Phytobacterium plantarum JM065 and application thereof

Abstract

The invention discloses a plant lactobacillus JM065 and application thereof, and belongs to the technical field of microorganisms. The lactobacillus plantarum JM065 is preserved in Guangdong Province Microbial Culture Collection Center, Guangzhou, the preservation date is April 26, 2024, and the preservation number is GDMCC (China General Microbiological Culture Collection Center) NO: 64565. The lactobacillus plantarum JM065 has the advantages that the lactobacillus plantarum JM065 is preserved in Guangdong Province, Guangzhou, the preservation date is April 26, 2024; according to the preparation method, the fermented blueberry juice which is soft in acidity, high in total phenol content and high in oxidation resistance is prepared by combining enzymolysis of four enzymes in a specific ratio, fermentation of plant lactobacillus JM065 and ultrasonic-assisted fermentation technologies before and after fermentation. The field of functional products can be enriched, and a theoretical basis can be provided for research and development of relevant healthy food and health care products such as blueberries to a certain extent.

Description

Technical Field

[0001] The present invention relates to a Lactiplantibacillus plantarum JM065 and its application, belonging to the field of microbial technology. Background Art

[0002] Blueberry juice has attracted much attention due to its rich nutritional value and health benefits. Bioactive substances such as blueberry polyphenols show great potential in anti-aging research. However, most of the polyphenol substances in blueberries exist in the form of glycosides, so their biological activities cannot be well exerted, which limits the improvement of product quality and market promotion. In addition, during traditional processing, problems such as loss of active ingredients, instability of taste and flavor, and precipitation and stratification caused by pulp particles and colloidal substances are likely to occur, affecting the uniformity and sensory quality of the product. Moreover, when functional ingredients (such as probiotics) are added to blueberry juice, problems such as ingredient instability or incompatibility with the juice matrix are likely to occur, affecting the functionality and taste of the product.

[0003] In order to further improve the quality of blueberry juice, the stability of functional ingredients, their compatibility with the juice matrix, and their impact on taste are still technical difficulties. The enzymatic hydrolysis technology of the present invention can break the blueberry cell wall structure through specific enzymes, increase the juice yield, and release more active ingredients. The fermentation technology can produce more active metabolites through lactic acid bacteria fermentation, while improving the taste and stability of the juice. Due to its high efficiency and environmental friendliness, ultrasonic technology can assist in the processing of blueberry juice, promote the destruction of cell walls, release active ingredients, and improve the uniformity and stability of the juice. Therefore, it is necessary to prepare fermented blueberry juice with mild acidity, high total phenol content and high antioxidant activity by combining enzymatic hydrolysis and ultrasonic-assisted fermentation technology to improve the sour-sweet balance and aroma of blueberry juice, enhance the taste uniformity, and ensure the stability and effectiveness of functional ingredients. It can also provide a theoretical basis for the research and development of related healthy foods such as blueberries and promote the development of the functional food field. Summary of the Invention

[0004] The object of the present invention is to provide a Lactiplantibacillus plantarum JM065. The present invention uses this strain to ferment blueberry juice and evaluates the physicochemical properties of the fermented blueberry juice, and develops fermented blueberry juice with mild acidity, high total phenol content and high antioxidant activity.

[0005] At the same time, the object of the present invention is to provide an application of Lactiplantibacillus plantarum JM065 in the preparation of fermented juice.

[0006] Meanwhile, the purpose of the present invention is to provide a preparation method of fermented blueberry juice, which combines the enzymatic hydrolysis of four enzymes with a specific ratio, the fermentation of Lactiplantibacillus plantarum JM065, and the ultrasonic-assisted fermentation technology before and after fermentation, and obtains fermented blueberry juice with mild acidity, high total phenol content and high antioxidant activity.

[0007] Meanwhile, the purpose of the present invention is to provide a blueberry juice fermented by Lactiplantibacillus plantarum JM065.

[0008] Meanwhile, the purpose of the present invention is to provide the application of a blueberry juice fermented by Lactiplantibacillus plantarum JM065 in the preparation of health foods and health products.

[0009] Meanwhile, the purpose of the present invention is to provide a health food or health product, which is prepared by using the blueberry juice fermented by Lactiplantibacillus plantarum JM065 of the present invention.

[0010] To solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0011] Lactiplantibacillus plantarum JM065, which is preserved in the Guangdong Provincial Microbial Culture Collection Center, Guangzhou, with the preservation date of April 26, 2024 and the preservation number of GDMCC NO: 64565.

[0012] The application of Lactiplantibacillus plantarum JM065 in the preparation of fermented fruit juice, and the fruit juice includes blueberry juice.

[0013] A preparation method of fermented blueberry juice, comprising the following steps:

[0014] Step 1, prepare blueberry juice;

[0015] Step 2, enzymatic hydrolysis pretreatment: Pectinase, pectin lyase, cellulase and hemicellulase are added to the blueberry juice in a mass ratio of 2:1:2:1, the enzyme dosage is 0.1-0.5% of the weight of fresh blueberries, and the treatment conditions are incubation at 35-45 °C for at least 4 h and pH of 4.5; after the enzyme treatment, inactivate the enzyme, adjust the pH value of the blueberry juice after enzyme treatment to 4.3, adjust the soluble solid content of the blueberry juice after enzyme treatment to 13 °Brix, water bath at 85 °C for 15 min, and after cooling, obtain unfermented enzymatically hydrolyzed blueberry juice;

[0016] Step 3, preparation of blueberry juice fermented by Lactiplantibacillus plantarum JM065:

[0017] Lactiplantibacillus plantarum JM065 was added to unfermented enzymatically hydrolyzed blueberry juice at an inoculation amount of 1 wt%, and fermentation was carried out at 25 - 37 °C for 10 - 15 h. In addition, ultrasonic treatment was performed before and after fermentation; after the ultrasonic treatment was completed, Lactiplantibacillus plantarum JM065 - fermented blueberry juice was obtained.

[0018] In step one, the method for preparing blueberry juice was as follows: After washing the blueberries, they were mixed at a mass ratio of 1:2 of material to liquid, crushed using a blender, and then filtered through an 80 - mesh sieve to obtain fruit juice; the pH value of the blueberry juice was adjusted to 4.3, the soluble solid content of the blueberry juice was adjusted to 13 °Brix, and it was placed in a water bath at 85 °C for 15 min. After cooling, it was obtained.

[0019] The pH value of the blueberry juice was adjusted using 1 mol / L Na2CO3, and the soluble solid content of the blueberry juice was adjusted using glucose.

[0020] In step two, the method for inactivating the enzyme was: performing a 10 - min treatment in a boiling water bath.

[0021] In step three, the ultrasonic conditions were: the ultrasonic frequency was 15 - 45 kHz, the ultrasonic power was 50 - 100 W, the ultrasonic time was 1 - 4 min, and for every 10 s of ultrasonic treatment, it was stopped for 5 s.

[0022] Lactiplantibacillus plantarum JM065 - fermented blueberry juice obtained by a method for preparing fermented blueberry juice.

[0023] The application of Lactiplantibacillus plantarum JM065 - fermented blueberry juice in the preparation of healthy foods and health products.

[0024] A healthy food or health product prepared by using the Lactiplantibacillus plantarum JM065 - fermented blueberry juice of the present invention.

[0025] The present invention has the following beneficial effects:

[0026] Plant bioactive substances such as blueberry polyphenols show great potential in anti - aging research. However, most of the polyphenol substances in blueberries exist in the form of glycosides, so their biological activities cannot be well exerted. The probiotic Lactiplantibacillus plantarum JM065 of the present invention has the ability to secrete β - glucosidase during its growth and metabolism. This enzyme can convert polyphenol substances in glycoside form into aglycone form that is more easily absorbed and utilized by the body.

[0027] In this invention, Lactiplantibacillus plantarum JM065 (L. plantarum JM065) was selected as the research object. Then, this strain was used to ferment blueberry juice, and the physicochemical properties of the fermented blueberry juice (FBJ) were evaluated. A fermented blueberry juice with mild acidity, high total phenol content, and high antioxidant activity was developed. Through this research, the field of functional products can be enriched, and to a certain extent, a theoretical basis can be provided for the research and development of related healthy foods and health products such as blueberries. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a graph of β-glucosidase activity. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] The present invention will be further described below with reference to the accompanying drawings.

[0030] In the present invention, Lactiplantibacillus plantarum JM065 (L. plantarum JM065) was deposited with the Guangdong Provincial Culture Collection Center of Microorganisms, Guangzhou. The deposit date was April 26, 2024, and the deposit number was GDMCC NO: 64565.

[0031] Example 1

[0032] 1. Materials and Methods

[0033] 1.1 Preparation of Blueberry Juice

[0034] After washing the blueberries, they were mixed at a mass ratio of 1:2 (the material refers to fresh blueberries, and the liquid refers to water, preferably purified water, blueberry: water = 1:2). Then, a blender was used for crushing, and the juice was filtered through an 80-mesh sieve. Thereafter, the pH value of the blueberry juice was adjusted to 4.3 with 1 mol / L Na2CO3, and the soluble solids content of the blueberry juice was adjusted to 13 °Brix with glucose. It was placed in a water bath at 85 °C for 15 min, and after cooling, it was the unfermented blueberry juice (BJ).

[0035] Enzymatic pretreatment: Pretreat blueberry juice with pectinase, pectin lyase, cellulase and hemicellulase. The enzyme dosage is set at 0.1 - 0.5% (v / w) of the fresh fruit weight, and the treatment conditions are incubation at 35 - 45 °C for 4 h with a pH of 4.5. After enzyme treatment, all groups are treated in a boiling water bath for 10 min to inactivate the enzyme. Thereafter, the pH of the blueberry juice is adjusted to 4.3 with 1 mol / L Na2CO3, the soluble solids content of the blueberry juice is adjusted to 13 °Brix with glucose, and it is heated in a water bath at 85 °C for 15 min. After cooling, it is the unfermented enzymatically hydrolyzed blueberry juice (E - BJ).

[0036] Preparation of fermented blueberry juice with L.plantarum JM065

[0037] L.plantarum JM065 is inoculated into blueberry juice (BJ) and enzymatically hydrolyzed blueberry juice (E - BJ) at an inoculum size of 1 wt%, and fermented at 25 - 37 °C for 10 - 15 h. Samples are taken as blueberry juice at the end of fermentation (FBJ and E - FBJ). In addition, during fermentation, an ultrasonic - assisted fermentation technology is added. The ultrasonic frequency is 15 - 45 kHz, the ultrasonic power is 50 - 100 W, and the ultrasonic time is 1 - 4 min. Samples are taken as blueberry juice at the end of fermentation.

[0038] The fermentation parameters in Tables 1 and 2 below: The fermentation temperature is 28.9 °C and the fermentation time is 12.7 h.

[0039] The ultrasonic parameters in Table 2 below: ① Ultrasonic conditions before fermentation: The ultrasonic frequency is 25 kHz, the ultrasonic power is 50 W, and the ultrasonic time is 4 min (ultrasonic for 10 s, stop for 5 s, repeat 24 times); ② Ultrasonic conditions during fermentation: The ultrasonic frequency is 25 kHz, the ultrasonic power is 50 W, and it is ultrasonic for 1 min at 0 h, 3 h, 6 h and 9 h of fermentation respectively (ultrasonic for 10 s, stop for 5 s, repeat 6 times); ③ Ultrasonic conditions after fermentation: The ultrasonic frequency is 25 kHz, the ultrasonic power is 50 W, and the ultrasonic time is 4 min (ultrasonic for 10 s, stop for 5 s, repeat 24 times).

[0040] Table 1 Key enzymatic hydrolysis parameters of fermented blueberry juice

[0041]

[0042]

[0043] Table 2 Key fermentation parameters of fermented blueberry juice

[0044]

[0045]

[0046] 1.3 Evaluation of pH and viable cell count The pH value was determined with reference to the national standard "Methods for the determination of pH value of fruits and vegetables products" (GB / T 10468-1989), and the pH change of blueberry juice was detected by a pH meter. The viable cell count was determined with reference to the national standard "National food safety standard Microbiological examination of foods - Examination of lactic acid bacteria" (GB 4789.35-2023), and detected by the plate counting method.

[0047] 1.4 Determination of total phenol content

[0048] The total phenol content was determined by a spectrophotometer with reference to the group standard "Determination of total polyphenol content in plant extracts and their products - Spectrophotometry" (T / AHFIA005-2018).

[0049] 1.5 Total antioxidant capacity

[0050] The total antioxidant capacity (T-AOC) detection kit was used to determine the total antioxidant capacity of blueberry juice.

[0051] 1.6 β-Glucosidase activity

[0052] 1 mL of fermented blueberry juice was mixed evenly with 1.25 mL of pNPG (1 mmol / L) and 3.75 mL of citrate-phosphate buffer (pH 5.0), and then reacted in a water bath at 40 °C for 30 min. After the reaction was completed, 5 mL of Na2CO3 (1 mol / L) was added to terminate the reaction. The absorbance of the reaction solution was measured at 400 nm, which was the concentration of the product pNP. The β-glucosidase activity was defined as the amount of enzyme required to catalyze the formation of 1 μmol of pNP within 1 min under the condition of 40 °C.

[0053] 1.7 Determination of organic acid content

[0054] The organic acid content was determined by high performance liquid chromatography. (1) Determination of standards: Standard solutions of various organic acids were prepared at different concentrations and filtered through a 0.22 μm aqueous filter membrane, and qualitatively analyzed by high performance liquid chromatography. (2) Determination of samples: A certain amount of blueberry juice was taken into a centrifuge tube, and the supernatant was obtained after centrifugation (10000×g, 10 min). The obtained supernatant was filtered through a 0.22 μm aqueous filter membrane into an injection vial for on-machine detection. (3) Chromatographic analysis conditions: The chromatographic column was an Agilent Zorbax SB-Aq C18 column; isocratic elution was used, and the mobile phase was a mixture of phosphoric acid (97.5%) and methanol (2.5%), and the concentration of the phosphoric acid solution was 0.1%; the flow rate was 0.4 mL / min; the injection volume was 20 μL.

[0055] 2 Results and discussion

[0056] 2.1 Physicochemical and Functional Indices of Blueberry Juice Fermented by L. plantarum JM065

[0057] pH value and viable cell count are important indices for evaluating the fermentation ability and growth of L. plantarum JM065 in blueberry juice, and the results are shown in Table 3. Compared with the unfermented blueberry juice (Sample A), after the blueberry juice was fermented by L. plantarum JM065 (Sample B), the pH value decreased from 4.28 ± 0.01 to 3.75 ± 0.01, and the viable cell count in Sample B remained at 1.25×10 8 CFU / mL. In addition, the total phenol content and total antioxidant capacity both increased to a certain extent and were statistically significant. The total phenol content increased from 306.08 ± 6.67 mg / L before fermentation to 476.52 ± 9.75 mg / L after fermentation, an increase of 56%, and the total antioxidant capacity increased from 39.71 ± 2.24 U / mL before fermentation to 50.40 ± 0.99 U / mL after fermentation, an increase of 27%. Therefore, it was found that Sample B contained a higher total phenol content and had better antioxidant capacity.

[0058] In the study of fermented enzymatically hydrolyzed blueberry juice, compared with the directly fermented blueberry juice (Sample B), the fermented enzymatically hydrolyzed blueberry juice (Sample C-T) could significantly reduce the pH, increase the viable cell count, and both the total phenol content and total antioxidant capacity increased significantly. This shows that enzymatic treatment of blueberry juice before fermentation can release more fermentable sugars, thus producing more metabolites during the fermentation process. In addition, when fermenting single-enzyme hydrolyzed blueberry juice, there was no significant difference in the viable cell count. Through pH, total phenol content and antioxidant capacity, it was found that cellulase and pectinase hydrolyzed blueberry juice had a good effect on improving the fermentation performance, and pectin lyase and hemicellulase hydrolyzed blueberry juice could improve the fermentation performance to a certain extent.

[0059] Furthermore, by treating blueberry juice with multiple enzymes and then fermenting it, it was found that the pH value showed a trend of fermented single-enzyme hydrolyzed blueberry juice (samples C-F) > fermented double-enzyme hydrolyzed blueberry juice (samples G-J) > fermented triple-enzyme hydrolyzed blueberry juice (samples K-N) > fermented quadruple-enzyme hydrolyzed blueberry juice (samples O-T). The viable cell count, total phenols, and total antioxidant capacity all showed a trend of single-enzyme hydrolyzed blueberry juice (samples C-F) < fermented double-enzyme hydrolyzed blueberry juice (samples G-J) < fermented triple-enzyme hydrolyzed blueberry juice (samples K-N) < fermented quadruple-enzyme hydrolyzed blueberry juice (samples O-T). Fermenting blueberry juice after multi-enzyme treatment can significantly improve its fermentation performance, degrade the pH, and increase the viable cell count, total phenol content, and antioxidant capacity. This indicates that multi-enzyme treatment has a certain synergistic effect, and quadruple-enzyme treatment can significantly increase the viable cell count, total phenol content, and antioxidant capacity of fermented blueberry juice. Through the study of the ratio of the four enzymes, compared with samples O-S, sample T (pectinase: pectin lyase: cellulase: hemicellulase = 2:1:2:1) showed a lower pH value and significantly increased the viable cell count (3.67×10 9 CFU / mL), total phenol content (694.00 ± 1.00 mg / L), and antioxidant capacity (73.10 ± 0.62 U / mL).

[0060] Table 3 Fermentation index of blueberry juice under different enzymatic hydrolysis treatments

[0061]

[0062]

[0063] Note: Different letters in the same column represent significant differences (p < 0.05).

[0064] Ultrasonic treatment technology can promote the growth and proliferation of microbial cells and improve the overall efficiency of the fermentation process. This technology enhances the membrane permeability of cell membranes through cavitation effects and accelerates the release of intracellular enzymes. It can also improve the metabolic activity of active ingredients such as probiotics, shorten the processing time, thereby reducing the loss of active ingredients during processing, enhance the release of flavor substances, inhibit the growth of harmful bacteria, and improve the bioavailability of nutrients. In this study, ultrasonic treatment was carried out before, during, and after fermentation (Table 4). By comparing sample B with B1-B3 and sample T with T1-T3, it was found that ultrasonic treatment could improve the fermentation performance, specifically showing that during fermentation > before fermentation > after fermentation. The increase in total phenol content and antioxidant capacity was most significant when ultrasonic technology was added during fermentation. In addition, compared with sample B2, quadruple-enzyme hydrolyzed pretreated blueberry juice with ultrasonic-assisted fermentation (sample T2) could significantly reduce the pH value of fermented blueberry juice and increase the viable cell count, total phenol content, and antioxidant capacity.

[0065] Compared with the fermentation without ultrasound and single ultrasound treatment, the combined ultrasound treatment and fermentation (B4 - B7; T4 - T7) significantly reduced the pH value of the fermented blueberry juice, and significantly increased the viable cell count, total phenol content and antioxidant capacity, significantly improving the fermentation performance of Lactiplantibacillus plantarum JM065 in blueberry juice, specifically manifested as ultrasound before and after fermentation > ultrasound before, during and after fermentation > ultrasound before and during fermentation > ultrasound during and after fermentation. In addition, compared with sample B6, the four - enzyme hydrolysis pretreatment of blueberry juice and ultrasound treatment before and after fermentation (sample T6) could significantly reduce the pH value of the fermented blueberry juice, and increase the viable cell count, total phenol content and antioxidant capacity.

[0066] Table 4 Fermentation index of blueberry juice under different hydrolysis and ultrasound treatments

[0067]

[0068]

[0069] Note: Different letters in the same column represent significant differences (p < 0.05).

[0070] 2.2 Probiotic β - glucosidase activity

[0071] Probiotics produce β - glucosidase during metabolism, and the enzyme activity shown is evaluated as the amount of enzyme that hydrolyzes pNPG and releases pNP per unit time. In this experiment, the pNP standard was used as a standard reference, and the obtained standard curve equation was y = 0.0132x + 0.0753, with the correlation coefficient R 2 = 0.999, meeting the requirements of subsequent experiments.

[0072] Through analysis, it was found that ( Figure 1 ) the β - glucosidase of sample B was significantly higher than that of sample A, indicating that fermentation could improve the β - glucosidase activity; the β - glucosidase of sample T was significantly higher than that of sample B, and the β - glucosidase of sample T6 was significantly higher than that of sample B6, indicating that fermentation after enzymatic hydrolysis pretreatment of blueberry juice could improve the β - glucosidase activity; the β - glucosidase of sample B6 was significantly higher than that of sample B, and the β - glucosidase of sample T6 was significantly higher than that of sample T, indicating that adding ultrasound technology before and after fermentation could significantly improve the β - glucosidase activity. In addition, four - enzyme hydrolysis pretreatment of blueberry juice and ultrasound - assisted treatment before and after fermentation (sample T6) could significantly improve the β - glucosidase activity of fermented blueberry juice.

[0073] 2.3 Organic acid content

[0074] Organic acids are important compounds in blueberries, which can affect the sensory properties of blueberry juice, such as flavor, color, and aroma. In this experiment, the contents of five organic acids (oxalic acid, malic acid, lactic acid, citric acid, and succinic acid) were determined, and the standard curve equations and correlation coefficients obtained using the standard products of oxalic acid, malic acid, lactic acid, citric acid, and succinic acid as references were as follows: y = 1798.3x - 1939.2, R 2 = 0.9991, y = 410.22x - 426.49, R 2 = 0.9994, y = 596.23x - 634.53, R 2 = 0.9992, y = 353.31x - 376.18, R 2 = 0.9993, y = 194.92x - 208.34, R 2 = 0.9991, meeting the requirements of subsequent experiments. The changes in the contents of the five organic acids before and after fermentation are shown in Table 5. Compared with sample A, the contents of oxalic acid, malic acid, and citric acid in sample B decreased to a certain extent, and there were significant differences (p < 0.05), which were 1.085 ± 0.003 mg / mL, 2.047 ± 0.007 mg / mL, and 3.115 ± 0.014 mg / mL, respectively. The contents of succinic acid and lactic acid increased significantly (p < 0.05), reaching 1.718 ± 0.017 mg / mL and 5.623 ± 0.102 mg / mL after fermentation, respectively, indicating that fermentation with L. plantarum JM065 can reduce the contents of organic acids with stronger acidity (i.e., oxalic acid, malic acid, and citric acid), while increasing the contents of organic acids with milder acidity (i.e., succinic acid and lactic acid), improving the flavor and taste of blueberry juice.

[0075] Compared with sample B, the oxalic acid, malic acid, and citric acid in sample T decreased significantly, while the lactic acid and succinic acid increased significantly. Compared with sample B6, sample T6 showed the same change trend, indicating that fermentation after enzymatic pretreatment of blueberry juice can reduce the contents of organic acids with stronger acidity and increase the contents of organic acids with milder acidity; compared with sample B, the oxalic acid, malic acid, and citric acid in sample B6 decreased significantly, while the lactic acid and succinic acid increased significantly. Compared with sample T, sample T6 showed the same change trend, indicating that adding ultrasonic technology before and after fermentation can significantly reduce the contents of organic acids with stronger acidity and increase the contents of organic acids with milder acidity; in addition, four-enzyme enzymatic pretreatment of blueberry juice and ultrasonic treatment before and after fermentation (sample T6) were the most significant in reducing the contents of organic acids with stronger acidity and increasing the contents of organic acids with milder acidity.

[0076] Table 5 Changes in the contents of five organic acids before and after fermentation

[0077]

[0078] Note: Different letters in the same column represent significant differences (p < 0.05).

[0079] As described above, after optimization, the preparation method of L. plantarum JM065 fermented blueberry juice in this example is as follows: Wash the blueberries and mix them in a mass ratio of 1:2 of material to liquid, then use a blender to crush them, and then filter through an 80-mesh sieve to obtain the juice. Then, adjust the pH value of the blueberry juice to 4.3 with 1 mol / L Na2CO3, adjust the soluble solid content of the blueberry juice to 13 °Brix with glucose, and water bath at 85 °C for 15 min. After cooling, it is the unfermented blueberry juice (BJ).

[0080] Enzymatic hydrolysis pretreatment: Pretreat the blueberry juice with pectinase, pectin lyase, cellulase and hemicellulase (pectinase:pectin lyase:cellulase:hemicellulase = 2:1:2:1, mass ratio), the enzyme dosage is set to 0.3% (v / w) of the fresh fruit weight, and the treatment conditions are incubation at 40 °C for 4 h and pH of 4.5. After enzyme treatment, all groups are treated in a boiling water bath for 10 min to inactivate the enzyme. Then, adjust the pH value of the blueberry juice to 4.3 with 1 mol / L Na2CO3, adjust the soluble solid content of the blueberry juice to 13 °Brix with glucose, and water bath at 85 °C for 15 min. After cooling, it is the unfermented enzymatically hydrolyzed blueberry juice (E-BJ).

[0081] Preparation of L. plantarum JM065 fermented blueberry juice:

[0082] Add L. plantarum JM065 to the unfermented enzymatically hydrolyzed blueberry juice (E-BJ) at an inoculation amount of 1 wt%, ferment at 28.9 °C for 12.7 h, and sample the blueberry juice at the end of fermentation (E-FBJ). In addition, ultrasonic treatment is carried out before and after fermentation. The ultrasonic conditions before fermentation are: ultrasonic frequency is 25 kHz, ultrasonic power is 50 W, and ultrasonic time is 4 min (ultrasonic for 10 s, stop for 5 s, repeat 24 times); the ultrasonic conditions after fermentation are: ultrasonic frequency is 25 kHz, ultrasonic power is 50 W, and ultrasonic time is 4 min (ultrasonic for 10 s, stop for 5 s, repeat 24 times). After ultrasonic treatment, sample the blueberry juice at the end of fermentation, that is, obtain the L. plantarum JM065 fermented blueberry juice of this example.

[0083] Application of L. plantarum JM065 in this example in the preparation of fermented blueberry juice.

[0084] L. plantarum JM065 fermented blueberry juice obtained by the preparation method of a fermented blueberry juice in this example.

[0085] Application of the L. plantarum JM065 fermented blueberry juice in this example in the preparation of health foods and health products.

[0086] A health food or health product is prepared by fermenting blueberry juice with Lactiplantibacillus plantarum JM065 of this embodiment.

[0087] Example 2

[0088] The difference between this example and Example 1 is only that: during enzymatic hydrolysis pretreatment, the enzyme dosage is set to 0.1% (v / w) of the fresh fruit weight, and the treatment condition is incubation at 35 °C for 5 h.

[0089] When fermenting blueberry juice, fermentation is carried out at 25 °C, and the fermentation time is 15 h; the ultrasonic frequency is 15 kHz, the ultrasonic power is 80 W, and the ultrasonic time before and after fermentation is 1 min.

[0090] Example 3

[0091] The difference between this example and Example 1 is only that: during enzymatic hydrolysis pretreatment, the enzyme dosage is set to 0.5% (v / w) of the fresh fruit weight, and the treatment condition is incubation at 45 °C for 4.1 h.

[0092] When fermenting blueberry juice, fermentation is carried out at 37 °C, and the fermentation time is 10 h; the ultrasonic frequency is 45 kHz, the ultrasonic power is 100 W, and the ultrasonic time before and after fermentation is 2 min.

[0093] Example 4

[0094] The difference between this example and Example 1 is only that: during enzymatic hydrolysis pretreatment, the enzyme dosage is set to 0.2% (v / w) of the fresh fruit weight, and the treatment condition is incubation at 40 °C for 4.2 h.

[0095] When fermenting blueberry juice, fermentation is carried out at 30 °C, and the fermentation time is 13 h; the ultrasonic frequency is 30 kHz, the ultrasonic power is 70 W, and the ultrasonic time before and after fermentation is 3 min.

[0096] Example 5

[0097] The difference between this example and Example 1 is only that: during enzymatic hydrolysis pretreatment, the enzyme dosage is set to 0.4% (v / w) of the fresh fruit weight, and the treatment condition is incubation at 37 °C for 4 h.

[0098] When fermenting blueberry juice, fermentation is carried out at 35 °C, and the fermentation time is 12 h; the ultrasonic frequency is 40 kHz, the ultrasonic power is 90 W, and the ultrasonic time before and after fermentation is 4 min.

[0099] The above are only the preferred embodiments of the present invention. It should be noted that: for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can still be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. Lactiplantibacillus plantarum JM065, characterized in that, The Lactiplantibacillus plantarum is deposited in the Guangdong Microbial Culture Collection Center, Guangzhou, with the deposit date of April 26, 2024 and the deposit number of GDMCC NO: 64565.

2. Use of Lactiplantibacillus plantarum JM065 according to claim 1 in the preparation of fermented fruit juice, characterized in that, The fruit juice includes blueberry juice.

3. A method for preparing fermented blueberry juice, characterized in that, It includes the following steps: Step 1, prepare blueberry juice; Step 2, enzymatic hydrolysis pretreatment: Pectinase, pectin lyase, cellulase and hemicellulase are added to the blueberry juice in a mass ratio of 2:1:2:1, the enzyme dosage is 0.1-0.5% of the weight of fresh blueberries, and the treatment conditions are incubation at 35-45 °C for at least 4 h and a pH of 4.5; after the enzyme treatment, inactivate the enzyme, adjust the pH value of the enzyme-treated blueberry juice to 4.3, adjust the soluble solids content of the enzyme-treated blueberry juice to 13 °Brix, and perform a water bath at 85 °C for 15 min. After cooling, the unfermented enzymatically hydrolyzed blueberry juice is obtained; Step 3, preparation of Lactiplantibacillus plantarum JM065-fermented blueberry juice: Lactiplantibacillus plantarum JM065 is added to the unfermented enzymatically hydrolyzed blueberry juice at an inoculation amount of 1 wt%, and fermentation is carried out at 25-37 °C for 10-15 h. In addition, ultrasonic treatment is performed before and after fermentation; after the ultrasonic treatment is completed, the Lactiplantibacillus plantarum JM065-fermented blueberry juice is obtained.

4. The preparation method of a fermented blueberry juice according to claim 3, characterized in that, In Step 1, the preparation method of blueberry juice is as follows: After washing the blueberries, mix them in a mass ratio of 1:2 of solid to liquid, use a pulper to crush them, and then filter them through an 80-mesh sieve to obtain the fruit juice; adjust the pH value of the blueberry juice to 4.3, adjust the soluble solids content of the blueberry juice to 13 °Brix, perform a water bath at 85 °C for 15 min, and after cooling, it is obtained.

5. The preparation method of a fermented blueberry juice according to claim 3 or 4, characterized in that Adjusting the pH value of the blueberry juice is carried out by using 1 mol / L Na2CO3, and adjusting the soluble solids content of the blueberry juice is carried out by using glucose.

6. The preparation method of a fermented blueberry juice according to claim 3, wherein, In Step 2, the method for inactivating the enzyme is: Perform a 10-min treatment in a boiling water bath.

7. The preparation method of a fermented blueberry juice according to claim 3, characterized in that, In Step 3, the ultrasonic conditions are: The ultrasonic frequency is 15-45 kHz, the ultrasonic power is 50-100 W, the ultrasonic time is 1-4 min, and for every 10 s of ultrasonic treatment, stop for 5 s.

8. The Lactiplantibacillus plantarum JM065-fermented blueberry juice obtained by the method for preparing a fermented blueberry juice according to claim 3.

9. The application of the Lactiplantibacillus plantarum JM065-fermented blueberry juice according to claim 8 in the preparation of health foods and health products.

10. A health food or health product, characterized in that, It is prepared by using the Lactiplantibacillus plantarum JM065-fermented blueberry juice according to claim 8.

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