Preparation method and application of nitrite degradation agent

Abstract

The invention discloses a preparation method of a nitrite degradation agent, and belongs to the field of microbe application, the adopted preparation raw materials are all food-grade edible materials, the safety of the raw materials is high, and the nitrite degradation agent is prepared by compounding the preparation raw materials. Based on the film-forming property and cross-linking property of the enzymolysis soy isolate protein, the gel property of the pectin and the thermal stability of the maltodextrin, the enzymolysis soy isolate protein, the gelatin and the maltodextrin are doped as wall materials, and the probiotics are used as a core material to prepare the edible microcapsule, so that the thermal stability and the storage stability of the probiotics can be remarkably improved; the high survival rate can be guaranteed, and then the more excellent nitrate degradation effect is achieved. Besides, when the nitrite degrading agent prepared by the method is added into processing of prefabricated food, the nitrite degrading agent can play a role in degrading nitrite, and can also play a remarkable degrading effect in a high-concentration nitrite environment.

Description

Technical Field

[0001] The present invention relates to the technical field of microbial application, and in particular to a preparation method and application of a nitrite degrading agent. Background Art

[0002] There are many food safety issues in the processing and storage of pre-prepared foods, including microbial contamination and harmful substances produced during the processing, such as nitrite. In addition, as a food additive, improper use of nitrite will lead to high levels of residual nitrite in food, which has a certain impact on human health. Therefore, how to efficiently control the nitrite content in pre-prepared foods and reduce their dietary exposure risks is a technical problem that needs to be solved at present.

[0003] At present, the methods for degrading nitrite mainly include physical methods, chemical methods and biological methods. Biological methods are often used to degrade nitrite in food by adding functional microorganisms due to their high health and safety. Lactobacillus plantarum (LP), as a probiotic, is widely present in traditional fermented foods and has the characteristics of efficient nitrite degradation. More and more studies have shown that LP plays an important role in maintaining human health and is generally considered safe. However, probiotics are very sensitive to the external environment and are easily damaged by harmful factors such as high temperature, moisture, oxygen, high salt, and strong acid during food processing, transportation, and storage. After being ingested and entering the human body, they still need to undergo the test of adverse conditions such as strong gastric acid and bile salts. Therefore, it is difficult to colonize in the appropriate parts of the human body and exert physiological effects, and the resistance to adversity is poor.

[0004] For example, the Chinese patent publication number CN1990853A discloses a microbial nitrite degrading agent, which cultured Bacillus subtilis and nitrifying bacteria respectively, and then solidified the culture by centrifugation, adsorption and sodium alginate-calcium chloride embedding method, and finally mixed and granulated to obtain the product; the advantage of the invention is that it uses a specific fermentation method to make the product contain a large number of beneficial microorganisms and physiologically active metabolism; it uses a composite solidification method to fix multiple components on a special carrier, but it is applied to the purification of water quality and fails to solve the problem of nitrite resistance in food. Another example is that the Chinese patent publication number CN113234648A discloses a nitrite efficient degradation strain and its application, which is used to treat sewage, but still fails to solve the problem of poor resistance of probiotics. Summary of the invention

[0005] Based on this, in order to solve the technical problem that probiotics in the prior art have poor stress resistance during application, the present invention provides a preparation method and application of a nitrite degrading agent, and the specific technical scheme is as follows:

[0006] A method for preparing a nitrite degrading agent, wherein the nitrite degrading agent is used in food processing, and the preparation method comprises the following steps:

[0007] The probiotics are added to an edible liquid culture medium, and a probiotic culture solution is obtained after culturing, and then centrifuged to collect the bacterial bodies, and then washed several times with sterile physiological saline, and the washed bacterial bodies are suspended with sterile water to obtain a probiotic suspension;

[0008] Pectin is added to water, and magnetically stirred at a speed of 800 r / min to 1000 r / min and a temperature of 25° C. to dissolve until no crystals are found, and then enzymatically hydrolyzed soy protein isolate is added and stirred at a speed of 50 r / min to 100 r / min for 5 h to 8 h to form a mixture with a uniform texture, and then the probiotic suspension is added to the mixture, and the stirring is continued at a speed of 50 r / min to 100 r / min for 30 min to 60 min, and finally maltodextrin is added and stirred at a speed of 100 r / min to 250 r / min for 20 min to 60 min to prepare a probiotic microcapsule liquid;

[0009] The probiotic microcapsule liquid is spray-dried to obtain a nitrite degrading agent.

[0010] Furthermore, the probiotic is Lactobacillus plantarum HYY-DB9, which was deposited in Guangdong Provincial Microbiological Culture Collection Center on September 21, 2022, with a deposit number of CGMCC NO.62815 and a classification name of Lactiplantibacillus plantarum HYY-DB9.

[0011] Furthermore, the edible liquid culture medium includes the following components: (1.5-2) g / 100 mL glucose, (0.5-2) g / 100 mL beef powder, (0.5-2) g / 100 mL peptone, (0.7-1.5) g / 100 mL magnesium sulfate, (0.1-0.5) g / 100 mL organic acid and pure water.

[0012] Furthermore, the organic acid is obtained by mixing lactic acid and citric acid in a mass ratio of (1-3):(1-5).

[0013] Furthermore, the ratio of the probiotics to the edible liquid culture medium is (1-3) mg / 100 mL.

[0014] Furthermore, the probiotics are cultured at a temperature of 35°C to 38°C for 24 hours.

[0015] Furthermore, the centrifugal conditions are 6000r / min to 8000r / min, and the time is 10min to 15min.

[0016] Furthermore, the number of live bacteria in the probiotic suspension is (1.0-1.2)×10 9 CFU / mL.

[0017] Furthermore, the added amount of the pectin is (1-3) g / 100 mL, the added amount of the enzymatically hydrolyzed soy protein isolate is (8-12) g / 100 mL, and the added amount of the maltodextrin is (3-5) g / 100 mL.

[0018] Furthermore, the inlet temperature of the spray drying is 125°C to 135°C, and the outlet temperature is 65°C to 75°C.

[0019] Compared with the prior art, this application has the following beneficial effects:

[0020] 1. The raw materials used in the present invention are all food-grade edible materials with high safety. In addition, by compounding the raw materials, based on the film-forming property and cross-linking property of enzymatically hydrolyzed soy protein isolate, the gel property of pectin and the thermal stability of maltodextrin, enzymatically hydrolyzed soy protein isolate, gelatin and maltodextrin are added as wall materials, and probiotics are used as core materials to prepare edible microcapsules, which can significantly improve the thermal stability and storage stability of probiotics, and ensure a high survival rate thereof, thereby exerting a more excellent effect of degrading nitrates.

[0021] 2. The nitrite degrading agent prepared by the present invention is added to the processing of pre-prepared food, which can play its role in degrading nitrite and can also play a significant degradation effect in a high-concentration nitrite environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention can be further understood from the following description in conjunction with the accompanying drawings. The components in the figures are not necessarily drawn to scale, but the emphasis is placed on illustrating the principles of the embodiments. In different views, the same reference numerals designate corresponding parts.

[0023] Figure 1 Schematic diagram of the microstructure of the nitrite degradation agent of Example 1 of the present invention is a scanning electron microscope diagram and an optical microscope diagram;

[0024] Figure 2 Schematic diagram of the microstructure of the nitrite degradation agent of Example 2 of the present invention is a scanning electron microscope diagram and an optical microscope diagram;

[0025] Figure 3 Schematic diagram of the microstructure of the nitrite degradation agent of Example 3 of the present invention is a scanning electron microscope schematic diagram and an optical microscope schematic diagram;

[0026] Figure 4 Schematic diagram of the microstructure of the nitrite degradation agent of Comparative Example 1 of the present invention is a scanning electron microscope diagram and an optical microscope diagram;

[0027] Figure 5 This is a schematic diagram of the results of the nitrite degrading agent in Example 2 in the pre-prepared pickled fish test. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with its embodiments. It should be understood that the specific implementation methods described herein are only used to explain the present invention and do not limit the scope of protection of the present invention.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0030] A method for preparing a nitrite degrading agent in one embodiment of the present invention, wherein the nitrite degrading agent is used in food processing, comprises the following steps:

[0031] The probiotics are added to an edible liquid culture medium, and a probiotic culture solution is obtained after culturing, and then centrifuged to collect the bacterial bodies, and then washed several times with sterile physiological saline, and the washed bacterial bodies are suspended with sterile water to obtain a probiotic suspension;

[0032] Pectin is added to water, and magnetically stirred at a speed of 800 r / min to 1000 r / min and a temperature of 25° C. to dissolve until no crystals are found, and then enzymatically hydrolyzed soy protein isolate is added and stirred at a speed of 50 r / min to 100 r / min for 5 h to 8 h to form a mixture with a uniform texture, and then the probiotic suspension is added to the mixture, and the stirring is continued at a speed of 50 r / min to 100 r / min for 30 min to 60 min, and finally maltodextrin is added and stirred at a speed of 100 r / min to 250 r / min for 20 min to 60 min to prepare a probiotic microcapsule liquid;

[0033] The probiotic microcapsule liquid is spray-dried to obtain a nitrite degrading agent.

[0034] In one embodiment, the probiotic is Lactobacillus plantarum HYY-DB9, which was deposited in Guangdong Microbiological Culture Collection Center on September 21, 2022, with a deposit number of CGMCCNO.62815 and a classification name of Lactiplantibacillus plantarum HYY-DB9.

[0035] In one embodiment, the edible liquid culture medium includes the following ingredients: (1.5-2) g / 100 mL glucose, (0.5-2) g / 100 mL beef powder, (0.5-2) g / 100 mL peptone, (0.7-1.5) g / 100 mL magnesium sulfate, (0.1-0.5) g / 100 mL organic acid and pure water.

[0036] In one embodiment, the organic acid is obtained by mixing lactic acid and citric acid in a mass ratio of (1-3):(1-5).

[0037] In one embodiment, the ratio of the probiotics to the edible liquid culture medium is (1-3) mg / 100 mL.

[0038] In one embodiment, the probiotics are cultured at a temperature of 35° C. to 38° C. for 24 hours.

[0039] In one embodiment, the centrifugal condition is 6000r / min to 8000r / min, and the time is 10min to 15min.

[0040] In one embodiment, the number of live bacteria in the probiotic suspension is (1.0-1.2)×10 9 CFU / mL.

[0041] In one embodiment, the probiotic suspension accounts for 1% to 10% of the volume of the mixture.

[0042] In one embodiment, the added amount of pectin is (1-3) g / 100 mL, the added amount of enzymatically hydrolyzed soy protein isolate is (8-12) g / 100 mL, and the added amount of maltodextrin is (3-5) g / 100 mL.

[0043] In one embodiment, the inlet temperature of the spray drying is 125°C to 135°C, and the outlet temperature is 65°C to 75°C.

[0044] The nitrite degrading agent obtained by the above scheme has high thermal stability and storage stability, and can be applied in the processing of pre-prepared dishes to stably exert its nitrite degrading effect.

[0045] The embodiments of the present invention will be described in detail below with reference to specific examples.

[0046] Embodiment 1:

[0047] A method for preparing a nitrite degradation agent comprises the following steps:

[0048] 2 mg of Lactobacillus plantarum HYY-DB9 was added to 50 mL of edible liquid culture medium, and cultured at 37 °C for 24 h to obtain a probiotic culture solution, which was then centrifuged at 6000 r / min for 15 min, the supernatant was discarded, the cells were collected, and then washed twice with sterile saline, and the washed cells were suspended with sterile water to obtain a viable cell count of 10 9 CFU / mL of probiotic suspension;

[0049] 1 g of pectin was added to 100 mL of water, and magnetically stirred at a speed of 800 r / min and a temperature of 25° C. to dissolve until no crystals were found, and then 8 g of enzymatically hydrolyzed soy protein isolate was added and stirred at a speed of 100 r / min for 8 h to form a mixture with a uniform texture, and the volume ratio was 1:20, and then the probiotic suspension was added to the mixture, and the stirring was continued at a speed of 100 r / min for 45 min, and finally 3 g of maltodextrin was added, and stirred at a speed of 100 r / min for 30 min to prepare a probiotic microcapsule liquid;

[0050] The probiotic microcapsule liquid was spray-dried at an inlet temperature of 125° C. and an outlet temperature of 75° C. to obtain a nitrite degrading agent.

[0051] Embodiment 2:

[0052] A method for preparing a nitrite degradation agent comprises the following steps:

[0053] 2 mg of Lactobacillus plantarum HYY-DB9 was added to 50 mL of edible liquid culture medium, and cultured at 37 ° C for 24 h to obtain a probiotic culture solution, which was then centrifuged at 6000 r / min for 15 min, the supernatant was discarded, the cells were collected, and then washed twice with sterile saline, and the washed cells were suspended with sterile water to obtain a viable cell count of 10 9 CFU / mL of probiotic suspension;

[0054] 1 g of pectin was added to 100 mL of water, and magnetically stirred at a speed of 800 r / min and a temperature of 25° C. to dissolve until no crystals were found, and then 8 g of enzymatically hydrolyzed soy protein isolate was added and stirred at a speed of 100 r / min for 8 h to form a mixture with a uniform texture, and the volume ratio was 1:20, and then the probiotic suspension was added to the mixture, and the stirring was continued at a speed of 100 r / min for 45 min, and finally 4 g of maltodextrin was added, and stirred at a speed of 100 r / min for 30 min to prepare a probiotic microcapsule liquid;

[0055] The probiotic microcapsule liquid was spray-dried at an inlet temperature of 130° C. and an outlet temperature of 70° C. to obtain a nitrite degrading agent.

[0056] Embodiment 3:

[0057] A method for preparing a nitrite degradation agent comprises the following steps:

[0058] 2 mg of Lactobacillus plantarum HYY-DB9 was added to 50 mL of edible liquid culture medium, and cultured at 37 ° C for 24 h to obtain a probiotic culture solution, which was then centrifuged at 6000 r / min for 15 min, the supernatant was discarded, the cells were collected, and then washed twice with sterile saline, and the washed cells were suspended with sterile water to obtain a viable cell count of 10 9 CFU / mL of probiotic suspension;

[0059] 1 g of pectin was added to 100 mL of water, and magnetically stirred at a speed of 800 r / min and a temperature of 25° C. to dissolve until no crystals were found, and then 8 g of enzymatically hydrolyzed soy protein isolate was added and stirred at a speed of 100 r / min for 8 h to form a mixture with a uniform texture, and the volume ratio was 1:20, and then the probiotic suspension was added to the mixture, and the stirring was continued at a speed of 100 r / min for 45 min, and finally 5 g of maltodextrin was added, and stirred at a speed of 100 r / min for 30 min to prepare a probiotic microcapsule liquid;

[0060] The probiotic microcapsule liquid was spray-dried at an inlet temperature of 135° C. and an outlet temperature of 75° C. to obtain a nitrite degrading agent.

[0061] Comparative Example 1:

[0062] The difference between Comparative Example 1 and Example 3 is that maltodextrin is not added in Comparative Example 1, and the rest is the same as Example 3.

[0063] Comparative Example 2:

[0064] The difference between Comparative Example 2 and Example 3 is that the added amount of maltodextrin in Comparative Example 2 is 1 g / 100 mL, and the others are the same as Example 3.

[0065] Comparative Example 3:

[0066] The difference between Comparative Example 3 and Example 3 is that the added amount of maltodextrin in Comparative Example 3 is 10 g / 100 mL, and the others are the same as Example 3.

[0067] Comparative Example 4:

[0068] The difference between Comparative Example 4 and Example 3 is that no enzymatically hydrolyzed soy protein isolate is added in Comparative Example 4, and the rest is the same as Example 3.

[0069] The nitrite degradation agent samples prepared in Examples 1 to 3 and the nitrite degradation agent comparison samples prepared in Comparative Examples 1 to 4 were subjected to stability tests.

[0070] 1. Scanning electron microscope test method for microstructure of nitrite degrading agent:

[0071] The microstructure of the surface of the nitrite degrading agent is observed to determine whether the probiotics are successfully embedded and whether the nitrite degrading agent is successfully prepared. The dried nitrite degrading agent is observed under an optical microscope, and after gold spraying, it is placed on a scanning electron microscope sample test table to observe its microscopic morphology.

[0072] The test objects are the nitrite degradation agent samples prepared in Examples 1 to 3 and the nitrite degradation agent comparison sample of Comparative Example 1. Figure 1 Schematic diagram of the microstructure of the nitrite degradation agent of Example 1 of the present invention is a scanning electron microscope schematic diagram and an optical microscope schematic diagram; Figure 2 Schematic diagram of the microstructure of the nitrite degradation agent of Example 2 of the present invention is a scanning electron microscope schematic diagram and an optical microscope schematic diagram; Figure 3 Schematic diagram of the microstructure of the nitrite degradation agent of Example 3 of the present invention is a scanning electron microscope schematic diagram and an optical microscope schematic diagram;

[0073] Figure 4 It is a scanning electron microscope schematic diagram and an optical microscope schematic diagram of the microstructure of the nitrite degradation agent of Comparative Example 1 of the present invention.

[0074] Depend on Figures 1 to 4 It can be seen that the Lactobacillus plantarum HYY-DB9 in the embodiment of the present application is successfully embedded, presenting a spherical microcapsule state of similar size, with obvious white bright spots evenly distributed in the microcapsule pores, but the probiotics (Lactobacillus plantarum HYY-DB9) in Comparative Example 1 are not embedded, indicating that the addition of maltodextrin in the present application helps to promote the embedding rate of Lactobacillus plantarum HYY-DB9, thereby ensuring its stability in use.

[0075] 2. Thermal stability test

[0076] The nitrite degrader was placed in a hot and humid environment to evaluate the thermal stability of the nitrite degrader. First, 0.2 g of nitrite degrader was weighed into a sterilized EP tube, 4.8 mL of sterile phosphate buffer was added, and heat-treated at 55°C, 65°C, and 75°C for 10 min. After the heat treatment, 15 mL of phosphate buffer was added to the sterile tube, which was rapidly cooled. Finally, the dilution plate method was used to count the viable bacteria and calculate the survival rate. The results are shown in Table 1 below.

[0077] Table 1:

[0078]

[0079]

[0080] From the data analysis of Table 1, it can be seen that after optimizing the components and component ratios, the nitrite degrading agent prepared in the present application still has a high survival rate in an environment of 55°C to 75°C, and the overall thermal stability is excellent.

[0081] 3. Storage stability test

[0082] The nitrite degrading agent obtained by spray drying was collected in a sterile glass bottle and stored at 4°C for 4 weeks. 0.1 g of nitrite degrading agent was weighed into a sterile EP tube every week, 19.9 mL of phosphate buffer was added, and then the viable bacteria were counted by the dilution plate method and the survival rate was calculated. The results are shown in Table 2 below.

[0083] Table 2: Storage stability

[0084] Survival rate (%) 0d 7d 14d 21d 28d Example 1 100±0.00 99.56±0.33 98.11±0.63 97.26±0.49 93.66±0.84 Example 2 100±0.00 99.98±0.01 98.52±0.99 98.36±1.07 95.36±0.09 Example 3 100±0.00 99.43±0.91 98.81±0.13 97.14±0.36 94.74±0.36 Comparative Example 1 100±0.00 95.16±0.64 90.25±0.25 89.05±0.89 86.19±0.94 Comparative Example 2 100±0.00 90.23±0.38 88.26±0.34 85.23±0.68 79.87±0.37 Comparative Example 3 100±0.00 95.26±0.45 90.27±0.46 85.26±0.37 76.89±0.46 Comparative Example 4 100±0.00 94.37±0.34 90.23±0.76 84.37±0.28 77.56±0.29

[0085] From the data analysis of Table 2, it can be seen that the nitrite degrading agent of the present application still has a high survival rate after storage for 28 days.

[0086] 4. The nitrite degrading agent was applied to the pre-prepared pickled fish, and the nitrite degrading agent prepared in Example 2 with high thermal stability and storage stability was used as the test sample. The specific method is as follows:

[0087] Prepare the pre-prepared sauerkraut fish dish, the production steps are as follows: thaw the pre-prepared fish meat without pulp, wash the sauerkraut and set aside; sauté the garlic, ginger and chili with a little oil, then pick out and add to the sauerkraut to stir-fry until fragrant; add cold water and boil, then add the thawed fish meat without pulp; wait for the soup to boil again and the fish meat to change color before turning off the heat and serving. Divide the prepared sauerkraut fish into equal proportions, add different concentrations of nitrite (0, 2.5, 5, 7.5, 10, 12.5 mmol / L) and the nitrite degrading agent prepared in Example 2, place at room temperature, and take the soup every 12 hours to measure the nitrite content, number of viable bacteria, pH and total acid content. The results are as follows Figure 5 shown.

[0088] Figure 5 This is a schematic diagram of the results of the nitrite degradation agent in Example 5 in the pre-prepared pickled fish test. Figure 5 A. is pH; B is total acid content; C is nitrite content after adding nitrite degrading agent; D is the number of viable probiotic bacteria. NIT0-12.5 means that the nitrite concentration in pickled fish is 0-12.5mmol / L. Figure 2 It can be seen from the analysis that the nitrite degrading agent prepared by the present invention can reduce the nitrite content in pre-prepared pickled fish, and also has a significant degradation effect in pickled fish with high nitrite concentration (12.5mmol / L). During the degradation process, the pH decreases, the total acid content increases, and the number of live bacteria increases, indicating that the organic acids, bacteriocins and other metabolites produced by probiotics and the organic acids released by microcapsules may play a major role in degrading nitrite.

[0089] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0090] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for preparing a nitrite degradation agent, characterized in that: The nitrite degradation agent is used in food processing, and the preparation method comprises the following steps: The probiotics are added to an edible liquid culture medium, and a probiotic culture solution is obtained after culturing, and then centrifuged to collect the bacterial bodies, and then washed several times with sterile physiological saline, and the washed bacterial bodies are suspended with sterile water to obtain a probiotic suspension; Pectin is added to water, and magnetically stirred at a speed of 800 r / min to 1000 r / min and a temperature of 25° C. to dissolve until no crystals are found, then enzymatically hydrolyzed soy protein isolate is added and stirred at a speed of 50 r / min to 100 r / min for 5 h to 8 h to form a mixture with a uniform texture, then the probiotic suspension is added to the mixture, and the mixture is continuously stirred at a speed of 50 r / min to 100 r / min for 30 min to 60 min, and finally maltodextrin is added and stirred at a speed of 100 r / min to 250 r / min for 20 min to 60 min to prepare a probiotic microcapsule liquid; The probiotic microcapsule liquid is spray-dried to obtain a nitrite degrading agent.

2. The preparation method according to claim 1, characterized in that: The probiotic is Lactobacillus plantarum HYY-DB9, which was deposited in the Guangdong Provincial Microbiological Culture Collection Center on September 21, 2022, with the preservation number CGMCC NO.62815 and the classification name Lactiplantibacillus plantarum HYY-DB9.

3. The preparation method according to claim 1, characterized in that: The edible liquid culture medium includes the following components: (1.5-2) g / 100 mL glucose, (0.5-2) g / 100 mL beef powder, (0.5-2) g / 100 mL peptone, (0.7-1.5) g / 100 mL magnesium sulfate, (0.1-0.5) g / 100 mL organic acid and pure water.

4. The preparation method according to claim 3, characterized in that: The organic acid is obtained by mixing lactic acid and citric acid in a mass ratio of (1-3):(1-5).

5. The preparation method according to claim 1, characterized in that: The ratio of the probiotics to the edible liquid culture medium is (1-3) mg / 100 mL.

6. The preparation method according to claim 2, characterized in that: The probiotics are cultured at a temperature of 35° C. to 38° C. for 24 hours.

7. The preparation method according to claim 1, characterized in that The centrifugal conditions are 6000r / min to 8000r / min, and the time is 10min to 15min.

8. The preparation method according to claim 1, characterized in that: The number of live bacteria in the probiotic suspension is (1.0-1.2)×10 9 CFU / mL.

9. The preparation method according to claim 1, characterized in that: The added amount of the pectin is (1-3) g / 100 mL, the added amount of the enzymatically hydrolyzed soy protein isolate is (8-12) g / 100 mL, and the added amount of the maltodextrin is (3-5) g / 100 mL.

10. The preparation method according to claim 1, characterized in that: The inlet temperature of the spray drying is 125°C to 135°C, and the outlet temperature is 65°C to 75°C.

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