CN118203116A - A method for maintaining probiotic activity and active protection composition - Google Patents

Abstract

The invention relates to the technical field of microorganisms, in particular to a method for maintaining the activity of probiotics and an activity protection composition. The method comprises adding an active protective composition to a probiotic powder; the active protection composition comprises milk powder and sodium citrate, wherein the mass ratio of the milk powder to the sodium citrate is 10-25:1. The acid and alkali salt resistance of the probiotics can be effectively improved by adding the active protective composition comprising whole milk or skim milk powder and sodium citrate into the probiotics; the further active protection method and the active protection composition can ensure that the microbial probiotics in the prepared probiotic powder keep low water activity by matching with the granulation process, maintain high viable bacteria number and have good powder bagging process compliance.

Description

A method for maintaining the activity of probiotics and an activity protection composition

Technical Field

The present invention relates to the field of microbial technology, and in particular to a method for maintaining the activity of probiotics and an activity protection composition.

Background technique

In 2001, the World Health Organization and the Food and Agriculture Organization of the United Nations jointly defined "probiotics". When ingested in appropriate quantities, live bacteria that can play a beneficial role in the health of the host are called probiotics. In recent years, scientific research has shown that probiotics colonize the host's intestines and play a beneficial role in the host by improving the balance of intestinal microecology, such as regulating host immunity and improving host metabolism. Related research results have brought broad application prospects for probiotics in the field of biomedicine. In recent years, many probiotic drugs around the world have been in clinical research. In probiotic products, "live strains" and "sufficient numbers" are the two core elements of probiotics. However, as microorganisms, probiotics are very fragile and easily affected by environmental factors. At present, many probiotic products die in large numbers during production, processing and environmental storage, and the number of live bacteria is low. At the same time, surviving probiotics need to pass through multiple biological barriers to reach the human intestine. The tolerance and adhesion ability of probiotics to the gastrointestinal tract are necessary conditions for them to exert their physiological effects. Among the many defense mechanisms of the human body, the strong acid environment provided by gastric juice and the high bile salt environment provided by intestinal juice have the greatest impact on the activity of microorganisms. After bacteria enter the digestive tract from the mouth, the gastric acid, bile salts, digestive enzymes, electrolytes, etc. contained in the stomach and small intestine environment will affect the activity of microorganisms, affect the composition of the biofilm, change the fluidity of the biofilm, affect the microorganism's absorption of nutrients and the excretion of metabolic products, and cause damage to or even inactivate the microorganisms.

Powders, with their mature bag-packing technology, high consumer acceptance, and wide application in the sales of ordinary foods and health foods, have been widely developed and applied as the main dosage form of probiotic products on the market. Probiotic powders are a kind of bacterial agent made from approved active microorganisms through fermentation, enrichment, emulsification or non-emulsification, drying or non-drying, addition or non-addition of excipients, mixing or non-mixing, packaging and other processes. At present, how to maintain the number of live bacteria in probiotic-related products represented by probiotic powders has become one of the focuses of the industry's research and development and innovation process.

Chinese invention patent application CN108813450A discloses a powder composition for improving intestinal microorganisms and a preparation method thereof, which contains dietary fiber, vegetable composition, fruit composition and prebiotics, and each 100g contains: 20-60% dietary fiber; 15-40% vegetable composition; 10-50% fruit composition; 5.0-8.5 billion CFU of prebiotics. The powder composition for improving intestinal microorganisms and the preparation method thereof can quickly supplement the more effective probiotic vitality combination containing lactic acid bacteria and bifidobacteria from the intestines, and bacillus that creates an environment for reproduction in the intestines, so that the human stomach and intestines are in a benign and healthy environment.

Chinese invention patent application CN111066888A discloses a probiotic powder, which includes the following components by mass: 5-10 parts of probiotic powder, 300-350 parts of probiotic protective agent, and 20-30 parts of sweetener. The probiotic powder includes plant lactobacillus, bifidobacterium bifidum, and lactobacillus casei, and the total bacterial content of the probiotic powder is greater than 16 billion cfu/g, wherein lactobacillus casei accounts for 55%-65% of the total weight of the probiotic powder. The probiotic protective agent includes skim milk, inulin, trehalose, maltodextrin and cereal fiber powder, wherein skim milk accounts for 50%-60% of the total weight of the probiotic protective agent, and cereal fiber powder accounts for 20%-30% of the total weight of the probiotic protective agent. The invention can effectively regulate intestinal flora, promote the growth of probiotics in the intestine, and ensure the amount of live probiotics in the intestine. Probiotic protective agents play a protective role on probiotic powder, especially the combination of cereal fiber and skim milk, which can reduce the loss of probiotics in extreme environments such as gastric acid and bile, and increase the amount of live bacteria when they reach the intestines.

After industrial production, factors such as oxygen and moisture will have a serious impact on the activity of probiotics during the long shelf life. In addition, after eating, due to the increase in stomach contents, the pH value of gastric juice will rise to about 3-4 in a short period of time, and the bile salts secreted by the liver will enter the small intestine in large quantities along with the bile. The low pH and high bile salt environment of the gastrointestinal tract will also have a serious impact on the activity of probiotics. Therefore, whether the strain can resist various environmental factors during the shelf life, as well as the complex environment of low pH and high bile salts in the body, and successfully reach the intestine to survive, reproduce and have metabolic activity, is one of the key indicators for testing product quality.

In the prior art, a large number of probiotic-related products have not effectively considered various environmental factors of the shelf life, as well as the survival of the product after ingestion through the lower digestive tract (especially affected by factors such as gastric juice, bile salts and intestinal juice), which seriously affects the actual effect and quality of the probiotic powder. Some prior art mentions probiotic protective agents, but does not fully consider various influencing factors, and there are problems such as the complex composition of the protective agent system and the protection effect has not been scientifically verified. Taking CN111066888A as an example, its protective agent is composed of skim milk, inulin, trehalose, maltodextrin and cereal fiber powder. The protective agent is complex in composition, and the protection effect has not been scientifically verified, which affects the applicability of the system in probiotic products. It can be seen that the prior art lacks probiotic protective agents and product formulas with wide applicability and good protection effect.

How to develop a method for protecting the active probiotics with wide adaptability and good protection effect, and provide an active protection composition that can significantly improve the survival rate of live bacteria through the lower digestive tract of the human body, and effectively improve the stability of live bacteria during the shelf life of the product is a technical problem that needs to be urgently solved in this field.

Summary of the invention

Through extensive research, the present invention unexpectedly discovered a simple and effective method for maintaining the activity of probiotics and an activity protection composition, which can not only significantly improve the survival rate of live bacteria through the lower digestive tract of the human body, but also effectively improve the stability of live bacteria during the shelf life of the product.

The present invention is achieved through the following technical solutions:

The first aspect of the present invention provides a method for maintaining the activity of probiotics, the method comprising adding an activity protection composition to probiotic powder; the activity protection composition comprises milk powder and sodium citrate, and the mass ratio of the milk powder to the sodium citrate is 10-25:1.

Preferably, the active protective composition is prepared by mixing, granulating and sieving the milk powder and sodium citrate; the sieving specifically comprises: the active protective composition is sieved through a 180-220 mesh sieve, the content of the sieve under material is less than 60% of the total amount, the sieve under material is sieved through a 35-45 mesh sieve, the content of the sieve under material is greater than 90% of the total amount, and the sieve under material is sieved through a 10-20 mesh sieve, the content of the sieve under material is equal to 100%.

The second aspect of the present invention provides an active protective composition for maintaining the activity of probiotics, wherein the active protective composition comprises milk powder and sodium citrate, wherein the mass ratio of the milk powder to the sodium citrate is 10-25:1.

Preferably, the mass ratio of the milk powder to sodium citrate is 15-25:1.

Preferably, the active protective composition further comprises a filler, and the mass ratio of the filler: milk powder: sodium citrate is 150-180:15-25:1.

Further preferably, the filler is selected from at least one of dietary fiber, sugar alcohol, oligosaccharides and fruit juice powder, wherein the dietary fiber is selected from at least one of resistant dextrin and maltodextrin, the sugar alcohol is selected from at least one of erythritol and maltitol, and the oligosaccharides are selected from at least one of fructo-oligosaccharides and galacto-oligosaccharides.

Further preferably, the filler comprises resistant dextrin, erythritol and maltitol, and the mass ratio of the resistant dextrin, erythritol and maltitol is 3-5:2-3:2-3.

Preferably, the active protective composition is prepared by the following steps:

(1) mixing a filler, whole milk powder or skim milk powder, and sodium citrate to obtain a mixture A;

(2) The mixture A is placed in a granulator for granulation, and dried to a moisture content of less than 0.5% and a water activity of less than 0.1, and sieved to obtain the active protective composition.

Further preferably, the sieving standard in step (2) is: after passing through a 180-220 mesh sieve, the content of the sieve undersize is less than 60% of the total amount; after passing through a 35-45 mesh sieve, the content of the sieve undersize is greater than 90% of the total amount; after passing through a 10-20 mesh sieve, the content of the sieve undersize is equal to 100%.

Further preferably, the sieving standard in step (2) is: after passing through a 200-mesh sieve, the content of the sieve undersize is less than 60% of the total amount; after passing through a 40-mesh sieve, the content of the sieve undersize is greater than 90% of the total amount; after passing through a 10-mesh sieve, the content of the sieve undersize is equal to 100%.

The third aspect of the present invention is to provide a high-activity probiotic powder comprising the above-mentioned active protection composition.

Preferably, the mass ratio of the probiotic powder to the active protection composition in the probiotic powder is 80-100:1-15.

Preferably, the probiotic is selected from the group consisting of Bifidobacterium, Lactobacillus, Lactobacillus casei, Lactobacillus mucosus, Lactobacillus plantarum, Lactobacillus unisomeris, Lactobacillus spp., Streptococcus, Lactococcus, Propionibacterium, Propionibacterium, Leuconostoc, Pediococcus, Weizmannella, Zoococcus, Staphylococcus, or any combination thereof.

In certain embodiments, the probiotic of the genus Bifidobacterium is selected from the group consisting of Bifidobacterium adolescentis, Bifidobacterium animalis subsp. animalis, Bifidobacterium animalis subsp. lactis, Bifidobacterium bifidum, Bifidobacterium breve, Bifidobacterium longum subsp. infantis, Bifidobacterium longum subsp. longum, or any combination thereof.

In certain embodiments, the probiotic of the genus Lactobacillus is selected from: Lactobacillus acidophilus, Lactobacillus crispatus, Lactobacillus delbrueckii subsp. bulgaricus, Lactobacillus delbrueckii subsp. lactis, Lactobacillus gasseri, Lactobacillus helveticus, Lactobacillus johnsonii, Lactobacilus kefiranofaciens subsp. Kefiranofaciens, or any combination thereof.

In certain embodiments, the probiotic bacteria of the genus Lactobacillus are selected from the group consisting of Lactobacillus casei, Lactobacillus brevis, Lactobacillus paracasei, Lactobacillus rhamnosus, or any combination thereof.

In certain embodiments, the probiotic bacteria of the genus Lactobacillus are selected from: Limosilactobacillus fermentum, Limosilactobacillus reuteri, or a combination thereof.

In certain embodiments, the probiotic of the genus Lactobacillus is Lactobacillus plantarum.

In certain embodiments, the probiotic of the genus Lactobacillus is Ligilactobacillus salivarius.

In certain embodiments, the probiotic Streptococcus is Streptococcus salivarius subsp. thermophilus.

In certain embodiments, the probiotic bacteria of the genus Propionibacterium is Propionibacterium freudenreichii subsp. shermanii.

In certain embodiments, the probiotic bacteria of the genus Propionibacterium is Propionibacterium acidipropionici.

In certain embodiments, the probiotic bacteria of the genus Lactococcus are selected from: Lactococcus lactis subsp. Lactis, Lactococcus lactis subsp. Lactis biovar diacetylactis, Lactococcus cermoris, or any combination thereof.

Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention combines whole-fat or skimmed milk powder and sodium citrate in a certain proportion, and controls the particle size of the composition within a certain range through a granulation process. The prepared active protective composition can effectively ensure the water activity, and has good powder bag packaging process compliance, and can significantly improve the survival rate of live bacteria passing through the lower digestive tract of the human body; (2) The active protective composition prepared by the present invention is combined with probiotics and other food ingredients to produce a probiotic powder product, whose water activity value is less than 0.15, and can significantly improve the stability of live bacteria, fully ensuring the quality requirements of the number of live bacteria during the shelf life of the product; (3) The active protective composition prepared by the present invention has simple ingredients and wide applicability, and can be widely used in various probiotic powder products.

Detailed ways

The technical solutions in the embodiments of the present invention are further clearly described. The described embodiments are only a part of the present invention and are used to explain the present invention but not to limit the present invention. Therefore, other embodiments obtained by other technicians in the field without creative work all belong to the protection scope of the present invention.

The raw materials used in the embodiments of the present invention are all commercially available.

Example 1

On the basis of adding the same filler (resistant dextrin is selected in this example), whole milk powder or skim milk powder and sodium citrate are used as components, and the amount of each component is adjusted to form an active protection composition; and its pH in a hydrochloric acid solution of pH 3.0 is tested to evaluate the buffering capacity of different formula samples. In order to meet the future application of the composition in probiotic powder products, water activity and total viable bacteria count are added as screening items.

Preparation:

(1) Weighing and preparing materials: weigh whole milk powder or skim milk powder, sodium citrate, resistant dextrin and probiotic powder according to the formula. The specific formula is shown in Table 1-1;

(2) Mixing and granulation: whole milk powder or skim milk powder, sodium citrate and resistant dextrin are placed in a mixer, mixed evenly, placed in a granulator, spray granulated, and dried to a moisture content of less than 0.5% to obtain an active protective composition having a particle size of 100% passing through a 10-mesh sieve, more than 90% passing through a 40-mesh sieve, and less than 60% passing through a 200-mesh sieve;

(3) Total mixing: Put the probiotic powder (Bifidobacterium animalis subsp. lactis HN019: Lactobacillus rhamnosus GG: Lactobacillus rhamnosus HN001=1:1:1) and the above composition into a mixer, mix well and then discharge to obtain a probiotic powder.

Detection method:

The specific operation of the pH value and total viable bacteria count of the sample before acid treatment is as follows: 1.0 g of the sample is dissolved in an appropriate amount of physiological saline (0.9%, 99.0 mL) to prepare a sample solution and measure its pH value; then the total probiotic count is detected using GB4789.35.

The detection of water activity can refer to GB5009.238-2016, National Food Safety Standard Determination of Water Activity of Food.

The specific operation of acid treatment and detection of total viable bacteria of samples is as follows: 25.0g of samples with different proportions are dissolved in 225mL of pH 3.0 hydrochloric acid solution, shaken at 37℃ for 2h, and then the total number of probiotics is detected using GB4789.35. The test results are shown in Table 1-2.

Table 1-1 Sample formulas of different ratios of whole or skim milk powder and sodium citrate

Table 1-2 Test results of sample formulas with different ratios of whole-fat or skimmed milk powder and sodium citrate

Selection criteria: (1) In order to ensure the biological activity of probiotics, formulas with a probiotic survival rate greater than 80% are preferred. (2) Water activity reflects the degree of water binding (free degree) in food. The higher the value, the lower the degree of binding, and vice versa. Water activity is an important indicator of food preservation performance, and water activity has an important impact on the shelf life of probiotic products. Considering the specificity of the strain, production cost, processing technology and other aspects, it is generally believed that the water activity of powder products containing probiotics should be controlled below 0.20. And in accordance with the requirements of GB5009.238, the specific results are retained to two significant figures. Therefore, in order to meet the quality requirements of probiotic powder products, formulas with a water activity of less than 0.20 and an acid treatment survival rate greater than 80% are preferred.

From the above results, it can be seen that based on the pH detection values of different combination formulas in pH 3.0 solution and their viable bacterial survival rates, as well as the water activity of the samples, test groups 1-6, 1-7, 1-8 and 1-9 can all meet the screening requirements.

Example 2

Based on the results of Example 1, this example tests the probiotic powder samples obtained from test groups 1-7 and 1-8 with acid treatment survival rates greater than 90% to verify the tolerance of the two groups in simulated human standard gastric fluid (SGF).

The specific operations are as follows:

(1) Preparation of simulated human standard gastric juice (SGF): weigh 2.0 g of NaCl and 3.2 g of pepsin (800-2500 active units per mg), add 7.0 ml of concentrated HCl, and make up to 1000 ml with distilled water. Mix well and adjust the pH to 3.0. Let stand for 2 h, filter and sterilize before use.

(2) Preheat the simulated gastric fluid to 37°C, dilute the probiotic powder sample (10-fold dilution, 25 g probiotic powder sample + 225 ml SGF), mix well, shake at 37°C for 2 hours, and then test the total number of probiotics according to GB 4789.35-2023. The test results are shown in Table 2.

Table 2 Simulated gastric juice tolerance results of samples with different ratios of whole or skim milk powder and sodium citrate

From the above results, it can be seen that test groups 1-7 and test groups 1-8 have good tolerance in simulated human gastric juice, and the survival rate of live probiotics in both groups exceeds 80%.

Example 3

Based on the results of Example 2, this example further verifies the tolerability of the test group formula samples formed by using the above active protective composition and probiotic powder under simulated lower digestive tract conditions. Correspondingly, a control group formula sample without adding the above active protective composition is set up.

The specific operations are as follows:

(1) Test group formula: resistant dextrin (339 mg) + erythritol (212 mg) + maltitol (212 mg) + probiotic powder (132 mg, Lactobacillus rhamnosus GG: Bifidobacterium animalis subsp. lactis BL-04: Bifidobacterium animalis subsp. lactis Bi-07: Lactobacillus acidophilus NCFM = 3:1:1:1) + whole milk powder (100 mg) + sodium citrate (5 mg);

(2) Comparative group formula: resistant dextrin (388 mg) + erythritol (240 mg) + maltitol (240 mg) + probiotic powder (132 mg, Lactobacillus rhamnosus GG: Bifidobacterium animalis subsp. lactis BL-04: Bifidobacterium animalis subsp. lactis Bi-07: Lactobacillus acidophilus NCFM = 3:1:1:1);

(3) Preparation of simulated human standard gastric juice (SGF): weigh 2.0 g of NaCl and 3.2 g of pepsin (800-2500 active units per mg), add 7.0 mL of concentrated HCl, and dilute to 1000 mL with distilled water. After mixing well, adjust the pH value to 3.0, let stand for 2 h, filter and sterilize, and set aside.

(4) Preparation of simulated intestinal fluid containing 0.3% bile salts: Weigh 6.8 g potassium dihydrogen phosphate, dissolve it with an appropriate amount of _dH2O , add 77 mL 0.2 mol/L NaOH, make up to 1000 mL, sterilize, add 10.0 g pancreatic enzyme and 3.0 g bile salts, mix well, adjust the pH to 6.8 with HCl or NaOH solution, let stand, filter and sterilize for later use.

(5) Under sterile conditions, weigh 25 g of the test group and control group samples respectively into sterile containers, add 225 mL of simulated gastric fluid (SGF) respectively, homogenize for 1 to 2 min to dissolve the samples, and incubate anaerobically at 37 °C for 2 h;

(6) Take 25 mL of the sample solution treated with simulated gastric juice for 2 hours, add 225 mL of simulated intestinal juice containing 0.3% bile salt, mix well, incubate at 37°C for 2 hours, and measure the total number of lactic acid bacteria according to GB 4789.35. The test results are shown in Table 3.

Table 3 Tolerance test results of different formula samples under simulated human lower digestive tract conditions

From the above results, it can be seen that compared with the control group without adding the active protective composition, the test group with added active protective composition has significantly improved tolerance in conditions simulating the lower digestive tract of the human body, which can better help probiotics resist interference from factors such as gastric acid, bile salts and intestinal fluid in the human body, and improve the survival rate of live bacteria through the lower digestive tract of the human body.

Example 4

In order to meet the requirements of the probiotic powder production process on material fluidity, this example examines the compliance of the above-mentioned active protective composition with the bag packaging process at different particle sizes after granulation.

Preparation:

(1) Weighing and preparing materials: Weigh 860 mg of resistant dextrin, 35 mg of probiotic powder (Lactobacillus paracasei LPB27: Lactobacillus plantarum 6595 = 2:1), 100 mg of whole milk powder and 5 mg of sodium citrate respectively;

(2) Mixing and granulating: placing whole milk powder, sodium citrate and resistant dextrin in a mixer, adjusting spraying conditions, controlling the particle size of powder granulation, and obtaining an active protective composition;

(3) Total mixing: putting the probiotic powder and the active protection composition into a mixer, mixing them evenly and then discharging the mixture to obtain a probiotic powder;

(4) Packaging: Adjust the equipment to control the net weight to an average of 1.0 g per bag, with a packing difference of ±6.5% per bag. Check the packing difference and appearance every 30 minutes.

In the above formula, the powders were prepared in the same production environment, the same granulation equipment, the same mixing equipment, and the same bagging machine. The active protective compositions of different particle sizes were replaced to investigate the sealing and loading differences in the powder preparation process. The particle size and test results are shown in Table 4.

Table 4 Process compliance and taste scores of powders containing active protective compositions of different particle sizes

Note: (1) Oral dissolution score: 0-10 points, powder clumping and sticking to teeth - powder dissolving without residue feeling; (2) Coarseness score index: 0-10 points, high particle size - high fineness. (3) Selection criteria: Taking into account the feasibility of production process, the combination of oral dissolution score/coarseness score greater than 7/6 is preferred.

From the above results, it can be seen that the active protective composition with 100% passing 10 mesh, more than 90% passing 40 mesh, and less than 60% passing 200 mesh has good process compliance when applied to actual production, and achieves the requirements of fast oral dissolution and delicate taste.

Example 5

This example investigates the process compliance and viable bacteria survival stability of powders with different probiotic powder contents.

The process compliance, shelf life stability, pH value and viable bacteria survival rate of different powders were analyzed to evaluate the applicability of the active protection composition in probiotic powder products with different viable bacteria counts.

Preparation:

(1) Weighing and preparing materials: weigh whole milk powder, sodium citrate, resistant dextrin and probiotic powder (Lactobacillus paracasei Lpc-37: Lactobacillus rhamnosus HN001: Lactobacillus gasseri Lg36: Bifidobacterium breve M-16V=1:1:1:4) according to the formula. The specific formula is shown in Table 5-1 below; (2) Mixing and granulating: put whole milk powder, sodium citrate and resistant dextrin in a mixer, mix them evenly, put them in a granulator, spray granulate, and dry them until the moisture content is less than 0.5%, to obtain an active protective composition with a particle size of 100% passing through a 10-mesh sieve, more than 90% passing through a 40-mesh sieve, and less than 60% passing through a 200-mesh sieve;

(3) Total mixing: putting the probiotic powder and the active protection composition into a mixer, mixing them evenly and then discharging the mixture to obtain a probiotic powder;

(4) Packaging: Adjust the equipment to control the net weight to an average of 1.0 g per bag, with a packing difference of ±6.5% per bag. Check the packing difference and appearance every 30 minutes.

Table 5-1 Powder formulation composition with different bacterial powder contents

Test group 5-1 Test group 5-2 Test group 5-3 Resistant dextrin 860mg 860mg 860mg Probiotic powder 18mg 78mg 146mg Whole milk powder 100mg 100mg 100mg Sodium citrate 5mg 5mg 5mg

The above-mentioned probiotic powder is replaced with the same probiotic powder of different contents under the same production environment, the same mixing equipment and the same bag packaging machine.

The process compliance of powder preparation (such as sealing, filling volume difference, recovery rate) and water activity were investigated. The test results are shown in Table 5-2.

Table 5-2 Powder process compliance results of probiotic powders with different contents

Detection Indicator Test group 5-1 Test group 5-2 Test group 5-3 Sealing Vacuum inspection without leakage Vacuum inspection without leakage Vacuum inspection without leakage Difference in filling volume Stable loading Stable loading Stable loading Recovery rate 99.78% 99.25% 99.65% Water activity 0.05 0.06 0.08

From the above results, it can be seen that the active protection composition of the present invention (such as resistant dextrin, whole milk powder, sodium citrate) has good process compliance when applied to formulas with different probiotic powder addition amounts, and the water activity is controlled to be no more than 0.1.

The probiotic content in the prepared powder and its water activity after accelerated 3-month stability study were tested. The test results are shown in Table 5-3.

Table 5-3 Results of stability test of probiotic powder with different contents

Detection Indicator Test group 5-1 Test group 5-2 Test group 5-3 Theoretical probiotic results, 100 million CFU/g 75 320 600 Probiotic test results of samples after bagging, 100 million CFU/g 95 450 730 Accelerated (37℃, 75%) probiotic count after 3 months, 100 million CFU/g 74 350 620 Accelerated (37℃, 75%) water activity after 3 months 0.08 0.09 0.11

Note: The evaluation criteria are in line with the group standard requirements for the first-level live bacteria standard.

From the above results, it can be seen that the active protection composition (such as resistant dextrin, whole milk powder, sodium citrate) applied to the formula with different probiotic powder addition amounts has good live bacteria stability.

The prepared powder was treated with simulated gastric acid solution, and the total number of viable bacteria and its survival rate were tested. The test results are shown in Table 5-4.

Table 5-4 Analysis of the tolerance of probiotic powders with different contents to acid treatment

Detection Indicator Test group 5-1 Test group 5-2 Test group 5-3 Sample probiotic test results, 100 million CFU/g 95 450 730 Total number of probiotics after acid treatment, 100 million CFU/g 88 410 660 Live bacteria survival rate 92.6% 91.1% 90.4%

From the above results, it can be seen that the active protective composition (such as resistant dextrin, whole milk powder, sodium citrate) applied to powders with different probiotic powder addition amounts has a good caching capacity for acid solvents and can better protect probiotics from damage by gastric acid.

Example 6

Whole milk powder and sodium citrate were used in combination with sugar alcohols, oligosaccharides, dietary fiber, fruit juice powder and other food raw materials and auxiliary ingredients commonly used in probiotic powder products, as well as probiotic powder to form different formula powder samples. The survival rates of live bacteria of different formula powder samples after treatment with simulated gastric juice and intestinal juice were compared and analyzed, and the applicability of the active protection composition in different probiotic powder products was evaluated.

6.1: Add dietary fiber:

Experimental group 6.1.1 resistant dextrin (965 mg) + probiotic powder (35 mg);

Test group 6.1.2: resistant dextrin (860 mg) + probiotic powder (35 mg) + whole milk powder (100 mg) + sodium citrate (5 mg);

6.2: Add dietary fiber + sugar alcohols:

Experimental group 6.2.1: resistant dextrin (431 mg) + erythritol (267 mg) + maltitol (267 mg) + probiotic powder (35 mg);

Experimental group 6.2.2: resistant dextrin (380 mg) + erythritol (240 mg) + maltitol (240 mg) + probiotic powder (35 mg) + whole milk powder (100 mg) + sodium citrate (5 mg);

6.3: Add dietary fiber + sugar alcohol + oligosaccharides

Experimental group 6.3.1: resistant dextrin (385 mg) + erythritol (240 mg) + maltitol (240 mg) + oligofructose (100 mg) + probiotic powder (35 mg);

Experimental group 6.3.2: resistant dextrin (340 mg) + erythritol (210 mg) + maltitol (210 mg) + oligofructose (100 mg) + probiotic powder (35 mg) + whole milk powder (100 mg) + sodium citrate (5 mg);

6.4: Add dietary fiber + sugar alcohol + oligosaccharides + fruit juice powder:

Experimental group 6.4.1: resistant dextrin (340 mg) + erythritol (212.5 mg) + maltitol (212.5 mg) + oligofructose (100 mg) + cranberry juice powder (100 mg) + probiotic powder (35 mg);

Experimental group 6.4.2 Resistant dextrin (294 mg) + erythritol (183 mg) + oligofructose (183 mg) + cranberry juice powder (100 mg) + probiotic powder (35 mg) + whole milk powder (100 mg) + sodium citrate (5 mg).

The composition ratio of the above probiotic powder is: Lactobacillus rhamnosus Lr32 28.7%; Bifidobacterium animalis lactis subsp. BL-04 7.3%; Lactobacillus plantarum Lp115 7.3%; Lactobacillus rhamnosus GG 9.6%; Streptococcus salivarius thermophilic subsp. St21 5.9%; Lactobacillus casei Lc-11 7.8%; Lactobacillus paracasei Lpc-37 2.9%; Lactobacillus rhamnosus HN001 2.0%; Bifidobacterium animalis lactis subsp. HN019 2.3%; Lactobacillus gasseri Lg36 2.3%; Lactobacillus delbrueckii subsp. bulgaricus Lb-87 3.7%; Lactobacillus reuteri mucin 1E1 3.7%; Bifidobacterium longum infantis subsp. M-63 3.4%; Bifidobacterium breve M-16V 7.3% and Bifidobacterium longum subsp. BB536 5.7%.

Preparation method of probiotic powder:

(1) Weighing, preparing materials, and mixing: Weighing according to the formula amount, placing the other raw materials in each group except the probiotic powder in a mixer, and mixing until the materials have a uniform color and texture to obtain a mixture;

(2) Granulation: placing the mixture obtained in step (1) in a granulator, spraying granulation, and drying until the moisture content is less than 0.5% and the water activity is less than 0.1, to obtain an active protective composition having a particle size of 100% passing through a 10-mesh sieve, more than 90% passing through a 40-mesh sieve, and less than 60% passing through a 200-mesh sieve;

(3) Total mixing: putting the probiotic powder and the above-mentioned active protective composition into a mixer, mixing them evenly and then discharging the mixture to obtain a probiotic powder;

(4) Packaging: Adjust the equipment to control the net weight to an average of 1.0 g per bag, with a packing difference of ±6.5% per bag. Check the packing difference and appearance every 30 minutes.

The viable bacterial survival rates of powder samples with different formulas after treatment with simulated gastric acid and intestinal fluid were investigated. The test results are shown in Table 6.

Table 6 pH value and viable bacteria survival rate test results of different formula powder samples after acid treatment

From the above results, it can be seen that the active protective composition of the present invention, combined with sugar alcohols, oligosaccharides, dietary fibers, fruit juice powders and other food raw materials and auxiliary materials commonly used in probiotic powder products, has wide adaptability. At the same time, through comparative data, it can be seen that the active protective composition of the present invention can effectively improve the tolerance of the overall formula to the lower digestive tract, thereby significantly improving the survival rate of the live bacteria components in the probiotic powder through the gastrointestinal tract.

The above detailed description is a specific description of one feasible embodiment of the present invention. The embodiment is not intended to limit the patent scope of the present invention. Any equivalent implementation or modification that does not deviate from the present invention should be included in the scope of the technical solution of the present invention.

Claims (10)

1. A method of maintaining the activity of a probiotic, the method comprising adding an active protective composition to a probiotic powder; the active protection composition comprises milk powder and sodium citrate, wherein the mass ratio of the milk powder to the sodium citrate is 10-25:1.

2. The method of claim 1, wherein the active protective composition is prepared by mixing, granulating, and sieving the milk powder and sodium citrate; the sieving is specifically as follows: the active protective composition is screened through a sieve with 180-220 meshes, the content of undersize is less than 60% of the total amount, the undersize is screened through a sieve with 35-45 meshes, the content of undersize is more than 90% of the total amount, the undersize is screened through a sieve with 10-20 meshes, and the content of undersize is equal to 100%.

3. An active protection composition for maintaining the activity of probiotics, which is characterized by comprising milk powder and sodium citrate, wherein the mass ratio of the milk powder to the sodium citrate is 10-25:1.

4. An active protective composition according to claim 3, wherein the mass ratio of milk powder to sodium citrate is 15-25:1.

5. The active protective composition according to claim 3, further comprising a filler, wherein the mass ratio of filler to milk powder to sodium citrate is 150-180:15-25:1.

6. The active protective composition according to claim 5, wherein the filler is selected from at least one of dietary fiber selected from at least one of resistant dextrin and maltodextrin, sugar alcohol selected from at least one of erythritol and maltitol, oligosaccharide selected from at least one of fructo-oligosaccharides and galacto-oligosaccharides.

7. The active protective composition of claim 5, wherein the filler comprises resistant dextrin, erythritol and maltitol in a mass ratio of 3-5:2-3:2-3.

8. The active protective composition according to any one of claims 3 to 7, wherein the active protective composition is screened through a 180-220 mesh screen, the undersize content is less than 60% of the total amount, screened through a 35-45 mesh screen, the undersize content is greater than 90% of the total amount, screened through a 10-20 mesh screen, and the undersize content is equal to 100%.

9. A high activity probiotic powder comprising the active protective composition of any one of claims 3-7.

10. The probiotic powder according to claim 9, characterized in that the mass ratio of probiotic powder to active protective composition in the probiotic powder is 80-100:1-15.