Bamboo shoot lactic acid bacteria powder rich in gamma-aminobutyric acid and preparation method and application thereof

Abstract

The invention provides bamboo shoot lactic acid bacteria powder rich in gamma-aminobutyric acid as well as a preparation method and application of the bamboo shoot lactic acid bacteria powder, and belongs to the technical field of biology. The bamboo shoot lactic acid bacteria powder is a product obtained by inoculating lactobacillus plantarum R1 into a culture solution for fermentation and then freeze-drying the lactobacillus plantarum R1, the lactobacillus plantarum R1 is a strain which is preserved in the China Center for Type Culture Collection, and the preservation number of the lactobacillus plantarum R1 is CCTCC NO: M 2022659; the culture solution comprises the following components in percentage by mass: 1-20% of bamboo shoot powder, 3-6% of skimmed milk powder, 5-10% of white granulated sugar and the balance of water. The bamboo shoot lactic acid bacteria powder prepared by the method is high in amino acid, dietary fiber and trace element content, good in sensory evaluation and high in viable count which is higher than that of existing lactic acid bacteria powder in the market; meanwhile, the bamboo shoot lactic acid bacteria powder is rich in gamma-aminobutyric acid content, and can be used for preparing food or health food with high gamma-aminobutyric acid content. Therefore, the method has a good application prospect.

Description

Technical Field

[0001] The invention belongs to the field of biotechnology, and particularly relates to a bamboo shoot lactic acid bacteria powder rich in gamma-aminobutyric acid, a preparation method and application thereof. Background Art

[0002] Gamma-aminobutyric acid (GABA) is a non-protein amino acid widely found in plants and animals. It serves as an inhibitory neurotransmitter in the mammalian central nervous system, exhibiting numerous physiological functions, including improving sleep, lowering blood pressure, and regulating mood (e.g., alleviating anxiety and depression). With the accelerating pace of life and an aging population, the body's ability to synthesize GABA is gradually declining. Dietary GABA supplementation has become a hot topic in the development of functional foods. In 2009, the Chinese Ministry of Health approved GABA as a new resource food, stipulating a daily intake of no more than 500 mg. GABA can be used in general foods such as beverages, candies, and baked goods, as well as in health foods with health benefits such as "improving sleep" and "assisting in lowering blood pressure." The Chinese Nutrition Society indicates that a daily intake of 26.4-100 mg of GABA can significantly improve insomnia, depressive symptoms, and psychological stress. As of October 2024, there were 14 sleep-enhancing health foods in China using GABA as an ingredient, primarily in combination with medicinal and edible ingredients such as casein hydrolysate and jujube seeds.

[0003] Lactic acid bacteria powder is a preparation containing active lactic acid bacteria that has the effects of regulating intestinal flora, promoting digestion, enhancing immunity, preventing diseases, and improving nutrient absorption. Lactic acid bacteria powder is a powdered product made by high-density cultivation, concentration, and drying (spray drying or freeze drying) of one or more lactic acid bacteria. It can be used directly as a probiotic food, health food, or fermentation agent. The γ-aminobutyric acid content in lactic acid bacteria powder on the market is very low, usually less than 1 mg / g, and the viable cell count is also low, generally around 1.0×10 6 ~1.0×10 8 How to prepare a lactic acid bacteria powder with high viable count and rich in γ-aminobutyric acid requires further research. Summary of the Invention

[0004] The present invention aims to provide a bamboo shoot lactic acid bacteria powder rich in gamma-aminobutyric acid, a preparation method thereof and uses thereof.

[0005] The invention provides bamboo shoot lactic acid bacteria powder rich in gamma-aminobutyric acid. The powder is a product obtained by inoculating Lactobacillus plantarum R1 into a culture solution, fermenting the solution, and then freeze-drying the solution. The Lactobacillus plantarum R1 is a strain deposited in the China Center for Type Culture Collection with a deposit number of CCTCC NO: M 2022659. The culture solution contains 1-20% by mass of bamboo shoot powder, 3-6% by mass of skim milk powder, 5-10% by mass of white sugar, and the balance being water.

[0006] Furthermore, the culture solution contains 2-5% by mass of bamboo shoot powder, 3-6% by mass of skim milk powder, 6% by mass of white sugar, and the balance being water.

[0007] Furthermore, the culture solution contains 4-5% by mass of bamboo shoot powder, 5% by mass of skim milk powder, 6% by mass of white sugar, and the balance being water.

[0008] Preferably, the culture solution contains 4.1-4.2% by mass of bamboo shoot powder, 5% by mass of skim milk powder, 6% by mass of white sugar, and the balance being water.

[0009] Furthermore, the inoculation volume percentage of the Lactobacillus plantarum R1 is 6 to 10%; and / or the concentration of the Lactobacillus plantarum R1 during inoculation is 10 8 ~10 10 CFU / mL.

[0010] Preferably, the inoculation volume percentage of the Lactobacillus plantarum R1 is 8 to 8.5%; and / or the concentration of the Lactobacillus plantarum R1 during inoculation is 10 8 CFU / mL.

[0011] Furthermore, the fermentation temperature is 37-43° C., and the fermentation time is 48-120 h.

[0012] Preferably, the fermentation temperature is 37±1° C., and the fermentation time is 72 h.

[0013] Furthermore, the preparation method of the bamboo shoot powder comprises the following steps: Boil fresh bamboo shoots for 3 to 15 minutes, rinse with water, dry, crush and sieve to obtain bamboo shoot powder.

[0014] Preferably, the fresh bamboo shoots are boiled in water at 100° C. to remove the cellulase activity in the bamboo shoots.

[0015] Preferably, the sieving is a 40-100 mesh sieve.

[0016] The present invention also provides a method for preparing the aforementioned bamboo shoot lactic acid bacteria powder, which comprises the following steps: (1) Preparation of culture medium: Add bamboo shoot powder, skim milk powder and white sugar to water and sterilize to obtain culture medium; (2) inoculating Lactobacillus plantarum R1 into the culture medium and fermenting to obtain a fermentation liquid; (3) Freeze-drying the fermentation liquid to obtain bamboo shoot lactic acid bacteria powder.

[0017] Preferably, in step (1), the sterilization is performed at 112-121°C for 15-30 min.

[0018] Preferably, in step (2), the temperature is cooled to 35-37° C. before inoculating Lactobacillus plantarum R1 into the culture solution.

[0019] Further, In step (2), the volume percentage of the inoculation amount of the Lactobacillus plantarum R1 is 6-10%; And / or, in step (2), the concentration of the Lactobacillus plantarum R1 during inoculation is 10 8 ~10 10 CFU / mL; And / or, in step (2), the fermentation temperature is 37-43° C., and the fermentation time is 48-120 h.

[0020] Preferably, in step (2), the volume percentage of the inoculation amount of the Lactobacillus plantarum R1 is 8-8.5%.

[0021] Preferably, in step (2), the concentration of the Lactobacillus plantarum R1 during inoculation is 10 8 CFU / mL.

[0022] Preferably, in step (2), the fermentation temperature is 37±1°C and the fermentation time is 72 h.

[0023] The present invention also provides use of the bamboo shoot lactic acid bacteria powder in preparing food or health food.

[0024] Furthermore, the health food is a health food that improves sleep and / or assists in lowering blood pressure.

[0025] The present invention has achieved the following beneficial effects: The present invention provides a bamboo shoot lactic acid bacteria powder rich in γ-aminobutyric acid (GABA). This powder is prepared by fermenting a specific bamboo shoot containing Lactobacillus plantarum R1. The powder has high amino acid, dietary fiber, and trace element contents, exhibits excellent sensory evaluation, and has a high viable bacterial count, exceeding that of existing commercially available lactic acid bacteria powders. Furthermore, this powder is rich in GABA and can be used to prepare foods or health foods high in GABA. Therefore, the present invention has promising application prospects.

[0026] Obviously, based on the above contents of the present invention, according to common technical knowledge and customary means in this field, without departing from the above basic technical ideas of the present invention, other various forms of modifications, replacements or changes can be made.

[0027] The following is a further detailed description of the present invention through specific embodiments in the form of examples. However, this should not be construed as limiting the scope of the present invention to the following examples. All technologies implemented based on the above-mentioned content of the present invention fall within the scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is the appearance of the bamboo shoot powder and bamboo shoot lactic acid bacteria powder prepared in Example 1.

[0029] Figure 2 This is the amino acid liquid phase distribution diagram of the bamboo shoot lactic acid bacteria powder prepared in Example 1.

[0030] Figure 3 The liquid morphology of formulas 1-1, 2-1, 3-1, and 4-1 after mixing and before inoculation of strains.

[0031] Figure 4 The liquid morphology of formulas 1-2, 2-2, 3-2, and 4-2 after mixing and before inoculation with strains.

[0032] Figure 5 The liquid morphology of formulas 1-3, 2-3, 3-3, and 4-3 after mixing and before inoculation of strains.

[0033] Figure 6 The results of the total colony count of bamboo shoot lactic acid bacteria powder prepared with different formulas.

[0034] Figure 7 This is the standard absorption peak result diagram of γ-aminobutyric acid (GABA).

[0035] Figure 8 This is the standard curve of γ-aminobutyric acid (GABA).

[0036] Figure 9 This is the liquid chromatography spectrum of γ-aminobutyric acid (GABA) standard.

[0037] Figure 10 Liquid phase spectra of each sample.

[0038] Figure 11 This is a SEM image of the bamboo shoot powder prepared in Example 1 at a magnification of 1000 times.

[0039] Figure 12 This is a SEM image of the bamboo shoot powder prepared in Example 1 at a magnification of 10,000 times.

[0040] Figure 13 This is a SEM image of the bamboo shoot lactic acid bacteria powder prepared in Example 1 at a magnification of 2000 times.

[0041] Figure 14This is a SEM image of the bamboo shoot lactic acid bacteria powder prepared in Example 1 at a magnification of 5000 times. DETAILED DESCRIPTION

[0042] Unless otherwise specified, the raw materials and equipment used in the present invention are all known products and are obtained by purchasing commercially available products.

[0043] Materials: Fresh bamboo shoots, produced in Liuzhou, Guangxi Zhuang Autonomous Region; white sugar, purchased from Chan Xiaoya Food Co., Ltd., Kunming, Yunnan Province; Lactobacillus plantarum R1 ( Lactobacillus plantarum. R1) is a strain preserved in our laboratory, deposited with the China Center for Type Culture Collection (CCTCC) at Wuhan University, Wuhan, Hubei, China, on May 18, 2022, with the deposit number CCTCC NO: M 2022659. This strain is also recorded in a Chinese patent application with application number 202210576703.3, filed on May 25, 2022. Ultrapure water was provided by Laboratory 219, College of Food Science and Technology, Huazhong Agricultural University.

[0044] Reagents: skim milk powder, purchased from Beijing LABLEAD Co., Ltd.; MRS solid culture medium, purchased from Beijing LABLEAD Co., Ltd.; MRS liquid culture medium, purchased from Beijing LABLEAD Co., Ltd.; MC culture medium, purchased from Qingdao High-tech Industrial Park Haibo Biotechnology Co., Ltd.

[0045] Example 1: Preparation of Bamboo Shoot Lactic Acid Bacteria Powder of the Present Invention 1. Activation and purification of Lactobacillus plantarum R1 Inoculate Lactobacillus plantarum R1 stored in a -80°C ultra-low temperature freezer onto MRS solid medium. Incubate the culture at 37°C in a biochemical incubator for 30 minutes. Then, inoculate a loopful of culture onto differential MC medium using an inoculating loop in a clean bench. Incubate the culture at 37°C in a biochemical incubator for 24 ± 2 hours. Subculture any strain that exhibits a calcium-dissolving ring in the differential medium for subsequent experiments.

[0046] 2. Preparation of bamboo shoot powder Fresh bamboo shoots are cut into small pieces of uniform size, pre-cooked in 100°C water for 3-15 minutes (to remove the cellulase activity in the bamboo shoots), rinsed with running water, dried and crushed in a grinder, and the crushed particles are collected after passing through a 40-100 mesh sieve and vacuum-sealed to prevent the infiltration of moisture in the air, thereby obtaining bamboo shoot powder.

[0047] 3. Preparation of bamboo shoot lactic acid bacteria powder Take 1.0 g of bamboo shoot powder, add 24 mL of ultrapure water, then add 6 wt% white sugar and 5 wt% skim milk powder, sterilize at 112-121 ° C for 15-30 min, and inoculate activated Lactobacillus plantarum R1 when the temperature is cooled to 35-37 ° C. The concentration of the bacteria is 10 8 CFU / mL, the inoculation volume was 2 mL, and the culture was carried out at 37±1℃ for 72 h to obtain the fermentation liquid. The fermentation liquid was freeze-dried to obtain the bamboo shoot lactic acid bacteria powder. The appearance of the bamboo shoot lactic acid bacteria powder was as follows: Figure 1 shown.

[0048] The freeze-drying conditions were as follows: pre-freeze in a -18°C refrigerator for 24 h, and then dry in a vacuum freeze dryer. Parameters included cold trap temperature of -55°C, vacuum degree of 10 Pa, and drying time of 24 to 48 h.

[0049] Example 2: Determination of the Lactic Acid Bacteria Powder of Bamboo Shoots of the Present Invention The bamboo shoot lactic acid bacteria powder prepared in Example 1 was subjected to the following measurements.

[0050] 1. Amino acid determination The testing method is carried out in accordance with GB 5009.124-2016.

[0051] The amino acid liquid phase distribution diagram of bamboo shoot lactic acid bacteria powder is as follows Figure 2 The percentage distribution of each amino acid in bamboo shoot lactic acid bacteria powder is shown in Table 1.

[0052] Table 1. Distribution of amino acid percentages in bamboo shoot lactic acid bacteria powder Depend on Figure 2 As shown in Table 1, the bamboo shoot lactic acid bacteria powder prepared by the present invention contains a variety of amino acids, wherein the crude protein content is 14.74%.

[0053] 2. Dietary fiber determination The detection method is carried out in accordance with GB 5009.88-2023.

[0054] According to the measurement, the dietary fiber percentage of the bamboo shoot lactic acid bacteria powder prepared by the present invention is 5.38%, and the content of trace elements is high.

[0055] 3. Trace elements The determination of iron, copper, manganese, zinc, and selenium in bamboo shoot lactic acid bacteria powder all adopted national standard methods. For details, please refer to GB 5009.90-2016 Determination of Iron in Foods, GB 5009.13-2017 Determination of Copper in Foods, GB 5009.242-2017 Determination of Manganese in Foods, GB 5009.14-2017 Determination of Zinc in Foods, and GB 5009.93-2017 Determination of Selenium in Foods.

[0056] After measurement, the iron content of the bamboo shoot lactic acid bacteria powder prepared by the present invention is 11 mg / kg, the manganese content is 9.3 mg / kg, the copper content is 3.7 mg / kg, the zinc content is 26 mg / kg, and the selenium content is 0.057 mg / kg.

[0057] 4. Sensory evaluation The bamboo shoot lactic acid bacteria powder prepared in Example 1 was subjected to sensory evaluation by 20 food science students, 10 males and 10 females, aged 22 to 25 years. The sensory evaluation indicators are shown in Table 2.

[0058] Table 2. Sensory evaluation index table The sensory evaluation results are as follows: Taste: 16 reviewers felt it was "no peculiar smell, soft and refreshing, with a light sour taste and a sweet aftertaste", while 4 reviewers reported "no peculiar smell but slightly sour"; the average score was 27 points.

[0059] Aroma: 15 reviewers perceived a "harmonious bamboo shoot fragrance and lactic acid bacteria fermentation flavor," while 5 reviewers felt that the "bamboo shoot fragrance was relatively weak." The average score was 25 points.

[0060] Color: 14 evaluators rated it as "granular, uniform color, light yellow", 5 rated it as "granular, uniform color, light brown", and 1 rated it as "granular, uneven color, light brown"; the average score was 17.

[0061] Condition: 13 reviewers observed "uniform particles with a delicate feel," 6 found "slightly rough particles," and 1 found "uneven and rough particles"; the average score was 16.

[0062] Overall, the bamboo shoot lactic acid bacteria powder performed outstandingly in terms of taste and aroma indicators. Although there was some controversy about its color and state, it generally met the high-quality standards. The overall average sensory evaluation score was 85 points.

[0063] The beneficial effects of the present invention are demonstrated by experimental examples below.

[0064] Experimental Example 1: Determination of the amount of bamboo shoot powder used in preparing bamboo shoot lactic acid bacteria powder according to the present invention Bamboo shoot powder was prepared according to the method described in Example 1, and the amount of bamboo shoot powder was set to six gradients of 0.5 g, 1.0 g, 1.5 g, 2.5 g, 3.5 g, and 4.5 g. When observed with 24 mL of added water, the viscosity of the system gradually increased and the fluidity weakened. When it exceeded 1.5 g, the system had basically no visible fluidity to the naked eye, so the amount of bamboo shoot powder was determined to be 0.5 g-1.5 g.

[0065] Experimental Example 2: Determination of the amount of skim milk powder used in preparing bamboo shoot lactic acid bacteria powder according to the present invention Bamboo shoot powder was prepared according to the method described in Example 1, with the amount of bamboo shoot powder determined to be 1.0 g, the amount of water added being 24 mL, the concentrations of skim milk powder being set to 3wt%, 6wt%, 9wt%, 12wt%, and 15wt%, respectively. The powder was shaken in a test tube, and the color and odor changes were observed after it stabilized. It was found that with the increase of the skim milk powder content, the system gradually changed from light yellow to white, and its odor gradually changed from light milk fragrance to strong fragrance, but its fluidity gradually weakened, and the system gradually thickened. Based on the above indicators, the concentration of skim milk powder was set to 3wt%-6wt%.

[0066] Example 3: Determination of the Optimal Formula for Preparing Bamboo Shoot Lactic Acid Bacteria Powder of the Present Invention 1. Observation of culture medium morphology According to the method described in Example 1, only the amount of bamboo shoot powder (0.5g, 1.0g, 1.5g) and the concentration of skim milk powder (3wt%, 4wt%, 5wt% and 6wt%) were changed. The experimental groups were: Formula 1-1: 0.5g bamboo shoot powder, 3wt% skim milk powder; Formula 2-1: 0.5g bamboo shoot powder, 4wt% skim milk powder; Formula 3-1: 0.5g bamboo shoot powder, 5wt% skim milk powder; Formula 4-1: 0.5g bamboo shoot powder, 6wt% skim milk powder; Formula 1-2: 1.0g bamboo shoot powder, 3wt% skim milk powder; Formula 2-2: 1.0g bamboo shoot powder, 4wt% skim milk powder; Formula 3-2: 1.0g bamboo shoot powder, 5wt% skim milk powder; Formula 4-2: 1.0g bamboo shoot powder, 6wt% skim milk powder; Formula 1-3: 1.5g bamboo shoot powder, 3wt% skim milk powder concentration; Formula 2-3: 1.5g bamboo shoot powder, 4wt% skim milk powder concentration; Formula 3-3: 1.5g bamboo shoot powder, 5wt% skim milk powder concentration; Formula 4-3 group: 1.5g bamboo shoot powder, 6wt% skim milk powder concentration.

[0067] Each formula group added bamboo shoot powder to ultrapure water, then added skim milk powder and 6wt% white sugar, mixed them and observed the fermentation system status before inoculating the strain. The results are as follows Figure 3-Figure 5 As shown, the experimental groups containing 1.5 g of bamboo shoot powder (i.e., formulations 1-3, 2-3, 3-3, and 4-3) lacked fluidity, so they were not inoculated or subsequently counted. Subsequently, only the total colony counts of the bamboo shoot lactic acid bacteria powder obtained by fermentation with formulations 1-1, 2-1, 3-1, 4-1, 1-2, 2-2, 3-2, and 4-2 were studied.

[0068] 2. Study on the total colony count of bamboo shoot lactic acid bacteria powder with different formulas Formulas 1-1, 2-1, 3-1, 4-1, 1-2, 2-2, 3-2, and 4-2 were used to prepare bamboo shoot lactic acid bacteria powder according to the method described in Example 1. The total colony count of the bamboo shoot lactic acid bacteria powder prepared in each group of formulas was detected according to the method of GB4789.35-2023. Figure 6 As shown by Figure 6 It can be seen that the total number of colonies in group 3-2 reached 3.4×10 9 The number of live bacteria in the bamboo shoot lactic acid bacteria powder prepared by the optimal formula of the present invention is significantly better than that of the existing lactic acid bacteria powder.

[0069] Example 4: Determination of γ-aminobutyric acid (GABA) content in the bamboo shoot lactic acid bacteria powder of the present invention Commercially available lactic acid bacteria powder: Instant lactic acid bacteria probiotic powder (Hebei Yiran Biotechnology Co., Ltd.). The following method was used to quantitatively measure the γ-aminobutyric acid (GABA) content in each sample group (bamboo shoot powder and bamboo shoot lactic acid bacteria powder prepared in Example 1, commercially available lactic acid bacteria powder, and other bamboo shoot lactic acid bacteria powders prepared according to the method of Example 1 using Formulas 1-1, 2-1, 3-1, 4-1, 1-2, 2-2, and 4-2). The detection method is as follows: The detection was performed according to the UV detection method A.1 in "QB / T 5633.7-2022 Amino Acids, Amino Acid Salts and Analogs Part 7: γ-Aminobutyric Acid" with slight modifications. The specific operation is as follows: GABA standard (50.3 mg) was dissolved in purified water and the volume was adjusted to 200 mL. Then, 0 mL, 5 mL, 12.5 mL, 20 mL, 27.5 mL, 35 mL, and 42.5 mL of the solution were added to 5 mL of derivatization buffer (prepared by dissolving 4.2 g NaHCO3 in 100 mL of water) and 2.5 mL of acetonitrile solution containing 1% 2,4-dinitrochlorobenzene (DNFB). The derivatization reaction was carried out in a water bath at 60°C for 1 h. After cooling, the solution was diluted to 50 mL with 1.36 g / L potassium dihydrogen phosphate aqueous solution. The standard gradient solution to be tested was filtered through a 0.22 μm filter membrane.

[0070] 200 mg of sample was weighed and dissolved in purified water to 1 mL. 5 mL of derivatization buffer (prepared by dissolving 4.2 g of NaHCO₃ in 100 mL of water) and 2.5 mL of acetonitrile containing 1% 2,4-dinitrochlorobenzene (DNFB) were added. The sample was derivatized in a 60°C waterbath for 1 h. After cooling, the sample was diluted to 10 mL with 1.36 g / L potassium dihydrogen phosphate aqueous solution and filtered through a 0.22 μm filter to obtain the sample. The mobile phase and elution conditions remained unchanged.

[0071] The liquid chromatography spectra of GABA standards and samples are shown in Figure 2. Figures 7-10 The results of γ-aminobutyric acid (GABA) content in different samples are shown in Table 3.

[0072] Table 3. Gamma-aminobutyric acid (GABA) content in different samples In the table, “-” means not detected.

[0073] The experimental data above demonstrate that the GABA content of the bamboo shoot lactic acid bacteria powder prepared in Example 1 (Formula 3-2) (1589.51 mg / kg) is significantly higher than that of pure bamboo shoot powder (1145.41 mg / kg). Compared to commercially available lactic acid bacteria powder, the GABA content of the bamboo shoot lactic acid bacteria powder prepared in Example 1 is significantly higher (56.33 mg / kg). Furthermore, a comparison of bamboo shoot lactic acid bacteria powders prepared using different formulas revealed that the GABA content of the bamboo shoot lactic acid bacteria powder prepared using other formulas was significantly lower (less than 1300 mg / kg) than that of the bamboo shoot lactic acid bacteria powder in Example 1, demonstrating that the bamboo shoot lactic acid bacteria powder prepared in Example 1 exhibits a significant advantage in GABA content. This demonstrates that the specific method of the present invention can produce bamboo shoot lactic acid bacteria powder with a high GABA content.

[0074] Example 5: Microscopic morphology observation of the bamboo shoot lactic acid bacteria powder of the present invention SEM images of the bamboo shoot lactic acid bacteria powder prepared in Example 1 were taken to observe the morphological distribution of Lactobacillus plantarum R1 in the powder. After vacuum drying and gold spraying, the powder was imaged in high vacuum mode at an accelerating voltage of 15 kV. The images were taken at different magnifications, focusing on the integrity of the Lactobacillus plantarum R1 cells (maintaining their rod-shaped morphology), their attachment state (adherence, entrapment, or free) on the surface of the milk powder particles, and their spatial distribution uniformity within the matrix. The bamboo shoot powder prepared in Example 1 was used as a control.

[0075] The morphological distribution results of bamboo shoot powder are as follows Figure 11 and Figure 12 As shown in the figure, the morphological distribution results of bamboo shoot lactic acid bacteria powder are as follows: Figure 13 and Figure 14 As shown in the figure, the results of the bamboo shoot lactic acid bacteria powder show that at 2000x and 5000x magnification, Lactobacillus plantarum R1 maintains a complete rod-shaped morphology (1-3 μm in length). Most bacteria are tightly embedded in the bamboo shoot powder's network structure, with some adhering to the particle surface, effectively encapsulating and protecting the bacteria. The bacteria are evenly distributed across different viewing angles, with no aggregation. This demonstrates that the processing method of the present invention effectively maintains the morphological integrity of the probiotic bacteria and achieves uniform dispersion. The present invention utilizes the unique structure of bamboo shoot powder to effectively encapsulate and protect Lactobacillus plantarum.

[0076] In summary, the present invention provides a bamboo shoot lactic acid bacteria powder rich in γ-aminobutyric acid, which is prepared by fermenting a specific formula containing bamboo shoots with Lactobacillus plantarum R1. The bamboo shoot lactic acid bacteria powder prepared by the present invention has high content of amino acids, dietary fiber and trace elements, good sensory evaluation, and a high number of viable bacteria, which is higher than the existing lactic acid bacteria powder on the market; at the same time, the bamboo shoot lactic acid bacteria powder is rich in γ-aminobutyric acid and can be used to prepare foods or health foods with high γ-aminobutyric acid content. Therefore, the present invention has good application prospects.

Claims

1. A bamboo shoot lactic acid bacteria powder rich in γ-aminobutyric acid, characterized by: The product is obtained by inoculating Lactobacillus plantarum R1 into a culture solution, fermenting the solution, and then freeze-drying the solution. The Lactobacillus plantarum R1 is a strain deposited in the China Center for Type Culture Collection with a deposit number of CCTCC NO: M 2022659. The culture solution contains 1-20% by mass of bamboo shoot powder, 3-6% by mass of skim milk powder, 5-10% by mass of white sugar, and the balance being water.

2. The bamboo shoot lactic acid bacteria powder according to claim 1, characterized in that: The culture solution contains 2-5% by mass of bamboo shoot powder, 3-6% by mass of skim milk powder, 6% by mass of white sugar, and the balance being water.

3. The bamboo shoot lactic acid bacteria powder according to claim 1, characterized in that: The culture solution contains 4-5% by mass of bamboo shoot powder, 5% by mass of skim milk powder, 6% by mass of white sugar, and the balance being water.

4. The bamboo shoot lactic acid bacteria powder according to any one of claims 1 to 3, characterized in that: The inoculation volume percentage of the plant lactobacillus R1 is 6 to 10%; and / or the concentration of the plant lactobacillus R1 during inoculation is 10 8 ~10 10 CFU / mL.

5. The bamboo shoot lactic acid bacteria powder according to any one of claims 1 to 3, characterized in that: The fermentation temperature is 37-43° C., and the fermentation time is 48-120 h.

6. The bamboo shoot lactic acid bacteria powder according to any one of claims 1 to 3, characterized in that: The preparation method of the bamboo shoot powder comprises the following steps: Boil fresh bamboo shoots for 3 to 15 minutes, rinse with water, dry, crush and sieve to obtain bamboo shoot powder.

7. The method for preparing the bamboo shoot lactic acid bacteria powder according to any one of claims 1 to 6, characterized in that: It includes the following steps: (1) Preparation of culture medium: Add bamboo shoot powder, skim milk powder and white sugar to water and sterilize to obtain culture medium; (2) inoculating Lactobacillus plantarum R1 into the culture medium and fermenting to obtain a fermentation liquid; (3) Freeze-drying the fermentation liquid to obtain bamboo shoot lactic acid bacteria powder.

8. The preparation method according to claim 7, characterized in that: In step (2), the volume percentage of the inoculation amount of the Lactobacillus plantarum R1 is 6-10%; And / or, in step (2), the concentration of the Lactobacillus plantarum R1 during inoculation is 10 8 ~10 10 CFU / mL; And / or, in step (2), the fermentation temperature is 37-43° C., and the fermentation time is 48-120 h.

9. Use of the bamboo shoot lactic acid bacteria powder according to any one of claims 1 to 6 in preparing food or health food.

10. The use according to claim 9, characterized in that: The health food is a health food that improves sleep and / or assists in lowering blood pressure.

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