Preparation method and application of lactic acid bacteria fermented mung bean product

Abstract

The application discloses a preparation method and application of a lactic acid bacteria fermented mung bean product, and belongs to the field of food. The preparation method comprises the following steps: soaking mung beans in water, steaming and cooling the mung beans after draining water, and obtaining pretreated mung beans; obtaining a fermentation liquor by activating and fermenting Lactobacillus fermentum GBJ; mixing the pretreated mung beans and the fermentation liquor after preparing a sugar water by using white granulated sugar, and fermenting to obtain lactic acid bacteria fermented mung bean porridge. The lactic acid bacteria fermented mung bean porridge is separated into mung beans and the fermentation liquor, and then mixed with a sugar sol to prepare lactic acid bacteria fermented mung bean jelly. The method has simple and easily obtained raw materials, can be mass-produced, and provides more forms of mung bean products, and can meet diversified demands of consumers. The lactic acid bacteria fermented mung bean product prepared by the application has the effects of antioxidation and immunity enhancement, and provides a feasible method and direction for exertion of the effects of mung bean food.

Description

Technical Field

[0001] This invention relates to the food industry, and in particular to a method for preparing and applying a lactic acid bacteria fermented mung bean product. Background Technology

[0002] Mung beans are a traditional legume, rich in protein, as well as various vitamins, calcium, phosphorus, iron, and other nutrients. Besides their nutritional value, mung beans also possess medicinal value. The cooling properties of mung beans are found in the skin, while their detoxifying properties are found within the beans themselves. In summer, mung bean soup is a common household beverage for relieving heat, stimulating appetite, and detoxifying, making it suitable for all ages. While making mung bean soup or adding it as an ingredient to porridge are common methods, on the one hand, making soup results in significant nutrient loss, and adding it to porridge, due to the small quantity, makes it difficult to fully utilize the nutritional and medicinal value of mung beans. On the other hand, given that people frequently use dietary supplements to address sub-health conditions caused by stress from life and work, and considering that mung beans are a food with both nutritional and medicinal value, traditional methods of making soup are time-consuming and laborious, and making porridge doesn't fully utilize their medicinal value. Therefore, creating more diverse forms of mung bean products to expand the nutritional value of mung beans is essential. Summary of the Invention

[0003] The purpose of this invention is to provide a method for preparing and applying a lactic acid bacteria fermented mung bean product, in order to solve the problems existing in the prior art. The product obtained by fermenting mung beans with Lactobacillus GBJ helps to resist oxidation and enhance immunity, providing a method and direction for expanding the ways of eating and the application value of mung beans.

[0004] To achieve the above objectives, the present invention provides the following solution:

[0005] This invention provides a method for preparing lactic acid bacteria fermented mung bean porridge, comprising the following steps:

[0006] After soaking mung beans in water, drain them, steam them, and cool them to obtain pre-treated mung beans.

[0007] After activation and fermentation of Lactobacillus fermentum GBJ, a fermentation broth was obtained.

[0008] After white sugar is made into sugar water, it is mixed with the pretreated mung beans and the fermentation liquid to obtain lactic acid bacteria fermented mung bean porridge.

[0009] Preferably, the soaking time is 12 hours and the steaming time is 1 hour.

[0010] Preferably, the culture medium for activating or fermenting Lactobacillus GBJ comprises whey powder solution and apple juice, wherein the volume ratio of the whey powder solution to the apple juice is 85:15, and the mass concentration of the whey powder solution is 8%.

[0011] Preferably, the activation includes a first activation and a second activation. The first activation is as follows: the glycerol-preserved Lactobacillus fermentum GBJ is inoculated into a culture medium and cultured at 33°C for 24 hours. The second activation is as follows: the activated solution obtained after the first activation is inoculated into a culture medium at an inoculation amount of 3% and cultured at 33°C for 24 hours.

[0012] The fermentation process involves inoculating the activated solution obtained after the second activation into the culture medium at an inoculation rate of 3% and culturing at 33°C for 24 hours.

[0013] Preferably, the sugar syrup is obtained by mixing granulated sugar and water in a ratio of 10g:100g.

[0014] Preferably, based on the mass of the mung beans, the ratio of mung beans to sugar water is 30g:45mL, and the inoculum amount of the fermentation liquid is 7%.

[0015] Preferably, the mixed fermentation conditions are 33°C for 24 hours.

[0016] This invention also provides a method for preparing a lactic acid bacteria fermented mung bean jelly, comprising the following steps:

[0017] Separate the lactic acid bacteria fermented mung bean porridge prepared by the preparation method according to any one of claims 1-7, and obtain mung beans and fermentation liquid respectively;

[0018] Water, carrageenan, and white sugar are boiled, cooled, and then citric acid is added to prepare a gelling liquid. The gelling liquid is then pasteurized, and the mung beans and fermentation liquid are added and mixed evenly to obtain lactic acid bacteria fermented mung bean jelly.

[0019] Preferably, the mass ratio of the white sugar, carrageenan, and water is 4g:1.4g:100g;

[0020] The mass ratio of citric acid to water is 0.1g:100g;

[0021] The ratio of the adhesive, mung beans, and fermentation liquid is 52g:20g:28mL.

[0022] The present invention also provides the application of the lactic acid bacteria fermented mung bean porridge prepared by the preparation method described above, or the lactic acid bacteria fermented squeezable jelly prepared by the preparation method described above, in the preparation of health foods that help with antioxidation and enhance immunity.

[0023] The present invention discloses the following technical effects:

[0024] This invention utilizes Lactobacillus fermentum GBJ to ferment mung beans. It only requires white sugar as a carbon source for mixed fermentation to obtain fermented mung bean porridge or fermented mung bean jelly. Both of these products are convenient to carry and consume, providing consumers with greater convenience.

[0025] The fermented mung bean porridge or fermented mung bean jelly prepared by this invention expands the ways in which mung beans can be consumed, and the preparation method is simple and easy to operate, making it suitable for large-scale production.

[0026] In preparing fermented mung bean porridge or fermented mung bean jelly, this invention uses *Lactobacillus fermentum* GBJ, which produces a large amount of extracellular polysaccharides. These polysaccharides consist of eight components: fucose, rhamnose, arabinose, galactose, glucose, xylose, galacturonic acid, and guluronic acid (molar ratio 0.33:3.16:33.43:21.00:16.45:9.27:15.31:1.05). Due to the production of these specific polysaccharide components, the prepared fermented lactic acid bacteria product possesses antioxidant and immune-enhancing functions. Therefore, this invention provides a feasible method and direction for exploring the health benefits of mung beans. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 The effect of different inoculum amounts on the fermentation of mung bean porridge by lactic acid bacteria;

[0029] Figure 2 The effect of different amounts of added white sugar on lactic acid bacteria fermented mung bean porridge;

[0030] Figure 3 The effect of different fermentation temperatures on lactic acid bacteria fermentation of mung bean porridge;

[0031] Figure 4 The effect of different fermentation times on lactic acid bacteria fermented mung bean porridge;

[0032] Figure 5 Results of antioxidant activity assay for mung bean porridge fermented with lactic acid bacteria; A: DPPH, B: ABTS + C: hydroxyl radical, D: FRAP; different letters represent significant differences between different groups of the same concentration (P < 0.05);

[0033] Figure 6This is a gel chromatogram of EPS; the red line in the figure represents the multi-angle laser light scattering signal (i.e., LS, unit is V), the blue line represents the difference signal (i.e., RI, unit is RIU), and the black line represents the molecular weight fitted by the two signals.

[0034] Figure 7 The monosaccharide composition ion chromatograms of monosaccharide standards (A) and EPS (B) are shown.

[0035] Figure 8 Results of in vitro antioxidant activity assay for EPS; A: DPPH, B: ABTS + C: hydroxyl radical, D: FRAP; different letters represent significant differences between different groups of the same concentration (P < 0.05);

[0036] Figure 9 The effect of different concentrations of EPS on the viability of RAW264.7 cells; different letters represent significant differences (P < 0.05);

[0037] Figure 10 The effect of different concentrations of EPS on the phagocytic rate of neutrophils in RAW264.7 cells; different letters represent significant differences (P < 0.05);

[0038] Figure 11 The effect of different concentrations of EPS on nitric oxide (NO) release in RAW264.7 cells; different letters represent significant differences (P < 0.05);

[0039] Figure 12 The effect of different concentrations of EPS on acid phosphatase activity in RAW264.7 cells; different letters represent significant differences (P < 0.05);

[0040] Figure 13 The effect of different concentrations of EPS on cytokine secretion by RAW264.7 macrophages; different letters represent significant differences (P < 0.05);

[0041] Figure 14 The effect of carrageenan addition on the number of lactic acid bacteria and sensory score of lactic acid bacteria fermented mung bean jelly; different letters represent significant differences (P < 0.05);

[0042] Figure 15 The effect of the amount of fermentation broth added on the number of lactic acid bacteria and sensory scores of lactic acid bacteria fermented mung bean jelly; different letters represent significant differences (P < 0.05);

[0043] Figure 16 The effect of citric acid addition on the number of lactic acid bacteria and sensory score of lactic acid bacteria fermented mung bean jelly; different letters represent significant differences (P < 0.05);

[0044] Figure 17 The effect of added white sugar on the number of lactic acid bacteria and sensory score of lactic acid bacteria fermented mung bean jelly; different letters represent significant differences (P < 0.05);

[0045] Figure 18 The response curve shows the effect of the interaction between the amount of carrageenan added and the amount of fermentation broth added on the overall score of the lactic acid bacteria fermented mung bean squeezable jelly production process.

[0046] Figure 19 The response curve shows the effect of the interaction between the amount of carrageenan and the amount of citric acid added on the overall score of the production process of lactic acid bacteria fermented mung bean jelly.

[0047] Figure 20 The response curve shows the effect of the interaction between the amount of fermentation broth added and the amount of white sugar added on the overall score of the lactic acid bacteria fermented mung bean squeezable jelly production process.

[0048] Figure 21 The response curve shows the effect of the interaction between the amount of carrageenan and the amount of white sugar on the overall score of the production process of lactic acid bacteria fermented mung bean jelly.

[0049] Figure 22 The response curve shows the effect of the interaction between the amount of fermentation broth added and the amount of citric acid added on the overall score of the lactic acid bacteria fermented mung bean squeezable jelly production process.

[0050] Figure 23 The response curve is the effect of the interaction between the amount of citric acid added and the amount of white sugar added on the overall score of the production process of lactic acid bacteria fermented mung bean squeezable jelly.

[0051] Figure 24 Results of antioxidant activity assay for lactic acid bacteria fermented mung bean squeezable jelly; A: DPPH, B: ABTS + C: hydroxyl radical, D: FRAP; different letters represent significant differences between different groups of the same concentration (P < 0.05). Detailed Implementation

[0052] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0053] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0054] The Lactobacillus fermentum GBJ involved in the following examples has been disclosed in the literature "Study on the structure, antioxidant and immune activity of Lactobacillus fermentum GBJ capsular polysaccharide" and is stored in the laboratory of the College of Food Science and Technology, Heilongjiang Bayi Agricultural Reclamation University. The public can obtain it from the above-mentioned institution.

[0055] Example 1: Preparation method of lactic acid bacteria fermented mung bean porridge

[0056] 1. Process flow of lactic acid bacteria fermented mung bean porridge

[0057] 1.1 Culture medium preparation

[0058] Mix 8% whey powder solution with apple juice at a volume ratio of 85:15, heat to dissolve, and dispense into containers. Sterilize at 108℃ for 15 minutes and set aside.

[0059] 1.2 Activation of microbial strains

[0060] Microbial activation process: First activation → Second activation → Inoculation and fermentation. The specific steps are as follows:

[0061] The glycerol-preserved Lactobacillus fermentum GBJ was inoculated into the culture medium and cultured at 33°C for 24 hours for the first activation; it was then inoculated at 3% (v / v) and cultured at 33°C for 24 hours for the second activation; finally, it was inoculated at 3% (v / v) and fermented at 33°C for 24 hours.

[0062] 1.3 Fermentation Process Flow

[0063] The specific steps of the lactic acid bacteria fermentation process for mung bean porridge are as follows:

[0064] Raw material pretreatment: Select high-quality mung beans with bright color and uniform particle size, wash and soak for 12 hours, drain the water and steam for 1 hour, then cool.

[0065] For bottling the sugar syrup: Add 10% white sugar based on 100g of drinking water. Add sugar syrup according to a mung bean:sugar syrup ratio of 30:45 (g:mL).

[0066] Inoculation and fermentation: After two activations, Lactobacillus fermentum GBJ is inoculated at a rate of 7% (m / v) based on the weight of mung beans, and fermented at 33℃ for 24 hours to obtain the finished product of lactic acid bacteria fermented mung bean porridge.

[0067] 2. Results of a single-factor experiment on lactic acid bacteria fermented mung bean porridge

[0068] 2.1 Effects of different inoculum sizes on the fermentation of mung bean porridge with lactic acid bacteria

[0069] Depend on Figure 1It was observed that with increasing inoculum size, acidity increased, sugar content decreased, and sensory scores initially rose and then fell. When the inoculum size was below 10%, fermentation was incomplete, resulting in a weak flavor in the fermented mung bean porridge, with poor texture and mouthfeel. At an inoculum size of 10%, the lactic acid bacteria multiplied rapidly, producing more flavor compounds while simultaneously consuming sugars to generate organic acids and other flavor metabolites, resulting in a balanced sweet and sour taste and the highest sensory score. Excessive inoculum size led to excessive metabolites and high acidity, negatively impacting the mouthfeel. Therefore, orthogonal experiments were conducted with inoculum sizes of 7%, 10%, and 13%.

[0070] 2.2 Effects of different amounts of added white sugar on lactic acid bacteria fermentation of mung bean porridge

[0071] White sugar is a traditional sweetener. Adding it appropriately when making porridge can improve the taste, mask any unpleasant odors, and enhance the quality. Figure 2 It was found that when 4% white sugar was added, the taste of the lactic acid bacteria fermented mung bean porridge was unpleasant. This was because the amount added was too small to completely mask the sour taste, resulting in a low sensory score. When 10% white sugar was added, the sensory score was the highest, with a delicate texture and a balanced sweet and sour taste. As the amount added increased, the taste became sweeter, and the sensory score decreased. When the amount added was 16%, the sweetness was excessive, significantly reducing the quality, and the sensory score dropped below 80 points. Therefore, orthogonal experiments were conducted with white sugar addition amounts of 7%, 10%, and 13%.

[0072] 2.3 Effects of different fermentation temperatures on lactic acid bacteria fermentation of mung bean porridge

[0073] Depend on Figure 3 It was found that the sensory score of fermented mung bean porridge with lactic acid bacteria first increased and then decreased with increasing fermentation temperature. The sensory score gradually increased between 29 and 33℃, reaching its highest at 33℃. This is because if the fermentation temperature is too low, the activity of the bacteria is affected, resulting in slow growth and development of the lactic acid bacteria, insufficient acidity, and poor taste; if the fermentation temperature is too high, the activity of the bacteria is affected, leading to over-fermentation and off-flavors. Therefore, orthogonal experiments were conducted at fermentation temperatures of 31℃, 33℃, and 35℃.

[0074] 2.4 Effects of different fermentation times on lactic acid bacteria fermentation of mung bean porridge

[0075] Different fermentation times result in different amounts of acid produced during lactic acid fermentation, thus affecting the product flavor. Figure 4It was found that as the fermentation time was extended from 12 hours to 24 hours, the sensory score gradually increased, reaching its highest point at 24 hours. This indicates that insufficient fermentation time leads to poor fermentation results, and the product lacks the original flavor of lactic acid bacteria fermented mung bean porridge. With increasing fermentation time, acid production increases, and the fermentation effect improves. After fermentation time exceeded 24 hours, the sensory score significantly decreased. This is because excessive fermentation time leads to nutrient consumption, reduced sweetness, excessive acidity, and the production of unpleasant flavors, affecting the taste. Therefore, orthogonal experiments were conducted with fermentation times of 18 hours, 24 hours, and 30 hours.

[0076] 2.5 Results and Analysis of Orthogonal Experiments

[0077] Based on the single-factor experiments, inoculum amounts of 7%, 10%, and 13%, white sugar additions of 7%, 10%, and 13%, fermentation temperatures of 31℃, 33℃, and 35℃, and fermentation times of 18h, 24h, and 30h were selected. An orthogonal experiment L9(3) was then set up using sensory scores as the evaluation index. 4 The results of the orthogonal design and experiment are shown in Table 1.

[0078] Table 1. Factors and levels in the orthogonal experiment for optimizing the fermentation process of mung bean porridge using lactic acid bacteria.

[0079]

[0080] The range analysis in Table 1 shows that the influence of the four factors on the sensory score of lactic acid bacteria fermented mung bean porridge is in the order of C > B > D > A, i.e., fermentation temperature > amount of added white sugar > fermentation time > inoculum size. Comparing the ranges, the optimal levels for each factor are determined, and the best combination is A1B2C2D2. This means the optimal fermentation conditions for lactic acid bacteria fermented mung bean porridge are an inoculum size of 7%, an added white sugar amount of 10%, a fermentation temperature of 33℃, and a fermentation time of 24 hours.

[0081] 3. Physicochemical properties, microbiological indicators, and antioxidant activity analysis of lactic acid bacteria fermented mung bean porridge

[0082] 3.1 Physicochemical index testing

[0083] pH value: Measured using a pH meter.

[0084] Sugar content: Measured using a handheld saccharimeter.

[0085] Acidity: Determined in accordance with GB 5009.239-2016 "National Food Safety Standard - Determination of Acidity in Food".

[0086] 3.2 Microbiological Indicator Methods

[0087] Lactic acid bacteria were counted according to GB 4789.35—2023 "Microbiological Examination of Food - Examination of Lactic Acid Bacteria".

[0088] 3.3 Antioxidant methods

[0089] 3.3.1 Determination of DPPH free radical scavenging rate

[0090] Take 2 mL of sample solution and mix thoroughly with 2 mL of DPPH-ethanol solution (0.1 mmol / L). React at room temperature in the dark for 30 min, and measure the absorbance at 517 nm (A1). Simultaneously measure the absorbance of 2 mL of sample solution and 2 mL of distilled water (A2), and the absorbance of 2 mL of DPPH-ethanol solution and 2 mL of distilled water (A0). Using Vc as a control, calculate the DPPH free radical scavenging rate according to the following formula:

[0091]

[0092] 3.3.2 ABTS + Free radical scavenging rate determination

[0093] A 2.45 mmol / L potassium persulfate solution and a 7 mmol / L ABTS solution were mixed in a 1:1 volume ratio and incubated at room temperature in the dark for 12–16 hours. The mixture was then diluted with anhydrous ethanol. ABTS was obtained when the absorbance at 734 nm stabilized at 0.70 ± 0.02. + Working solution. Take 1 mL of sample solution and mix it with 4 mL of ABTS. + The working solution was thoroughly mixed and reacted at room temperature in the dark for 6 min. The absorbance was measured at 734 nm (A1). Simultaneously, the absorbance of 1 mL of sample solution and 4 mL of anhydrous ethanol was measured (A2), and the absorbance of 1 mL of anhydrous ethanol and 4 mL of ABTS was measured. + The absorbance (A0) of the working solution, with vitamin C as a control, is used to calculate ABTS using the following formula. + Free radical scavenging rate:

[0094]

[0095] 3.3.3 Hydroxyl radical scavenging rate determination

[0096] Add 1 mL of FeSO4 (9 mmol / L), 1 mL of salicylic acid solution (9 mmol / L, 50% ethanol), 1 mL of sample solution, and 1 mL of H2O2 (0.03%) to a test tube. React in a water bath at 37°C for 1 h, cool to room temperature, and measure the absorbance at 510 nm (A1). Measure the absorbance using 1 mL of 50% ethanol solution instead of salicylic acid solution (A2), and use 1 mL of distilled water instead of sample solution (A0). Use vitamin C as a control. Calculate the hydroxyl radical scavenging rate using the following formula:

[0097]

[0098] 3.3.4 Determination of the reducing power of iron ions

[0099] Prepare FRAP working solution: Mix 25 mL of 300 mmol / L acetate-sodium acetate buffer (pH = 3.6), 2.5 mL of 10 mmol / L TPTZ HCl solution and 2.5 mL of 20 mmol / L FeCl3 solution thoroughly to obtain FRAP working solution.

[0100] Take 0.1 mL of FeSO4 solution of different concentrations, add 3 mL of FRAP working solution and 2 mL of distilled water, mix, and react at room temperature in the dark for 50 min. Measure the absorbance at 596 nm. Plot the standard curve with FeSO4 solution concentration on the x-axis and absorbance on the y-axis.

[0101] Take 1 mL of sample solution, add 3 mL of FRAP working solution and 2 mL of distilled water, mix thoroughly, and react at room temperature in the dark for 50 min. Measure the absorbance at 596 nm. Using Vc as a control, the reducing power is expressed as the FeSO4 equivalent concentration of the sample, converted from the absorbance value at 596 nm, and recorded as the FRAP value.

[0102] 4. Methods for measuring immune activity indicators

[0103] 4.1 Cell Culture

[0104] The revived RAW246.7 cells were cultured in DMEM high-glucose medium containing 10% fetal bovine serum and 1% penicillin / streptomycin, and incubated in a 37°C, 5% CO2 cell culture incubator. When the cells covered 80% of the bottom of the culture flask, they were passaged, and cells in the logarithmic growth phase were used for experiments.

[0105] 4.2 Cell viability assay

[0106] Cell viability was determined using the MTT assay. RAW264.7 cells (2 × 10⁻⁶) were... 5 Cells were seeded into 96-well plates at a density of 100 μL per well and cultured at 37°C and 5% CO2 for 24 h. The culture medium was then removed, and control groups (without EPS) and different concentrations of EPS (25, 50, 100, 200, 400, and 600 μg / mL) were added for 24 h. Wells without seeded cells were designated as blank groups. The culture medium was then removed, and 100 μL of MTT (1 mg / mL) was added to each well for 4 h. The supernatant was removed, and 100 μL of DMSO was added. After mixing thoroughly, the mixture was incubated at room temperature for 10 min, and the absorbance was measured at 490 nm using a microplate reader. Cell viability was calculated using the formula.

[0107]

[0108] 4.3 Assay of cellular phagocytic capacity

[0109] Cell phagocytic capacity was determined using the neutral red assay. Following the cell culture and grouping procedures described in section 4.2, a blank control group and an experimental group were established, with LPS (1 μg / mL) serving as the positive control. After culture, the supernatant was aspirated, and 100 μL of 0.1% neutral red staining solution was added to each well. The cells were incubated at 37°C for 2 hours, followed by washing three times with PBS. Then, 100 μL of cell lysis buffer was added to each well, and the absorbance was measured at 540 nm using a microplate reader. The neutral red phagocytic rate was calculated using the formula.

[0110]

[0111] 4.4 Acid phosphatase activity assay

[0112] Cell culture and grouping were performed according to the method in 4.3. After culture, the supernatant was aspirated, and 40 μL of 1% Triton X-100 was added to each well. The cells were incubated at 37°C for 10 min, and the absorbance was measured at 405 nm according to the kit instructions.

[0113]

[0114] 4.5 Measurement of Nitric Oxide (NO) and Cytokine Secretion Levels

[0115] Cells were grouped and cultured according to the method described in section 4.3. After culture, 50 μL of supernatant was aspirated from each well into a 96-well plate. The levels of NO and cytokines (TNF-α, IL-1β, IL-6, IL-10) secreted were determined according to the kit instructions.

[0116] 5. Results and Analysis

[0117] 5.1 Physicochemical Properties and Microbiological Indicators of Lactic Acid Bacteria Fermented Mung Bean Porridge

[0118] Lactic acid bacteria fermented mung bean porridge was prepared according to the optimal fermentation process conditions, and the physicochemical and microbiological indicators are shown in Table 2.

[0119] Table 2 Physicochemical and microbiological indicators of lactic acid bacteria fermented mung bean porridge before and after fermentation.

[0120]

[0121] 5.2 Antioxidant Activity Analysis of Lactic Acid Bacteria Fermented Mung Bean Porridge

[0122] 5.2.1 DPPH free radical scavenging activity

[0123] like Figure 5As shown in Figure A, lactic acid bacteria-fermented mung bean porridge exhibits a concentration-dependent, dose-dependent DPPH free radical scavenging effect. At a concentration of 1.0 μg / mL, the DPPH free radical scavenging rate of lactic acid bacteria-fermented mung bean porridge was 90.06 ± 0.65%; at a concentration of 5.0 μg / mL, the DPPH free radical scavenging rate was 98.62 ± 1.56%, higher than that of vitamin C (98.10 ± 0.15%). This result indicates that lactic acid bacteria-fermented mung bean porridge possesses excellent DPPH free radical scavenging activity.

[0124] 5.2.2 ABTS + Free radical scavenging activity

[0125] like Figure 5 As shown in Figure B, lactic acid bacteria fermented mung bean porridge has an effect on ABTS. + The scavenging effect of free radicals is dose-dependent. At a concentration of 5 μg / mL, lactic acid bacteria-fermented mung bean porridge showed an effect on ABTS. + The free radical scavenging rate was 43.17 ± 0.16%; while at a concentration of 25 μg / mL, lactic acid bacteria fermented mung bean porridge showed a significant effect on ABTS. + The free radical scavenging rate was 64.48 ± 0.42%. The results indicate that lactic acid bacteria fermented mung bean porridge exhibits good ABTS (Alternative Acid-Reduced Toxin) activity. + Free radical scavenging activity.

[0126] 5.2.3 Hydroxyl radical scavenging activity

[0127] like Figure 5 As shown in Figure C, the scavenging effect of lactic acid bacteria fermented mung bean porridge on hydroxyl radicals was dose-dependent. Within the concentration range of 10–50 μg / mL, the hydroxyl radical scavenging rate of lactic acid bacteria fermented mung bean porridge increased from 60.45 ± 0.38% to 68.88 ± 0.44%.

[0128] 5.2.4 Iron ion reducing ability

[0129] The effect of lactic acid bacteria fermentation on the iron-reducing capacity of mung bean porridge is as follows: Figure 5 As shown in Figure D, and compared with vitamin C as a positive control, the iron ion reducing power of the fermented mung bean porridge gradually increased in a dose-dependent manner with increasing concentration of lactic acid bacteria. Within the concentration range of 0.2 mg / mL to 1.0 mg / mL, the reducing agent (FRAP) of the fermented mung bean porridge increased from 0.301 ± 0.001 mmol / L to 0.469 ± 0.013 mmol / L. Within the same concentration range, the FRAP of vitamin C increased from 0.492 ± 0.002 mmol / L to 1.279 ± 0.022 mmol / L.

[0130] 5.3 Analysis of the polysaccharide structure and immunomodulatory activity of lactic acid bacteria fermented mung bean porridge

[0131] 5.3.1 After centrifuging fermented mung bean porridge at 4000 r / min for 10 min, the supernatant was collected, and 1 / 19 volume of 80% trichloroacetic acid was added. The mixture was precipitated at 4℃ for 8-9 h, then centrifuged at 10000 r / min for 10 min. The supernatant was collected, concentrated under reduced pressure at 55℃, and then 3 volumes of anhydrous ethanol were added. The mixture was allowed to stand overnight at 4℃. The resulting precipitate was dissolved in a small amount of distilled water, centrifuged at 4000 r / min for 5 min, dialyzed for 3 days, and then freeze-dried under vacuum to obtain crude polysaccharide (EPS).

[0132] 5.3.2 Absolute molecular weight analysis of EPS

[0133] The molecular weight of polysaccharides is closely related to their immunomodulatory activity. Detection results are as follows... Figure 6 As shown, the absolute molecular weight of EPS is 1.25 × 10⁻⁶. 6 Da.

[0134] 5.3.3 Monosaccharide Composition Analysis of EPS

[0135] Polysaccharides are composed of monosaccharide residues linked by glycosidic bonds; therefore, analyzing the monosaccharide composition is a crucial step in polysaccharide structure analysis. For example... Figure 7 As shown, comparison with the chromatograms of monosaccharide standards revealed that EPS is composed of eight polysaccharides: fucose, rhamnose, arabinose, galactose, glucose, xylose, galacturonic acid, and guluronic acid, with a molar ratio of 0.33:3.16:33.43:21.00:16.45:9.27:15.31:1.05. The highest content was arabinose at 33.43%, followed by galactose at 21.00%.

[0136] 5.4 Analysis of the in vitro antioxidant activity of EPS

[0137] 5.4.1 DPPH free radical scavenging activity

[0138] like Figure 8 As shown in Figure A, EPS exhibits a concentration-dependent, dose-dependent DPPH free radical scavenging effect. At a concentration of 1.0 mg / mL, the DPPH free radical scavenging rate of EPS was 27.19 ± 0.15%; while at a concentration of 5.0 mg / mL, the DPPH free radical scavenging rate was 68.42 ± 0.20%. These results indicate that EPS possesses good DPPH free radical scavenging activity.

[0139] 5.4.2 ABTS + Free radical scavenging activity

[0140] like Figure 8 As shown in Figure B, EPS corresponds to ABTS. +The scavenging effect of EPS on ABTS is dose-dependent. At a concentration of 1.0 mg / mL, EPS showed a significant effect on ABTS. + The free radical scavenging rate was 65.07 ± 0.52%; while at a concentration of 5.0 mg / mL, EPS showed a greater effect on ABTS. + The free radical scavenging activity was 95.44 ± 0.42%, similar to that of vitamin C (99.82 ± 0.08%). The results indicate that EPS exhibits good ABTS (absorbent polymerase chain reaction). + Free radical scavenging activity.

[0141] 5.4.3 Hydroxyl radical scavenging activity

[0142] like Figure 8 As shown in Figure C, the scavenging effect of EPS on hydroxyl radicals is dose-dependent. Within the concentration range of 1.0–5.0 mg / mL, the hydroxyl radical scavenging rate of EPS increased from 31.30 ± 0.73% to 54.44 ± 0.38%.

[0143] 5.4.4 Iron ion reducing ability

[0144] The effect of EPS on the reducing power of iron ions, such as Figure 8 As shown in Figure D, and compared with vitamin C as a positive control, the iron ion reducing power gradually increased with increasing EPS concentration in a dose-dependent manner. Within the concentration range of 1.0 mg / mL to 5.0 mg / mL, the FRAP of EPS increased from 0.125 ± 0.002 mmol / L to 0.215 ± 0.004 mmol / L. Within the same concentration range, the FRAP of vitamin C increased from 1.613 ± 0.037 mmol / L to 1.968 ± 0.012 mmol / L.

[0145] 5.5 Immunoactivity Analysis

[0146] 5.5.1 Cell Viability

[0147] like Figure 9 As shown, compared with the control group, the cell viability of RAW 264.7 cells treated with 25–400 μg / mL EPS was significantly enhanced (P < 0.05), and the cell viability reached a maximum of 149.68% at 400 μg / mL. However, as the concentration increased to 600 μg / mL, the cell viability significantly decreased (P < 0.05). For safety reasons, a concentration range of 25–400 μg / mL was selected for subsequent experiments.

[0148] 5.5.2 Phagocytosis

[0149] Increased phagocytic activity is a significant characteristic of activated macrophages; the phagocytic function of macrophages helps the body effectively resist and eliminate pathogens. For example... Figure 10As shown, the phagocytic rate of neutral red in the LPS group reached 144.92% of that in the control group, indicating that LPS significantly enhanced the phagocytic activity of RAW264.7 cells (P < 0.05). Compared with the control group, after treatment with 25–400 μg / mL EPS, the phagocytic rate of cells showed a trend of first increasing and then decreasing, with the neutral red phagocytic rate reaching its maximum value of (139.27 ± 3.16)% when the EPS concentration was 100 μg / mL.

[0150] 5.5.3 NO Emission

[0151] NO is a signaling molecule produced by macrophages during activation and plays an important role in host defense against pathogens. For example... Figure 11 As shown, compared with the control group, NO release from EPS exhibited a dose-dependent relationship within the range of 25–400 μg / mL. The NO release in the 400 μg / mL treatment group significantly increased (P < 0.05) to 15.20 μmol / L, which was 1.52 times that of the control group, but lower than that in the LPS group, thus avoiding inducing excessive inflammatory responses in macrophages. These results indicate that EPS can enhance immunomodulatory activity by stimulating NO release from RAW264.7 cells.

[0152] 5.5.4 Acid phosphatase activity

[0153] like Figure 12 As shown, both LPS and EPS treatments significantly enhanced the acid phosphatase activity of macrophages (P<0.05). The acid phosphatase activity index in the LPS group was 1.99 times that of the control group. In the EPS group, the acid phosphatase activity index first increased and then decreased with increasing concentration, reaching a maximum value of 1.41 at 200 μg / mL. These results indicate that EPS has a strong enhancing effect on the acid phosphatase activity of macrophages.

[0154] 5.5.5 Cytokine secretion levels

[0155] The balance of cytokines in the body is of great importance. Existing research has confirmed that while elevated levels of inflammatory factors in the body are beneficial for cell repair, excessively high levels of inflammatory factors can lead to inflammatory damage. Therefore, it is essential to maintain the secretion of inflammatory factors at normal levels to exert their optimal effects. Figure 13The effects of different concentrations of EPS on the secretion of immune cytokines by RAW 264.7 macrophages were investigated. RAW 264.7 cells were treated with EPS at concentrations of 50, 100, 200, and 400 μg / mL, and the secretion levels of TNF-α, IL-1β, IL-6, and IL-10 in the supernatant were measured. EPS treatment led to a concentration-dose effect of increased secretion of TNF-α, IL-1β, IL-6, and IL-10 in RAW264.7 cells (50–200 μg / mL), while the secretion of cytokines decreased at a concentration of 400 μg / mL. At an EPS concentration of 200 μg / mL, the secretion levels of TNF-α, IL-1β, IL-6, and IL-10 were 2.00, 1.69, 1.20, and 1.62 times that of the control group, respectively. These results indicate that EPS can exert an immunomodulatory effect by increasing cytokine secretion.

[0156] Example 2: Preparation method of lactic acid bacteria fermented mung bean squeezable jelly

[0157] 1. Process flow for lactic acid bacteria fermented mung bean jelly

[0158] The process of fermenting mung beans with lactic acid bacteria to make a squeezable jelly:

[0159] The mung beans and fermentation liquid in the lactic acid bacteria fermented mung bean porridge were separated using a filtration device and set aside. An appropriate amount of carrageenan and white sugar were added to 100 mL of drinking water, stirred until no obvious particles remained, heated to boiling for 5 minutes, cooled to 80°C, and then an appropriate amount of citric acid was added for adjustment. The resulting gel solution was pasteurized (90°C, 20 minutes) and dispensed into 150 mL sterile bottles. When the gel solution cooled to 46°C, mung beans and fermentation liquid were added to the gel solution according to a ratio of gel solution:mung beans:fermentation liquid of 52 g: 20 g: 28 mL. After mixing thoroughly, the mixture was dispensed into sterile bags, sealed, and immediately stored at 4°C to obtain the finished product.

[0160] 2. Product testing methods

[0161] 2.1 Determination of textural properties

[0162] Using the P / 0.5 gel strength probe of the TA-XT2i texture analyzer, the texture of the jelly was tested under the conditions of a test speed of 1.0 mm / s, a test distance of 50 mm, a trigger point load of 5 g, and a compression deformation of 30%. The texture indicators of the jelly, such as hardness, elasticity, cohesiveness, adhesiveness, and chewiness, were recorded.

[0163] 2.2 Microbiological Indicator Methods

[0164] Lactic acid bacteria were counted according to GB 4789.35—2023 "Microbiological Examination of Food - Examination of Lactic Acid Bacteria".

[0165] 3. Sensory evaluation criteria

[0166] Table 1 Sensory Evaluation Criteria for Lactic Acid Bacteria Fermented Mung Bean Squeezable Jelly

[0167]

[0168] 4. Results and Analysis

[0169] 4.1 Results of a single-factor experiment on lactic acid bacteria fermented mung bean jelly

[0170] 4.1.1 Effect of different amounts of carrageenan added on lactic acid bacteria fermented mung bean jelly

[0171] As shown in Table 3, with the increase of carrageenan addition, the hardness, elasticity, chewiness, and number of lactic acid bacteria in the jelly all showed an upward trend, while the adhesiveness showed a downward trend. The sensory scores first increased and then decreased, reaching a maximum of 82 points when the addition amount was 1.3%, which was significantly different from other groups (P < 0.05). The number of lactic acid bacteria in the lactic acid bacteria fermented mung bean absorbable jelly was higher than 1 × 10⁻⁶. 7 CFU·g -1 The quantity is greater than the number specified in the national standard (1×10). 6 CFU·g -1 )(See Figure 14 ).

[0172] Table 3. Effects of carrageenan addition on textural properties and color difference of lactic acid bacteria fermented mung bean jelly.

[0173]

[0174]

[0175] 4.1.2 Effect of different fermentation broth addition amounts on lactic acid bacteria fermentation of mung bean jelly

[0176] As shown in Table 4, with the increase of fermentation broth addition, the hardness, elasticity, and chewiness of the jelly decreased; the number of lactic acid bacteria and adhesiveness increased; the sensory score first increased and then decreased, reaching its maximum at an addition amount of 30%. When the addition amount was 20%–25%, the overall texture of the jelly was relatively firm; when the addition amount was 35%–40%, the overall texture of the jelly was relatively thin; and the sensory score was highest at an addition amount of 30% (see Table 4). Figure 15 In summary, the optimal fermentation broth addition rate is 30%.

[0177] Table 4. Effects of Fermentation Broth Addition Amount on Texture Properties and Color Difference of Lactic Acid Bacteria-Fermented Mung Bean Suckling Jelly

[0178]

[0179] 4.1.3 Effect of different citric acid addition amounts on lactic acid bacteria fermented mung bean jelly

[0180] Citric acid has functions such as flavor regulation, pH adjustment, and promoting the dissolution of colloidal components in food. Its dosage significantly affects the flavor, elasticity, and chewiness of jelly. Table 5 shows that with increasing citric acid content, the hardness, elasticity, adhesiveness, and chewiness of the jelly first increase and then decrease; sensory scores first increase and then decrease, reaching their maximum at an addition level of 0.1%. At an addition level of 0.06%–0.08%, the jelly is generally sweet; at 0.12%–0.14%, it is generally acidic; and at an addition level of 0.10%, the sensory score is highest, and the product has a suitable balance of sweet and sour (see Table 5). Figure 16 ).

[0181] Table 5. Effects of citric acid addition on textural properties and color difference of lactic acid bacteria-fermented mung bean absorbable jelly.

[0182]

[0183]

[0184] 4.1.4 Effect of different amounts of added white sugar on lactic acid bacteria fermented mung bean jelly

[0185] White sugar, as a sweetener, not only provides the carbon source needed for the life activities of lactic acid bacteria, but also buffers the acidic taste brought by organic acids. As shown in Table 6, with the increase of white sugar addition, the hardness, elasticity, and chewiness of the jelly decreased; the stickiness and the number of lactic acid bacteria increased; the sensory score first increased and then decreased, reaching its maximum at an addition of 4%. When the addition amount was 1% to 3%, the overall taste of the jelly was acidic; when the addition amount was 5%, the overall taste of the jelly was sweet; and when the addition amount was 4%, the overall taste of the jelly was more suitable, and the sensory score was the highest (see Table 6). Figure 17 In summary, the optimal amount of white sugar added is 4%.

[0186] Table 6. Effects of white sugar addition on textural properties and color difference of lactic acid bacteria fermented mung bean jelly.

[0187]

[0188] 4.2 Optimal Conditions for the Production Process of Lactic Acid Bacteria Fermented Mung Bean Suckable Jelly

[0189] 4.2.1 Box-Behnken Experiment Optimization of the Production Process of Lactic Acid Bacteria Fermented Mung Bean Suckable Jelly

[0190] Based on the results of the single-factor experiment, the Box-Behnken optimization experiment was conducted using Design-Expert 13 software. The levels and response values ​​are shown in Table 7. The binary regression equation was fitted and variance analysis was performed on the experiment.

[0191] Table 7. Experimental Design and Sensory Score Response Values ​​of Lactic Acid Bacteria Fermented Mung Bean Squeezable Jelly (Box-Behnken Experimental Design)

[0192]

[0193] The regression model showed highly significant differences (P < 0.01), while the lack-of-fit term was not significant (P > 0.05), indicating that the model fits well and can predict actual situations. R 2 =0.9542, R 2 Adj =0.9084, the two are basically close, indicating that the model can be used to optimize the production process of lactic acid bacteria fermented mung bean squeezable jelly. The linear terms A and B in the model are highly significant (P < 0.01). Except for the interaction terms C and D, which have a highly significant impact on the overall score of the response value (P < 0.01), the other interaction terms are not significant (P > 0.05). The quadratic terms A², B², C², and D² are all highly significant (P < 0.01). From the P-values, the influence of the four experimental factors on the overall score of the lactic acid bacteria fermented mung bean squeezable jelly production process is in the order of A = B > C > D. The stepwise regression yields the quadratic polynomial equation:

[0194] Y=88.80+5.28A-3.94B-0.7225C+0.2217D-2.00AB-0.3325AC-1.17AD+0.5800BC-0.5825BD+6.75CD-5.66A 2 -6.83B 2 -5.25C 2 -5.00D 2 See Table 8.

[0195] Table 8. Analysis of Variance in the Box-Behnken Experiment of Lactic Acid Bacteria-Fermented Mung Bean Squeezable Jelly

[0196]

[0197] 4.2.2 Response Surface Analysis of the Influence of Interactions of Various Factors on Sensory Scores of Lactic Acid Bacteria Fermented Mung Bean Suckable Jelly Production Process

[0198] Based on the obtained regression equation and the corresponding 3D response surface plot and contour plot, the interaction between any two of the four factors—carrageenan addition, fermentation broth addition, citric acid addition, and white sugar addition—can be visually observed on the quality of lactic acid bacteria fermented mung bean jelly, thus allowing for the determination of the optimal factor level range. A steeper slope in the 3D response surface plot indicates a greater impact on quality, and vice versa. Similarly, a contour plot with a shape closer to a circle indicates a less significant interaction between the two factors, while an ellipse indicates a significant interaction.

[0199] like Figures 18-23 As shown, the 3D response surface plots are all umbrella-shaped surfaces opening downwards, with maximum and minimum points on the surface. The response surface curve of CD is the steepest, with dense contour lines, indicating that the interaction between citric acid addition and sugar temperature has the most significant impact on the overall score of lactic acid bacteria fermented mung bean jelly. Next are the response surfaces of AB and AD, while the response surfaces of BD, BC, and AC are relatively flat with sparse contour lines, indicating that the interaction between BD, BC, and AC has a smaller impact on the overall score of lactic acid bacteria fermented mung bean jelly. The order of influence of the interaction on the overall score of lactic acid bacteria fermented mung bean jelly is: CD > AB > AD > BD > BC > AC.

[0200] 4.2.3 Optimization Results and Validation of Best Conditions

[0201] The optimal production process for lactic acid bacteria fermented mung bean jelly was determined through response surface methodology (RSM) optimization experiments. The optimal RSM was: 1.411% carrageenan, 28.14% fermentation broth, 0.09576% citric acid, and 3.836% white sugar. Under these conditions, the sensory score of the lactic acid bacteria fermented mung bean jelly was 91.058. Considering the objective conditions of actual production, the optimal conditions were modified to: 1.4% carrageenan, 28% fermentation broth, 0.1% citric acid, and 4% white sugar. Three parallel experiments were conducted to verify this process. The average sensory score of the lactic acid bacteria fermented mung bean jelly was 90.33, with an error of 0.728 points compared to the theoretical prediction (91.058). This indicates that the model has a high degree of fit with the actual situation and good predictive performance. Therefore, the optimized production process of lactic acid bacteria fermented mung bean jelly can be applied in actual production.

[0202] 4.3 Sensory evaluation, textural properties, microbial limits, and antioxidant activity analysis of lactic acid bacteria fermented mung bean squeezable jelly

[0203] 4.3.1 Sensory evaluation results of lactic acid bacteria fermented mung bean jelly

[0204] A lactic acid bacteria fermented mung bean jelly was prepared according to the optimal processing technology, and its color, appearance, texture, and taste were evaluated. The evaluation results are as follows:

[0205] Table 9 Sensory evaluation results of lactic acid bacteria fermented mung bean jelly

[0206]

[0207] 4.3.2 Texture characteristics of lactic acid bacteria fermented mung bean squeezable jelly

[0208] Table 10 shows the textural results of the lactic acid bacteria fermented mung bean jelly, reflecting key indicators such as hardness, elasticity, and cohesiveness. The lactic acid bacteria fermented mung bean jelly prepared by this invention has a soft and palatable texture.

[0209] Table 10 Texture characteristics of lactic acid bacteria fermented mung bean jelly

[0210]

[0211] 4.3.3 Microbial Limit Analysis of Lactic Acid Bacteria-Fermented Mung Bean Suckable Jelly

[0212] The microbial limits of lactic acid bacteria fermented mung bean jelly were tested according to national standards. Table 11 shows the results: the total bacterial count of the lactic acid bacteria fermented mung bean jelly was 39 CFU / g. -1 Coliform bacteria were not detected, and the mold count was 3.33 CFU / g. -1 The yeast count was 12.67 CFU / g. -1 All comply with GB 19299-2015 "National Food Safety Standard for Jelly".

[0213] Table 11 Microbial Limits for Lactic Acid Bacteria-Fermented Mung Bean Suckable Jelly

[0214]

[0215] 4.4 Antioxidant Activity Analysis of Lactic Acid Bacteria-Fermented Mung Bean Suckable Jelly

[0216] 4.4.1 DPPH free radical scavenging activity

[0217] like Figure 24 As shown in Figure A, the lactic acid bacteria fermented mung bean scavenging jelly exhibits a concentration-dependent, dose-dependent DPPH free radical scavenging effect. At a concentration of 1.0 μg / mL, the DPPH free radical scavenging rate of the lactic acid bacteria fermented mung bean scavenging jelly was 88.85 ± 1.37%; at a concentration of 5.0 μg / mL, the DPPH free radical scavenging rate was 95.76 ± 1.05%, close to the scavenging rate of vitamin C (98.10 ± 0.15%). This result indicates that the lactic acid bacteria fermented mung bean scavenging jelly possesses excellent DPPH free radical scavenging activity.

[0218] 4.4.2 ABTS + Free radical scavenging activity

[0219] like Figure 24 As shown in Figure B, lactic acid bacteria fermented mung bean jelly has an effect on ABTS. + The scavenging effect of free radicals is dose-dependent. At a concentration of 5 μg / mL, lactic acid bacteria-fermented mung bean absorbable jelly showed efficacy against ABTS. +The free radical scavenging rate was 39.85±1.12%; while at a concentration of 25 μg / mL, the free radical scavenging rate of lactic acid bacteria-fermented mung bean jelly was significantly reduced against ABTS. + The free radical scavenging rate was 85.52 ± 0.16%. The results indicate that lactic acid bacteria-fermented mung bean jelly has good ABTS (absorbable soluble starch) properties. + Free radical scavenging activity.

[0220] 4.4.3 Hydroxyl radical scavenging activity

[0221] like Figure 24 As shown in Figure C, the scavenging effect of lactic acid bacteria fermented mung bean absorbable jelly on hydroxyl radicals was dose-dependent. Within the concentration range of 10–50 μg / mL, the hydroxyl radical scavenging rate of lactic acid bacteria fermented mung bean absorbable jelly increased from 43.48 ± 0.97% to 91.95 ± 0.99%.

[0222] 4.4.4 Iron ion reducing ability

[0223] The effect of lactic acid bacteria fermented mung bean jelly on the iron ion reducing capacity, such as Figure 24 As shown in Figure D, and compared with vitamin C as a positive control, the iron reducing power (FRAP) of the lactic acid bacteria-fermented mung bean jelly gradually increased with increasing concentration, exhibiting a dose-dependent effect. Within the concentration range of 0.2 mg / mL to 1.0 mg / mL, the FRAP of the lactic acid bacteria-fermented mung bean jelly increased from 0.277 ± 0.004 mmol / L to 0.340 ± 0.002 mmol / L. Within the same concentration range, the FRAP of vitamin C increased from 0.492 ± 0.002 mmol / L to 1.279 ± 0.022 mmol / L.

[0224] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for preparing lactic acid bacteria fermented mung bean porridge, characterized in that, Includes the following steps: Soak mung beans in water, drain and steam for 1 hour, then cool to obtain pre-treated mung beans. After activation and fermentation of Lactobacillus fermentum GBJ, a fermentation broth was obtained. After white sugar is made into sugar water, it is mixed with the pretreated mung beans and the fermentation liquid to obtain lactic acid bacteria fermented mung bean porridge. The activation includes a first activation and a second activation. The first activation is as follows: the glycerol-preserved Lactobacillus fermentum GBJ is inoculated into the culture medium and cultured at 33°C for 24 hours. The second activation is as follows: the activated solution obtained after the first activation is inoculated into the culture medium at an inoculation amount of 3% by volume and cultured at 33°C for 24 hours. The fermentation process involves inoculating the activated solution obtained after the second activation into the culture medium at a volume percentage of 3% and culturing at 33°C for 24 hours. The culture medium used for activating or fermenting Lactobacillus GBJ is prepared by mixing an 8% whey powder solution and apple juice at a volume ratio of 85:15, heating to dissolve, dispensing, and sterilizing at 108°C for 15 minutes. The sugar syrup is obtained by mixing white sugar and water in a ratio of 10g:100g. Based on the mass of the mung beans, the ratio of mung beans to sugar water is 30g:45mL, and the inoculation amount of the fermentation liquid is 7:100 (volume-to-mass ratio of fermentation liquid to mung beans). The conditions for the mixed fermentation were 33°C for 24 hours.

2. The preparation method according to claim 1, characterized in that, The soaking time is 12 hours.

3. A method for preparing a lactic acid bacteria fermented mung bean squeezable jelly, characterized in that, Includes the following steps: Separate the lactic acid bacteria fermented mung bean porridge prepared by the preparation method described in claim 1 or 2, and obtain mung beans and fermentation liquid respectively; Water, carrageenan, and white sugar are boiled, cooled, and then citric acid is added to prepare a gelling liquid. The gelling liquid is then pasteurized, and the mung beans and fermentation liquid are added and mixed evenly to obtain lactic acid bacteria fermented mung bean jelly.

4. The preparation method according to claim 3, characterized in that, The mass ratio of the white sugar, carrageenan, and water is 4g:1.4g:100g; The mass ratio of citric acid to water is 0.1g:100g; The ratio of the adhesive, mung beans, and fermentation liquid is 52g:20g:28mL.

5. The application of the lactic acid bacteria fermented mung bean porridge prepared by the preparation method according to claim 1 or 2, or the lactic acid bacteria fermented mung bean squeezable jelly prepared by the preparation method according to claim 3 or 4, in the preparation of health foods that help with antioxidation and enhance immunity.

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