A gamma-aminobutyric acid-enriched bamboo shoot lactobacillus powder, a preparation method and use thereof

Abstract

The application provides a bamboo shoot lactic acid bacteria powder rich in gamma-aminobutyric acid and a preparation method and application thereof, and belongs to the technical field of biotechnology. The bamboo shoot lactic acid bacteria powder is a product obtained by inoculating lactobacillus plantarum R1 into a culture solution, carrying out fermentation and freeze-drying; the lactobacillus plantarum R1 is a strain preserved in the China Center for Type Culture Collection, and the preservation number is CCTCC NO: M 2022659; the culture solution contains 1-20% bamboo shoot powder, 3-6% skimmed milk powder and 5-10% white granulated sugar in terms of mass percentage, and the rest is water. The bamboo shoot lactic acid bacteria powder prepared by the application has high contents of amino acids, dietary fibers and trace elements, good sensory evaluation, and high number of live bacteria, higher than existing lactic acid bacteria powder on the market; meanwhile, the bamboo shoot lactic acid bacteria powder is rich in gamma-aminobutyric acid, and can be used for preparing food or health-care food with high gamma-aminobutyric acid content. Therefore, the application has a good application prospect.

Description

TECHNICAL FIELD

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

[0002] Gamma-aminobutyric acid (GABA) is a non-protein amino acid, which widely exists in animals and plants, is an inhibitory neurotransmitter of the central nervous system of mammals, and has multiple physiological functions such as improving sleep, reducing blood pressure, regulating mood (such as reducing anxiety and depression), etc. With the acceleration of life rhythm and the aging of population, the synthesis ability of GABA in human body gradually decreases, and dietary supplementation of GABA has become a hot spot for the development of functional foods.

[0003] Lactic acid bacteria powder is a preparation containing active lactic acid bacteria, which has the effects of regulating intestinal flora, promoting digestion, enhancing immunity, preventing diseases, and improving nutrient absorption. The lactic acid bacteria powder is a powdery product prepared by high-density culture, concentration and drying (spray drying or freeze drying) of one or more lactic acid bacteria, and can be directly used as probiotic food, health food or leavening agent. The content of gamma-aminobutyric acid in the lactic acid bacteria powder on the market is very low, usually <1 mg / g, and the content of viable bacteria is low, generally 1.0x10 6 ~1.0x10 8 CFU / g. How to prepare a lactic acid bacteria powder rich in gamma-aminobutyric acid and having a high content of viable bacteria needs further research. SUMMARY

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

[0005] The present application provides a bamboo shoot lactic acid bacteria powder rich in gamma-aminobutyric acid, which is a product prepared by inoculating Lactobacillus plantarum R1 into a culture solution, and then freeze-drying the product; the Lactobacillus plantarum R1 is a strain preserved in China Center for Type Culture Collection, and the preservation number is CCTCC NO: M 2022659; the culture solution contains 1-20% bamboo shoot powder, 3-6% skim milk powder and 5-10% white granulated sugar by mass percentage, and the balance is water.

[0006] Further, the culture solution contains 2-5% bamboo shoot powder, 3-6% skim milk powder and 6% white granulated sugar by mass percentage, and the balance is water.

[0007] Further, the culture solution contains 4-5% bamboo shoot powder, 5% skim milk powder and 6% white granulated sugar by mass percentage, and the balance is water.

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

[0009] Further, the inoculation amount of the Lactobacillus plantarum R1 is 6-10% in volume percentage; and / or, the concentration of the Lactobacillus plantarum R1 when inoculated is 10 8 ~10 10 CFU / mL.

[0010] Preferably, the inoculation amount of the Lactobacillus plantarum R1 is 8-8.5% in volume percentage; and / or, the concentration of the Lactobacillus plantarum R1 when inoculated is 10 8 CFU / mL.

[0011] Further, the fermentation temperature is 37-43℃, and the fermentation time is 48-120 h.

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

[0013] Further, the preparation method of the bamboo shoot powder comprises the following steps:

[0014] The fresh Dendrocalamus latiflorus shoot is boiled for 3-15 minutes, then washed with water, dried, crushed, and sieved to obtain the bamboo shoot powder.

[0015] Preferably, the fresh Dendrocalamus latiflorus shoot is boiled in water at 100℃, so as to remove the fiber enzyme activity in the Dendrocalamus latiflorus shoot.

[0016] Preferably, the sieving is 40-100 mesh sieving.

[0017] The application also provides a preparation method of the aforementioned bamboo shoot lactic acid bacteria powder, which comprises the following steps:

[0018] (1) preparing a culture solution: adding bamboo shoot powder, skim milk powder and white sugar into water, and sterilizing to obtain the culture solution;

[0019] (2) inoculating Lactobacillus plantarum R1 into the culture solution to ferment, and obtaining a fermentation solution;

[0020] (3) freeze-drying the fermentation solution to obtain the bamboo shoot lactic acid bacteria powder.

[0021] Preferably, in step (1), the sterilization is sterilization at 112-121℃ for 15-30 min.

[0022] Preferably, in step (2), before inoculating Lactobacillus plantarum R1 into the culture solution, the temperature is cooled to 35-37℃.

[0023] Further,

[0024] In step (2), the inoculation volume percentage of the Lactobacillus plantarum R1 is 6-10%;

[0025] Preferably, in step (2), the concentration of the Lactobacillus plantarum R1 is 10 8 ~10 10 CFU / mL.

[0026] Preferably, in step (2), the fermentation temperature is 37-43℃, and the fermentation time is 48-120h.

[0027] Preferably, in step (2), the inoculation volume percentage of the Lactobacillus plantarum R1 is 8-8.5%.

[0028] Preferably, in step (2), the concentration of the Lactobacillus plantarum R1 is 10 8 CFU / mL.

[0029] Preferably, in step (2), the fermentation temperature is 37±1℃, and the fermentation time is 72h.

[0030] The present application also provides a use of the aforementioned bamboo shoot lactic acid bacteria powder in the preparation of food or health food.

[0031] Further, the health food is health food that helps improve sleep and / or helps maintain a healthy level of blood pressure.

[0032] The present application has the following beneficial effects:

[0033] The present application provides a bamboo shoot lactic acid bacteria powder rich in gamma-aminobutyric acid, which is prepared by fermenting a specific bamboo shoot-containing formula with Lactobacillus plantarum R1. The bamboo shoot lactic acid bacteria powder prepared by the present application has high content of amino acids, dietary fiber and trace elements, good sensory evaluation, and high number of live bacteria, which is higher than existing lactic acid bacteria powder on the market; at the same time, the bamboo shoot lactic acid bacteria powder has rich content of gamma-aminobutyric acid, and can be used to prepare food or health food with high content of gamma-aminobutyric acid. Therefore, the present application has good application prospect.

[0034] Obviously, according to the above content of the present application, according to the ordinary technical knowledge and common means in the art, other various forms of modifications, replacements or changes can be made without departing from the above technical idea of the present application.

[0035] The above content of the present application will be further described in detail through the following embodiment. However, it should not be understood that the scope of the above subject matter of the present application is limited to the following embodiments. Any technology realized based on the above content of the present application belongs to the scope of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 Appearance of bamboo shoot powder and bamboo shoot lactic acid bacteria powder prepared in Example 1.

[0037] Figure 2 Amino acid liquid chromatogram of bamboo shoot lactic acid bacteria powder prepared in Example 1.

[0038] Figure 3 Liquid appearance before inoculating strains after mixing of Formulas 1-1, 2-1, 3-1, and 4-1.

[0039] Figure 4 Liquid appearance before inoculating strains after mixing of Formulas 1-2, 2-2, 3-2, and 4-2.

[0040] Figure 5 Liquid appearance before inoculating strains after mixing of Formulas 1-3, 2-3, 3-3, and 4-3.

[0041] Figure 6 Result graph of total number of colonies of bamboo shoot lactic acid bacteria powder prepared in different formulas.

[0042] Figure 7 Result graph of standard absorption peak of γ-aminobutyric acid (GABA).

[0043] Figure 8 Graph of standard curve of γ-aminobutyric acid (GABA).

[0044] Figure 9 Liquid chromatogram of γ-aminobutyric acid (GABA) standard.

[0045] Figure 10 Liquid chromatogram of each sample.

[0046] Figure 11 SEM graph of bamboo shoot powder prepared in Example 1 at 1000 times magnification.

[0047] Figure 12 SEM graph of bamboo shoot powder prepared in Example 1 at 10000 times magnification.

[0048] Figure 13 SEM graph of bamboo shoot lactic acid bacteria powder prepared in Example 1 at 2000 times magnification.

[0049] Figure 14 SEM graph of bamboo shoot lactic acid bacteria powder prepared in Example 1 at 5000 times magnification. DETAILED DESCRIPTION

[0050] Unless otherwise specified, the raw materials and equipment used in the present application are known products, which are obtained by purchasing commercially available products.

[0051] Materials: Fresh Dendrocalamus latiflorus, produced in Liuzhou, Guangxi Zhuang Autonomous Region; white granulated sugar, purchased from Chixiaoya Food Co., Ltd. in Kunming, Yunnan Province; Lactobacillus plantarum R1 (R1) is a preserved strain in our laboratory, preserved in the China Center for Type Culture Collection (CCTCC) located in Wuhan University in Wuhan, Hubei Province, China on May 18, 2022, with the preservation number CCTCC NO: M 2022659, and the strain is recorded in the Chinese patent with the application date of May 25, 2022 and the application number 202210576703.3; ultrapure water, provided by the 219 Laboratory of the School of Food Science and Technology, Huazhong Agricultural University. Lactobacillus plantarum. R1)is a preserved strain in our laboratory, preserved in the China Center for Type Culture Collection (CCTCC) located in Wuhan University in Wuhan, Hubei Province, China on May 18, 2022, with the preservation number CCTCC NO: M 2022659, and the strain is recorded in the Chinese patent with the application date of May 25, 2022 and the application number 202210576703.3; ultrapure water, provided by the 219 Laboratory of the School of Food Science and Technology, Huazhong Agricultural University.

[0052] Reagents: skimmed milk powder, purchased from Beijing LABLEAD Co., Ltd.; MRS solid medium, purchased from Beijing LABLEAD Co., Ltd.; MRS liquid medium, purchased from Beijing LABLEAD Co., Ltd.; MC medium, purchased from Haibo Biotechnology Co., Ltd. in Qingdao High-tech Industrial Park.

[0053] Example 1, Preparation of Dendrocalamus latiflorus Lactobacillus powder

[0054] 1. Activation and purification of Lactobacillus plantarum R1

[0055] Take Lactobacillus plantarum R1 preserved at -80℃ ultra-low temperature freezer and inoculate it in MRS solid medium, then place it in a biochemical incubator at 37℃ for 30 min, then use an inoculation ring to pick a ring in the differential MC medium on a clean bench, then incubate it in a biochemical incubator at 37℃ for 24±2 h. Take the strain that appears a calcium dissolution ring in the differential medium for subculture to prepare for subsequent experiments.

[0056] 2. Preparation of Dendrocalamus latiflorus powder

[0057] Cut fresh Dendrocalamus latiflorus into small pieces of uniform size, pre-cook them in water at 100℃ for 3-15 min (to remove the fibrozyme activity in Dendrocalamus latiflorus), rinse them with running water, dry them, and then crush them in a crusher. Collect the crushed particles through a 40-100 mesh screen and vacuum seal them to prevent moisture from the air from entering. This gives Dendrocalamus latiflorus powder.

[0058] 3. Preparation of Dendrocalamus latiflorus Lactobacillus powder

[0059] Take 1.0 g of Dendrocalamus latiflorus powder, add 24 mL of ultrapure water, then add white granulated sugar with a concentration of 6 wt% and skimmed milk powder with a concentration of 5 wt%, sterilize at 112~121℃ for 15-30 min, and when the temperature cools down to 35-37℃, inoculate the activated Lactobacillus plantarum R1 with a concentration of 10 8CFU / mL, 2 mL of inoculum, 37±1℃ incubation for 72 h, to obtain the fermentation broth. The fermentation broth was freeze-dried to obtain the bamboo shoot lactobacillus powder, and the appearance of the bamboo shoot lactobacillus powder was as shown in Figure 1 .

[0060] The freeze-drying conditions were as follows: pre-freezing for 24 h in a-18℃ refrigerator, vacuum freeze-drying machine drying, parameters: cold trap temperature: -55℃, vacuum degree: 10 Pa, and drying time was 24-48 h.

[0061] Example 2, determination of the bamboo shoot lactobacillus powder of the present application

[0062] The bamboo shoot lactobacillus powder prepared in Example 1 was taken for the following determination.

[0063] 1. Amino acid determination

[0064] The detection method was carried out according to GB 5009.124-2016.

[0065] The liquid chromatogram of the amino acids of the bamboo shoot lactobacillus powder was as shown in Figure 2 , and the percentage content distribution of each amino acid in the bamboo shoot lactobacillus powder was as shown in Table 1.

[0066] Table 1. Percentage content distribution of each amino acid in the bamboo shoot lactobacillus powder

[0067]

[0068] From Figure 2 and Table 1, it can be seen that the bamboo shoot lactobacillus powder prepared in the present application contains a variety of amino acids. The percentage content of crude protein is 14.74%.

[0069] 2. Dietary fiber determination

[0070] The detection method was carried out according to GB 5009.88-2023.

[0071] Through determination, the percentage content of dietary fiber in the bamboo shoot lactobacillus powder prepared in the present application was 5.38%, and the content of trace elements was high.

[0072] 3. Trace elements

[0073] The determination of iron, copper, manganese, zinc and selenium in the bamboo shoot lactobacillus powder was carried out by the national standard method, and details were shown in GB 5009.90-2016 Determination of Iron in Food, GB 5009.13-2017 Determination of Copper in Food, GB 5009.242-2017 Determination of Manganese in Food, GB 5009.14-2017 Determination of Zinc in Food, and GB 5009.93-2017 Determination of Selenium in Food.

[0074] Determination shows that the prepared bamboo shoot lactic acid bacteria powder has iron content of 11 mg / kg, manganese content of 9.3 mg / kg, copper content of 3.7 mg / kg, zinc content of 26 mg / kg and selenium content of 0.057 mg / kg.

[0075] 4. Sensory evaluation

[0076] The bamboo shoot lactic acid bacteria powder prepared in Example 1 is subjected to sensory evaluation, and 20 food professional students are selected, including 10 males and 10 females, with an age of 22-25 years old. The sensory evaluation indexes are shown in Table 2.

[0077] Table 2. Sensory evaluation index table

[0078]

[0079] The sensory evaluation results are as follows:

[0080] Taste: 16 evaluators think that "there is no peculiar smell, soft and refreshing, with a slight sour taste and sweet aftertaste", and 4 evaluators think that "there is no peculiar smell but slightly sour"; the average score is 27.

[0081] Aroma: 15 evaluators perceive "harmonious bamboo shoot fragrance and lactic acid bacteria fermentation flavor", and 5 evaluators think that "the bamboo shoot fragrance is light"; the average score is 25.

[0082] Color: 14 evaluators determine that "the particles are uniform, and the color is light yellow", 5 evaluators think that "the particles are uniform, and the color is light brown", and 1 evaluator thinks that "the particles are not uniform, and the color is light brown"; the average score is 17.

[0083] State: 13 evaluators observe that "the particles are uniform, and the hand feeling is delicate", 6 evaluators find that "the particles are slightly rough", and 1 evaluator finds that "the particles are not uniform and rough"; the average score is 16.

[0084] In summary, the bamboo shoot lactic acid bacteria powder is outstanding in taste and aroma indexes, and although there is a small amount of controversy in color and state, it is overall in line with the high-quality standard. The overall average score of sensory evaluation is 85.

[0085] The beneficial effects of the present application are demonstrated by the following experimental examples.

[0086] Experimental Example 1, Determination of the amount of bamboo shoot powder in the preparation of bamboo shoot lactic acid bacteria powder of the present application

[0087] Bamboo shoot powder was prepared according to the method described in Example 1, and the bamboo shoot powder dosage 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, and the viscosity of the system gradually increased and the fluidity gradually decreased when the water dosage was 24 mL. When the bamboo shoot powder dosage exceeded 1.5 g, the system had substantially no visible fluidity, and therefore the bamboo shoot powder dosage was determined to be 0.5 g-1.5 g.

[0088] Experimental Example 2, Determination of skimmed milk powder dosage in preparation of bamboo shoot lactic acid bacteria powder according to the present application

[0089] Bamboo shoot powder was prepared according to the method described in Example 1, and the bamboo shoot powder dosage was determined to be 1.0 g, and the water dosage was 24 mL. The skimmed milk powder concentration was set to 3wt%, 6wt%, 9wt%, 12wt%, and 15wt%, respectively, and the color and aroma of the system were observed after shaking in a test tube and stabilizing. It was found that the system gradually changed from light yellow to white, and the aroma gradually became stronger, but the fluidity gradually decreased and the system gradually thickened as the skimmed milk powder content increased. Based on the above indexes, the skimmed milk powder concentration was determined to be 3wt%-6wt%.

[0090] Example 3, Determination of the optimal formula in preparation of bamboo shoot lactic acid bacteria powder according to the present application

[0091] 1. Observation of the morphology of the culture solution

[0092] According to the method described in Example 1, only the bamboo shoot powder dosage (0.5 g, 1.0 g, 1.5 g) and the skimmed milk powder concentration (3wt%, 4wt%, 5wt%, and 6wt%) were changed, and the experimental groups were as follows:

[0093] Formula 1-1: bamboo shoot powder 0.5 g, skimmed milk powder concentration 3wt%; Formula 2-1: bamboo shoot powder 0.5 g, skimmed milk powder concentration 4wt%; Formula 3-1: bamboo shoot powder 0.5 g, skimmed milk powder concentration 5wt%; Formula 4-1: bamboo shoot powder 0.5 g, skimmed milk powder concentration 6wt%;

[0094] Formula 1-2: bamboo shoot powder 1.0 g, skimmed milk powder concentration 3wt%; Formula 2-2: bamboo shoot powder 1.0 g, skimmed milk powder concentration 4wt%; Formula 3-2: bamboo shoot powder 1.0 g, skimmed milk powder concentration 5wt%; Formula 4-2: bamboo shoot powder 1.0 g, skimmed milk powder concentration 6wt%;

[0095] Formula 1-3: bamboo shoot powder 1.5 g, skimmed milk powder concentration 3wt%; Formula 2-3: bamboo shoot powder 1.5 g, skimmed milk powder concentration 4wt%; Formula 3-3: bamboo shoot powder 1.5 g, skimmed milk powder concentration 5wt%; Formula 4-3: bamboo shoot powder 1.5 g, skimmed milk powder concentration 6wt%.

[0096] Each formulation group added bamboo shoot powder to ultrapure water, then added skim milk powder and 6wt% white sugar. Before inoculating the bacterial strain, the fermentation system was observed, and the results were as follows: Figures 3-5 As shown: The experimental group with a bamboo shoot powder content of 1.5 g (i.e., formulas 1-3, 2-3, 3-3, and 4-3) did not have flowability, so it was not inoculated or subsequently counted. The subsequent study only investigated the total bacterial count of the bamboo shoot lactic acid bacteria powder obtained from fermentation using formulas 1-1, 2-1, 3-1, 4-1, 1-2, 2-2, 3-2, and 4-2.

[0097] 2. Study on the total bacterial count of bamboo shoot lactic acid bacteria powder with different formulations

[0098] Bamboo shoot lactic acid bacteria powder was prepared according to the method described in Example 1 using formulas 1-1, 2-1, 3-1, 4-1, 1-2, 2-2, 3-2, and 4-2. The total bacterial count of the bamboo shoot lactic acid bacteria powder prepared using each formula was tested according to GB4789.35-2023. The results are as follows. Figure 6 As shown, by Figure 6 It can be seen that the total number of colonies in group 3-2 reached 3.4 × 10⁻⁶. 9 CFU, meaning this formula is the optimal formula. The number of live bacteria in the bamboo shoot lactic acid bacteria powder prepared by the optimal formula of this invention is significantly better than that of existing lactic acid bacteria powders.

[0099] Example 4: Determination of γ-aminobutyric acid (GABA) content in the bamboo shoot lactic acid bacteria powder of the present invention

[0100] Commercially available lactic acid bacteria powder: Instant-eat lactic acid bacteria probiotic powder (Hebei Yiran Biotechnology Co., Ltd.). The following method was used to quantitatively detect the γ-aminobutyric acid (GABA) content in each group of samples (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 in 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:

[0101] According to the A.1 ultraviolet detection method in QB / T 5633.7-2022 Amino acids, amino acid salts and their analogues Part 7: Gamma-aminobutyric acid, with slight modifications, the specific operation is as follows: GABA standard (50.3 mg) was dissolved in purified water to 200 mL, and then 0 mL, 5 mL, 12.5 mL, 20 mL, 27.5 mL, 35 mL, 42.5 mL of the solution was added to 5 mL of the derivative buffer (prepared by dissolving 4.2 g of NaHCO3 in 100 mL of water) and 2.5 mL of 1% 2,4-dinitrochlorobenzene (DNFB) acetonitrile solution, and then the reaction was carried out at 60°C water bath for 1 h; after cooling, the solution was diluted to 50 mL with 1.36 g / L potassium dihydrogen phosphate aqueous solution, and then filtered through a 0.22 μm filter membrane to obtain the test standard gradient solution.

[0102] The sample was weighed 200 mg, dissolved in purified water to 1 mL, and then 5 mL of the derivative buffer (prepared by dissolving 4.2 g of NaHCO3 in 100 mL of water) and 2.5 mL of 1% 2,4-dinitrochlorobenzene (DNFB) acetonitrile solution were added, and then the reaction was carried out at 60°C water bath for 1 h; after cooling, the solution was diluted to 10 mL with 1.36 g / L potassium dihydrogen phosphate aqueous solution, and then filtered through a 0.22 μm filter membrane to obtain the test sample. The mobile phase and elution conditions were not changed.

[0103] The GABA standard and sample liquid chromatograms are shown in Figures 7~10 The content of γ-aminobutyric acid (GABA) in different samples is shown in Table 3.

[0104] Table 3. Content of γ-aminobutyric acid (GABA) in different samples

[0105]

[0106] In the table, “-” represents not detected.

[0107] The above experimental data show that the GABA content (1589.51 mg / kg) of the bamboo shoot lactobacillus powder (formula 3-2) prepared in Example 1 is significantly higher than that of the pure bamboo shoot powder (1145.41 mg / kg). Compared with the commercially available lactobacillus powder, the GABA content of the bamboo shoot lactobacillus powder prepared in Example 1 is much higher than that of the commercially available lactobacillus powder (56.33 mg / kg). In addition, by comparing the bamboo shoot lactobacillus powders prepared by different formulas, it is found that the GABA content of the bamboo shoot lactobacillus powder prepared by other formulas is significantly reduced (less than 1300 mg / kg) compared with the bamboo shoot lactobacillus powder of Example 1, and the GABA content of the bamboo shoot lactobacillus powder prepared in Example 1 has a significant advantage. It is proved that the specific method of the present application can be used to prepare bamboo shoot lactobacillus powder with high GABA content.

[0108] Example 5, micro-morphology observation of the bamboo shoot lactobacillus powder of the present application

[0109] The bamboo shoot lactobacillus powder prepared in Example 1 was taken for SEM image observation to observe the morphological distribution of Lactobacillus plantarum R1 in the bamboo shoot lactobacillus powder. After vacuum drying and gold spraying treatment of the bamboo shoot lactobacillus powder, under high vacuum mode, using 15 kV accelerating voltage, under different magnifications, the integrity of Lactobacillus plantarum R1 (rod-shaped form retention), the adhesion state (adhesion, embedding or free) on the surface of the lactobacillus powder particles and the uniformity of its spatial distribution in the matrix were observed. The bamboo shoot powder prepared in Example 1 was used as a control.

[0110] The morphological distribution results of the bamboo shoot powder are shown in Figure 11 and Figure 12 The morphological distribution results of the bamboo shoot lactobacillus powder are shown in Figure 13 and Figure 14 It can be seen from the results of the bamboo shoot lactobacillus powder that under 2000 and 5000 magnifications, Lactobacillus plantarum R1 maintains the integrity of the rod-shaped form (length 1-3 μm), most of the bacterial bodies are tightly embedded in the network structure of the bamboo shoot powder, and part of them are adhered to the surface of the particles, which well forms the wrapping and protection of the bacterial bodies; the bacterial bodies are uniformly distributed under different fields of view without aggregation, which shows that the processing technology of the present application effectively maintains the morphological integrity of the probiotics and realizes uniform dispersion. The present application uses the special structure of bamboo shoot powder to well wrap and protect Lactobacillus plantarum.

[0111] In conclusion, the present application provides a bamboo shoot lactic acid bacteria powder rich in gamma-aminobutyric acid, which is prepared by fermenting a specific bamboo shoot-containing formula with Lactobacillus plantarum R1. The bamboo shoot lactic acid bacteria powder prepared by the present application has high contents of amino acids, dietary fibers and trace elements, good sensory evaluation, and high number of live bacteria, higher than existing lactic acid bacteria powder on the market. Meanwhile, the bamboo shoot lactic acid bacteria powder is rich in gamma-aminobutyric acid, and can be used to prepare food or health food with high gamma-aminobutyric acid content. Therefore, the present application has good application prospect.

Claims

1. A bamboo shoot lactic acid bacteria powder enriched with γ-aminobutyric acid, characterized by: It is the product of freeze-drying after Lactobacillus plantarum R1 is inoculated in culture solution and fermented; the Lactobacillus plantarum R1 is the strain preserved in China Center for Type Culture Collection, the preservation number of which is CCTCC NO: M 2022659; the culture solution contains 4-5% bamboo shoot powder, 5% skimmed milk powder and 6% white sugar by mass percentage, and the rest is water; the preparation method of the bamboo shoot powder comprises the following steps: Fresh Dendrocalamus latiflorus shoot is boiled for 3-15 minutes, then washed with water, dried, crushed and sieved to obtain the bamboo shoot powder. 2.The bamboo shoot lactic acid bacteria powder according to claim 1, characterized by: The inoculation amount of the Lactobacillus plantarum R1 is 6-10% by volume percentage; and / or, the concentration of the Lactobacillus plantarum R1 at the time of inoculation is 10 8 ~10 10 CFU / mL. 3.The bamboo shoot lactic acid bacteria powder according to claim 1, characterized by: The fermentation temperature is 37-43℃, and the fermentation time is 48-120 h.

4. The method of producing the bamboo shoot lactic acid bacteria powder according to any one of claims 1 to 3, characterized by: It comprises the following steps: (1) preparing culture solution: bamboo shoot powder, skimmed milk powder and white sugar are added into water, and the culture solution is obtained after sterilization; (2) inoculating Lactobacillus plantarum R1 in the culture solution to ferment, and obtaining fermentation solution; (3) freeze-drying the fermentation solution to obtain bamboo shoot lactobacillus powder.

5. The preparation method according to claim 4, characterized in that: in step (2), the inoculation amount of Lactobacillus plantarum R1 is 6-10% by volume percentage; And / or, in step (2), the concentration of Lactobacillus plantarum R1 at the time of inoculation is 10 8 ~10 10 CFU / mL; and / or, in step (2), the fermentation temperature is 37-43℃, and the fermentation time is 48-120 h.

6. Use of the bamboo shoot lactobacillus powder according to any one of claims 1-3 in the preparation of food.

7. Use of the bamboo shoot lactobacillus powder according to any one of claims 1-3 in the preparation of health food.

8. Use according to claim 7, characterized in that: The health food is health food that helps to improve sleep and / or helps to maintain a healthy level of blood pressure.

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