A postbiotic milk-based nutritional composition and preparation method thereof

Abstract

The present invention discloses a postbiotic milk-based nutritional composition and a preparation method thereof, wherein the postbiotic milk-based nutritional composition comprises the following components in parts by weight: 30-50 parts of whole milk powder, 20-40 parts of skim milk powder, 0-10 parts of prebiotics, 1-5 parts of inactivated yeast postbiotics, and 0-1 parts of a compound nutritional enhancer; the whole milk powder encapsulates the inactivated yeast postbiotics to form encapsulated particles. The postbiotic milk-based nutritional composition provided by the present invention, inactivated yeast postbiotics are encapsulated by whole milk powder to form encapsulated particles, which can greatly reduce the hygroscopicity of inactivated yeast postbiotics and products, and can mask the bad flavor of inactivated yeast postbiotics, improve product taste, and can meet the clinical effective dose of postbiotics at the same time, and provide the nutrition required by the human body.

Description

Technical Field

[0001] The present invention relates to the technical field of nutritional products, and in particular to a postbiotic milk-based nutritional composition and a preparation method thereof. Background Art

[0002] Postbiotics include bacteria and metabolites, which have many health benefits for the human body. Among them, inactivated yeast postbiotics are a mixture that is dried into a powder after a fermentation process, which includes brewer's yeast and the beneficial metabolites produced by brewer's yeast during the fermentation process. Inactivated yeast postbiotics have the function of supporting human immunity and intestinal health. However, inactivated yeast postbiotics have strong hygroscopicity, and their performance is greatly affected by environmental humidity, and they are prone to agglomeration. Therefore, it is necessary to design a reasonable processing environment and process in the process of processing inactivated yeast postbiotics. In addition, inactivated yeast postbiotics have a special fermentation flavor, which is specifically reflected in soy sauce flavor and caramel smell. Some consumers are prone to discomfort when taking products containing inactivated yeast postbiotics. Therefore, for the development of nutritional compositions containing inactivated yeast postbiotics, there are also great challenges in the selection of final product dosage forms and product taste balance.

[0003] Currently, products containing inactivated yeast postbiotics are mostly in the form of capsules and tablets.

[0004] Among them, the capsule dosage form is not ideal for protecting products that are prone to moisture absorption. During the shelf life, the capsule dosage form of inactivated yeast postbiotics tends to absorb moisture and clump, which affects the appearance and taste of the product and may even cause problems such as microbial contamination.

[0005] For tablet products, inactivated yeast postbiotics, as the main ingredient, need to account for a large proportion in the tablet formula. However, inactivated yeast postbiotics have strong hygroscopicity, resulting in the brittleness and hardness of the finished tablets failing to meet the qualified standards. In addition, the content of inactivated yeast postbiotics in tablet products is relatively high, the taste defects of the products will be more obvious, the fermented flavor of the finished products will be prominent, and it is difficult to achieve a good balance in the overall taste of the tablet products. At the same time, due to the limitation of tablet volume, the mass of a single tablet is generally controlled within 3g. In order to enhance compressibility, it is usually necessary to add sorbitol, xylitol, milk powder, lactose and other materials as a base, which makes the actual content of inactivated yeast postbiotics in a single tablet product not particularly high.

[0006] In view of the deficiencies of the prior art, the technical problem to be solved by the present invention is: based on the characteristics of inactivated yeast postbiotics, a nutritional composition that can improve the hygroscopic characteristics of inactivated yeast postbiotics and has good taste and flavor is reasonably designed. Summary of the invention

[0007] In order to overcome the deficiencies of the prior art, one of the objects of the present invention is to provide a postbiotic milk-based nutritional composition.

[0008] A second object of the present invention is to provide a method for preparing a postbiotic milk-based nutritional composition.

[0009] One of the purposes of the present invention is achieved by the following technical solution:

[0010] A postbiotic milk-based nutritional composition comprises the following components in parts by weight: 30-50 parts of whole milk powder, 20-40 parts of skim milk powder, 0-10 parts of prebiotics, 1-5 parts of inactivated yeast postbiotics, and 0-1 part of a compound nutritional enhancer; the inactivated yeast postbiotics are encapsulated to form encapsulated particles.

[0011] As a preferred embodiment of the present invention, the whole milk powder encapsulates the inactivated yeast postbiotics to form encapsulated particles.

[0012] In the present invention, whole milk powder and skim milk powder can mask the bad flavor of inactivated yeast postbiotics and improve the taste. In addition, whole milk powder, as an embedding agent for inactivated yeast postbiotics, can reduce the hygroscopicity of inactivated yeast postbiotics; at the same time, whole milk powder has a better taste, and whole milk powder is wrapped on the outer surface of inactivated yeast postbiotics. Its sweet taste can neutralize the soy sauce flavor and caramel flavor of inactivated yeast postbiotics, and improve the taste of the product. Both whole milk powder and skim milk powder contain lactose, which is one of the main components and is a highly hygroscopic substance. Specifically, the lactose content in whole milk powder is 30-40%, and the lactose content in skim lactose is 50-60%. Therefore, from the perspective of lactose content alone, after skim milk powder is de-fatted, there is a large amount of lactose, and its hygroscopicity is stronger. In comparison, whole milk powder is more suitable as a packaging carrier for inactivated yeast postbiotics than skim milk powder.

[0013] As a preferred embodiment of the present invention, the whole milk powder is divided into two parts, which are respectively recorded as the first part of whole milk powder and the second part of whole milk powder. The first part of whole milk powder encapsulates the inactivated yeast postbiotics to form encapsulated particles; the encapsulated particles, the second part of whole milk powder, the skimmed milk powder, the prebiotics and the compound nutritional enhancer are uniformly mixed to form the nutritional composition; the mass ratio of the inactivated yeast postbiotics to the first part of whole milk powder is 1:(1-3), and more preferably 1:(1-1.5).

[0014] The weight of the whole milk powder encapsulating the inactivated yeast postbiotics of the present invention is 1-3 times that of the inactivated yeast postbiotics, which can ensure that the inactivated yeast postbiotics are fully encapsulated by the whole milk powder, reduce their hygroscopicity to the greatest extent, and cover up the bad flavor of the inactivated yeast postbiotics to the greatest extent. Moreover, within this ratio range, the obtained encapsulated particles can have a suitable particle size distribution, meet the requirements of powder products, and ensure their fluidity and solubility.

[0015] As a preferred embodiment of the present invention, the postbiotic milk-based nutritional composition comprises the following components in parts by weight: 30-50 parts of whole milk powder, 20-40 parts of skim milk powder, 5-10 parts of prebiotics, 1-5 parts of inactivated yeast postbiotics, and 0.1-1 parts of compound nutritional enhancers.

[0016] In the present invention, adding an appropriate amount of prebiotics helps improve the health performance of the product, helps the product's nutrient absorption, and helps intestinal health. Adding an appropriate amount of compound nutrient enhancers can make the product provide more comprehensive nutrition to meet the needs of consumers.

[0017] As a preferred embodiment of the present invention, the prebiotics include one or any combination of inulin, galacto-oligosaccharides, xylo-oligosaccharides, polydextrose, resistant dextrin, isomaltooligosaccharide, stachyose, yeast β-glucan, trehalose and chitosan oligosaccharide.

[0018] As a preferred embodiment of the present invention, the compound nutritional enhancer includes one or a combination of compound minerals and compound vitamins.

[0019] As a preferred embodiment of the present invention, the inactivated yeast postbiotic has the following properties:

[0020] Color: Free-flowing light to dark brown powder; Bulk density 0.55–0.75 g / mL: Tap density 0.66–0.90 g / mL;

[0021] Protein ≥ 25%, total dietary fiber ≥ 10%, total polyphenols ≥ 3%, moisture ≤ 8%;

[0022] Aerobic colony count <5000 cfu / g;

[0023] Yeast and mold <100 cfu / g;

[0024] Total E. coli <10 cfu / g;

[0025] Enterobacteriaceae was less than <100 cfu / g.

[0026] The present invention adopts the inactivated yeast postbiotics with the above properties, which can provide better nutrients, so that the obtained product has better fluidity and ensures the product quality.

[0027] The second object of the present invention is achieved by adopting the following technical solution:

[0028] A method for preparing a postbiotic milk-based nutritional composition comprises the following steps:

[0029] The inactivated yeast postbiotic screening step: screening the inactivated yeast postbiotic;

[0030] The step of forming coated particles: taking the sieved inactivated yeast postbiotics and part of the whole milk powder in a stirring device, stirring at high speed to form coated particles, wherein the core layer of the coated particles is the inactivated yeast postbiotics, and the shell layer is the whole milk powder;

[0031] Mixing step: feeding the remaining whole milk powder, the coated particles, the skim milk powder, the prebiotics and the compound nutritional enhancer into a dry powder mixer, first pre-mixing at a low speed, and then increasing the speed for sufficient mixing to obtain the dry powder.

[0032] As a preferred embodiment of the present invention, in the inactivated yeast postbiotic screening step, the inactivated yeast postbiotic is taken, the ambient temperature is controlled at 20-25° C., the humidity is controlled at 45-55%, and the inactivated yeast postbiotic is screened using a 30-60 mesh screen.

[0033] In the present invention, when the inactivated yeast postbiotics are screened, the temperature and humidity in the screening process environment must be strictly controlled. The postbiotic milk-based nutritional composition obtained by the present invention is a powdered product. During the mixing process of the raw materials, the physical properties of the raw materials are required to be dry and have good fluidity to ensure the uniformity of product mixing and to ensure that the product can flow freely in processes such as mixing tanks, conveying pipelines, and filling machines. However, inactivated yeast postbiotics are sensitive to environmental humidity and will inevitably produce pseudo-agglomeration during storage. Therefore, reasonable pretreatment of the postbiotics is a necessary means to ensure the quality of the final product, and the pretreatment environment needs to maintain a humidity of 45-55% to effectively avoid moisture absorption and re-agglomeration.

[0034] According to the storage requirements of raw materials and experimental verification results, the inventors learned that the physical properties of inactivated yeast postbiotics are relatively stable at a humidity of 45-55%, and it is not easy to clump. At the same time, the ambient temperature needs to be controlled at 20-25°C so that the ambient humidity can be stabilized at the required level, which is also conducive to keeping the raw materials dry.

[0035] In addition, the present invention screens the inactivated yeast postbiotics. Screening can effectively block foreign matter and can also make the inactivated yeast postbiotics looser, improve their fluidity, and facilitate the dispersion of subsequent mixing steps and ensure the uniformity of the final product. Reasonable selection of the mesh size of the screen needs to be adapted to the particle size and physical properties of the final product and raw materials. If the mesh size of the selected screen is too large, the screening effect may not be achieved; if the mesh size is too small, the material will clog the sieve holes and cannot pass through the screen. After implementation verification, the inactivated yeast postbiotics are suitable for screening using a 30-60 mesh sieve, and the raw materials can pass through the sieve smoothly to ensure that they are evenly dispersed in the final product.

[0036] As a preferred embodiment of the present invention, in the step of forming coated particles, the sieved inactivated yeast postbiotics are taken and placed in a stirring device according to a mass ratio of inactivated yeast postbiotics to whole milk powder of 1:(1-3), the stirring device is provided with a high-speed stirring blade, the filling height of the total amount of powder accounts for 1 / 3-2 / 3 of the height of the stirring device, the stirring device is turned on, the stirring speed is set to 200-800 r / min, and the stirring time is 1-3h to form coated particles.

[0037] In the present invention, whole milk powder is used as an embedding agent for inactivated yeast postbiotics, and the inactivated yeast postbiotic powder and the whole milk powder are placed in a stirring device for mixing. The whole milk powder is used to wrap the inactivated yeast postbiotics through the impact, stirring and extrusion generated by the high-speed rotation of the stirring device to prepare wrapped particles, which can reduce the hygroscopicity of the inactivated yeast postbiotics. During the wrapping, the mass ratio of the inactivated yeast postbiotics to the whole milk powder is 1: (1-3), the stirring speed is 200-800r / min, and the stirring time is 1-3h, which can ensure that the inactivated yeast postbiotics are completely wrapped by the whole milk powder, thereby better reducing the hygroscopicity of the postbiotics, and within these parameter ranges, it can be ensured that the formed wrapped particles have a suitable particle size distribution.

[0038] As a preferred embodiment of the present invention, in the mixing step, the ambient temperature is controlled at 20-30°C and the humidity is 50-70%, and the remaining whole milk powder, the coated particles, the skimmed milk powder, the prebiotics and the compound nutritional enhancer are fed into a dry powder mixer for pre-stirring, and the pre-stirring speed is set to 10-15 rpm and the pre-stirring time is 40-50 seconds; followed by sufficient stirring, and the sufficient stirring speed is set to 30-60 rpm and the stirring time is 85-95 seconds to obtain a postbiotic milk-based nutritional composition, wherein the moisture content of the postbiotic milk-based nutritional composition is controlled within 5%.

[0039] In the present invention, the mixing step needs to ensure that all the remaining materials are mixed evenly with the coated particles, and also prevent the coated particles from being broken up and their structure destroyed by the excessive stirring speed during the stirring process. After repeated experiments, the inventors found that it is necessary to pre-stir for 40-50 seconds at a low speed, and then increase the speed and dry mix for 85-95 seconds. Under such conditions, the structural integrity of the coated particles can be protected and the materials can be mixed evenly.

[0040] As a preferred embodiment of the present invention, the method for preparing the postbiotic milk-based nutritional composition further comprises one or a combination of the following steps:

[0041] Powder sieving step: passing the nutritional composition obtained in the mixing step through a vibrating screen to make the particle size of the powder uniform, retaining the undersize, and removing the oversize as powder residue;

[0042] Powder discharging step: collect the powder in a sterilized powder collecting box and transport it from the powder discharging room to the powder loading room;

[0043] Powdering step: putting the nutritional composition obtained in the powdering step into a powder storage tank on a packaging machine according to packaging requirements;

[0044] Packaging steps: nitrogen filling and packaging by automatic packaging machines of different specifications; the oxygen content during nitrogen filling is lower than 1-5%, and the composition is packaged into strips of required specifications;

[0045] Packing step: pack the packed strips into packing boxes;

[0046] Finished product inspection steps: Sampling inspection of packaged products according to the inspection plan;

[0047] Warehouse inspection steps: Products that pass the inspection are put into storage at room temperature with humidity ≤ 65%.

[0048] In the present invention, the milk-based product to which the inactivated yeast postbiotics are added is packaged in a 10-50g strip pack specification, and a single pack is prepared and taken, which can effectively prevent the product from absorbing moisture, and reduce the risk of microbial contamination, which is better for consumers and safer. However, milk-based nutritional supplements in this field are commonly packaged in cans with specifications of 300-1000 grams. The disadvantage of canning is that the lid needs to be opened repeatedly during use, and the product is frequently in contact with the air, which is easy to cause moisture absorption, agglomeration, and may also cause microbial contamination in the long term.

[0049] As a preferred embodiment of the present invention, the method for preparing the postbiotic milk-based nutritional composition comprises the following steps:

[0050] Weighing step: weigh 50 parts by weight of whole milk powder, 40 parts by weight of skim milk powder, 8 parts by weight of inulin, and 1 part by weight of a compound nutritional enhancer;

[0051] The inactivated yeast postbiotics pulverizing step: pulverizing the inactivated yeast postbiotics;

[0052] The inactivated yeast postbiotic screening step: taking the crushed inactivated yeast postbiotic, controlling the ambient temperature to 25° C. and the humidity to 50%, and screening with a 30-mesh sieve;

[0053] The step of forming coated particles is as follows: taking 1 weight portion of the sieved inactivated yeast postbiotics, placing the inactivated yeast postbiotics and whole milk powder in a ratio of 1:1.5 by mass in a stirring device, wherein a high-speed stirring blade is provided in the stirring device, and the filling height of the total amount of powder accounts for 1 / 3-2 / 3 of the height of the stirring device, turning on the stirring device, setting the stirring speed to 500 r / min, and the stirring time to 1.5 h, to form coated particles;

[0054] Mixing step: controlling the ambient temperature to 28° C. and the humidity to 60%, feeding the remaining whole milk powder, the coated particles, the skimmed milk powder, the prebiotics and the compound nutritional enhancer into a dry powder mixer for pre-stirring, setting the pre-stirring speed to 12 rpm and the pre-stirring time to 45 seconds; then fully stirring, setting the full stirring speed to 45 rpm and the stirring time to 90 seconds to obtain a postbiotic milk-based nutritional composition, wherein the moisture content of the postbiotic milk-based nutritional composition is controlled within 5%.

[0055] As a preferred embodiment of the present invention, the method for preparing the postbiotic milk-based nutritional composition also includes the step of preparing an inactivated yeast postbiotic: activating the yeast in an activation medium, then transferring the activated bacteria to a fermentation tank, adding water and nutrients for fermentation; after the fermentation is completed, filtering the wet fermentation product with a filter with a pore size of less than 300 microns, then drying the obtained yeast and its metabolites to obtain a mixture rich in yeast cell fragments, its metabolites and other nutrients, and crushing the mixture to obtain the inactivated yeast postbiotic.

[0056] As a preferred embodiment of the present invention, in the step of preparing postbiotics from inactivated yeast, the nutrients during fermentation are: 0.25% yeast extract, 0.2% maltose, 0.02% sodium chloride, 0.82% sodium acetate, and the balance is water.

[0057] As a preferred embodiment of the present invention, in the step of preparing postbiotics from inactivated yeast, the nutrients during fermentation are: 1-3% peptone, 1-3% beef extract, 1-3% yeast extract, 6-8% glucose, 0.3% diammonium citrate, 0.2% dipotassium hydrogen phosphate, 0.09% magnesium sulfate, 0.025% manganese sulfate, 0.025% ferrous sulfate, and the balance is water.

[0058] Compared with the prior art, the present invention has the following beneficial effects:

[0059] (1) The postbiotic milk-based nutritional composition provided by the present invention is a powder product with a reasonable formula design. It can not only meet the clinically effective dose of postbiotics, but also provide good taste and flavor, and can provide the nutrition required by the human body. The whole milk powder, skim milk powder, inactivated yeast postbiotics, prebiotics, compound nutritional enhancers and other raw materials in the formula are reasonably formulated, nutritionally balanced, and have proper flavor coordination. The synergistic effect of various raw materials helps to support immune health and intestinal health, and has the effects of enhancing immunity and moisturizing the intestines and promoting bowel movements.

[0060] (2) In the postbiotic milk-based nutritional composition provided by the present invention, the inactivated yeast postbiotics are wrapped by whole milk powder to form wrapped particles, which can greatly reduce the hygroscopicity of the inactivated yeast postbiotics and the product, and can mask the unpleasant flavor of the inactivated yeast postbiotics, thereby improving the taste of the product. In addition, the particle size distribution of the formed wrapped particles is reasonable, which meets the requirements of powder products and can improve the fluidity of the product.

[0061] (3) The preparation method of the postbiotic milk-based nutritional composition provided by the present invention has a reasonable process, is simple and easy to control, and can be produced on a large scale. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 The figure shows the hygroscopicity test results of Example 3 of the present invention and Comparative Examples 1-9;

[0063] Figure 2 It is a graph showing the hygroscopicity test results of the postbiotic milk-based nutritional compositions AC of Example 4 and Comparative Examples 10-11 of the present invention. DETAILED DESCRIPTION

[0064] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments. It should be noted that, under the premise of no conflict, the embodiments or technical features described below can be arbitrarily combined to form new embodiments. The raw materials, equipment, etc. used in the following embodiments can be obtained by purchase unless otherwise specified.

[0065] Example 1

[0066] Prepare inactivated yeast postbiotics as follows:

[0067] First, yeast fermentation is performed: the brewer's yeast is activated in an activation medium, and then the activated strain is transferred to a fermentation tank, and water and nutrients are added to the fermentation tank for fermentation. The wet fermentation product is filtered with a filter with a pore size of less than 300 microns, and then the obtained yeast and its metabolites are dried at 200°F to obtain a mixture rich in yeast cell fragments, their metabolites and other nutrients. The mixture is crushed in a pulverizer, and then packaged and stored.

[0068] The properties of the obtained inactivated yeast postbiotic part are as follows:

[0069] Color: Free-flowing light to dark brown powder. Bulk density 0.55-0.75 g / mL; tap density 0.66-0.90 g / mL.

[0070] Protein ≥ 25%, total dietary fiber ≥ 10%, total polyphenols ≥ 3%, moisture ≤ 8%.

[0071] Aerobic colony count <5000 cfu / g; yeast and mold <100 cfu / g;

[0072] Total E. coli <10 cfu / g;

[0073] Enterobacteriaceae: less than <100 cfu / g.

[0074] In the present invention, the nutrients put into the fermentation tank are:

[0075] 0.25% yeast extract, 0.2% maltose, 0.02% sodium chloride, 0.82% sodium acetate, and the balance is water.

[0076] The specific liquid fermentation environment is: temperature 25-35℃, humidity 60-70%, pH value <7, fermentation under anaerobic conditions, mixer power 1~2kwh / m 3 , the culture time is 35h.

[0077] Example 2

[0078] The inactivated yeast postbiotics obtained in Example 1 are crushed and sieved, comprising the following steps:

[0079] Step 1: Crush the inactivated yeast postbiotics. To ensure that the raw materials before sieving have no obvious agglomeration or no particles larger than 2 cm visually, crush the inactivated yeast postbiotics first.

[0080] Step 2: The crushed inactivated yeast postbiotics obtained in step 1 are sieved with a 45-mesh sieve to obtain a loose raw material with a particle size below 45 mesh and good fluidity, and then weighed according to the amount required for production for later use. The ambient temperature during the sieving process is controlled at 25° C. and the humidity is controlled at 50%.

[0081] The particle size distribution of the sieved inactivated yeast postbiotics obtained in Example 2 is concentrated and conforms to the normal distribution. 50 Below 94.6 microns, D 90 Below 206 microns, within the particle size distribution range of the target product.

[0082] Table 1 Particle size distribution data of inactivated yeast postbiotics after sieving

[0083]

[0084]

[0085] Example 2 adopts appropriate crushing and screening treatment methods, which can effectively control the particle size of the inactivated yeast postbiotics, improve its fluidity, and not destroy its beneficial ingredients, and can ensure that the inactivated yeast postbiotics are evenly mixed with other raw materials in subsequent steps.

[0086] Example 3

[0087] The encapsulated particles X1 were prepared using whole milk powder as an embedding agent under high-speed stirring conditions, and the steps are as follows:

[0088] Take the inactivated yeast postbiotics after sieving in Example 2, and place them in a stirring device according to the mass ratio of inactivated yeast postbiotics to whole milk powder of 1:1.5. The stirring device is provided with a high-speed stirring blade, and the filling height of the total amount of powder accounts for 1 / 3-2 / 3 of the height of the stirring device. Turn on the stirring device, set the stirring speed to 500 r / min, and the stirring time to 1.5 h to form encapsulated particles X1.

[0089] Table 2 Particle size distribution data of encapsulated particles X1

[0090] Sample name Dx(10)(micrometer) Dx(50)(micrometer) Dx(90)(micrometer) Package particles X1 54.6 207 491

[0091] The particle size distribution of the coated particles formed in Example 3 is concentrated and conforms to the normal distribution, with D50 below 207 microns and D90 below 491 microns, which are still within the particle size distribution range of the target product.

[0092] Comparative Example 1

[0093] The encapsulated particles X2 were prepared using skim milk powder as an embedding agent under high-speed stirring conditions, and the steps are as follows:

[0094] Take the sieved inactivated yeast postbiotics in Example 2, and place them in a stirring device according to the mass ratio of inactivated yeast postbiotics and skimmed milk powder of 1:1.5. The stirring device is provided with a high-speed stirring blade, and the filling height of the total amount of powder accounts for 1 / 3-2 / 3 of the height of the stirring device. Turn on the stirring device, set the stirring speed to 500 r / min, and the stirring time to 1.5 h to form encapsulated particles X2.

[0095] Table 3 Particle size distribution data of encapsulated particles X2

[0096] Sample name Dx(10)(micrometer) Dx(50)(micrometer) Dx(90)(micrometer) Packaged particles X2 53.2 210 489

[0097] Comparative Example 2

[0098] The encapsulated particles X3 were prepared using whole milk powder as the embedding agent under normal mixing conditions, and the steps are as follows:

[0099] The sieved inactivated yeast postbiotics in Example 2 were taken and placed in a mixer according to a mass ratio of inactivated yeast postbiotics to whole milk powder of 1:1.5. The mixing conditions were as follows: pre-stirring was performed in the mixer at a speed of 12 rpm and a pre-stirring time of 45 seconds. The speed was then increased to perform a dry mixing process at a speed of 30 rpm and a stirring time of 90 seconds to form encapsulated particles X3.

[0100] Table 4 Particle size distribution data of encapsulated particles X3

[0101] Sample name Dx(10)(micrometer) Dx(50)(micrometer) Dx(90)(micrometer) Packaged particles X3 70.4 215 505

[0102] Comparative Example 3

[0103] Using skim milk powder as an embedding agent, encapsulated particles X4 were prepared under normal mixing conditions, and the steps are as follows:

[0104] The inactivated yeast postbiotics sieved in Example 2 were placed in a mixer according to a mass ratio of inactivated yeast postbiotics and skimmed milk powder of 1:1.5. The mixing conditions were as follows: pre-stirring was performed in the mixer at a speed of 12 rpm and a pre-stirring time of 45 seconds. The speed was then increased for dry mixing at a speed of 30 rpm and a stirring time of 90 seconds to form encapsulated particles X4.

[0105] Table 5 Particle size distribution data of encapsulated particles X4

[0106] Sample name Dx(10)(micrometer) Dx(50)(micrometer) Dx(90)(micrometer) Packaged particles X4 65.5 212 499

[0107] Comparative Example 4

[0108] The sieved inactivated yeast postbiotic in Example 2 was taken without packaging and recorded as inactivated yeast postbiotic X5.

[0109] Comparative Example 5

[0110] The difference between Comparative Example 5 and Example 3 is that the ratio of inactivated yeast postbiotics to whole milk powder is changed, and the mass ratio of inactivated yeast postbiotics to whole milk powder is 1:0.8. The rest is the same as Example 3, forming encapsulated particles X6.

[0111] After the amount of whole milk powder is reduced, the encapsulation of the inactivated yeast postbiotics is incomplete, and some inactivated yeast postbiotic particles are not encapsulated by the whole milk powder, and the postbiotic particles exist alone. Since the particle size of the postbiotic particles is small, the overall particle size distribution is smaller, and the smaller the particle size, the more hygroscopic it is. The hygroscopicity of the encapsulated particles X6 is higher than that of the encapsulated particles X1.

[0112] Table 6 Particle size distribution data of encapsulated particles X6

[0113] Sample name Dx(10)(micrometer) Dx(50)(micrometer) Dx(90)(micrometer) Packaged particles X6 36.5 97.6 216

[0114] Comparative Example 6

[0115] The difference between Comparative Example 6 and Example 3 is that the stirring device is turned on, the stirring speed is set to 150 r / min, the stirring time is set to 3.5 h, and the rest is the same as Example 3 to form wrapped particles X7.

[0116] Table 7 Particle size distribution data of encapsulated particles X7

[0117] Sample name Dx(10)(micrometer) Dx(50)(micrometer) Dx(90)(micrometer) Packaged particles X7 56.5 236 508

[0118] Comparative Example 7

[0119] The difference between Comparative Example 7 and Example 3 is that the stirring device is turned on, the stirring speed is set to 850 r / min, the stirring time is set to 0.8 h, and the rest is the same as Example 3 to form wrapped particles X8.

[0120] Table 8 Particle size distribution data of encapsulated particles X8

[0121] Sample name Dx(10)(micrometer) Dx(50)(micrometer) Dx(90)(micrometer) Packaged particles X8 49.2 197 458

[0122] Comparative Example 8

[0123] The difference between Comparative Example 8 and Example 2 is that during the sieving process in step 2: the sieving process environment temperature is controlled at 30° C. and the humidity is controlled at 65%. The inactivated yeast postbiotic X9 obtained in Comparative Example 8 is not packaged.

[0124] Table 9 Particle size distribution data of encapsulated particles X9

[0125]

[0126] Comparative Example 9

[0127] The encapsulated particles X10 were prepared using whole milk powder as an embedding agent under high-speed stirring conditions. The steps are as follows:

[0128] Take the sieved inactivated yeast postbiotics of Comparative Example 8, and place them in a stirring device according to the mass ratio of inactivated yeast postbiotics to whole milk powder of 1:1.5. The stirring device is provided with a high-speed stirring blade, and the filling height of the total amount of powder accounts for 1 / 3-2 / 3 of the height of the stirring device. Turn on the stirring device, set the stirring speed to 500r / min, and the stirring time to 1.5h to form encapsulated particles X10.

[0129] Hygroscopicity test of encapsulated particles

[0130] Hygroscopicity experiments were conducted on samples obtained from Example 3 and Comparative Examples 1-9, including coated particles X1-X4, X6-X8, X10, and uncoated inactivated yeast postbiotics X5 and X9.

[0131] The method of the hygroscopicity test is as follows:

[0132] The samples are X1-X10 manufactured in the above examples and comparative examples. The sample amount used in all experiments is about 8 mg. In the hygroscopicity experiment, the humidification gas flow rate is 100 mL / min and the protective gas flow rate is 5 mL / min.

[0133] The initial mass of samples X1-X10 was first weighed at 0% relative humidity. Then, after being exposed to 60% relative humidity for 12 hours, the mass of the exposed samples X1-X10 was weighed again. The percentage of weight gain due to moisture absorption was calculated as (mass of the exposed samples X1-X10 minus the initial mass of X1-X10) / initial mass of X1-X10.

[0134] The results are as follows Figure 1 As shown, from Figure 1 It can be seen that the hygroscopicity of the encapsulated particles X1 obtained in Example 3 was the weakest during the experiment. Example 3 used whole milk powder as an embedding agent and carried out embedding under high stirring conditions, which could greatly improve its hygroscopicity. It can be seen from Comparative Example 1 that when skim milk powder was used as an embedding agent and embedded under high-speed stirring conditions, the hygroscopicity of the encapsulated particles was also improved to a certain extent, but the improvement effect of the skim milk powder-embedded particles X2 was not as good as that of the whole milk powder-embedded particles X1.

[0135] Although whole milk powder was used for encapsulation in Comparative Example 2, the encapsulation was carried out under ordinary mixing conditions with a slow stirring speed, and the hygroscopicity of the obtained encapsulated particles X3 was higher than that of the encapsulated particles X1.

[0136] Comparative Example 4 is uncoated inactivated yeast postbiotic X5, which has a relatively strong hygroscopicity, much higher than the other coated particles (X1-X4, X6-X8, X10) coated with whole milk powder / skim milk powder.

[0137] In comparative example 5, when preparing coated particles X6, the mass ratio of inactivated yeast postbiotics to whole milk powder was 1:0.8, and the amount of whole milk powder was reduced, resulting in its hygroscopicity being stronger than that of coated particles X1.

[0138] In the preparation of the coated particles in Comparative Examples 6 and 7, the stirring conditions were changed, resulting in the formed coated particles X7 and X8 having stronger hygroscopicity than the coated particle X1.

[0139] Comparative Example 8 is an uncoated inactivated yeast postbiotic X9, but compared with the uncoated inactivated yeast postbiotic X5, the difference is that the different screening conditions lead to the hygroscopicity of X9 being stronger than that of X5. It can be seen that the use of a suitable screening process in the embodiment of the present invention is also helpful to reduce the hygroscopicity of the product.

[0140] The encapsulated particles X10 formed in Comparative Example 9 are made of X9 and have much higher hygroscopicity than X1.

[0141] It can be seen that in Example 2 of the present invention, when preparing the inactivated yeast postbiotic coated particles, a suitable inactivated yeast postbiotic screening process is adopted, the weight ratio of the inactivated yeast postbiotic to the whole milk powder is reasonably controlled, and the process parameters in the process of forming the coated particles are reasonably controlled, which can greatly reduce the hygroscopicity of the coated particles.

[0142] Example 4

[0143] A postbiotic milk-based nutritional composition, comprising the following components: 50 parts by weight of whole milk powder, 40 parts by weight of skim milk powder, 8 parts by weight of inulin, 1 part by weight of inactivated yeast postbiotics, and 1 part by weight of a compound nutritional enhancer. The composition is prepared according to the following method:

[0144] Step 1: Grind the inactivated yeast postbiotics. To ensure that the raw materials before sieving have no obvious agglomeration or particles larger than 2 cm visually, first grind the inactivated yeast postbiotics;

[0145] Step 2: Sieve the inactivated yeast postbiotics obtained in step 1 through a 45-mesh sieve to obtain a loose raw material with a particle size below 45 mesh and good fluidity, and then weigh 1 part by weight according to the amount required for production for later use. The ambient temperature during the sieving process is controlled at 25°C and the humidity is controlled at 50%;

[0146] Step 3: Take the sifted inactivated yeast postbiotics and mix them with whole milk powder in a mass ratio of 1:1.5 and put them into a stirring device. A high-speed stirring blade is provided in the stirring device. The filling height of the total amount of powder accounts for 1 / 3-2 / 3 of the height of the stirring device. Turn on the stirring device, set the stirring speed to 500r / min, and the stirring time to 1.5h to form coated particles.

[0147] Step 4: Under the condition that the ambient temperature is controlled below 28°C and the humidity is controlled at 60%, all the remaining components are mixed evenly with the coated particles. The mixing occurs in a dry powder mixer. Pre-mixing is first performed. The pre-mixing conditions are a speed of 12 rpm and a pre-mixing time of 45 seconds. Then the speed is increased for dry mixing, the speed is 45 rpm, and the mixing time is 90 seconds. The moisture content of the resulting composition is controlled within 5%.

[0148] Step 5: Powder screening: Use a vibrating screen to make the powder particle size uniform, retain the undersize material, and remove the oversize material as powder residue.

[0149] Step 6: Powder discharge: Collect the powder in a sterilized powder box and transport it from the powder discharge room to the powder loading room.

[0150] Step 7: Powdering: put the composition into the powder storage tank on the large and small packaging machines according to the packaging requirements.

[0151] Step 8: Packaging: Automatic packaging machines of different specifications are used for nitrogen filling and packaging; the oxygen content during nitrogen filling is lower than 5%, and the composition is packaged into strips of 25 g / bag.

[0152] Step 9: Packing: Pack the packed strips into the packing boxes.

[0153] Step 10: Finished product inspection: Sampling inspection is carried out on the packaged products according to the inspection plan.

[0154] Step 11: Storage: Products that have passed the inspection are stored in the warehouse at room temperature with humidity ≤ 65%.

[0155] The product obtained in Example 4 is recorded as postbiotic milk-based nutritional composition A.

[0156] Comparative Example 10

[0157] The difference between Comparative Example 10 and Example 4 is that the step of preparing the coated particles in step 3 is missing, and after the screening of the inactivated yeast postbiotics is completed in step 2, step 4 is directly entered, all components are evenly mixed according to the method of step 4, and subsequent operations are performed in sequence, and finally a bar packaged product of 25g / bag is obtained, which is recorded as postbiotic milk-based nutritional composition B.

[0158] Comparative Example 11

[0159] The difference between Comparative Example 11 and Example 4 is that the low-speed pre-mixing process is omitted in step 4; the prepared coated particles are directly subjected to a dry mixing process with all the remaining components, the rotation speed of the dry mixing process is 45 rpm, and the mixing time is 90 seconds. The remaining steps are the same as those in Example 4, and finally a bar package product packaged into 25g / bag is obtained, which is recorded as a postbiotic milk-based nutritional composition C.

[0160] Hygroscopicity test of postbiotic milk-based nutritional composition AC

[0161] The specification of the postbiotic milk-based nutritional composition AC is 25g / pack of bar products. Compared with the canned products with a specification of 700-1000g, during use, the bar-packed products can be used according to the bar-pack dosage as needed, avoiding the need to open the canned products for multiple uses, and can more effectively reduce product agglomeration.

[0162] The final products A, B and C were subjected to a hygroscopic challenge test and stored at a temperature of 37°C and a humidity of 75% for 6 months. The results showed that products A, B and C remained in a free-flowing powder state without any agglomeration, and the moisture content was always kept below 5%, which met the requirements of the national standard for milk powder GB 19644.

[0163] like Figure 2As shown in the figure, the moisture content of product A obtained by embedding whole milk powder under high-speed stirring conditions increases more slowly and at a smaller rate than that of product C and product B over the storage time. Product B does not form particles of whole milk powder encapsulating inactivated yeast postbiotics, and its hygroscopicity is the strongest. Although product C forms particles of whole milk powder encapsulating inactivated yeast postbiotics, it lacks a low-speed pre-mixing procedure during the dry mixing process, which destroys the structure of the encapsulated particles and makes it more hygroscopic than product A.

[0164] Taste evaluation of postbiotic milk-based nutritional composition AC

[0165] Take the postbiotic milk-based nutritional supplement A prepared in Example 4, and after a week of trial by 100 professionals, the staff visited and collected their overall sensory evaluation of the product. The full score of each indicator is 100 points, and the higher the score, the higher the evaluation of the indicator. The average score of each indicator and the average total score are shown in Table 10.

[0166] Among them, inactivated yeast postbiotics are a brownish-brown raw material that affects the color of the final product. If inactivated yeast postbiotics are fully coated with whole milk powder, they will not be brown, but the off-white color of whole milk powder.

[0167] Table 10 Taste evaluation result record

[0168]

[0169]

[0170] From the records in Table 10, it can be seen that the formula and dosage form of the postbiotic milk-based nutritional supplement A prepared in Example 4 can be well matched with the postbiotics containing inactivated yeast, the milky aroma of the milk base and the fermented flavor of the postbiotics are well balanced, and the overall taste of the product is recognized by consumers.

[0171] The above-mentioned embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. A postbiotic milk-based nutritional composition, characterized in that: The invention comprises the following components in parts by weight: 30-50 parts of whole milk powder, 20-40 parts of skim milk powder, 0-10 parts of prebiotics, 1-5 parts of inactivated yeast postbiotics, and 0-1 part of a compound nutritional enhancer; the inactivated yeast postbiotics are encapsulated to form encapsulated particles; The postbiotic milk-based nutritional composition is prepared according to the following method: The inactivated yeast postbiotic screening step: taking the inactivated yeast postbiotic, controlling the ambient temperature to 20-25° C. and the humidity to 45-55%, and screening with a 30-60 mesh sieve; The step of forming coated particles is as follows: taking the sieved inactivated yeast postbiotics, placing the inactivated yeast postbiotics and whole milk powder in a mass ratio of 1:(1-3) in a stirring device, wherein a high-speed stirring blade is provided in the stirring device, and the filling height of the total amount of powder accounts for 1 / 3-2 / 3 of the height of the stirring device, turning on the stirring device, setting the stirring speed to 200-800 r / min, and the stirring time to 1-3 hours, to form coated particles; The core layer of the wrapped particles is inactivated yeast postbiotics, and the shell layer is whole milk powder; In the mixing step: the ambient temperature is controlled at 20-30° C. and the humidity is controlled at 50-70%, and the remaining whole milk powder, the coated particles, the skim milk powder, the prebiotics and the compound nutritional enhancer are fed into a dry powder mixer for pre-mixing, and the pre-mixing speed is set at 10-15 rpm for 40-50 seconds; Then, the mixture is stirred sufficiently, with the stirring speed set at 30-60 rpm and the stirring time set at 85-95 seconds to obtain a postbiotic milk-based nutritional composition, wherein the moisture content of the postbiotic milk-based nutritional composition is controlled within 5%.

2. The postbiotic milk-based nutritional composition according to claim 1, characterized in that The mass ratio of the inactivated yeast postbiotic to the first part of whole milk powder is 1:(1-1.5).

3. The postbiotic milk-based nutritional composition according to claim 1, characterized in that The invention comprises the following components in parts by weight: 30-50 parts of whole milk powder, 20-40 parts of skim milk powder, 5-10 parts of prebiotics, 1-5 parts of inactivated yeast postbiotics, and 0.1-1 parts of compound nutritional enhancer.

4. The postbiotic milk-based nutritional composition according to claim 1, characterized in that The prebiotics include one or any combination of inulin, galacto-oligosaccharide, xylo-oligosaccharide, polydextrose, resistant dextrin, isomaltooligosaccharide, stachyose, yeast β-glucan, trehalose and chito-oligosaccharide; The compound nutritional enhancer comprises one or a combination of compound minerals and compound vitamins.

5. The postbiotic milk-based nutritional composition according to claim 1, characterized in that The inactivated yeast postbiotic has the following properties: Color: Free-flowing light to dark brown powder; Bulk density 0.55–0.75 g / mL: Tap density 0.66–0.90 g / mL; Protein ≥ 25%, total dietary fiber ≥ 10%, total polyphenols ≥ 3%, moisture ≤ 8%; Aerobic colony count < 5000 cfu / g; Yeast and mold <100 cfu / g; Total E. coli <10 cfu / g; Enterobacteriaceae was less than <100 cfu / g.

6. The postbiotic milk-based nutritional composition according to claim 1, characterized in that The invention also includes the steps of preparing postbiotics from inactivated yeast: activating yeast in an activation medium, then transferring the activated yeast to a fermentation tank, adding water and nutrients for fermentation; After fermentation is completed, the wet fermentation product is filtered using a filter with a pore size of less than 300 microns, and then the obtained yeast and its metabolites are dried to obtain a mixture rich in yeast cell fragments, its metabolites and other nutrients, and the mixture is crushed to obtain the inactivated yeast postbiotics.

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