected as the optimal parameter of inoculation size.

[0050] Example 4: Determination of growth performance of strains in fermented apricot and plum juice

[0051] 1. The prepared apricot and plum juice was placed in a constant temperature incubator at 37°C for fermentation. Samples were taken from the apricot and plum juice for viable bacterial count at 2h, 4h, 6h, 8h, 10h, 12h, 14h, 16h, 18h, 20h, 22h, 24h, 26h, 28h, 30h, 32h, 34h, 36h, 38h, 40h, 42h, 44h, 46h, and 48h of fermentation.

[0052] 2. Refer to GB4789.35-2016 "Food Microbiology Test for Lactic Acid Bacteria" and use the plate dilution method. Dilute 1mL of fermented juice to 10 -5 , 10 -6 , 10 -7 , spread evenly on MRS agar, culture anaerobically at 37℃ for 48h, count the plates with colony counts of 30CFU to 300CFU, and repeat 3 times for each group.

[0053] Changes in the number of viable bacteria of Lactobacillus plantarum FMBL L23251 FJX growing in apricot and plum juice Figure 2 As shown in the figure, the total amount of bacteria in the apricot and plum juice fermented by Lactobacillus plantarum FMBL L23251 FJX showed an overall upward trend during the culturing period of 0-48h at 37℃, and the growth of Lactobacillus plantarum FMBL L23251 FJX was good during the fermentation process, from the initial 9.3×10 6 The CFU / mL increased to 3.47×10 9 CFU / mL. It is well known in the art that the strains used to ferment juice need to have the ability to grow in juice up to 10 8CFU / mL, it is worth developing products. The growth capacity of the Lactobacillus plantarum FMBLL23251 FJX is 3.47×10 9 CFU / mL, with the prospect of developing apricot and plum juice products.

[0054] Example 5: Changes in pH and total acid during fermentation of apricot and plum juice by Lactobacillus plantarum FMBLL23251 FJX

[0055] 1. The prepared apricot and plum juice was placed in a constant temperature incubator at 37°C for fermentation. Samples were taken from the apricot and plum juice at 0h, 6h, 12h, 18h, 24h, 30h, 36h, 42h, and 48h of fermentation to determine pH and total acid.

[0056] 2. The pH value was measured using a PHS-3C pH acidity meter, with each group repeated 3 times.

[0057] 3. Dilute 1 mL of apricot juice with 20 mL of deionized water and titrate with 0.1 mol / L sodium hydroxide solution. Stir the solution until the pH stabilizes at 8.2 ± 0.1. The calculation formula is:

[0058]

[0059] Where V1: volume of sodium hydroxide solution consumed, mL; V2: volume of apricot and plum juice, mL; C NaOH : Concentration of sodium hydroxide, mol / L, content expressed as malic acid (k=0.067).

[0060] The acid production curve of apricot and plum juice fermented by Lactobacillus plantarum FMBL L23251 FJX Figure 3 As shown, the total acid content of apricot and plum juice generally shows an upward trend during the fermentation process of 0-48h, and the pH generally shows a downward trend. In the early stage of fermentation, lactic acid bacteria metabolize lactose to produce lactic acid, increase the total acid content in the juice, and reduce the pH value of the juice. The generation of lactic acid makes the environment acidic, and the fermentation produces an appropriate amount of CO2, which inhibits the growth of other microorganisms and plays a preservative role. After 48h of fermentation, the pH of the apricot and plum juice dropped to 3.68, but Lactobacillus plantarum FMBL L23251 FJX can still survive, indicating that it has extremely strong acid resistance. Combined with the growth of the strain during the fermentation process and the changes in the total acid content and pH of the juice, it can be seen that the optimal time for Lactobacillus plantarum FMBL L23251 FJX to ferment apricot and plum juice is 24h. Example 6. Changes in total phenol content during the fermentation of apricot and plum juice by Lactobacillus plantarum FMBL L23251 FJX

[0061] 1. The prepared apricot and plum juice was placed in a constant temperature incubator at 37°C for fermentation, and 1 mL of samples were taken from the apricot and plum juice at 0h, 6h, 12h, 18h, 24h, 30h, 36h, 42h, and 48h of fermentation for determination of total phenol content.

[0062] 2. Determination of total phenol content in samples by Folin phenol method

[0063] (1) Fermented apricot and plum juice at different fermentation stages was diluted 10 times with distilled water to prepare a sample test solution.

[0064] (2) Take 150 μL of sample test solution and add 150 μL of foline phenol, vortex evenly, and react for 10 minutes. Then add 600 μL of 20% Na2CO3 solution and react for 20 minutes in the dark. Then measure the absorbance at a wavelength of 765 nm. Prepare a gallic acid stock solution with a mass concentration of 200 μg / mL, dilute it into a series of standard solutions with a mass concentration of 0-200 μg / mL, and obtain the linear regression equation of Y=0.0108X+0.0743, R 2 =0.9992.

[0065] like Figure 4 As shown, during the fermentation of apricot and plum juice by plant lactobacillus FMBL L23251 FJX (0-48h), the total phenol content showed a trend of first rising and then falling. During the fermentation 0-24h, the total phenol content in the apricot and plum juice was gradually improved by the initial 334.475mg / L, and was improved to 499.003mg / L at 12h, and was improved to 584.504mg / L at 24h, which was significantly higher than the total phenol content before fermentation, but was reduced to 512.834mg / L in the late fermentation period (48h). The total phenol content in the apricot and plum juice after fermentation for 24 hours was improved by 74.75% compared with that before fermentation, which shows that plant lactobacillus FMBL L23251 FJX can significantly increase the polyphenol content in the apricot and plum juice when fermenting for 24h, and the optimum time for the plant lactobacillus FMBL L23251 FJX fermentation of apricot and plum juice obtained with Example 3 is consistent with 24h.

[0066] Example 7: Changes in antioxidant activity during fermentation of apricot and plum juice by Lactobacillus plantarum FMBLL23251 FJX

[0067] 1. The prepared inoculated apricot and plum juice was placed in a constant temperature incubator at 37°C for fermentation. 1 mL of samples were taken from the apricot and plum juice at 0h, 6h, 12h, 18h, 24h, 30h, 36h, 42h, and 48h of fermentation to determine the antioxidant activity of the fermented juice.

[0068] 2. Determination of ABTS free radical scavenging ability: Mix 7.4mmol / L ABTS solution and 2.6mmol / L potassium persulfate solution in a ratio of 1:1, and react in the dark for 12 to 16 hours. Then dilute the mixture with ethanol to make the absorbance at 734nm 0.70±0.02, and use it as ABTS working solution. Add 40μL of the sample to be tested to 800μL of the working solution, react in the dark for 20 minutes, and measure the sample absorbance A at 734nm. s The blank group was distilled water containing ABTS, and the control group was distilled water and samples. The absorbance was measured as A b and A c .

[0069]

[0070] 3. Determination of DPPH free radical scavenging ability: prepare 0.025g / L DPPH solution, take 0.1mL of juice sample and mix it evenly with 3.9mL DPPH solution, react for 30min in dark conditions, and measure its absorbance at 515nm as Bs; in addition, replace the juice with 0.1mL anhydrous ethanol, mix it with 3.9mL DPPH solution and measure its absorbance as Bc, which serves as the blank control group.

[0071]

[0072] The results of ABTS free radical scavenging rate and DPPH free radical scavenging rate are as follows Figure 5 As shown, during the fermentation of apricot and plum juice by plant lactobacillus FMBLL23251FJX (0-48h), the ABTS free radical scavenging rate and the DPPH free radical scavenging rate both showed a trend of first rising and then falling. At 24h of fermentation, the ABTS free radical scavenging rate reached 94.87%, which was significantly increased by 23.46% compared with the unfermented apricot and plum juice (76.84%); the DPPH free radical scavenging rate reached 59.56%, which was significantly increased by 91.33% compared with the unfermented apricot and plum juice (31.13%). However, at 48h of fermentation, the ABTS free radical scavenging rate decreased to 85.46%, and the DPPH free radical scavenging rate decreased to 50.04%. The results show that the apricot and plum juice fermented by plant lactobacillus FMBL L23251 FJX of the present invention significantly improves the ABTS free radical scavenging rate and DPPH free radical scavenging rate of apricot and plum juice, indicating that fermented apricot and plum juice has the potential to become a product with antioxidant activity.

[0073] Example 8. α-Amylase and α-Glucosidase Inhibitory Activity of Fermented Apricot and Plum Juice

[0074] (1) Determination of α-glucosidase activity inhibition ability

[0075] Pipette 50 μL of sample and 100 μL of 0.2U / mL α-glucosidase solution into a test tube, mix well, and react at 37°C for 10 min; then add 50 μL of 5mmol / L p-nitrophenol-α-D-pyranoglucoside solution, mix well, and react in a 37°C constant temperature water bath for 20 min, then add 50 μL of 0.2mol / L Na2CO3 solution to terminate the reaction, and measure the absorbance of the reaction solution at a wavelength of 400nm.

[0076]

[0077] Wherein: A is the sample group, containing sample solution and α-glucosidase solution; B is the sample blank group, containing sample solution but not α-glucosidase solution; C is the control group, containing no sample solution but α-glucosidase solution; D is the blank group, containing no sample solution and no α-glucosidase solution.

[0078] (2) Determination of α-amylase activity inhibition ability

[0079] 125 μL of sample solution was mixed with 1 mg / mL α-amylase solution in equal volumes, and reacted at 37°C for 15 min. Then, the reaction solution was added to 250 μL of 1% soluble starch solution, and reacted at 37°C for 15 min. 500 μL of DNS solution was added, and the mixture was rapidly cooled to room temperature after 5 min in a boiling water bath, and then diluted 20 times and allowed to stand at room temperature, and the absorbance was measured at 540 nm. PBS solution (0.1 mol / L, pH=6.8) was used as a blank control for the α-amylase solution and the sample to be tested.

[0080]

[0081] Wherein: A is the sample group, containing sample solution and α-amylase solution; B is the sample blank group, containing sample solution but not α-amylase solution; C is the control group, containing no sample solution but α-amylase solution; D is the blank group, containing no sample solution and no α-amylase solution.

[0082] Table 2 α-amylase and α-glucosidase inhibitory activity

[0083]

[0084] The results are shown in Table 2. The inhibition rates of α-amylase and α-glucosidase of apricot and plum juice fermented by Lactobacillus rhamnosus FMBL L2323251FJX were 90.03% and 78.29%, respectively, which were 41.33% and 59.15% higher than those of unfermented apricot and plum juice, respectively. This indicates that Lactobacillus plantarum FMBL L2323251FJX fermentation can significantly enhance the application potential of apricot and plum juice in lowering blood sugar, and can be used in the preparation of blood sugar-related products.

[0085] Example 9: Preparation of apricot and plum solid beverage

[0086] 1.0×10 7 CFU / mL of plant lactobacillus FMBL L23251 FJX is added to the apricot and plum juice prepared in the above embodiment, and after fermentation at 37°C for 24 hours, 3-10% maltodextrin, 0.5-1% trehalose and 1% galacto-oligosaccharide are added, and after uniform mixing, the fermented apricot and plum juice freeze-dried powder is prepared by freeze drying or spray drying to obtain an apricot and plum solid beverage. It should be noted that any value of maltodextrin and trehalose within the above range can achieve the preparation of a solid beverage.

[0087] In summary, the present invention provides the use of Lactobacillus plantarum FMBL L23251 FJX in fermenting apricot and plum juice. In the process of fermenting apricot and plum juice, the growth of Lactobacillus plantarum FMBL L23251 is good, from the initial 8.5×10 6 The CFU / mL increased to 3.47×10 9 CFU / mL, with the advantage of stable growth; the total acid content of apricot and plum juice showed an overall upward trend during the fermentation process of 0-48h, the pH showed an overall downward trend, and the total phenol content showed a trend of first increasing and then decreasing; at 24h of fermentation, the total phenol content in apricot and plum juice increased from the initial 334.475mg / L to 584.504mg / L, a significant increase of 74.75%; the ABTS and DPPH free radical scavenging rates of fermented apricot and plum juice were increased by 23.46% and 91.33% respectively compared with those before fermentation; the inhibition rates of α-amylase and α-glucosidase were increased by 41.33% and 59.15% respectively; it can be widely used in the fermentation of apricot and plum juice to extend the shelf life of apricot and plum.

Claims

1. Application of Lactiplantibacillus plantarum FMBL L23251 FJX in the preparation of fermented apricot and plum products, characterized in that: The plant lactobacillus FMBL L23251 FJX was deposited in the China Center for Type Culture Collection on June 26, 2023, with a deposit number of CCTCC NO: M 20231110.

2. A fermented apricot and plum product, characterized in that: The fermented apricot and plum product is obtained by fermenting Lactobacillus paracasei and Lactobacillus plantarum FMBL L23251 FJX. The Lactobacillus plantarum FMBL L23251 FJX was deposited in the China Center for Type Culture Collection on June 26, 2023, with a deposit number of CCTCC NO: M 20231110.

3. The fermented apricot and plum product according to claim 2, characterized in that: The product is one or more of a liquid beverage, a solid beverage, fermented milk or a freeze-dried powder.

4. A liquid apricot-plum beverage with significantly increased total phenol content, characterized in that: The apricot and plum liquid beverage is obtained by fermentation of Lactobacillus plantarum FMBL L23251 FJX. The Lactobacillus plantarum FMBL L23251 FJX was deposited in the China Center for Type Culture Collection on June 26, 2023, with a deposit number of CCTCC NO: M 20231110.

5. The method for preparing apricot-plum liquid beverage according to claim 4, characterized in that: The steps include: (1) Weigh apricot and plum fruits, wash them, drain them and set aside; (2) adding distilled water to the apricot and plum fruits obtained in step (1), beating into pulp, filtering, adding 3% to 7% w / v glucose and 0.3% to 1.5% w / v casein, and stirring evenly to obtain apricot and plum juice; (3) placing the apricot and plum juice obtained in step (2) at 95° C. for sterilization for 10 min, cooling to room temperature, and placing in a 4° C. refrigerator for later use; (4) placing the bacterial solution of Lactobacillus plantarum FMBL L23251 FJX on MRS solid medium for anaerobically culturing, activating, and picking a single colony for subculture in MRS liquid medium; (5) Take the second-generation bacterial solution obtained in step (4), centrifuge it, remove the supernatant, wash the precipitate with 0.9% saline, centrifuge it, and resuspend it with saline to make the bacterial density reach 1.0×10 7 CFU / mL; inoculate it into the apricot and plum juice obtained in step (3), culture it statically, and obtain a fermented apricot and plum liquid beverage.

6. The preparation method according to claim 5, characterized in that: In step (2), the amount of glucose added is 4% to 6%, the amount of casein added is 0.3% to 0.9%, and 100-300 mesh gauze is used for filtration; in step (5), the inoculation amount of plant lactobacillus FMBL L23251 FJX is 1% to 5%, and the fermentation time is 0h to 48h.

7. Application of apricot and plum fermented with Lactobacillus plantarum FMBL L23251 FJX in the preparation of antioxidant products, characterized in that: The plant lactobacillus FMBL L23251 FJX was deposited in the China Center for Type Culture Collection on June 26, 2023, with a deposit number of CCTCC NO: M 20231110.

8. Application of apricot plum fermented with Lactobacillus plantarum FMBL L23251 FJX in inhibiting α-glucosidase activity or preparing α-glucosidase inhibitors, characterized in that: The plant lactobacillus FMBL L23251 FJX was deposited in the China Center for Type Culture Collection on June 26, 2023, with a deposit number of CCTCC NO: M 20231110.

9. Application of apricot plum fermented with Lactobacillus plantarum FMBL L23251 FJX in inhibiting α-amylase activity or preparing α-amylase inhibitors, characterized in that: The plant lactobacillus FMBLL23251 FJX was deposited in the China Center for Type Culture Collection on June 26, 2023, with a deposit number of CCTCC NO: M20231110.

10. Application of apricot and plum fermented with Lactobacillus plantarum FMBL L23251 FJX in the preparation of a blood sugar lowering product, characterized in that: The plant lactobacillus FMBL L23251 FJX was deposited in the China Center for Type Culture Collection on June 26, 2023, with a deposit number of CCTCC NO: M 20231110.

Images