Safe breast milk freeze-drying method and application thereof

Abstract

The invention relates to a safe breast milk freeze-drying method and application thereof, and the method comprises the following steps: carrying out cold plasma sterilization and ultraviolet sterilization on breast milk to obtain pretreated breast milk; and mixing the pretreated breast milk with a protective agent, and freeze-drying to obtain the breast milk. The cold plasma treatment can destroy the surface structure of microorganisms, the ultraviolet sterilization treatment can penetrate through a lipid layer to inactivate internal pathogens, active factors and other components can be furthest kept not to be destroyed while sterilization is performed, the stability of the product can be improved, the water content of the freeze-dried powder can be reduced, and fat aggregation can be prevented.

Description

Technical Field

[0001] The invention belongs to the field of biotechnology and relates to a safe breast milk freeze-drying method and application thereof. Background Art

[0002] With the development of modern medicine and the evolution of parenting concepts, freeze-dried breast milk powder, as an important form of breast milk preservation, provides valuable nutritional support and health assurance for infants who cannot breastfeed directly. Breast milk is rich in essential nutrients such as protein, fat, and carbohydrates, as well as bioactive components such as immunoglobulins, lactoferrin, and lysozyme. These components collectively form a baby's first line of defense against disease, promoting intestinal development and immune system maturation. Its nutritional value and biological functions cannot be fully replaced by any other formula.

[0003] However, the current state-of-the-art technology for preparing freeze-dried breast milk powder still presents numerous challenges that need to be addressed. While traditional pasteurization effectively kills most harmful microorganisms, it is essentially a heat treatment process, typically at temperatures between 60-85°C and for periods ranging from tens of seconds to tens of minutes. These heat treatment conditions can be devastating for heat-sensitive components in breast milk. Take immunoglobulin A (IgA), for example. It's the most abundant immunoglobulin in breast milk and forms a protective layer on the surface of the infant's intestines, preventing pathogens from invading and playing a key role in passive immunity. However, during pasteurization, IgA's active structure is easily destroyed by high temperatures, significantly reducing its immune protection. Similarly, lactoferrin, which possesses numerous important functions, including antibacterial and antiviral properties and regulation of iron metabolism, undergoes irreversible changes in its unique three-dimensional structure after high-temperature treatment, significantly diminishing the nutritional value and health benefits of freeze-dried breast milk powder.

[0004] In the freeze-drying process, freeze-drying technology is the core process for preparing freeze-dried breast milk powder, but the damage caused to the microstructure of breast milk by the formation of ice crystals in this process cannot be underestimated. At present, breast milk freeze-drying technology mainly relies on low temperature and vacuum environment to remove moisture. Although traditional freeze-drying equipment can maintain the nutritional components of breast milk to a certain extent, it has shortcomings in fat processing. In the traditional freeze-drying process, the fat in breast milk is easily affected by oxygen and undergoes oxidation reaction, resulting in the loss of nutrients and affecting the quality and safety of breast milk. Fat is prone to forming lumps during the freeze-drying process, affecting the re-dissolution effect, and the oxidation reaction will lead to the loss of nutrients. The retention rate of heat-sensitive substances such as docosahexaenoic acid (DHA), immunoglobulin antibodies, vitamin C, etc. is generally low, which cannot meet the nutritional needs of breast milk.

[0005] Existing improved methods often involve complex equipment and processes, increasing production costs and operational difficulty, limiting their widespread adoption in practical applications. Therefore, developing an innovative preparation method that balances safety, activity retention, and stability has become an urgent need in the current field of breast milk research and application. This has important practical significance for ensuring the healthy growth of infants and promoting the development of breastfeeding technology. Summary of the Invention

[0006] In view of the deficiencies in the prior art, the present invention aims to provide a safe breast milk freeze-drying method and application thereof.

[0007] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a safe method for freeze-drying breast milk, comprising:

[0009] (1) sterilizing breast milk by cold plasma and ultraviolet to obtain pretreated breast milk;

[0010] (2) The pretreated breast milk is mixed with a protective agent and freeze-dried to obtain the product.

[0011] Cold plasma treatment destroys the surface structure of microorganisms, while UV sterilization penetrates the lipid layer to inactivate internal pathogens, while simultaneously preserving active factors and other components to the greatest extent possible. Safety refers to the low colony count in breast milk produced through the combined cold plasma and UV sterilization treatments.

[0012] Preferably, the frequency of the cold plasma is 40-45 kHz, the temperature is 4-40° C., and the time is 1-10 min.

[0013] The frequency can be selected from 40kHz, 41kHz, 42kHz, 43kHz, 44kHz, 45kHz, etc. The temperature can be selected from 4℃, 10℃, 15℃, 20℃, 25℃, 30℃, 35℃, 40℃, etc. The time can be selected from 1min, 2min, 3min, 4min, 5min, 6min, 7min, 8min, 9min, 10min, etc. Other specific point values ​​within the above numerical range can be selected, so they will not be listed here.

[0014] Preferably, the working gas of the cold plasma includes argon and oxygen.

[0015] Preferably, the wavelength of the ultraviolet sterilization is 260-270nm, and the irradiation dose is 100-140mJ / cm 2 , the temperature is 4-25℃.

[0016] The wavelength can be selected from 260nm, 262nm, 264nm, 266nm, 268nm, 270nm, etc., and the irradiation dose can be selected from 100mJ / cm 2 、105mJ / cm 2 、110mJ / cm 2 、115mJ / cm 2 、120mJ / cm 2 、125mJ / cm 2 、130mJ / cm 2 、135mJ / cm 2 、140mJ / cm 2 The temperature can be selected as 4℃, 8℃, 10℃, 12℃, 15℃, 18℃, 20℃, 22℃, 25℃, etc. Other specific point values ​​within the above numerical range can be selected, so they will not be listed here.

[0017] Preferably, after the pre-treated breast milk is mixed with the protective agent, the breast milk is further homogenized.

[0018] The freeze-drying process of fat is prone to agglomeration, oxidation and hardening, which affects re-dissolution. The present invention uses homogenization technology to homogenize breast milk to ensure the uniformity of breast milk and avoid fat aggregation and oxidation during the freeze-drying process.

[0019] Preferably, the frequency of the homogenization process is 20-40 kHz and the power density is 0.8-1 W / cm 2 .

[0020] The frequency can be selected from 20kHz, 25kHz, 30kHz, 35kHz, 40kHz, etc., and the power density can be selected from 0.8W / cm 2 , 0.85W / cm 2 , 0.9W / cm 2 , 0.95W / cm 2 , 1W / cm 2 Other specific point values ​​within the above numerical range can be selected and will not be described here one by one.

[0021] Preferably, the homogenization temperature is 35-45° C. and the time is 1-10 min.

[0022] The temperature can be selected as 35℃, 38℃, 40℃, 42℃, 45℃, etc., and the time can be selected as 1min, 2min, 3min, 4min, 5min, 6min, 7min, 8min, 9min, 10min, etc. Other specific point values ​​within the above numerical range can be selected, so they will not be listed here.

[0023] Preferably, the mass ratio of the pretreated breast milk to the protective agent is 1:(0.13-0.25), and the specific point values ​​in (0.13-0.25) can be selected from 0.13, 0.15, 0.17, 0.19, 0.21, 0.23, 0.25, etc. Other specific point values ​​within the above numerical range can be selected, and they will not be repeated here.

[0024] Preferably, the protective agent comprises sodium caseinate, tocopherol, lactoferrin, hydroxypropyl β-cyclodextrin and inulin.

[0025] Preferably, the mass ratio of sodium caseinate, tocopherol, lactoferrin, hydroxypropyl β-cyclodextrin and inulin is (0.3-0.8):(0.005-0.015):(0.03-0.06):(1-3):(1-3).

[0026] The specific point values ​​in (0.3-0.8) can be selected from 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, etc.; the specific point values ​​in (0.005-0.015) can be selected from 0.005, 0.008, 0.01, 0.012, 0.015, etc.; the specific point values ​​in (0.03-0.06) can be selected from 0.03, 0.035, 0.04, 0.045, 0.05, 0.055, 0.06, etc.; the specific point values ​​in (1-3) can be selected from 1, 1.2, 1.5, 1.8, 2, 2.2, 2.5, 2.8, 3, etc. Other specific point values ​​within the above numerical range can be selected, and they will not be listed here one by one.

[0027] Preferably, the protective agent further comprises lecithin, trehalose, ascorbyl palmitate, maltodextrin, and sodium citrate.

[0028] Preferably, the mass ratio of the lecithin, trehalose, ascorbyl palmitate, maltodextrin and sodium citrate is (0.2-0.5):(4-6):(0.01-0.03):(7-10):(0.08-0.12).

[0029] The specific point values ​​in (0.2-0.5) can be selected from 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, etc. The specific point values ​​in (4-6) can be selected from 4, 4.2, 4.5, 4.8, 5, 5.2, 5.5, 5.8, 6, etc. The specific point values ​​in (0.01-0.03) can be selected from 0.01, 0.015, 0.02, 0.025, 0.03, etc. , the specific point values ​​in (7-10) can be selected as 7, 7.2, 7.5, 7.8, 8, 8.2, 8.5, 8.8, 9, 9.2, 9.5, 9.8, 10, etc., and the specific point values ​​in (0.08-0.12) can be selected as 0.08, 0.085, 0.09, 0.095, 0.1, 0.012, etc. Other specific point values ​​within the above numerical range can be selected, so they will not be listed here one by one.

[0030] Preferably, before freeze-drying, the freeze dryer is sterilized with ozone.

[0031] Preferably, the disinfection time is 25-35 minutes, for example, 25 minutes, 28 minutes, 30 minutes, 32 minutes, 35 minutes, etc. Other specific point values ​​within the above numerical range can be selected, and they will not be repeated here.

[0032] Preferably, the freeze-drying includes pre-freezing and freeze-drying.

[0033] Preferably, the pre-freezing time is 3-5h, for example, 3h, 3.2h, 3.5h, 3.8h, 4h, 4.2h, 4.5h, 4.8h, 5h, etc. Other specific point values ​​within the above numerical range can be selected, and they will not be described here one by one.

[0034] Preferably, the pre-freezing and freeze-drying temperatures are independently -65 to -50°C, for example, -65°C, -63°C, -60°C, -58°C, -55°C, -53°C, -50°C, etc. Other specific point values ​​within the above numerical range can be selected and will not be repeated here.

[0035] Preferably, the freeze-drying is performed under vacuum conditions.

[0036] Preferably, the freeze-drying time is 16-20h, for example, 16h, 16.5h, 17h, 17.5h, 18h, 18.5h, 19h, 19.5h, 20h, etc. Other specific point values ​​within the above numerical range can be selected and will not be repeated here.

[0037] Preferably, the freeze-drying further includes low-temperature sterilization.

[0038] Preferably, the low-temperature sterilization temperature is 72-78° C. and the time is 10-20 seconds.

[0039] The temperature can be selected as 72℃, 73℃, 74℃, 75℃, 76℃, 77℃, 78℃, etc., and the time can be selected as 10s, 12s, 15s, 18s, 20s, etc. Other specific point values ​​within the above numerical range can be selected, so they will not be listed here one by one.

[0040] In a second aspect, the present invention provides a use of the safe breast milk freeze-drying method according to the first aspect in preparing freeze-dried breast milk powder.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] Cold plasma treatment destroys the surface structure of microorganisms, while UV sterilization penetrates the lipid layer to inactivate pathogens, while simultaneously preserving active ingredients and other components to the greatest extent possible. The addition of protective agents can block fat accumulation, inhibit ice crystal growth, protect active ingredients, enhance reconstitution, and inhibit oxidative rancidity. Homogenization ensures the uniformity of breast milk and prevents fat accumulation and oxidation during the freeze-drying process. DETAILED DESCRIPTION

[0043] The technical solution of the present invention is further described below by way of specific embodiments. It should be understood by those skilled in the art that the embodiments are merely to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0044] The sources of the functional ingredients contained in the products involved in the following examples and comparative examples are as follows (only the functional ingredients are reflected, and the necessary auxiliary ingredients contained in other commercially available raw materials are not repeated):

[0045] Lecithin was purchased from Cargill under the trade name Emulbesto TM 300C products;

[0046] Sodium caseinate was purchased from FrieslandCampina (Royal FrieslandCampina, Netherlands) under the trade name Nutricia TM Products of Caseinate-S INF;

[0047] Hydroxypropyl β-cyclodextrin was purchased from Wacker Chemie (Germany) under the trade name W8HP Pharma's products;

[0048] Ascorbyl palmitate was purchased from DSM (DSM, Netherlands) under the trade name Grindox TM APC-Infant's products;

[0049] Maltodextrin was purchased from Roquette (France) under the trade name IT19 products;

[0050] Inulin was purchased from BENEO (Germany) under the trade name HSI (High Performance Inulin) products;

[0051] Lactoferrin was purchased from FrieslandCampina (Royal FrieslandCampina, The Netherlands) under the trade name Lactoferrin 2.0 TM products.

[0052] Preparation Example 1

[0053] This preparation example provides a protective agent, which includes, by mass, 0.3 parts of lecithin, 0.5 parts of sodium caseinate, 5 parts of trehalose, 2 parts of hydroxypropyl β-cyclodextrin, 0.02 parts of ascorbyl palmitate, 0.01 parts of tocopherol, 8 parts of maltodextrin, 2 parts of inulin, 0.1 parts of sodium citrate, and 0.05 parts of lactoferrin.

[0054] The preparation method comprises the following steps: physically mixing the raw materials and sterilizing the mixture to obtain the product.

[0055] Preparation Example 2

[0056] This preparation example provides a protective agent, which includes, by mass, 0.2 parts of lecithin, 0.8 parts of sodium caseinate, 4 parts of trehalose, 3 parts of hydroxypropyl β-cyclodextrin, 0.01 parts of ascorbyl palmitate, 0.015 parts of tocopherol, 7 parts of maltodextrin, 3 parts of inulin, 0.08 parts of sodium citrate, and 0.06 parts of lactoferrin.

[0057] The preparation method is similar to that of Preparation Example 1.

[0058] Preparation Example 3

[0059] This preparation example provides a protective agent, which includes, by mass, 0.5 parts of lecithin, 0.3 parts of sodium caseinate, 6 parts of trehalose, 1 part of hydroxypropyl β-cyclodextrin, 0.03 parts of ascorbyl palmitate, 0.005 parts of tocopherol, 10 parts of maltodextrin, 1 part of inulin, 0.12 parts of sodium citrate, and 0.03 parts of lactoferrin.

[0060] The preparation method is similar to that of Preparation Example 1.

[0061] Preparation Example 4

[0062] This preparation example provides a protective agent, which differs from Preparation Example 1 only in that it does not contain sodium caseinate, and its reduced mass is proportionally distributed to the mass of hydroxypropyl β-cyclodextrin, tocopherol, inulin and lactoferrin, while the other ingredients and contents remain unchanged.

[0063] The preparation method is similar to that of Preparation Example 1.

[0064] Preparation Example 5

[0065] This preparation example provides a protective agent, which differs from Preparation Example 1 only in that it does not contain hydroxypropyl β-cyclodextrin, and its reduced mass is proportionally distributed to the mass of sodium caseinate, tocopherol, inulin and lactoferrin, while the other ingredients and contents remain unchanged.

[0066] The preparation method is similar to that of Preparation Example 1.

[0067] Preparation Example 6

[0068] This preparation example provides a protective agent, which differs from Preparation Example 1 only in that it does not contain tocopherol, and its reduced mass is proportionally distributed to the mass of sodium caseinate, hydroxypropyl β-cyclodextrin, inulin and lactoferrin, while the other ingredients and contents remain unchanged.

[0069] The preparation method is similar to that of Preparation Example 1.

[0070] Preparation Example 7

[0071] This preparation example provides a protective agent, which differs from Preparation Example 1 only in that it does not contain inulin, and its reduced mass is proportionally distributed to the mass of sodium caseinate, hydroxypropyl β-cyclodextrin, tocopherol and lactoferrin, while the other ingredients and contents remain unchanged.

[0072] The preparation method is similar to that of Preparation Example 1.

[0073] Preparation Example 8

[0074] This preparation example provides a protective agent, which differs from Preparation Example 1 only in that it does not contain lactoferrin, and its reduced mass is proportionally distributed to the mass of sodium caseinate, hydroxypropyl β-cyclodextrin, tocopherol and inulin, while the other ingredients and contents remain unchanged.

[0075] The preparation method is similar to that of Preparation Example 1.

[0076] Example 1

[0077] This embodiment provides a method for freeze-drying breast milk, comprising:

[0078] (1) Pre-treating breast milk with cold plasma using a 42 kHz cold plasma (working gas is argon and oxygen with a volume ratio of 9:1) for 5 min at a temperature of 20°C and a total flow rate of 5 L / min to obtain the first breast milk;

[0079] (2) The first breast milk was sterilized by ultraviolet light with a wavelength of 265 nm and an irradiation dose of 120 mJ / cm 2 , the temperature is 10°C, and the second breast milk is obtained;

[0080] (3) mixing the second breast milk with the protective agent described in Preparation Example 1 at a mass ratio of 1:0.2 to obtain the third breast milk;

[0081] (4) The third breast milk was homogenized at a frequency of 30 kHz and a power density of 0.9 W / cm 2 , the temperature is 40℃, the time is 5min, and the fourth breast milk is obtained;

[0082] (5) The freeze dryer was sterilized with ozone for 30 minutes, and the fourth breast milk was freeze-dried and sterilized at 75°C for 15 seconds. The freeze drying specifically included pre-freezing at -60°C for 4 hours and freeze-drying under vacuum conditions for 18 hours.

[0083] Example 2

[0084] This embodiment provides a method for freeze-drying breast milk, comprising:

[0085] (1) Pre-treating breast milk with cold plasma using a 40 kHz cold plasma (working gas is argon and oxygen with a volume ratio of 9:1) for 1 min at a temperature of 5°C and a total flow rate of 5 L / min to obtain the first breast milk;

[0086] (2) The first breast milk was sterilized by ultraviolet light with a wavelength of 260 nm and an irradiation dose of 140 mJ / cm 2 , the temperature is 20℃, and the second breast milk is obtained;

[0087] (3) mixing the second breast milk with the protective agent described in Preparation Example 2 at a mass ratio of 1:0.15 to obtain the third breast milk;

[0088] (3) The third breast milk was homogenized at a frequency of 40 kHz and a power density of 1 W / cm 2 , the temperature is 35℃, the time is 2min, and the fourth breast milk is obtained;

[0089] (5) The freeze dryer was sterilized with ozone for 30 minutes, and the fourth breast milk was freeze-dried and sterilized at 72°C for 20 seconds. The freeze drying specifically included pre-freezing at -65°C for 3 hours and freeze-drying under vacuum conditions for 20 hours.

[0090] Example 3

[0091] This embodiment provides a method for freeze-drying breast milk, comprising:

[0092] (1) Pre-treating breast milk with cold plasma using a 45 kHz cold plasma (working gas is argon and oxygen with a volume ratio of 9:1) for 10 min at a temperature of 35°C and a total flow rate of 5 L / min to obtain the first breast milk;

[0093] (2) The first breast milk was sterilized by ultraviolet light with a wavelength of 270 nm and an irradiation dose of 100 mJ / cm 2 , the temperature is 5°C, and the second breast milk is obtained;

[0094] (3) mixing the second breast milk with the protective agent described in Preparation Example 3 at a mass ratio of 1:0.25 to obtain the third breast milk;

[0095] (4) The third breast milk was homogenized at a frequency of 20 kHz and a power density of 0.8 W / cm 2 , the temperature is 45℃, the time is 8min, and the fourth breast milk is obtained;

[0096] (5) The freeze dryer was sterilized with ozone for 30 minutes, and the fourth breast milk was freeze-dried and sterilized at 78°C for 10 seconds. The freeze drying specifically included pre-freezing at -50°C for 5 hours and freeze-drying under vacuum conditions for 16 hours.

[0097] Example 4

[0098] This embodiment provides a method for freeze-drying breast milk, which differs from Example 1 only in that step (3) is "mixing the second breast milk with the protective agent described in Preparation Example 4 in a mass ratio of 1:0.2 to obtain the third breast milk", and other operations remain unchanged.

[0099] Example 5

[0100] This embodiment provides a method for freeze-drying breast milk, which differs from Example 1 only in that step (3) is "mixing the second breast milk with the protective agent described in Preparation Example 5 at a mass ratio of 1:0.2 to obtain the third breast milk", and other operations remain unchanged.

[0101] Example 6

[0102] This embodiment provides a method for freeze-drying breast milk, which differs from Example 1 only in that step (3) is "mixing the second breast milk with the protective agent described in Preparation Example 6 at a mass ratio of 1:0.2 to obtain the third breast milk", and other operations remain unchanged.

[0103] Example 7

[0104] This embodiment provides a method for freeze-drying breast milk, which differs from Example 1 only in that step (3) is "mixing the second breast milk with the protective agent described in Preparation Example 7 in a mass ratio of 1:0.2 to obtain the third breast milk", and other operations remain unchanged.

[0105] Example 8

[0106] This embodiment provides a method for freeze-drying breast milk, which differs from Example 1 only in that step (3) is "mixing the second breast milk with the protective agent described in Preparation Example 8 in a mass ratio of 1:0.2 to obtain the third breast milk", and other operations remain unchanged.

[0107] Example 9

[0108] This embodiment provides a method for freeze-drying breast milk, which differs from Example 1 only in that step (4) is not included, and other operations remain unchanged.

[0109] Comparative Example 1

[0110] This comparative example provides a method for freeze-drying breast milk, which differs from Example 1 only in that step (1) is not included and step (2) is "sterilizing the first breast milk with ultraviolet light at a wavelength of 265 nm and an irradiation dose of 140 mJ / cm 2 , the temperature is 10℃, and the second breast milk is obtained". Other operations remain unchanged.

[0111] Comparative Example 2

[0112] This comparative example provides a method for freeze-drying breast milk, which differs from Example 1 only in that step (2) is not included, and step (1) is "pre-treating the breast milk with cold plasma, using cold plasma with a frequency of 42 kHz (working gas is argon and oxygen with a volume ratio of 9:1) for 8 minutes, a temperature of 20°C, and a total flow rate of 5 L / min to obtain the first breast milk"; other operations remain unchanged.

[0113] Comparative Example 3

[0114] This comparative example provides a method for freeze-drying breast milk, which differs from Example 1 only in that step (3) is not included, and other operations remain unchanged.

[0115] Test Example 1

[0116] Detection of total colony count

[0117] Testing method: According to national standard GB5009.12-2023.

[0118] Table 1

[0119]

[0120] As can be seen from the data in Table 1, when only cold plasma treatment or only UV sterilization treatment is performed, even if the sterilization time is extended or the irradiation dose is increased, the number of colonies in the product is still higher than that in Examples 1-3, affecting the safety of the product.

[0121] Test Example 2

[0122] Docosahexaenoic acid (DHA) was determined using gas chromatography according to the method outlined in GB28404-2012. Human milk oligosaccharides in foods were determined using ion chromatography according to the industry standard T / CIFST 025-2024. Vitamin C (ascorbic acid) in foods was determined using high-performance liquid chromatography according to the national standard GB5009.86-2016.

[0123] Table 2

[0124]

[0125]

[0126] As can be seen from the data in Table 2, adding a protective agent during freeze-drying can ensure that the content of DHA, human milk oligosaccharides and vitamin C in the product is maintained at a high level, with minimal damage to the nutrients. In addition, the selection of the protective agent is very important. The present invention has found that sodium caseinate, tocopherol, lactoferrin, hydroxypropyl β-cyclodextrin and inulin have a certain synergistic effect on the above-mentioned effects.

[0127] Test Example 3

[0128] Lysozyme activity test

[0129] Determination of lysozyme activity in breast milk according to the national standard GB / T 30990-2014

[0130] Table 3

[0131]

[0132]

[0133] As can be seen from the data in Table 3, adding a protective agent during freeze-drying can ensure that the lysozyme in the product has a higher activity, and the selection of the protective agent is very important. The present invention found that sodium caseinate, tocopherol, lactoferrin, hydroxypropyl β-cyclodextrin and inulin have a certain synergistic effect on the above-mentioned efficacy.

[0134] Test Example 4

[0135] Active factor detection

[0136] Immunoglobulin IgA was detected by immunoturbidimetry, and immune cytokines (such as interleukin II, interleukin IV, interleukin VI, tumor necrosis factor α) and albumin were detected by chemiluminescence. The retention rate of each component was calculated based on the data of each component before and after freeze-drying preparation.

[0137]

[0138] It is uniformly stipulated that the ingredient retention rate before preparation is 100%.

[0139] Table 4

[0140]

[0141] As can be seen from the data in Table 4, the addition of a protective agent during freeze-drying can ensure a high retention rate of immunoglobulin IgA, interleukin II, interleukin IV, interleukin VI, and tumor necrosis factor α in the product, and the selection of the protective agent is very important. The present invention has found that sodium caseinate, tocopherol, lactoferrin, hydroxypropyl β-cyclodextrin, and inulin have a certain synergistic effect on the above-mentioned effects.

[0142] Test Example 5

[0143] Stability testing

[0144] Test method: The results of breast milk testing using a laser particle size analyzer (Shaanxi Prodi Company, model DPC-1512) are shown in Table 5 for the average particle size and reconstitution time.

[0145] Table 5

[0146] Average particle size (μm) Redissolution time (s) Example 1 3.5 30 Example 2 3.8 32 Example 3 3.9 33 Example 4 6.5 40 Example 5 6.9 42 Example 6 7.3 60 Example 7 7.5 59 Example 8 8.4 62 Example 9 10 108 Comparative Example 1 4.2 40 Comparative Example 2 3.9 38 Comparative Example 3 10 110

[0147] As can be seen from the data in Table 5, adding a protective agent during freeze-drying can reduce the particle size of the product, improve stability, and reduce the reconstitution time. The selection of the protective agent is very important. The present invention found that sodium caseinate, tocopherol, lactoferrin, hydroxypropyl β-cyclodextrin and inulin have a certain synergistic effect in the above-mentioned effects.

[0148] Test Example 6

[0149] Moisture content test

[0150] Test method: The moisture content was determined using the AKF coulometric method using the moisture detector from Shanghai Hegong, with a sample size of 30 mg.

[0151] Table 6

[0152] Moisture content Example 1 1.1％ Example 4 3.4％ Example 5 4.8％ Example 6 3.8％ Example 7 4.9％ Example 8 3.9％ Example 9 1.5％ Comparative Example 1 2％ Comparative Example 2 1.9％ Comparative Example 3 6％

[0153] As can be seen from the data in Table 6, adding a protective agent during freeze-drying can accelerate the freeze-drying of the product. At the same freeze-drying time, the moisture content of the product is lower, and the selection of the protective agent is very important. The present invention found that sodium caseinate, tocopherol, lactoferrin, hydroxypropyl β-cyclodextrin and inulin have a certain synergistic effect on the above-mentioned effects.

[0154] The applicant declares that the present invention uses the above-mentioned embodiments to illustrate a safe breast milk freeze-drying method and its application, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent replacements for various raw materials in the products of the present invention, addition of auxiliary ingredients, and selection of specific methods, etc., are all within the scope of protection and disclosure of the present invention.

[0155] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the scope of protection of the present invention.

[0156] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

Claims

1. A safe method for freeze-drying breast milk, characterized in that: The method comprises: (1) sterilizing breast milk by cold plasma and ultraviolet to obtain pretreated breast milk; (2) The pretreated breast milk is mixed with a protective agent and freeze-dried to obtain the product.

2. The method for freeze-drying breast milk according to claim 1, wherein The frequency of the cold plasma is 40-45 kHz, the temperature is 4-40° C., and the time is 1-10 min; Preferably, the wavelength of the ultraviolet sterilization is 260-270nm, and the irradiation dose is 100-140mJ / cm 2 , the temperature is 4-25℃.

3. The method for freeze-drying breast milk according to claim 1 or 2, characterized in that: After the pre-treated breast milk is mixed with the protective agent, it also includes homogenizing the breast milk; Preferably, the frequency of the homogenization process is 20-40 kHz and the power density is 0.8-1 W / cm 2 ; Preferably, the homogenization temperature is 35-45° C. and the time is 1-10 min.

4. The method for freeze-drying breast milk according to any one of claims 1 to 3, characterized in that The mass ratio of the pretreated breast milk to the protective agent is 1:(0.13-0.25).

5. The method for freeze-drying breast milk according to any one of claims 1 to 4, characterized in that The protective agent includes sodium caseinate, tocopherol, lactoferrin, hydroxypropyl β-cyclodextrin and inulin; Preferably, the mass ratio of sodium caseinate, tocopherol, lactoferrin, hydroxypropyl β-cyclodextrin and inulin is (0.3-0.8):(0.005-0.015):(0.03-0.06):(1-3):(1-3).

6. The method for freeze-drying breast milk according to any one of claims 1 to 5, characterized in that The protective agent also includes lecithin, trehalose, ascorbyl palmitate, maltodextrin, and sodium citrate; Preferably, the mass ratio of the lecithin, trehalose, ascorbyl palmitate, maltodextrin and sodium citrate is (0.2-0.5):(4-6):(0.01-0.03):(7-10):(0.08-0.12).

7. The method for freeze-drying breast milk according to any one of claims 1 to 6, characterized in that: Before freeze drying, the freeze dryer is sterilized with ozone; Preferably, the disinfection time is 25-35 minutes.

8. The method for freeze-drying breast milk according to any one of claims 1 to 7, characterized in that: The freeze drying includes pre-freezing and freeze drying; Preferably, the pre-freezing time is 3-5h; Preferably, the pre-freezing and freeze-drying temperatures are independently -65 to -50°C; Preferably, the freeze-drying is carried out under vacuum conditions; Preferably, the freeze-drying time is 16-20 hours.

9. The method for freeze-drying breast milk according to any one of claims 1 to 8, characterized in that: The freeze-drying step also includes low-temperature sterilization; Preferably, the low-temperature sterilization temperature is 72-78° C. and the time is 10-20 seconds.

10. Use of the safe breast milk freeze-drying method according to any one of claims 1 to 9 in preparing freeze-dried breast milk powder.

Images