Calcium 6S-5-methyltetrahydrofolate fortified sterilized milk and a preparation method thereof

Abstract

The application discloses 6S-5-methyltetrahydrofolate calcium fortified sterilized milk and a preparation method thereof, and steps are as follows: S1, acceptance of raw milk; S2, cleaning of milk; S3, storage of milk; S4, standardization; S5, preheating; S6, primary homogenization; S7, pasteurization; S8, secondary homogenization; S9, cooling; after homogenization, the sterilized milk is rapidly cooled to 4 DEG C; S10, aseptic filling; filling is performed at about 200mL per bag, temperature control is below 20 DEG C, and finished products enter a 4 DEG C cold storage. The preparation method of the (6S)-5-MTHF-Ca fortified sterilized milk can combine (6S)-5-MTHF-Ca and sterilized milk well by researching optimal preparation conditions, improves the stability of (6S)-5-MTHF-Ca in the sterilized milk, responds to the expansion of the application field of (6S)-5-MTHF-Ca, and provides a new way for pregnant women and lactating women to supplement folic acid.

Description

Technical Field

[0001] This invention relates to the field of sterilized milk production, specifically to a 6S-5-methyltetrahydrofolate calcium-fortified sterilized milk and its preparation method. Background Technology

[0002] Folic acid, also known as vitamin B9, is an essential vitamin for cell growth and reproduction. The human body cannot synthesize folic acid and must obtain it from food. However, folic acid from natural foods is unstable, easily affected by ultraviolet radiation and temperature, and its content is generally low. Therefore, ingesting synthetic folic acid is currently the common way to supplement folic acid. High doses of synthetic folic acid can have adverse effects on the human body, such as masking vitamin B12 deficiency and causing leukemia, arthritis, colon cancer, and ectopic pregnancy. Furthermore, the conversion of synthetic folic acid is affected by folic acid metabolic enzymes, and supplementing with inactive synthetic folic acid cannot meet the needs of individuals with MTHFR gene polymorphisms. Studies have found that UHT and pasteurized milk matrix are suitable carriers for folic acid supplementation, which can improve the bioavailability of dietary folic acid.

[0003] The preparation method provided by this invention uses natural folic acid (C) crystal form (6S)-5-methyltetrahydrofolate calcium ((6S)-5-MTHF-Ca) as a nutrient fortifier to prepare (6S)-5-MTHF-Ca fortified sterilized milk. (6S)-5-MTHF-Ca is based on active folic acid, with an upgraded production process: removing heavy metal catalysts harmful to embryonic development, formaldehyde, benzenesulfonic acid, and other processing aids, and strictly controlling impurities such as JK12A that pose safety hazards. (6S)-5-MTHF-Ca is the most active form of folic acid, and compared with synthetic folic acid, it has better safety, stability, effectiveness, and dosage assurance. It bypasses metabolic limitations and can be directly absorbed and utilized by all populations, making it a better choice for folic acid supplementation.

[0004] As my country's per capita income continues to rise, residents' dietary structure is also constantly changing. Consumers are increasingly demanding fresh, high-quality milk, leading to a sustained and rapid increase in demand for sterilized milk. Simultaneously, higher quality requirements are driving manufacturers to upgrade their milk sources and production processes. Currently, product demand is diversified, with sterilized milk designed for pregnant women and children finding corresponding markets.

[0005] There are two main methods for fortifying food with folic acid: One is dry fortification, where folic acid, 5-methyltetrahydrofolate, or their salts are directly added to the food in powder form. For example, Li Diaoying added folic acid powder to corn flour, wheat flour, starch, milk powder, cakes, black sesame paste, and chocolate ingredients to create folic acid-fortified foods. The other is wet fortification, where folic acid is dissolved in another solution and added in liquid form. For example, Sun Jingwen invented folic acid-fortified rice products by dissolving folic acid in a gelatin aqueous solution, adding stabilizers and sodium selenite to create a folic acid selenium aqueous solution, which is then sprayed onto the rice surface using a polishing machine's water pump. When fortifying sterilized milk with vitamins, the heat resistance of the fortified vitamins must be considered. For (6S)-5-MTHF-Ca, losses during processing must be considered during addition. For sterilized milk specifically designed for pregnant women or children, the processing method is basically the same as that for ordinary liquid dairy products. If heat-sensitive vitamins are added, an aseptic feeding system must be used. Vitamins are added after the product has been sterilized and cooled, but before aseptic filling.

[0006] The application of (6S)-5-MTHF-Ca in China is still in its early stages. Its application in food is currently limited, with most products on the market being dietary supplements. Liquid milk contains abundant bioactive components, and fortifying sterilized milk with (6S)-5-MTHF-Ca can achieve the purpose of folic acid supplementation, while simultaneously meeting the body's needs for various nutrients. However, because 6S-5-methyltetrahydrofolate is very unstable in aqueous solution, no 6S-5-methyltetrahydrofolate-fortified sterilized milk products have yet been launched. This invention's method for preparing (6S)-5-MTHF-Ca-fortified sterilized milk, through research on the optimal preparation process, effectively combines (6S)-5-MTHF-Ca with sterilized milk, improving the stability of (6S)-5-MTHF-Ca in sterilized milk. This not only responds to the expansion of the application fields of (6S)-5-MTHF-Ca but also provides a new way for pregnant and lactating women to supplement folic acid. Summary of the Invention

[0007] The purpose of this invention is to address the deficiencies of the prior art by providing a 6S-5-methyltetrahydrofolate calcium-fortified sterilized milk and its preparation method, thereby solving the problems mentioned in the background art.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a 6S-5-methyltetrahydrofolate calcium-fortified sterilized milk, wherein the concentration of the protective agent in the sterilized milk is 120 mg / L-240 mg / L, the concentration of 6S-5-methyltetrahydrofolate calcium is 0.4 mg / L-1.2 mg / L, and the protective agent is L-ascorbic acid and L / D cysteine.

[0009] A method for preparing 6S-5-methyltetrahydrofolate calcium-fortified sterilized milk, the specific steps of which are as follows:

[0010] S1. Acceptance of raw milk;

[0011] S2, Clean Milk;

[0012] The milk is purified by centrifugation in a separating bowl. The milk temperature during purification is 30-40℃. The purified raw milk should be cooled immediately.

[0013] S3, milk storage;

[0014] Using a mixer inside a steel milk storage tank can prevent fat from floating and ensure uniform mixing. The milk storage tank should be filled to prevent overheating and affecting the quality of the raw milk.

[0015] S4, Standardization;

[0016] Standardization is carried out on the raw milk in the storage tank, and the indicators meet the specified fat content.

[0017] S5, Preheating;

[0018] Before homogenization, the raw milk should be preheated to 60°C. Preheating initially kills bacteria and pathogens, improves product storability, inhibits enzyme activity, avoids fat hydrolysis and enzyme browning of the finished product, and improves the homogenization effect.

[0019] S6, First homogenization;

[0020] The standardized raw milk flows into a homogenizer, where the homogenization temperature is 60-70℃ and the homogenization pressure is 10-20 MPa.

[0021] S7. Pasteurization: After homogenization, the raw milk flows into the pasteurizer, where the temperature is usually 70-75°C for 15-20 seconds; or 80-85°C for 10-15 seconds.

[0022] S8, Secondary homogenization;

[0023] After pasteurization, the milk temperature is maintained at 65-70℃. The protective agent and 6S-5-methyltetrahydrofolate or its salt are drawn into a high-speed shear vacuum mixing tank through vacuum suction. Pasteurized milk is then added and vacuum mixed and homogenized. The vacuum degree of the vacuum mixing tank is -0.7 to -0.5 bar, the homogenization time is 15-20 min, the homogenization temperature is 60-70℃, and the homogenization pressure is 10-20 MPa.

[0024] S9. Cooling: After homogenization, the sterilized milk is rapidly cooled to 3-5°C.

[0025] S10. Aseptic filling: Filling is carried out at a temperature below 20℃, and the finished product is stored in a 4℃ cold storage.

[0026] As a preferred technical solution of the present invention, the raw milk in S1 is inspected and accepted in accordance with the provisions of GB 19301-2010 "National Food Safety Standard for Raw Milk".

[0027] As a preferred embodiment of the present invention, in step S2, foam generation should be prevented during the milk purification process.

[0028] As a preferred embodiment of the present invention, in step S4, when the fat content of the raw milk is lower than its level, cream is added or a portion of skim milk is removed; when the fat content of the raw milk is high, skim milk is added or a portion of cream is extracted.

[0029] The beneficial effects of this invention are:

[0030] The method of the present invention adds reducing substances, such as L-ascorbic acid, sodium ascorbate, L / D cysteine, glutathione, citric acid, etc., during the preparation of (6S)-5-MTHF-Ca fortified sterilized milk. Experiments have shown that the addition of reducing substances can block the degradation of (6S)-5-methyl-tetrahydrofolate, thereby improving the stability of (6S)-5-MTHF-Ca.

[0031] The method of this invention has been verified through previous work. The average recovery rate of (6S)-5-MTHF-Ca by dry addition was 86.50%, and the average recovery rate of (6S)-5-MTHF-Ca by wet addition was 73.21%. The average recovery rate of (6S)-5-MTHF-Ca added before sterilization was 80.03%, and the average recovery rate of (6S)-5-MTHF-Ca added after sterilization was 85.11%.

[0032] The method of the present invention prepares fortified sterilized milk by dry addition of (6S)-5-MTHF-Ca after milk sterilization. Compared with wet addition and addition before raw milk sterilization, the preservation rate of (6S)-5-MTHF-Ca is higher. After addition by this method, the stability of [6S]-5-MTHF-Ca is good when stored at 4°C in the dark. The preservation rate is 87.89% after 12 days. Moreover, the (6S)-5-MTHF-Ca fortified sterilized milk has good color, taste, odor and texture.

[0033] The preparation method of (6S)-5-MTHF-Ca fortified sterilized milk of the present invention can effectively combine (6S)-5-MTHF-Ca and sterilized milk by studying the optimal preparation conditions, thereby improving the stability of (6S)-5-MTHF-Ca in sterilized milk. This not only responds to the expansion of the application field of (6S)-5-MTHF-Ca, but also provides a new way for pregnant women and lactating mothers to supplement folic acid. Attached Figure Description

[0034] Figure 1: Flowchart of the method of the present invention; Detailed Implementation

[0035] The preferred embodiments of the present invention will be described in detail below so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby providing a clearer and more explicit definition of the scope of protection of the present invention.

[0036] Example 1: A method for preparing 6S-5-methyltetrahydrofolate calcium-fortified sterilized milk, the specific steps of which are as follows:

[0037] S1. Acceptance of raw milk;

[0038] Choose a suitable supplier and determine the source of raw materials. The raw milk should comply with the provisions of GB19301-2010 "National Food Safety Standard for Raw Milk".

[0039] S2, Clean Milk;

[0040] The centrifugal milk purification method is adopted, which utilizes the strong centrifugal force of the milk in the separation bowl to leave a large amount of mechanical impurities on the inner wall of the separation bowl, thus purifying the milk. The milk temperature during purification is 30-40℃, and foaming must be prevented during the purification process. The purified raw milk should be cooled to 4℃ immediately to inhibit bacterial growth and ensure the quality of the raw milk before processing.

[0041] S3, milk storage;

[0042] Using a mixer inside a steel milk storage tank prevents fat from floating and ensures uniform mixing. The tank should be filled completely to prevent overheating and affecting the quality of the raw milk.

[0043] S4, Standardization;

[0044] The purpose of standardization is to ensure that the fat content in the product meets the specified requirements. When the fat content of the raw milk is below its level, cream should be added or some skim milk should be removed; when the fat content of the raw milk is high, skim milk should be added or some cream should be extracted. Standardization is carried out on the raw milk in the storage tank, with the target fat content being 4.0%.

[0045] S5, Preheating;

[0046] The raw milk should be preheated to 60℃ before homogenization. Preheating can initially kill most bacteria and pathogens, making sterilization more thorough, improving product storability, inhibiting enzyme activity, avoiding adverse phenomena such as fat hydrolysis and enzyme browning of finished product, and improving homogenization effect.

[0047] S6, First homogenization;

[0048] The standardized raw milk flows into a homogenizer, where the homogenization temperature is 65℃ and the homogenization pressure is 10-20 MPa.

[0049] S7, pasteurization;

[0050] After homogenization, the raw milk flows into a pasteurizer, where the temperature is usually 75°C for 15–20 seconds; or 80–85°C for 10–15 seconds.

[0051] S8, Secondary homogenization;

[0052] After pasteurization, the milk temperature is maintained at 65℃. Under aseptic conditions, the protectant (including L-ascorbic acid, sodium ascorbate, L / D cysteine, glutathione, and citric acid) and naturalized folic acid (6S-5-MTHF-Ca) are drawn into a high-speed shear vacuum mixing tank in proportion (until the final concentration of the protectant is 150 mg / L and the final concentration of (6S)-5-MTHF-Ca is 1.2 mg / L). The pasteurized milk is then added and vacuum-mixed and homogenized to ensure that the naturalized folic acid and protectant are uniformly dispersed in the milk. The vacuum degree of the vacuum mixing tank is -0.7 to -0.5 bar, the homogenization time is 15 to 20 min, the homogenization temperature is 60 to 70℃, and the homogenization pressure is 10 to 20 MPa.

[0053] S9. Cooling; After homogenization, the sterilized milk should be cooled to 4°C as soon as possible.

[0054] S10, Aseptic filling;

[0055] Each bag contains approximately 200 mL, and the temperature is controlled below 20℃. The finished product is then stored in a 4℃ cold storage. After 12 days, the retention rate was determined by HPLC to be 87.89%.

[0056] Example 2: A method for preparing 6S-5-methyltetrahydrofolate calcium-fortified sterilized milk, the specific steps of which are as follows:

[0057] S1. Acceptance of raw milk;

[0058] Choose a suitable supplier and determine the source of raw materials. The raw milk should comply with the provisions of GB19301-2010 "National Food Safety Standard for Raw Milk".

[0059] S2, Clean Milk;

[0060] The centrifugal milk purification method is adopted, which utilizes the strong centrifugal force of the milk in the separation bowl to leave a large amount of mechanical impurities on the inner wall of the separation bowl, thus purifying the milk. The milk temperature during purification is 30-40℃. During the purification process, it is necessary to prevent the formation of foam. The purified raw milk should be cooled to 4℃ immediately to inhibit bacterial growth and ensure the quality of the raw milk before processing.

[0061] S3, milk storage;

[0062] Using a mixer inside a steel milk storage tank prevents fat from floating and ensures uniform mixing. The tank should be filled completely to prevent overheating and affecting the quality of the raw milk.

[0063] S4, Standardization;

[0064] The purpose of standardization is to ensure that the fat content in the product meets the specified requirements; when the fat content of the raw milk is below its level, cream should be added or some skim milk should be removed; when the fat content of the raw milk is high, skim milk should be added or some cream should be extracted; standardization is carried out on the raw milk in the storage tank, and the indicator meets the requirement of a fat content of 4.0%;

[0065] S5, Preheating;

[0066] The raw milk should be preheated to 60℃ before homogenization. Preheating can initially kill most bacteria and pathogens, making sterilization more thorough, improving product storability, inhibiting enzyme activity, avoiding adverse phenomena such as fat hydrolysis and enzyme browning of finished product, and improving homogenization effect.

[0067] S6, First homogenization;

[0068] The standardized raw milk flows into a homogenizer, where the homogenization temperature is 65℃ and the homogenization pressure is 10-20 MPa.

[0069] S7, pasteurization;

[0070] After homogenization, the raw milk flows into a pasteurizer, where the temperature is usually 75°C for 15–20 seconds; or 80–85°C for 10–15 seconds.

[0071] S8, Secondary homogenization;

[0072] After pasteurization, the milk temperature is maintained at 65℃. Under aseptic conditions, the protectant (including L-ascorbic acid, sodium ascorbate, L / D cysteine, glutathione, and citric acid) and naturalized folic acid (6S-5-MTHF-Ca) are drawn into a high-speed shear vacuum mixing tank in proportion (until the final concentration of the protectant is 210 mg / L and the final concentration of (6S)-5-MTHF-Ca is 0.8 mg / L). The pasteurized milk is then added and vacuum-mixed and homogenized to ensure that the naturalized folic acid and protectant are uniformly dispersed in the milk. The vacuum degree of the vacuum mixing tank is -0.7 to -0.5 bar, the homogenization time is 15 to 20 min, the homogenization temperature is 60 to 70℃, and the homogenization pressure is 10 to 20 MPa.

[0073] S9, Cooling;

[0074] After homogenization, sterilized milk should be cooled to 4°C as soon as possible;

[0075] S10, Aseptic filling;

[0076] Each bag contains approximately 200 mL, and the temperature is controlled below 20℃. The finished product is then stored in a 4℃ cold storage. After 12 days, the retention rate was determined by HPLC to be 88.35%.

[0077] Example 3: A method for preparing 6S-5-methyltetrahydrofolate calcium-fortified sterilized milk, the specific steps of which are as follows:

[0078] S1. Acceptance of raw milk;

[0079] Choose a suitable supplier and determine the source of raw materials. The raw milk should comply with the provisions of GB19301-2010 "National Food Safety Standard for Raw Milk".

[0080] S2, Clean Milk;

[0081] The milk is purified using a centrifugal purification method. The strong centrifugal force of the milk in the separator removes a large amount of mechanical impurities, leaving them on the inner wall of the separator. The milk temperature during purification is 30–40°C, and foam formation must be prevented during the process. The purified raw milk should be immediately cooled to 4°C to inhibit bacterial growth and ensure its quality before processing.

[0082] S3, milk storage;

[0083] Using a mixer inside a steel milk storage tank prevents fat from floating and ensures uniform mixing. The tank should be filled completely to prevent overheating and affecting the quality of the raw milk.

[0084] S4, Standardization;

[0085] The purpose of standardization is to ensure that the fat content in the product meets the specified requirements. When the fat content of the raw milk is below its level, cream should be added or some skim milk should be removed. When the fat content of the raw milk is high, skim milk should be added or some cream should be extracted. Standardization is carried out on the raw milk in the storage tank, with the target fat content being 4.0%.

[0086] S5, Preheating;

[0087] The raw milk should be preheated to 60℃ before homogenization. Preheating can initially kill most bacteria and pathogens, making sterilization more thorough, improving product storability, inhibiting enzyme activity, avoiding adverse phenomena such as fat hydrolysis and enzyme browning of finished product, and improving homogenization effect.

[0088] S6. First homogenization: The standardized raw milk flows into the homogenizer, and the homogenization temperature is 65℃, and the homogenization pressure is 10-20 MPa.

[0089] S7. Pasteurization: Homogenized raw milk flows into a pasteurizer, typically at 75°C for 15–20 seconds; or at 80–85°C for 10–15 seconds.

[0090] S8, Secondary homogenization;

[0091] After pasteurization, the milk temperature is maintained at 65℃. Under aseptic conditions, the protectant (including L-ascorbic acid, sodium ascorbate, L / D cysteine, glutathione, and citric acid) and naturalized folic acid (6S-5-MTHF-Ca) are drawn into a high-speed shear vacuum mixing tank in proportion (until the final concentration of the protectant is 240 mg / L and the final concentration of (6S)-5-MTHF-Ca is 0.6 mg / L). The pasteurized milk is then added and vacuum-mixed and homogenized to ensure that the naturalized folic acid and protectant are uniformly dispersed in the milk. The vacuum degree of the vacuum mixing tank is -0.7 to -0.5 bar, the homogenization time is 15 to 20 min, the homogenization temperature is 60 to 70℃, and the homogenization pressure is 10 to 20 MPa.

[0092] S9. Cooling; After homogenization, the sterilized milk should be cooled to 4°C as soon as possible.

[0093] S10. Aseptic filling: Approximately 200mL per bag is filled at a temperature controlled below 20℃, and the finished product is stored in a 4℃ cold storage. After 12 days, the retention rate was determined by HPLC to be 88.56%.

[0094] Verification showed that after adding [6S]-5-MTHF-Ca in this way, the stability of [6S]-5-MTHF-Ca was good when stored at 4℃ in the dark. The average retention rate after 12 days was 88.27%, and the (6S)-5-MTHF-Ca-fortified sterilized milk had good color, taste, odor and texture.

[0095] Example 3

[0096] Table 1: Determination of naturalized folic acid content after different forms of addition

[0097]

[0098] Note: The differences in the means of columns with no common superscript letters are significant (P<0.05).

[0099] The results of the determination of naturalized folic acid content after different addition methods are shown in Table 1. The results showed that the detection amount and recovery rate of naturalized folic acid at 0 h and 24 h were significantly higher after dry addition than after wet addition (P<0.05). Therefore, dry addition was selected as the method for adding naturalized folic acid.

[0100] Table 2: Effects of different preservatives and their dosage on the retention rate of naturalized folic acid

[0101]

[0102] Protective agents include L-ascorbic acid, sodium ascorbate, L / D cysteine, glutathione, and citric acid. Considering the protective effect and economic benefits of the protective agents, L-ascorbic acid and L / D cysteine ​​are preferred.

[0103] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention.

Claims

1. A process for the preparation of calcium 6S-5-methyltetrahydrofolate fortified sterilized milk, characterized by: The concentration of the protective agent in the sterilized milk is 120 mg / L-240 mg / L, and the concentration of 6S-5-methyltetrahydrofolate calcium is 0.4 mg / L-1.2 mg / L, and the protective agent is L-ascorbic acid; The specific steps of the preparation method of the 6S-5-methyltetrahydrofolate calcium fortified sterilized milk are as follows: S1, acceptance of raw milk; S2, net milk; The centrifugal net milk method is adopted, the milk is centrifuged in a separation bowl, the milk temperature during net milk is 30-40 DEG C, and the raw milk after purification should be cooled immediately; S3, milk storage; Using a stirrer in a steel milk storage tank can prevent fat floating and meet the requirements of uniform mixing, and the milk storage tank should be filled to prevent temperature rise and affect the quality of raw milk; S4, standardization; Standardization is carried out in the raw milk in the milk storage tank, and the index meets the specified fat content; S5, preheating; The raw milk should be preheated before homogenization, the preheating temperature is 60 DEG C, the preheating preliminarily kills bacteria and pathogens, improves product storage, inhibits enzyme activity, avoids fat hydrolysis and product enzyme browning phenomenon, and improves homogenization effect; S6, primary homogenization; The standardized raw milk flows into the homogenizer, the homogenization temperature is 60-70 DEG C, and the homogenization pressure is 10-20 MPa; S7, pasteurization; the homogenized raw milk flows into the pasteurizer, the temperature is usually 70-75 DEG C, and the duration is 15-20 seconds; or 80-85 DEG C, and the duration is 10-15 seconds; S8, secondary homogenization; After pasteurization, the milk temperature is kept at 65-70 DEG C, the protective agent and 6S-5-methyltetrahydrofolate calcium are sucked into the high-speed shearing vacuum mixing tank through vacuum suction, and the pasteurized milk is mixed and homogenized, the vacuum degree of the vacuum mixing tank is-0.7 to-0.5 bar, the homogenization time is 15-20 min, the homogenization temperature is 60-70 DEG C, and the homogenization pressure is 10-20 MPa; S9, cooling; the homogenized sterilized milk is rapidly cooled to 3-5 DEG C; S10, aseptic filling; filling is carried out, the temperature is controlled below 20 DEG C, and the finished product enters a 4 DEG C refrigerator for storage.

2. The process for the preparation of calcium fortified sterilized milk of 6S-5- methyltetrahydrofolic acid as claimed in claim 1, wherein: Foam generation should be prevented during net milk.

3. The process for the preparation of calcium fortified sterilized milk of 6S-5- methyltetrahydrofolic acid as claimed in claim 1, wherein: The concentration of the protective agent in the sterilized milk is 150 mg / L-240 mg / L, and the protective agent is L-ascorbic acid.

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