Process for the preparation of dry mixed powders

Abstract

This invention relates to the field of powder packaging technology, and more specifically, to a method for preparing a dry-mixed powder. The method includes: a dry mixing step to dry mix a milk-containing component and a vitamin component to obtain a mixture to be filled; and a filling step in which the mixture to be filled enters the transmission pipe through an inlet and is filled into a container after passing through the outlet of the transmission pipe. The horizontal height of the inlet is higher than that of the outlet. The mixture to be filled is transported in the transmission pipe under the action of gravity. Furthermore, a first horizontal static zone exists at the outlet of the transmission pipe, and the mixture to be filled is collected in the first horizontal static zone at the outlet and then filled into the container.

Description

Technical Field

[0001] This invention belongs to the field of food processing, specifically relating to the field of powder packaging technology, and more specifically, to a method for dry packaging milk powder products. Background Technology

[0002] Milk powder is a powdered product made primarily from milk and milk protein products, with added vitamins, minerals, and other ingredients, using physical processing methods. It can meet the nutritional needs of infants who cannot breastfeed due to work or health reasons, as well as the urgent need for healthy food among middle-aged and elderly people whose bodily functions are declining, who are prone to chronic diseases, and who lack micronutrients.

[0003] There are three main processing methods for milk powder: wet processing, dry processing, and a combination of wet and dry processing. The wet processing method involves adding nutrients to milk and then spray-drying it into powder. Milk powder produced using this method has stable physicochemical properties and a balanced composition, but many raw materials are very sensitive to processing conditions, leading to nutrient loss and off-flavors. The dry processing method involves adding various solid nutrients to milk powder, mixing thoroughly, and then packaging it. The dry processing method is relatively simple and allows for the addition of heat-sensitive nutrients. However, its solubility and taste are inferior to milk powder produced using the wet process. Building upon the first two methods, the wet-dry combination process can either directly add nutrients to fresh milk for a more balanced nutritional profile, or add more demanding nutrients during the dry mixing process, thus retaining the advantages of both wet and dry processing methods.

[0004] Vitamins, as nutrients, are commonly added to infant formula. Vitamins are classified into two types based on their properties: fat-soluble vitamins and water-soluble vitamins. Fat-soluble vitamins include vitamins A, K, E, and D, while water-soluble vitamins include vitamins B and C. Both fat-soluble and water-soluble vitamins work together to provide the essential nutrients for infant growth. The uniformity of vitamins in infant formula is crucial for dry mixing processes. Uneven distribution will affect the quality of the formula. Particle size, mixing volume, and subsequent packaging processes all influence vitamin uniformity. Existing technologies for improving the uniformity of infant formula mainly focus on the dry mixing process, such as adjusting the types and proportions of raw materials and additives used in dry mixing, the type of dry mixing (mechanical double-paddle agitator, three-dimensional planetary mixer, double-cone mixer, etc.), and the dry mixing time to enhance uniformity.

[0005] Reference 1 discloses a fully dry-mixed infant formula that provides nutritional balance and more uniform distribution of effective ingredients, which improves the uniformity of the formula during the dry mixing process by using the variety and ratio of added raw and auxiliary materials.

[0006] Reference 2 discloses a mixing method to improve the uniformity of formula milk powder components. It uses a three-dimensional motion mixer and an airflow mixer for premixing and dry mixing, which improves the uniformity of the milk powder.

[0007] However, in actual industrial production, due to the diversification and complexity of mixing processes, there is still room for further exploration regarding the homogenization of (composition / morphology) of canned and powdered products.

[0008] References:

[0009] Reference 1: CN104757123A

[0010] Reference 2: CN111990464A Summary of the Invention

[0011] The problem the invention aims to solve

[0012] To improve the stability or uniformity of the final product's composition or form, common improvement methods tend to focus on raw material selection and compounding processes. For example, in raw material selection, the quality of the final product is improved by optimizing specific components or their dosages. In compounding processes, the stability and uniformity of the final product are improved by optimizing specific equipment combinations or process parameters. For instance, references to CN113841743A, CN104757123A, CN113142306A, CN114176137A, CN103039605A, CN108450555A, CN108522655A, CN111990464A, and CN105053212A indicate that current technical solutions mainly focus on research into dry mixing processes for milk powder, such as the types and proportions of raw and auxiliary materials added for dry mixing, the type of dry mixing (mechanical double-paddle agitator, three-dimensional planetary mixer, double-cone mixer, etc.), and the dry mixing time.

[0013] However, the entire process of milk powder preparation has a complex impact on the quality and characteristics of the final product. In particular, during the inventors' further research, they unexpectedly discovered that in the dry mixing process, during the filling stage after dry mixing, different control methods or equipment parameters can also have a significant impact on the stability and uniformity of the composition and morphology of the final powder. Such a viewpoint has not yet been found in existing publicly available materials.

[0014] Therefore, based on the discovery and proposal of the above problems, in order to clarify the impact of equipment or process control parameters on the uniformity and stability of powder products, especially milk powder products, during subsequent pipeline transportation and canning, this invention proposes an optimized method for preparing dry-mixed powders. While taking into account production efficiency, this method can improve the uniformity and stability of the composition, morphological distribution, and other properties of the final powder product.

[0015] Solution for solving the problem

[0016] It has been found that the above-mentioned technical problems can be solved by implementing the following technical solutions:

[0017] [1]. This invention first provides a method for preparing a dry-mixed powder, wherein the method includes:

[0018] The dry mixing step is used to dry mix the milk-containing components with the vitamin components to obtain a mixture to be filled;

[0019] In the filling step, the mixture to be filled enters the transfer pipe through the inlet and is filled into a container after passing through the outlet of the transfer pipe. The horizontal level of the inlet is higher than that of the outlet. The mixture to be filled is transported in the transfer pipe under the action of gravity.

[0020] Furthermore, a first horizontal still zone exists at the outlet of the transmission pipeline, and the mixture to be filled is collected in the first horizontal still zone at the outlet and then filled into the container;

[0021] The method satisfies one or more of the following conditions:

[0022] (i) The D90 of the milk-containing component is below 250 μm;

[0023] (ii) The vertical height difference between the inlet of the transmission pipeline and the first horizontal static zone is less than 4m;

[0024] (iii) The radial direction of the transmission pipeline is at an angle of more than 30° and less than 90° with respect to the horizontal plane.

[0025] [2]. According to the method of [1], wherein the milk-containing component is obtained by spray drying, and the milk-containing component is selected from components containing cow's milk or sheep's milk.

[0026] [3]. The method according to [1] or [2], wherein the dry mixing is carried out by a dry mixer.

[0027] [4]. The method according to any one of [1] to [3], wherein the vitamin component includes one or more of water-soluble vitamins and fat-soluble vitamins.

[0028] [5]. The method according to any one of [1] to [4], wherein the absolute value of the difference between the D90 of the vitamin component and the D90 of the milk component is less than 50 μm.

[0029] [6]. The method according to any one of [1] to [5], wherein the D90 of the milk-containing component in condition (i) is 90 to 150 μm.

[0030] [7]. The method according to any one of [1] to [6], wherein the vertical height difference between the inlet of the transmission pipe and the first horizontal stationary zone in condition (ii) is 2.5 to 3.5 m.

[0031] [8]. The method according to any one of [1] to [7], wherein the radial direction of the transmission pipe in condition (iii) is at an angle of 30 to 50° with the horizontal plane.

[0032] [9]. The method according to any one of [1] to [8], wherein the method satisfies conditions (i) and (ii) simultaneously; or satisfies conditions (ii) and (iii) simultaneously; or satisfies conditions (i) and (ii) and (iii) simultaneously.

[0033]

[10] . Furthermore, the present invention also provides a method for preparing a milk powder product, wherein the method for preparing the milk product includes the method described in any one of [1] to [9] above.

[0034] The effects of the invention

[0035] By implementing the above technical solution, the present invention can achieve the following technical effects:

[0036] 1) This invention is the first to discover that different equipment parameters and process control methods in the final dry mixing-filling stage of powder products, especially milk powder products, will affect the uniformity and stability of the composition and morphology of the powder obtained in the final filling. Therefore, the primary effect of this invention is to further propose new aspects that can be optimized in the preparation process of powder products, especially milk powder products, which greatly fills the data gap, provides new theoretical and practical basis, and has very important industrial application value.

[0037] 2) Based on 1) above, by selecting appropriate can drop height, angle and semi-finished product particle size, the quality of dry-mixed powder products, especially milk powder products, after filling can be improved. Attached Figure Description

[0038] Explanation of reference numerals in the attached figures

[0039] Figure 1 Schematic diagram of the drop filling height experiment.

[0040] Figure 2 : Schematic diagram of the drop filling angle experiment.

[0041] Figure 3 The effect of drop filling height on the RSD of vitamin A and vitamin C in milk powder.

[0042] Figure 4 The effect of drop filling angle on the RSD of vitamin A and vitamin C in milk powder.

[0043] Figure 5 The effect of semi-finished product particle size on the RSD of vitamin A and vitamin C in milk powder.

[0044] Figure 6 Changes in milk powder composition during filling with existing equipment. Detailed Implementation

[0045] The present invention will now be described in detail. The descriptions of the technical features described below are based on representative embodiments and specific examples of the present invention, but the present invention is not limited to these embodiments and specific examples. It should be noted that:

[0046] In this specification, the range of values ​​referred to as "value A to value B" refers to the range including the endpoint values ​​A and B.

[0047] In this specification, the numerical range indicated by "above" or "below" refers to the numerical range that includes the stated number.

[0048] In this specification, the word "may" has two meanings: to perform a certain process and not to perform a certain process.

[0049] In this specification, the terms "optional" or "optional" are used to indicate the use or omission of certain substances, components, procedures, application conditions, etc.

[0050] In this manual, the term "children" refers to human beings who are older than 3 years but younger than 18 years, or who are older than 18 years but are still in the growth and development stage.

[0051] In this manual, the term "middle-aged and elderly" refers to human groups aged 45 years and older.

[0052] In this instruction manual, "infants and toddlers" refers to the human group under the age of 3 years.

[0053] In this instruction manual, "normal temperature" or "room temperature" refers to an indoor ambient temperature of "23±2℃".

[0054] In this manual, the use of "absolute value" includes both positive and negative values.

[0055] In this specification, D10, D50, and D90 are used to represent the particle size values ​​of the sample. The corresponding particle size values ​​mean that the volume content of particles smaller than this particle size accounts for 10%, 50%, and 90% of the total particles, respectively.

[0056] In this specification, the terms “milk” and “milk” should be interpreted broadly to encompass both raw milk (i.e., the liquid obtained directly from the mammary glands) and standardized dairy products (such as skim milk or whole milk), in which the concentration of milk fat has been reduced relative to the original raw milk.

[0057] All unit names used in this manual are international standard unit names, and unless otherwise stated, the "%" used refers to weight or mass percentage content.

[0058] In this specification, the term "substantially" is used to indicate that the standard deviation from the theoretical model or theoretical data is within 5%, preferably 3%, and more preferably 1%.

[0059] In this specification, the terms “comprising” and / or “including” are used to indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0060] In this specification, references to "some specific / preferred embodiments," "other specific / preferred embodiments," "implementation," etc., refer to specific elements (e.g., features, structures, properties, and / or characteristics) related to that embodiment, which are included in at least one of the embodiments described herein and may or may not be present in other embodiments. Furthermore, it should be understood that these elements may be combined in any suitable manner in various embodiments.

[0061] The present invention mainly provides a method for preparing a dry mixed powder product. Preferably, the mixed powder product can be a dairy product, and these mixed powder products also need to contain vitamin components.

[0062] Furthermore, the technical solution of this invention is mainly based on the following insights:

[0063] Unlike existing research directions on dry mixing preparation processes, this invention primarily focuses on optimizing the dry mixing process and the process from dry mixing to final filling. It has been found that in dry mixing-filling processes with added vitamin components, the uniformity of powder composition and morphology in the final filled product can be improved by implementing one or more of the following optimization methods:

[0064] Before dry mixing, the particle size of the emulsion-containing components is optimized and controlled; after dry mixing, the height and angle of the transmission pipeline are adjusted.

[0065] More specifically, the method for preparing the dry-mixed powder of the present invention includes at least a dry mixing step and a filling step. In the dry mixing step, the milk-containing component and the vitamin component are dry-mixed to obtain a mixture to be filled, and in the filling step, the mixture to be filled enters the transfer pipe through the inlet of the transfer pipe and is filled into a container after passing through the outlet of the transfer pipe.

[0066] (Powdered products)

[0067] The powdered products targeted by this invention mainly refer to powdered products containing milk and vitamin components.

[0068] There are no particular restrictions on the types of these milk-containing powdered products. Typical examples include powdered products used to prepare infant formula, children's milk powder, milk powder for the middle-aged and elderly, and milk powder for specific purposes.

[0069] Furthermore, the powdered products of the present invention also include powdered articles for preparing reconstituteable functional foods or nutritional products containing milk and vitamin components.

[0070] (Contains milk components)

[0071] In some specific embodiments, the milk-containing components of this invention can be derived from animal milk raw materials, including cow's milk, sheep's milk, horse's milk, camel's milk, etc. These milk-containing components can be freshly obtained liquid milk raw materials, or liquid, semi-solid, or solid milk raw materials that have undergone further optional processing. In some specific embodiments, these raw materials are compositionally adjusted, the main purpose of which is to remove components in animal milk that are incompatible with human health, especially with the health conditions of infants and children. In some preferred embodiments, these animal milk raw materials have undergone casein removal treatment. The invention does not impose any particular limitations on the method of casein removal; conventional methods used in the dairy industry can be followed, such as precipitation methods using pH adjustment.

[0072] Furthermore, the milk-containing component of the present invention, or the milk-containing component that has undergone further processing (e.g., component adjustment), can be used as the milk base material for the powdered product of the present invention.

[0073] In addition to the aforementioned milk base, other nutrients may be added to the milk-containing components of this invention as needed. There are no particular restrictions on the types and amounts of these nutrients; they can be added in accordance with existing dairy industry practices and legal regulations.

[0074] Such nutrients typically include: protein, fatty acids (esters), minerals, polysaccharides / dietary fiber, and carbohydrates.

[0075] Protein components that can be listed include whey protein or its hydrolyzed protein components, immune protein components, etc.

[0076] For fatty acid (ester) components, examples include various fatty acids (such as DHA, ARA, etc.) or fatty acid glycerides. These fatty acid glycerides can be derived from various vegetable oils, such as one or more of seed oil, olive oil, sesame oil, corn oil, flaxseed oil, and camellia seed oil; or, for fatty acid glycerides, they can also be fatty acid esters mainly containing one or more specific triglycerides. These fatty acid esters can contain appropriate amounts of OPO (1,3-dioleoyl-2-palmitoylglycerol), OPL (1-oleoyl-2-palmitoyl-3-linoleic acid triglyceride), MLCT (fatty acid esters mainly composed of medium- and long-chain fatty acid triglycerides), etc. The addition of such fatty acid esters can achieve an effect similar to breast milk and easily absorbed by the human body. In addition, for such fatty acid esters, typical examples can be found in various structured lipids or fatty acid ester compositions obtained therefrom, as disclosed in patent document CN115500390A. Furthermore,

[0077] For mineral components, including additives of various metallic mineral elements required by the human body, examples include one or more of the following: calcium citrate, L-calcium lactate, calcium hydrogen phosphate, potassium gluconate, sodium citrate, ferrous gluconate, potassium iodide, zinc gluconate, sodium selenite, copper gluconate, chromium sulfate, manganese gluconate, and magnesium gluconate.

[0078] For polysaccharide / dietary fiber components, the polysaccharide components mainly refer to disaccharide additives, including maltose, sucrose, and lactose, preferably lactose; the dietary fiber components include one or more of inulin, konjac flour, galactooligosaccharides, fructooligosaccharides, isomaltooligosaccharides, soybean polysaccharides, cyclodextrin, resistant dextrin, and soybean fiber.

[0079] For carbohydrate components, including starch or modified starch.

[0080] Furthermore, there are no particular limitations on the preparation method for milk-containing components. In some specific embodiments, the components can be mixed in the form of an aqueous solution, followed by spray drying or other methods. Alternatively, for temperature-sensitive components, other components can be mixed and spray-dried to obtain a powder before adding these components, and then dry-mixed with the temperature-sensitive components.

[0081] In addition, other processing techniques in the preparation of milk-containing components may optionally include adjusting the solid content of a single component or any mixture of multiple components, sterilizing or sterilizing a single component or any mixture of multiple components, etc.

[0082] (Vitamin components)

[0083] There are no particular restrictions on the types and amounts of vitamins used in this invention. They can be selected and added in accordance with conventional operating rules or legal regulations in the field.

[0084] In some specific implementations, the vitamin component may be one or more of water-soluble vitamins and fat-soluble vitamins.

[0085] In some preferred embodiments, the vitamin component may be selected from one or more of vitamin A, beta-carotene, vitamin D3, vitamin E, vitamin K1, vitamin B1, vitamin B2, vitamin B6, vitamin B12, vitamin C, pantothenic acid, folic acid, niacin, choline, inositol, and biotin.

[0086] The vitamins mentioned above can be obtained through commercial purchases.

[0087] (Steps for dry mixing)

[0088] The dry mixing step of this invention mainly refers to the process of mixing powdered milk-containing components with vitamin components to obtain a mixed powder. Furthermore, this mixed powder is a mixture awaiting further filling.

[0089] For the equipment used in the dry mixing step of this invention, a conventional dry mixer in the art can be used. Regarding the mixing method of the milk-containing component and the vitamin component, in some specific embodiments, at least a portion of the milk-containing component and the vitamin component can be mixed first, and then mixed with the remaining milk-containing component. Furthermore, there is no particular limitation on the mixing time, which can generally be controlled within the range of 60 to 200 seconds.

[0090] The mixture to be filled obtained by the above dry mixing can be further discharged through the lower outlet of the dry mixer into the transmission pipeline described below.

[0091] (The filling process)

[0092] The filling steps of the present invention mainly refer to: transporting the mixture obtained by dry mixing through a transmission pipe and dispensing it into containers. More specifically, in the filling steps, the mixture to be filled enters the transmission pipe through the inlet of the transmission pipe and is filled into containers after passing through the outlet of the transmission pipe. Furthermore, the horizontal height of the inlet is higher than that of the outlet, and the mixture to be filled is transported in the transmission pipe under the action of gravity.

[0093] The filling steps of this invention are mainly designed to improve the uniformity and stability of the final product in terms of composition and morphology (particle size distribution) without compromising production efficiency and continuity by adjusting process parameters.

[0094] It has been found that satisfying one or more of the following conditions contributes to achieving the aforementioned uniformity and stability:

[0095] (i) The D90 of the milk-containing component is below 250 μm;

[0096] (ii) The vertical height difference between the inlet of the transmission pipeline and the first horizontal static zone is less than 4m;

[0097] (iii) The radial direction of the transmission pipeline is at an angle of more than 30° and less than 90° with respect to the horizontal plane.

[0098] For condition (i)

[0099] It has been found that in the dry mixing step, making the particle size of the powdered milk-containing component similar to that of the vitamin component is beneficial to the compositional stability of the final product.

[0100] In some preferred embodiments, before or at the beginning of dry mixing, the D90 range for the milk-containing components can be below 250 μm, preferably below 200 μm, more preferably below 180 μm, and even more preferably below 150 μm. If the D90 is too large, it will lead to significant deviations in the uniformity and stability of vitamin content in the final product.

[0101] In some other preferred embodiments, the D90 range for the emulsion component can be 90 μm or more, preferably 95 μm or more, and more preferably 100 μm or more, before or at the beginning of dry mixing. If the D90 is too small, it will lead to an excessive increase in the dry mixing load, and the small particle size may also lead to agglomeration, thereby reducing processing efficiency.

[0102] Furthermore, in some preferred embodiments, from the perspective of improving the stability of the final product composition, the absolute value of the difference between the particle size of the milk-containing component and the particle size D90 of the vitamin component before or at the beginning of dry mixing is 50 μm or less, more preferably 40 μm or less, and even more preferably 30 μm or less.

[0103] For condition (ii)

[0104] It has been found that the vertical height of the mixture as it falls into the transmission pipeline before filling also affects the stability and uniformity of the final product's composition.

[0105] The vertical height (difference) mentioned here refers to the vertical height between the inlet and outlet of the transmission pipe at the first horizontal stationary zone. In some specific implementations, the inlet of the transmission pipe is set at the lower end of the feeding device.

[0106] The first horizontal stationary zone mainly refers to the area at the outlet of the transmission pipeline where the mixture to be filled can first stop horizontally. This area is also the endpoint where the mixture completes its fall before final filling. Usually, the mixture passing through this area is further sent into the container for filling or dispensing.

[0107] Furthermore, reducing the aforementioned vertical height (difference) can improve the uniformity of the powder composition in the final filled product.

[0108] In some specific implementations, the vertical height difference is less than 4m, preferably less than 3.5m, and more preferably less than 3.2m.

[0109] Furthermore, although it has been found that reducing the aforementioned vertical height is beneficial to the uniformity of product composition, if the height difference is too small, it may affect production efficiency, for example, by easily causing pipeline blockage. Therefore, in some preferred embodiments of the present invention, the vertical height difference can be 2m or more, preferably 2.5m or more.

[0110] Regarding condition (iii)

[0111] It has been found that variations in the angle between the radial direction of the transmission pipe and the horizontal plane can also affect the uniformity of the powder composition in the final filled product.

[0112] For (rigid) transmission pipes, they usually have a circular or near-circular cross-section. Therefore, the direction of the line connecting the centers of each cross-section is called the radial direction of the transmission pipe.

[0113] In this invention, the included angle is controlled to be above 30° and below 90°, preferably 30-80°, more preferably 30-70°, and most preferably 30-50°, such as 35°, 40°, and 45°. If the included angle is too large, although it is beneficial to improve production efficiency, it will lead to a decrease in the uniformity of powder composition in the final filled product. If the included angle is too small, it will significantly affect the continuity of production. For example, when the included angle is below 30°, the phenomenon of powder blockage in the transmission pipeline will be significantly aggravated during the transmission process, or under certain conditions, the powder entering from the pipeline inlet will become substantially stationary before reaching the first horizontal stationary zone mentioned above.

[0114] Of the three conditions mentioned above, it is advantageous to satisfy any two or all three conditions simultaneously. Furthermore, in some preferred embodiments, the powder mixture in the transport pipe is transported solely by gravity.

[0115] By applying the above conditions, it has been found that the final filled powder product exhibits improved uniformity and stability in composition during the production process. Furthermore, this improved uniformity and stability also leads to improved stability in the final product's morphology, such as particle size distribution.

[0116] (Dairy product preparation methods)

[0117] The dry-mixed powder products obtained by the present invention are particularly suitable for use as dairy products or their raw materials. Therefore, the present invention further provides a method for preparing dairy products, which includes the method for preparing the dry-mixed powder described above.

[0118] In addition to the above-mentioned dry-mixed powder preparation steps, the dairy products of the present invention also include a pretreatment process for any raw materials and an intermediate treatment process for intermediate materials obtained by mixing any raw materials.

[0119] In some specific embodiments of the present invention, the dairy products of the present invention can be infant formula milk powder, children's milk powder, milk powder for middle-aged and elderly people, milk powder for specific purposes, etc. Alternatively, the dairy products of the present invention may also include powdered products such as reconstituteable functional foods or nutritional products. These products can be directly filled using the dry mixing powder preparation method of the present invention.

[0120] In other specific embodiments, the dairy products of the present invention can also be other edible products made from the dry-mixed powder of the present invention (obtained through filling). Therefore, for the preparation methods of these edible products, in addition to the preparation steps using the dry-mixed powder of the present invention, any additional processing means can be used to obtain the final liquid, semi-solid, or solid dairy products.

[0121] Example

[0122] The technical solution of the present invention will be further described below through specific embodiments:

[0123] <Raw Material Information>

[0124] Semi-finished milk powder: Feihe Dairy

[0125] Vitamin A / Vitamin C: The D90 value of vitamin A, as measured by a laser particle size analyzer, is 115.80 μm, and the D90 value of vitamin C is 113.11 μm.

[0126] <Device Information>

[0127] Premixer: Shanghai Jinqi;

[0128] C2000R Dry Mixer: CEM Australia;

[0129] e2695 high-performance liquid chromatograph: Waters, USA;

[0130] UV-19001 UV-Vis Spectrophotometer: Shimadzu, Japan;

[0131] SN-DF-101S Digital Display Thermostatic Magnetic Stirrer: Shanghai Shangyi;

[0132] ME104E Electronic Analytical Balance: Shanghai Mettler;

[0133] SN-RE-201D Rotary Evaporator: Shanghai Shangyi;

[0134] RE-1005 Separating Funnel Shaker: Shanghai Cancun;

[0135] RF-5301PC Fluorescence Spectrophotometer: Shimadzu, Japan;

[0136] DHG-type forced-air drying oven: Shanghai Yiheng Technology;

[0137] Model 3000 Laser Particle Size Analyzer: Malvern, UK;

[0138] OCTAGON20 Vibrating Screen: Endeavour, UK;

[0139] Biological microscope: Guangdong Murzider.

[0140] <Experimental Procedure>

[0141] The effects of falling pattern and particle size on the uniformity of milk powder were investigated. In this embodiment, the experimental method included:

[0142] Dry mixing: Most of the semi-finished product is added to the dry mixer, while a small portion of the semi-finished product and nutrients (vitamins) are added to the premixer for mixing. After premixing, the mixture is then added to the dry mixer for further dry mixing. Conveying and falling process: The mixed milk powder is fed into the pipeline from the top and conveyed downwards using different methods. Testing steps: Samples are taken from three locations—before, during, and after the powder dispensing end—to test and calculate the relative standard deviation (RSD) values ​​of the nutrients.

[0143] More specifically, the experimental method in this embodiment first involves dry mixing the semi-finished product and nutrients to obtain a uniformly mixed milk powder sample, which is used to prepare for subsequent experiments.

[0144] ① When investigating the effect of semi-finished product particle size on uniformity, the milk powder sample needs to be sieved using a vibrating sieve to obtain milk powder samples with different particle sizes (this invention uses 50-mesh and 80-mesh vibrating sieves to sieve the semi-finished product into three particle size ranges: <50 mesh, 50-80 mesh, and >80 mesh. The corresponding particle size distribution of the semi-finished product is shown in Table 1:

[0145] Table 1:

[0146]

[0147] After sieving using a standard sieve, the particle size of the semi-finished product varies depending on the mesh size. The median particle sizes of the three sample groups were 309 μm, 196 μm, and 118 μm, respectively. The uniformly mixed milk powder sample was fed into the filling machine from the top, and samples were taken from three positions: front, middle, and back. The relative standard deviation (RSD) of the nutrients was measured and calculated, thus obtaining the RSD values ​​of nutrients at different drop heights.

[0148] ② When investigating the influence of the pipe angle, the pipe angle was set to different angles. The well-mixed milk powder sample was put into the filling machine from the top and transported down from the pipe at different angles. Samples were taken from the front, middle and back of the powder discharge end, and the relative standard deviation (RSD) value of the nutrients was detected and calculated. In this way, the RSD value of nutrients under different pipe angles can be obtained.

[0149] ③ When investigating the effect of vertical drop height, the well-mixed milk powder sample was dropped from different vertical heights, and samples were taken from three positions: front, middle and back of the powder drop end. The relative standard deviation (RSD) value of the nutrients was detected and calculated. This way, the RSD value of nutrients at different drop heights can be obtained.

[0150] The uniformity of nutrients is characterized by the RSD value; the larger the value, the worse the uniformity, and the smaller the value, the better the uniformity.

[0151] The following analysis is based on specific embodiments:

[0152] Example 1

[0153] First, add most of the semi-finished product to the dry mixer. Add a small portion of the semi-finished product, Vitamin A, and Vitamin C to the premixer and mix for 60 seconds. After premixing, add the mixture to the dry mixer and dry mix for 120 seconds. Then, add the mixed milk powder from the top of pipes at heights of 3 meters, 4 meters, 5 meters, and 6 meters respectively (e.g.,...). Figure 1 As shown in the figure, samples were taken from three positions at the front, middle and back of the powder feeding end, and the RSD values ​​of vitamin A and vitamin C were measured and calculated and compared with the RSD values ​​of the powder that was not fed.

[0154] Example 2

[0155] First, add most of the semi-finished product to the dry mixer. Add a small portion of the semi-finished product, Vitamin A, and Vitamin C to the premixer and mix for 60 seconds. After premixing, add the mixture to the dry mixer and dry mix for 120 seconds. Then, add the mixed milk powder from the top of the pipes at 30°C, 45°C, 60°C, and 90°C respectively (e.g.,...). Figure 2 As shown in the figure, the vertical height of the powder is 3 meters. Furthermore, samples are taken from the front, middle and back of the powder end to detect and calculate the RSD values ​​of vitamin A and vitamin C and compare them with the RSD values ​​of the powder that was not added.

[0156] Example 3

[0157] First, most of the semi-finished product was added to the dry mixer. A small portion of the semi-finished product, along with vitamins A and C, was added to the premixer and mixed for 60 seconds. After premixing, the mixture was added to the dry mixer and dry-mixed for 120 seconds. Particle size was scanned for the milk powder, vitamin A, and vitamin C, and the structure of the milk powder was observed using a biological microscope. The milk powder was then sieved using a vibrating sieve. The sieved milk powder with different particle sizes (median particle sizes of 309 μm, 196 μm, and 118 μm, respectively) was mixed with vitamins A and C and fed into a 3-meter-high pipe (perpendicular to the horizontal plane). Samples were taken from three positions—front, middle, and back—at the powder feeding end to test and calculate the RSD values ​​of vitamins A and C.

[0158] Analysis results

[0159] The effect of different drop filling heights on the RSD of vitamin A and vitamin C in milk powder was determined by... Figure 3It can be seen that the RSD values ​​of vitamin A and vitamin C in the milk powder after the drop filling process are greater than those in the milk powder that has not been dropped, indicating that the drop process affects the dry mixing uniformity and makes the dry mixing uniformity worse.

[0160] As the falling height increases, the RSD values ​​of vitamin A and vitamin C in milk powder show a gradual upward trend. This may be because with the increase in height, the falling distance is longer, and vitamin A and vitamin C are more likely to fall first compared to semi-finished powder, resulting in uneven distribution of components. The higher the RSD value, the higher the RSD value. The RSD value of vitamin A reaches 15.9%, and the RSD value of vitamin C reaches 13.6%.

[0161] The effect of different drop filling angles on the RSD of vitamin A and vitamin C in milk powder is determined by... Figure 4 It can be seen that the RSD values ​​of vitamin A and vitamin C in milk powder with different drop filling angles are greater than those in milk powder without drop filling, indicating that the dry mixing uniformity is affected by the drop angle. As the angle increases, the RSD values ​​of vitamin A and vitamin C in the milk powder show an upward trend, indicating worse dry mixing uniformity. This may be because the drop angle buffers the powder during the drop process; as the angle increases, the buffering effect on the milk powder during filling decreases, the gravitational force increases, the component distribution becomes more uneven, and the RSD value is higher. The highest RSD value for vitamin A reaches 11.1%, and for vitamin C, it reaches 11.2%.

[0162] The effect of semi-finished product particle size on the RSD of vitamin A and vitamin C in milk powder is determined by Figure 5 It can be seen that as the particle size of the semi-finished product increases, the RSD (Responsible Displacement) of vitamin A and vitamin C also gradually increases, with the highest RSD value for vitamin A reaching 14% and for vitamin C reaching 15.1%. This may be because when the semi-finished product and vitamins A and C are simultaneously subjected to gravity and fall, the larger the particle size of the semi-finished product, the greater the air resistance, the larger the interval between its fall and that of vitamins A and C, resulting in a higher RSD value and poorer dry mixing uniformity. When the vitamin particle size is similar to or smaller than that of the semi-finished product powder, the product mixing uniformity is high.

[0163] Reference Example

[0164] Using existing equipment (a 4.5-meter-high, vertically aligned pipeline), a dry-mixing process was performed on semi-finished milk powder and vitamins A and C. The same blend was then used to produce packaged products at different times. The composition of these packaged products was then analyzed.

[0165] Depend on Figure 6It can be seen that during the milk powder's falling filling process, the content of both vitamin A and vitamin C initially decreased, then stabilized, and then decreased again. This may be because the particle size of vitamin A and vitamin C is relatively small compared to the semi-finished powder, resulting in less air resistance during the falling process. This causes vitamin A and vitamin C to fall first, resulting in a higher content. At this point, the vitamin A content reaches 754 μgRE / 100g, and the vitamin C content reaches 122 mg / 100g. Subsequently, the content of the two vitamins in the milk powder gradually decreases. However, as the powder layer accumulates after falling, the distribution of vitamin A and vitamin C becomes more uniform, and the content remains relatively constant. When the milk powder is completely filled, the content of vitamin A and vitamin C is at its lowest, with vitamin A reaching 575 μgRE / 100g and vitamin C reaching 85 mg / 100g.

[0166] It should be noted that although the technical solution of the present invention has been described with specific examples, those skilled in the art will understand that this disclosure should not be limited thereto.

[0167] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

[0168] Industrial availability

[0169] This invention can be used in the production of milk powder products.

Claims

1. A method for the production of a dry mixed powder, characterized in that, The method includes: The dry mixing step is used to dry mix the milk-containing components with the vitamin components to obtain a mixture to be filled; In the filling step, the mixture to be filled enters the transfer pipe through the inlet and is filled into a container after passing through the outlet of the transfer pipe. The horizontal level of the inlet is higher than that of the outlet. The mixture to be filled is transported in the transfer pipe under the action of gravity. Furthermore, a first horizontal still zone exists at the outlet of the transmission pipeline, and the mixture to be filled is collected in the first horizontal still zone at the outlet and then filled into the container; The method wherein any two or three of the following conditions are simultaneously satisfied: (i) The D90 of the milk-containing component is less than 250 μm and more than 90 μm; (ii) The vertical height difference between the inlet of the transmission pipeline and the first horizontal static zone is less than 4m; (iii) The radial direction of the transmission pipe makes an angle of 30° or more but less than 90° with the horizontal plane. The milk-containing ingredient, after being prepared into powder form, is only dry-mixed with the vitamin ingredient, and the milk-containing ingredient comprises a milk base and other nutrients.

2. The method of claim 1, wherein, The milk-containing component is obtained by spray drying, and the milk-containing component is selected from components containing cow's milk or sheep's milk.

3. The method according to claim 1 or 2, characterized in that, The dry mixing is carried out using a dry mixer.

4. The method according to claim 1 or 2, characterized in that, The vitamin components include one or more of water-soluble vitamins and fat-soluble vitamins.

5. The method according to claim 1 or 2, characterized in that, The absolute value of the difference between the D90 of the vitamin component and the D90 of the milk component is less than 50 μm.

6. The method of claim 1 or 2, wherein, The D90 of the milk-containing component in condition (i) is 90–150 μm.

7. The method according to claim 1 or 2, characterized in that, The vertical height difference between the inlet of the transmission pipe and the first horizontal stationary zone in condition (ii) is 2.5 to 3.5 m.

8. The method of claim 1 or 2, wherein, The radial direction of the transmission pipe in condition (iii) is at an angle of 30 to 50° with the horizontal plane.

9. The method of claim 1 or 2, wherein, The method satisfies conditions (i) and (ii) simultaneously; or satisfies conditions (ii) and (iii) simultaneously; or satisfies conditions (i), (ii), and (iii) simultaneously.

10. A process for the preparation of a milk powder product, characterized in that, The method for preparing the milk powder product includes the method according to any one of claims 1 to 9.

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