Lactobacillus reuteri INM3109 and application thereof in rice products

Abstract

The invention provides lactobacillus reuteri INM3109 and application of the lactobacillus reuteri INM3109 in rice products, the lactobacillus reuteri INM3109 is preserved in Guangdong Microbial Culture Collection Center on August 13, 2024, the preservation number is GDMCC NO: 65002, the preservation number is CGMCC NO: 65002, and the preservation number is CGMCC NO: 65003. The preservation address is the fifth floor of the building 59, No.100 courtyard, Xianlie Middle Road, Guangzhou City. The lactobacillus reuteri has the advantages that the lactobacillus reuteri can effectively improve the yield of high-concentration p-coumaric acid after rice products are fermented.

Description

Technical Field

[0001] The invention relates to a strain of Lactobacillus reuteri INM3109 and application thereof in rice products. Background Art

[0002] p-Coumaric acid, chemically named 3-(4-hydroxyphenyl)-2-propenoic acid, is an organic compound with the chemical formula C9H8O3, molecular weight 164.15802, and is a white powder.

[0003] The application of p-coumaric acid in the food industry mainly includes the following aspects: Food preservatives: p-coumaric acid has antioxidant properties and can be used as a natural food preservative to help extend the shelf life of food. It can inhibit oxidation reactions in food, reduce fat oxidation and food spoilage. Food flavor enhancer: p-coumaric acid has an aromatic smell and can increase the aroma and taste of food. Therefore, it is often used as a food flavor enhancer for the preparation of seasonings, spices and flavors. Food pigments: p-coumaric acid can be used as a natural food pigment in some food processing to give food a specific color. Food nutritional enhancer: p-coumaric acid is a biologically active substance with certain health benefits, including antioxidant, anti-inflammatory and antibacterial effects. Therefore, it is used to prepare some nutritionally fortified foods.

[0004] Rice-based foods are rich in nutritional value, but they lack antioxidants, which makes them easy to age and regenerate after production and processing, affecting the taste of rice-based foods. However, with the increasing demand for rice-based foods, more technical means are needed to improve rice-based foods and related products.

[0005] In recent years, some people have tried to improve the quality of rice products and their products by using food preservatives, food additives, flavors and fragrances or enzymes, but the improvement effect is not ideal, especially in terms of anti-aging, flavor and color protection of rice products. Therefore, the rice product improvement technology needs to be explored to adapt to the development of the rice market.

[0006] At present, the research directions of p-coumaric acid are diverse. Patent: A trans-cinnamic acid-4-hydroxylase and its encoding gene and application-CN201710142604.2 The present invention relates to a trans-cinnamic acid-4-hydroxylase and its encoding gene and application, and discloses a trans-cinnamic acid-4-hydroxylase of Lycoris radiata, which has good substrate specificity and regioselectivity, and can catalyze the hydroxylation of the 4-C of trans-cinnamic acid to generate p-coumaric acid. However, genetically modified microorganisms cannot be added to food for direct application. Patent: A method for brewing cider using red flesh apples as raw materials CN201510092581.0, this invention discloses a method for brewing cider using freshly squeezed juice of red flesh apples as raw materials, and the advantage is that the brewed cider has a higher content of total phenols than cider brewed with white flesh apples. However, it does not involve the improvement of p-coumaric acid, on the contrary, the amount of p-coumaric acid is reduced during the fermentation process. Patent: A method for extracting ferulic acid and p-coumaric acid from xylose hydrolysate - CN202011639819.4. The present invention relates to a method for extracting ferulic acid and p-coumaric acid from xylose hydrolysate, in order to solve the problem of high production cost of traditional alkaline hydrolysis of ferulic acid and p-coumaric acid. However, this patent does not involve the application of p-coumaric acid in rice products.

[0007] Although the above patents use biological fermentation and plant extraction methods to obtain p-coumaric acid, they cannot be effectively applied to rice products, and the microorganisms therein are not on the edible list. Adding p-coumaric acid to food in the form of an additive is contrary to consumers' demands for clean labels. Therefore, it can be seen that developing a safe and effective strain to improve the nutritional value and flavor of rice products has a very broad application prospect.

[0008] Although many studies have shown that there are effective methods to increase the p-coumaric acid content, there are still some shortcomings in practical application: (1) The main microorganisms used in biological production are not on the list of edible fungi and cannot be used in food. (2) There is a lack of safe bacteria that can be directly used in the fermentation stage of rice products to increase the p-coumaric acid content in rice products. Summary of the invention

[0009] In view of the above problems, the present invention provides a strain of Lactobacillus reuteri INM3109 suitable for fermenting rice products to improve aroma and shelf life, and application thereof in rice products. On the basis of not changing the existing process, the present invention ferments rice products with Lactobacillus reuteri to prepare a method for improving the nutritional value of rice products, which not only enhances the p-coumaric acid content of the rice products, but also improves the flavor and quality of the rice products. The rice products produced by using the preparation do not affect the overall process of the rice products after fermentation, and not only improve the taste of the rice products but also improve the nutritional value of the rice products.

[0010] The purpose of the invention is achieved through the following scheme: A strain of Lactobacillus reuteri, Lactobacillus reuteri (Limosilactobacillus reuteri) INM3109, was deposited in Guangdong Provincial Microbiological Culture Collection Center on August 13, 2024, with the deposit number: GDMCC NO: 65002; the deposit address is: 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou.

[0011] Furthermore, the colony characteristics of Lactobacillus reuteri are as follows: after culturing on solid MRS plate medium for 48 hours, the colony diameter reaches 2 to 3 mm, the colonies are white, raised, round, with a smooth surface and neat edges.

[0012] A preparation method of Lactobacillus reuteri.

[0013] Step 1: Isolation of lactic acid bacteria: Isolation and screening of lactic acid bacteria from yogurt soup samples, adding dairy products into a slurry, adding to sterile water, diluting the concentration to 10 5 -10 6 , the dairy products of different dilution concentrations were evenly spread on the solid MRS medium, and then cultured in an incubator at 37°C for 48 hours. Then, the white colonies on the solid MRS medium and the lactic acid bacteria with the correct morphology were selected for screening;

[0014] Step 2: Lactic acid bacteria screening: The obtained lactic acid bacteria were cultured to the logarithmic growth phase, and then inoculated with 1% of the strain, and the final concentration of the strain was 1×10 6 cfu / mL, inoculated into modified MRS solution, placed in 37℃ for 3 days to obtain the fermentation liquid, and the content of p-coumaric acid was measured.

[0015] Furthermore, the formula of the improved MRS solution is: weigh 10g of peptone, 8g of beef extract powder, 4g of yeast extract powder, 20g of glucose, 2g of dipotassium hydrogen phosphate, 2g of diammonium hydrogen citrate, 5g of sodium acetate, 0.2g of magnesium sulfate, 0.04g of manganese sulfate, and 1g of Tween 80, dissolve in 1000mL of distilled water, 0.1MPa, sterilize at 121°C for 15min; add 0.1g of tyrosine after cooling.

[0016] An application of Lactobacillus reuteri, production application: according to the production process of rice products, in the fermented rice product liquid, the inoculation amount is 10 4 -10 8 cfu / mL of Lactobacillus reuteri, the fermentation time was 3d and the fermentation temperature was 37℃, and then arginine, ethyl caprylate and the sensory quality of the fermentation broth were detected.

[0017] Application of Lactobacillus reuteri in rice products.

[0018] An application of Lactobacillus reuteri that effectively increases the production of higher concentrations of p-coumaric acid after fermentation of rice products.

[0019] Advantages of the present invention: (1) The Lactobacillus reuteri of the present invention can effectively increase the production of p-coumaric acid at a higher concentration after fermentation of rice products.

[0020] (2) The Lactobacillus reuteri of the present invention has the characteristic of improving the shelf life of rice products.

[0021] (3) The screening method of Lactobacillus reuteri is universal and can be widely used in the screening of bacteria for improving the arginine content in rice products.

[0022] (4) Lactobacillus reuteri has substances that can enhance the flavor of rice products, and the fermented rice products will not have any peculiar smell. Later, they can be mixed with other grain powders, which means that the nutrition and flavor of rice products are retained without any safety risks. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Flow chart of strain screening.

[0024] Figure 2 This is a morphological observation diagram of Lactobacillus reuteri.

[0025] Figure 3 This is a picture of Lactobacillus reuteri observed under a microscope.

[0026] Figure 4 The inoculation concentration of Example 3 is 1.0×10 7 CFU / mL measurement of p-coumaric acid content.

[0027] Figure 5 This is a diagram of the production of p-coumaric acid by fermentation of the 9 strains in Example 1. DETAILED DESCRIPTION

[0028] The present invention will be further described below in conjunction with specific embodiments:

[0029] Unless otherwise specified, the experimental methods used in the following embodiments are all conventional methods; the materials, reagents, etc. used, unless otherwise specified, can be obtained from commercial channels.

[0030] Example 1, see attached Figure 1-5 , a strain of Lactobacillus reuteri, Limosilactobacillus reuteri INM3109, was deposited in Guangdong Provincial Microbiological Culture Collection Center on August 13, 2024, with the deposit number: GDMCC NO: 65002; the deposit address is: 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou.

[0031] A strain of Lactobacillus reuteri, the colony characteristics of Lactobacillus reuteri are as follows: after culturing on solid MRS plate medium for 48 hours, the colony diameter reaches 2 to 3 mm, the colonies are white, raised, round, with a smooth surface and neat colony edges.

[0032] An application of Lactobacillus reuteri, production application: according to the production process of rice products, in the fermented rice product liquid, the inoculation amount is 10 4 -10 8 cfu / mL of Lactobacillus reuteri, the fermentation time was 3d and the fermentation temperature was 37℃, and then arginine, ethyl caprylate and the sensory quality of the fermentation broth were detected.

[0033] Application of Lactobacillus reuteri in rice products.

[0034] An application of Lactobacillus reuteri that effectively increases the production of higher concentrations of p-coumaric acid after fermentation of rice products.

[0035] A preparation method of Lactobacillus reuteri.

[0036] 1. Processing of raw materials

[0037] Take the Inner Mongolia yogurt soup product and dilute it to 10 with sterile saline. -1 , 10 -2 , 10 -3 , 10 -4 , 10 -5 , 10 -6 concentration, made into bacterial dilutions, took 0.1 mL of each dilution and spread it evenly on an MRS solid culture medium plate, cultured at 37°C for 48 h, selected single colonies with white, raised colonies, smooth surface and neat colony edges, streaked the colonies on MRS solid culture medium for secondary purification, cultured at 37°C for 48 h, picked single colonies for glycerol preservation, and named them NM4201 to NM4209 respectively.

[0038] 2. Preliminary screening of bacterial strains

[0039] The 9 strains were inoculated into MRS liquid medium at 1% inoculum and cultured at 37°C for 24 h. Then, they were inoculated into modified MRS medium at 1% inoculum and cultured at 37°C for 24 h. The final cell density reached 10 6 cfu / mL.

[0040] After 24 hours of fermentation, samples were taken from each tube and centrifuged at 10,000 r / min for 10 minutes. The supernatant was the sample and tested for physical and chemical indicators. Figure 5 .

[0041] Detection of p-coumaric acid: CAPCELL PAK C18 UG120 S5 (4.6 mm×250 mm), mobile phase: 0.12% H3PO4: acetonitrile = 75:25; flow rate 1.0 mL / min; detection wavelength: 254 nm; injection volume: 5 μL.

[0042] Strains NM4202, NM4204 and NM4205 with high p-coumaric acid content were selected for rescreening.

[0043] 3. Strain rescreening

[0044] The lactic acid bacteria NM4202, NM4204, and NM4205 selected in the initial screening were reactivated and cultured at a bacterial concentration of 10 6 cfu / mL, and inoculated into polished japonica rice to make cooked rice for sensory evaluation. The results are shown in Table 1.

[0045] Table 1 Sensory analysis of fermented japonica rice

[0046] Species name Rice product appearance taste Average score NM4202 4.7 5.0 4.85 NM4204 4.5 5.0 4.75 NM4205 4.5 4.5 4.50

[0047] Note: The maximum score for each indicator is 5 points, and the higher the score, the better the result.

[0048] From the results in Table 1, we can see that NM4202 has the best sensory evaluation result. As the target strain for rescreening, the morphological observation of this strain on the solid MRS plate medium is as follows: Figure 2 As shown, the colony diameter is 2-3mm, the colony is milky white, the colony is convex and round, the surface is smooth, and the colony edge is neat. After Gram staining, it is observed under a microscope, usually 0.5×3.0μm or more, short rod-shaped, and the result is as follows Figure 3 shown.

[0049] The above-screened NM4202 was subjected to 16SrDNA sequencing and identification. After comparative analysis, the 16S region sequence obtained from the strain of the present invention was 99.80% similar to that of Limosilactobacillus reuteri. It can be determined that the strain is a strain of Lactobacillus reuteri, which can be used in the food fermentation industry. It is named Lactobacillus reuteri NM4202. The strain was deposited in the Guangdong Provincial Microbiological Culture Collection Center on August 11, 2024, with the deposit number: CGMCC 65002. Therefore, INM3109 and NM4202 refer to the same strain in this application. The strain INM3109 of the present invention was genetically identified, and its gene sequence is as follows:

[0050] AGCTCAGGATGAACGCCGGCGGTGTGCCTAATACATGCAAGTCGTACGCACTGGCCCAACTGA

[0051] TTGATGGTGCTTGCACCTGATTGACGATGGATCACCAGTGAGTGGCGGACGGGTGAGTAACAC

[0052] GTAGGTAACCTGCCCCGGAGCGGGGGATAACATTTGGAAACAGATGCTAATACCGCATAACAA

[0053] CAAAAGCCACATGGCTTTTGCTTGAAAGATGGCTTTGGCTATCACTCTGGGATGGACCTGCGG

[0054] TGCATTAGCTAGTTGGTAAGGTAACGGCTTACCAAGGCGATGATGCATAGCCGAGTTGAGAGA

[0055] CTGATCGGCCACAATGGAACTGAGACACGGTCCATACTCCTACGGGAGGCAGCAGTAGGGAAT

[0056] CTTCCACAATGGGCGCAAGCCTGATGGAGCAACACCGCGTGAGTGAAGAAGGGTTTCGGCTCG

[0057] TAAAGCTCTGTTGTTGGAGAAGAACGTGCGTGAGAGTAACTGTTCACGCAGTGACGGTATCCA

[0058] ACCAGAAAGTCACGGCTAACTACGTGCCAGCAGCCGCGGTAATACGTAGGTGGCAAGCGTTAT

[0059] CCGGATTTATTGGGCGTAAAGCGAGCGCAGGCGGTTGCTTAGGTCTGATGTGAAAGCCTTCGG

[0060] CTTAACCGAAGAAGTGCATCGGAAACCGGGCGACTTGAGTGCAGAAGAGGACAGTGGAACTCC

[0061] ATGTGTAGCGGTGGAATGCGTAGATATATGGAAGAACACCAGTGGCGAAGGCGGCTGTCTGGT

[0062] CTGCAACTGACGCTGAGGCTCGAAAGCATGGGTAGCGAACAGGATTAGATACCCTGGTAGTCC

[0063] ATGCCGTAAACGATGAGTGCTAGGTGTTGGAGGGTTTCCGCCCTTCAGTGCCGGAGCTAACGC

[0064] ATTAAGCACTCCGCCTGGGGAGTACGACCGCAAGGTTGAAACTCAAAGGAATTGACGGGGGCC

[0065] CGCACAAGCGGTGGAGCATGTGGTTTAATTCGAAGCTACGCGAAGAACCTTACCAGGTCTTGA

[0066] CATCTTGCGCTAACCTTAGAGATAAGGCGTTCCCTTCGGGGACGCAATGACAGGTGGTGCATG

[0067] GTCGTCGTCAGCTCGTGTCGTGAGATGTTGGGTTAAGTCCCGCAACGAGCGCAACCCTTGTTA

[0068] CTAGTTGCCAGCATTAAGTTGGGCACTCTAGTGAGACTGCCGGTGACAAACCGGAGGAAGGTG

[0069] GGGACGACGTCAGATCATCATGCCCCTTATGACCTGGGCTACACACGTGCTACAATGGACGGT

[0070] ACAACGAGTCGCAAGCTCGCGAGAGTAAGCTAATCTCTTAAAGCCGTTCTCAGTTCGGACTGT

[0071] AGGCTGCAACTCGCCTACACGAAGTCGGAATCGCTAGTAATCGCGGATCAGCATGCCGCGGTG

[0072] AATACGTTCCCGGGCCTTGTACACACCGCCCGTCACACCATGGGAGTTTGTAACGCCCAAAGT

[0073] CGGTGGCCTAACCTTTATGGAGGGAGCCGCCTAAGGCGGGACAGATGACTGGGGTGAAGTCGT

[0074] Example 2, genetic stability test of Lactobacillus reuteri INM3109

[0075] Lactobacillus reuteri INM3109 in Example 1 was continuously propagated for 10 generations on a modified MRS liquid medium, and the first, fifth, and tenth generation samples were centrifuged at 10,000 r / min for 10 min to obtain the supernatant, which was the sample, and subjected to physical and chemical index detection. The method for detecting the p-coumaric acid content was referenced to Example 1. At the same time, a sensory evaluation was performed to determine its stability in propagation, and the specific data are shown in Table 2.

[0076] Table 2 Results of the stability test for passage

[0077] Number of generations pH Total acid (g / L) p-Coumaric acid content (mg / L) INM3109 1st Generation 4.22±0.23 60.45±4.28 38.23±1.32 INM3109 5th Generation 4.19±0.38 61.70±2.13 37.38±0.78 INM3109 10th Generation 4.41±0.18 62.24±3.42 39.59±2.56

[0078] The results in Table 2 show that the fermentation performance of Lactobacillus reuteri INM3109 of different generations is normal, the change of coumarin resistance is within 10%, the strain has good genetic stability and meets the requirements for production and use.

[0079] Example 3: Fermentation of polished rice by Lactobacillus reuteri INM3109 to prepare cooked rice

[0080] Lactobacillus reuteri INM3109 was inoculated into polished rice to ferment polished rice balls. The weight ratio of polished rice to water was 1:1.5. The concentrations of inoculated fermentation bacteria were 10 4 -10 8 CFU / mL, respectively, to make fermented japonica rice. The fermentation method is as follows: the fermentation temperature is 30°C, the fermentation time is 24h, 10g sample is taken, centrifuged at 8000g for 10min, and the supernatant is taken for detection. The method for detecting the content of p-coumaric acid in rice products is as shown in Example 1, and NM4209 is used as the control strain. The results are shown in Table 3.

[0081] The fermented japonica rice was made into cooked rice, which was steamed at 100°C for 15 min. Professional tasters were asked to conduct a sensory evaluation of the rice flavor. The results are shown in Table 4.

[0082] Table 3 Detection of total acid and p-coumaric acid content in fermented japonica rice

[0083]

[0084]

[0085] Table 4 Sensory evaluation results of fermented japonica rice to make rice balls

[0086] Grouping Inoculation volume sour Sweetness Taste Overall Rating Control group 1 <![CDATA[1.0×10 4 ]]> 6.5 6.5 6.5 19.5 Experimental Group 1 <![CDATA[1.0×10 4 ]]> 7.7 7.8 8.5 24 Control group 2 <![CDATA[1.0×10 5 ]]> 7.3 8.2 7.6 23.1 Experimental Group 2 <![CDATA[1.0×10 5 ]]> 8.4 8.2 8.5 25.1 Control group 3 <![CDATA[1.0×10 6 ]]> 7.7 8.5 7.8 24 Experimental Group 3 <![CDATA[1.0×10 6 ]]> 9 9.3 9.5 27.8 Control group 4 <![CDATA[1.0×10 7 ]]> 7.5 7.8 8.4 23.7 Experimental Group 4 <![CDATA[1.0×10 7 ]]> 9.7 9.6 9.8 29.1 Control group 5 <![CDATA[1.0×10 8 ]]> 6.7 7.7 8.7 23.1 Experimental Group 5 <![CDATA[1.0×10 8 ]]> 8.8 8.9 8.7 26.4

[0087] Note: Each item has a full score of 10 points, with a scoring interval of 0.1, and the comprehensive score is the sum of the values ​​of each item.

[0088] The results in Tables 3 and 4 show that Lactobacillus reuteri INM3109 in fermented glutinous rice balls can significantly increase the p-coumaric acid content of glutinous rice products, and the more the inoculation amount, the higher the p-coumaric acid content; however, too high or too low inoculation concentration of Lactobacillus reuteri INM3109 will affect the sourness, sweetness and taste of rice products. The most suitable inoculation concentration is 1.0×10 7 CFU / mL, this concentration can produce enough p-coumaric acid content ( Figure 4 ), and can improve the flavor and taste of glutinous rice balls. Example 4, fermentation of mixed rice by Lactobacillus reuteri INM3109 to make rice balls

[0089] The final concentration of Lactobacillus reuteri INM3109 was 10 7 CFU / mL of fermented mixed rice (japonica rice, black rice, glutinous rice ratio of 1:2:1), the fermentation method and cooking method refer to Example 3, and another group of inoculated NM4209 was taken as the control group.

[0090] After the fermentation was completed, the p-coumaric acid content in the fermented mixed rice was detected according to the method in Experimental Example 3. At the same time, professional appraisers were asked to conduct sensory evaluation on the flavor of the mixed rice balls. The results are recorded in Table 5.

[0091] Table 5 Detection of p-coumaric acid in fermented mixed rice and sensory evaluation results of mixed rice balls

[0092]

[0093] Note: Each sensory evaluation item has a full score of 10 points, with a scoring interval of 0.1, and the comprehensive score is the sum of the values ​​of each item.

[0094] From the results in Table 5, we can see that in rice products, 7 CFU / mL Lactobacillus reuteri INM3109 can significantly increase the p-coumaric acid content of the fermented mixed rice balls; in addition, it can also improve the sensory evaluation of the mixed rice balls, increase the aroma of the mixed rice balls, and improve the flavor and taste of the mixed rice balls, making the mixed rice balls fragrant and sweet and sour.

[0095] Example 5: Preparation of Braised Pork Rice Balls with Lactobacillus reuteri INM3109

[0096] The final concentration of Lactobacillus reuteri INM3109 was 10 7CFU / mL of the dosage was used to make braised pork rice balls. The fermented mixed rice and rice ball making method referred to Example 3. 70 g of the prepared mixed rice balls were placed on seaweed and flattened, and 30 g of braised meat was added. The balls were packaged and shaped, and refrigerated at 4°C. Another group was inoculated with NM4209 as the control group.

[0097] After the fermentation was completed, the p-coumaric acid content of the rice product was detected according to the method in Experimental Example 1, and professional appraisers were asked to conduct sensory evaluation on the flavor of the rice balls. The results are recorded in Table 6.

[0098] Table 6 p-Coumaric acid content after mixed rice fermentation and sensory evaluation results of rice balls

[0099]

[0100] Note: Each sensory evaluation item has a full score of 10 points, with a scoring interval of 0.1, and the comprehensive score is the sum of the values ​​of each item.

[0101] From the results in Table 6, we can see that inoculation of 10 7 CFU / mL Lactobacillus reuteri INM3109 was used to make braised pork rice balls, which can significantly increase the content of p-coumaric acid in fermented mixed rice products; in addition, it can also improve the sensory evaluation of the braised pork rice balls, increase the aroma of the braised pork rice balls, and improve the flavor and taste of the braised pork rice balls, making the braised pork rice balls fragrant, sweet and sour and delicious.

[0102] Balance test: Two compression tests: Use a P / 36R probe and a glass dish with an inner diameter of 90mm. After the rice is cooked, open the lid immediately and use a rice spoon to quickly break up the rice in the pot (avoiding the edge of the pot and 20mm from the bottom of the pot) in a clockwise direction and gently stir it evenly (complete within 10 seconds). Then take a sample from the broken part, weigh 87g (accurate to 0.5g) of rice and put it in the glass dish. Use a medicine spoon to spread the rice evenly and press it flat with the lid of the dish. Then use a standard weight of 1kg to place the lid of the dish and press it for 5s before removing it. Repeat three times and then remove the lid of the dish. Place the glass dish on the test bench and ensure that the probe is in the middle of the rice to start the test. Repeat the test 8 times. The results are recorded in Table 7

[0103] Table 7 Shelf life test of rice samples

[0104]

[0105] Based on the results of the above embodiments, the Lactobacillus reuteri INM3109 provided by the present invention is applied to the fermentation of rice products. On the basis of not changing the existing process, the p-coumaric acid content in the relevant rice products can be significantly increased, and the aroma and taste of the rice products can be improved, and the shelf life of the rice products can be significantly increased.

[0106] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which fall within the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A strain of Lactobacillus reuteri, characterized in that: Lactobacillus reuteri (Limosilactobacillus reuteri) INM3109 was deposited in Guangdong Provincial Microbiological Culture Collection Center on August 13, 2024, with the deposit number: GDMCC NO: 65002; the deposit address is: 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou.

2. A strain of Lactobacillus reuteri according to claim 1, characterized in that: The colony characteristics of Lactobacillus reuteri are as follows: after culturing on solid MRS plate medium for 48 hours, the colony diameter reaches 2 to 3 mm, the colonies are white, raised, round, with a smooth surface and neat edges.

3. A method for preparing Lactobacillus reuteri according to claim 1, characterized in that: Step 1: Isolation of lactic acid bacteria: Isolation and screening of lactic acid bacteria from yogurt soup samples, adding dairy products into a slurry, adding to sterile water, diluting the concentration to 10 5 -10 6 , the dairy products of different dilution concentrations were evenly spread on the solid MRS medium, and then cultured in an incubator at 37°C for 48 hours. Then, the white colonies on the solid MRS medium and the lactic acid bacteria with the correct morphology were selected for screening; Step 2: Lactic acid bacteria screening: The obtained lactic acid bacteria were cultured to the logarithmic growth phase, and then inoculated with 1% of the strain, and the final concentration of the strain was 1×10 6 cfu / mL, inoculated into modified MRS solution, placed in 37℃ for 3 days to obtain the fermentation liquid, and the content of p-coumaric acid was measured.

4. The method for preparing Lactobacillus reuteri according to claim 1, wherein: The formula of the improved MRS solution is as follows: weigh 10g of peptone, 8g of beef extract powder, 4g of yeast extract powder, 20g of glucose, 2g of dipotassium hydrogen phosphate, 2g of diammonium hydrogen citrate, 5g of sodium acetate, 0.2g of magnesium sulfate, 0.04g of manganese sulfate, and 1g of Tween 80, dissolve in 1000mL of distilled water, sterilize at 0.1MPa and 121℃ for 15min; add 0.1g of tyrosine after cooling.

5. A use of Lactobacillus reuteri according to claim 1, characterized in that: Production application: According to the production process of rice products, the inoculation amount in the fermented rice product liquid is 10 4 -10 8 cfu / mL of Lactobacillus reuteri, the fermentation time was 3d and the fermentation temperature was 37℃, and then arginine, ethyl caprylate and the sensory quality of the fermentation broth were detected.

6. Use of the Lactobacillus reuteri according to claim 1 in rice products.

7. An application of the Lactobacillus reuteri according to claim 1 for effectively increasing the production of higher concentrations of p-coumaric acid in rice products after fermentation.

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