Method and application of improving nutritional retention rate of bovine colostrum

Abstract

The present invention relates to the technical field of dairy product processing, and in particular to a method and application for improving the nutritional retention rate of bovine colostrum. In the method for improving the nutritional retention rate of bovine colostrum provided by the present invention, the bovine colostrum is collected and then subjected to low-temperature bath quick freezing, storage and slow thawing treatments in sequence, and the bovine colostrum raw material sample finally obtained is in a uniform state, without unfavorable conditions such as fat floating, whey precipitation, and protein granulation, and the retention rate of nutrients in the obtained colostrum raw material is high, which can provide high-quality raw materials for further in-depth research and processing applications of bovine colostrum.

Description

Technical Field

[0001] The invention relates to the technical field of dairy product processing, and in particular to a method for improving the nutritional retention rate of bovine colostrum and an application thereof. Background Art

[0002] Bovine colostrum not only contains rich milk nutrients, but also contains a variety of biologically active ingredients, such as immunoglobulins, lactoferrin, lactoperoxidase, proline peptides, insulin growth factor, epidermal growth factor, transforming growth factor, etc. It has a series of physiological active functions such as immune regulation, improving gastrointestinal function, promoting growth and development, and inhibiting a variety of pathogenic microorganisms. It is known as the "healthy food of the 21st century" and is a very rare and precious resource. Bovine colostrum has high nutritional value and huge development potential, but due to the limitations of process, equipment and technology, the research, development and utilization of bovine colostrum is very difficult. The non-fat milk solids of bovine colostrum are significantly higher than those of normal milk, the quality is unstable, the acidity is high, the viscosity is high, the thermal stability is poor, and it is easy to coagulate when heated. Therefore, it is greatly restricted in development and application. Most of the active substances in bovine colostrum are very sensitive to temperature, and the heat treatment process can easily destroy their biological activity. The collection, transportation, processing and application of bovine colostrum must be carried out under low temperature conditions to preserve its immune activity. In addition, if the conditions of collection, transportation and processing are not appropriate, some key nutrients in colostrum are very easy to degrade, such as vitamins, immunoglobulins, lactoferrin, lactoperoxidase, osteopontin, etc. Therefore, the collection, transportation, temporary storage and processing of colostrum require precise control of conditions to avoid the corruption of colostrum and reduce the loss of various nutrients.

[0003] Due to the limited production of bovine colostrum and the difficulty of collecting it, the collected bovine colostrum has to be frozen, stored and transported first, and then thawed after collecting enough for research and processing applications. In order to ensure that the properties and active ingredients of bovine colostrum are not destroyed, strict control must be carried out from the source of colostrum collection to ensure the quality of colostrum raw materials. At present, the conventional bovine colostrum processing method is to fill the colostrum into a colostrum bag after the colostrum is collected, and then directly put it into a -20℃ refrigerator or cold storage for freezing and preservation. When used, it is transported to the processing factory by low-temperature cold chain, temporarily stored in a -20℃ cold storage, and finally taken out of the cold storage, thawed in a room temperature or 45℃ warm water bath for use. Ice crystals are easily formed in the frozen samples of this method, and the thawed samples are prone to fat floating, whey precipitation, protein granulation, and uneven samples. In addition, the nutrients such as vitamins and some immune active substances in the thawed samples of this method are severely lost, which greatly reduces the quality of the raw milk.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a method and application for improving the nutritional retention rate of bovine colostrum, which can retain various nutrients in bovine colostrum to a greater extent, improve the uniformity and stability of bovine colostrum, and provide high-quality raw materials for further in-depth research and processing applications of bovine colostrum.

[0006] Specifically, the technical solution of the present invention is as follows:

[0007] In a first aspect, the present invention provides a method for improving the nutritional retention rate of bovine colostrum, comprising: after the bovine colostrum is collected, it is sequentially subjected to low-temperature bath quick freezing, storage and thawing treatment; wherein the low-temperature bath uses ethanol as the conductive medium, the quick freezing agent is dry ice, and the quick freezing time is 10-40 minutes; the storage temperature is -20±5°C; the thawing step comprises: using ultrasonic treatment to treat the sample to be thawed at a temperature of -20±5°C, and then placing the sample after ultrasonic treatment in an environment of 4±2°C for 6-12 hours.

[0008] Due to the limited production of bovine colostrum and the difficulty of collecting it, the collected bovine colostrum has to be frozen, stored and transported first, and then thawed after collecting a sufficient amount for research and processing applications. The bovine colostrum raw material sample obtained after thawing is uniform in state, without undesirable conditions such as fat floating, whey precipitation, and protein granulation.

[0009] Compared with fresh bovine colostrum, the bovine colostrum treated by the method provided by the present invention after thawing has the following characteristics: immunoglobulin retention rate is ≥75.0%, lactoferrin retention rate is ≥63.7%, osteopontin retention rate is ≥62.0%, vitamin A retention rate is ≥66.2%, vitamin C retention rate is ≥44.8%, and vitamin E retention rate is ≥47.6%.

[0010] In the present invention, preferably, the quick freezing time is 10-15 min, 15-20 min, 20-25 min, 25-30 min, 30-35 min or 35-40 min.

[0011] In the present invention, the storage temperature is preferably -20±4°C, more preferably -20±3°C, more preferably -20±2°C, and more preferably -20±1°C.

[0012] In the present invention, the sample after ultrasonic treatment is preferably placed in an environment of 4±1°C; the placement time is preferably 6-8h, 8-10h or 10-12h.

[0013] In the present invention, preferably, the bovine colostrum collection speed is 5-15 min / head; the bovine colostrum collection tool maintains a temperature of 4±2° C., and the bovine colostrum temperature before quick freezing is 4-8° C.

[0014] In the present invention, the ultrasonic frequency is preferably 50-150kHz, more preferably 50-70kHz, 70-90kHz, 90-110kHz, 110-130kHz or 130-150kHz. The ultrasonic intensity is 0.3±0.1W / cm 2 The ultrasonic time is preferably 10-30 min, more preferably 10-15 min, 15-20 min, 20-25 min or 25-30 min.

[0015] Preferably, after placing the ultrasonically treated sample in a 4±2°C environment for 6-12 hours, a normal temperature water bath step is further included, wherein the water bath temperature is 10-30°C and the time is 1-3 hours.

[0016] In the present invention, preferably, the temperature of the low temperature bath is -72±5°C.

[0017] Further preferably, the method for improving the nutritional retention rate of bovine colostrum comprises the following steps:

[0018] (1) Use vacuum milking equipment to collect fresh colostrum. After milking, fill the colostrum in the milk bucket into a sterile milk storage bag and seal it;

[0019] (2) Place the sealed milk storage bag in a mixture of dry ice and ethanol for quick freezing;

[0020] (3) Transfer the quick-frozen samples to a -20±5℃ environment for storage and / or transportation;

[0021] (4) Treat the sample to be thawed using ultrasound, then place it in an environment of 4±2℃ for 6-12h, and finally thaw it in a water bath at room temperature.

[0022] In a second aspect, the present invention provides a bovine colostrum raw material product, which is obtained by the method described in the first aspect. The bovine colostrum raw material product provided by the present invention has relatively better stability and relatively higher nutrient retention rate.

[0023] In a third aspect, the present invention provides the method, or the use of the bovine colostrum raw material product in the preparation of milk-containing foods, health products or medicines.

[0024] In a fourth aspect, the present invention provides a method for detecting nutritional components of bovine colostrum, wherein the bovine colostrum sample to be detected is obtained by the method described in the first aspect.

[0025] Beneficial effects:

[0026] The present invention provides a method for improving the nutritional retention rate of bovine colostrum. After the bovine colostrum is collected and subjected to quick freezing, storage and slow thawing treatments in sequence, the obtained bovine colostrum raw material sample is in a uniform state without undesirable conditions such as fat floating, whey precipitation, and protein granulation. In addition, the retention rate of nutrients in the obtained colostrum raw material is high, and high-quality raw materials can be provided for further in-depth research and processing applications of bovine colostrum. DETAILED DESCRIPTION

[0027] Due to the limited production of bovine colostrum and the difficulty of collecting it, the collected bovine colostrum has to be frozen, stored and transported first, and then thawed after collecting a sufficient amount for research and processing applications. Bovine colostrum has a high total solid content, high fat and protein content. It is more likely to have undesirable conditions such as fat floating, whey precipitation, and protein granulation after being thawed again after freezing. In addition, when studying the composition of bovine colostrum, the collected samples cannot be tested in time. They need to be frozen and then thawed for testing, which will cause the degradation of certain nutrients and functional components, and the test values ​​are low, which cannot reflect the true situation of fresh bovine colostrum.

[0028] The present invention studies a series of processing methods such as bovine colostrum collection, quick freezing, transportation, thawing, processing and application, strictly controls the cooling method, transportation method and thawing method after sampling, detects the content of certain nutrients, and improves the detection accuracy, so as to protect and restore the nutrition and characteristics of bovine colostrum to a greater extent, and provide high-quality raw materials for further in-depth research and processing and application of bovine colostrum.

[0029] Specifically, during sample collection, the present invention cools down while milking, so that the fresh colostrum sample quickly reaches an equilibrium temperature, inhibits the growth of microorganisms, and ensures the freshness of the sample.

[0030] Specifically, after the sample is packaged, the milk storage bag is put into a mixture of dry ice and ethanol to quickly freeze the sample, and the milk sample is frozen into a solid in a short time and is not easy to form ice crystals. The quick freezing step of the present invention is simple to operate, and dry ice is continuously replenished during the quick freezing process, and dry ice is kept at the bottom of the container. The present invention uses a mixture of dry ice and ethanol to quickly form a low-temperature water bath of -72°C, and the temperature of the low-temperature water bath formed by other quick-freezing reagents is higher than -72°C. When dry ice is mixed with organic solvents such as acetone, ether, and chloroform to make a low-temperature water bath, a low temperature condition below -72°C can also be achieved, but acetone, ether, and chloroform are toxic, and human inhalation after volatilization can cause dizziness, headache, respiratory poisoning, etc., which are not suitable for operation under conventional conditions. In a more specific embodiment, the operation process of quick freezing is as follows: first add ethanol to a fixed container, the liquid level is 30-50cm, and then slowly add dry ice cubes to the solution. The reaction is relatively violent at the beginning, and do not add too fast. After the reaction is stable, a large amount of dry ice can be added, and dry ice can be kept at the bottom of the container. At this point, the low-temperature water bath is ready, and you can put the sealed colostrum bag in for rapid freezing, making sure the colostrum bag is completely submerged during freezing. During the process, you need to constantly add dry ice to keep dry ice at the bottom of the container to maintain the water bath temperature.

[0031] Specifically, the present invention adopts a method of slowly thawing samples in stages: take them out from a -20°C refrigerator or cold storage, first perform low-frequency ultrasonic treatment, shorten the thawing time, and improve thawing uniformity. After low-frequency ultrasonic treatment, slowly thaw step by step, and control the thawing temperature and time. First place it in a 4°C refrigerator for 8-12 hours to slowly thaw it, and then take it out and put it in a room temperature water bath to completely thaw it. Although the speed of slow thawing step by step is relatively slow, the state of the samples after thawing is uniform, without adverse conditions such as fat floating, whey precipitation, protein granulation, and less loss of vitamins and some immunoactive substances.

[0032] In a preferred embodiment, the present invention provides a process and method suitable for collecting, transporting and processing bovine colostrum, and the operating steps of the method include:

[0033] (1) Collection of fresh bovine colostrum: Use vacuum milking equipment to collect fresh bovine colostrum. After milking, fill the colostrum in the milk bucket into a sterile milk storage bag and seal it tightly. The specification of the milk storage bag is 1-5L.

[0034] (2) Rapid freezing: Place the milk storage bag in a mixture of dry ice and ethanol to quickly freeze the sample. The milk sample will freeze solid in a short time without forming ice crystals.

[0035] (3) Frozen storage and cold chain transportation: The quick-frozen samples are transferred to a -20℃ refrigerator or cold storage for storage. When used, they must be transported to the processing factory through the cold chain and cannot be thawed during the entire process.

[0036] (4) Slow thawing of samples: Take out from -20℃ refrigerator or cold storage, first perform low-frequency ultrasonic treatment to shorten the thawing time and improve thawing uniformity. Then place in a 4℃ refrigerator for 6-12 hours. After taking out, place in a room temperature water bath to thaw, and mix evenly after the sample is completely dissolved before use.

[0037] (5) Sample testing and processing application: The completely thawed samples are mixed evenly before testing and processing application.

[0038] In a more preferred and specific embodiment, the operation method of step (1) is: use vacuum milking equipment to collect fresh colostrum separately, adjust the appropriate milking speed to milk evenly, and it usually takes 5-15 minutes for a single cow to complete. Clean the milking machine before each milking, sterilize and dry the milking bucket at high temperature to reduce contamination during the milking process. During milking, strictly follow the standard milking specifications, and the processes such as pre-disinfection, drug bath, discarding the first three handfuls of milk, wiping, cupping, cup inspection, cup removal, and post-dip bathing must be standardized. During milking, the milk bucket is placed in a refrigeration type external circulation thermostat, the temperature is set to 4°C, and the milk is collected while cooling. At the end of milking, the temperature of the milk sample in the milking bucket is 4-8°C. Cooling while milking allows the fresh colostrum sample to quickly reach the equilibrium temperature, inhibits the growth of microorganisms, and ensures the freshness of the sample.

[0039] In a more preferred and specific embodiment, the operation method of step (2) is as follows: after milking, the milk in the milk bucket is quickly filled into a sterile milk storage bag in a clean environment, and the seal is tightened. The specification of the milk storage bag is 1000 ml. The milk storage bag is placed in a mixture of dry ice and ethanol to quickly freeze the sample. The quick freezing time is 10-40 minutes. The milk sample is frozen into a solid in a short time without forming large ice crystals, thereby ensuring the homogeneity of the sample.

[0040] The colostrum collected by the conventional method is directly placed in a -20°C cold storage for slow freezing, which is prone to ice crystals. In step (2) of the present invention, the milk storage bag is placed in a mixture of dry ice and ethanol to quickly freeze the sample, so that the milk sample is frozen into a solid in a short time and is not prone to forming ice crystals.

[0041] In a more preferred and specific embodiment, the operation method of step (4) is: take out from the -20°C refrigerator or cold storage, first perform low-frequency ultrasonic treatment to shorten the thawing time and improve the thawing uniformity. The ultrasonic frequency is 50-150kHz and the intensity is 0.2-0.4W / cm 2, ultrasonic time 10-30min. Then place in a 4℃ refrigerator for 6-12h. After taking out, put in a water bath to thaw for 1-3h, the water bath temperature is 10-30℃, and the sample is mixed evenly after it is completely dissolved. The tissue state of the slowly thawed sample is close to that of fresh milk, the sample is uniform, and there is no undesirable state such as fat floating, whey precipitation, and protein granulation. The thawing speed at room temperature is too slow. Although the thawing speed is relatively fast when thawing in a 45℃ warm water bath, it is easy to cause uneven samples, serious loss of vitamins and some immune active substances, reduce the quality of raw milk, and easily cause undesirable states such as fat floating, whey precipitation, and protein granulation after thawing. In step (4) of the present invention, the sample is first placed in a 4℃ refrigerator for 6-12h. Take it out and put it in a room temperature water bath to thaw for 1-3h, and mix it evenly after the sample is completely dissolved for use. After the low-frequency ultrasonic treatment, the present invention slowly thaws step by step to control the thawing temperature and time. The sample is in a uniform state after being slowly thawed step by step in the present invention, without unfavorable conditions such as fat floating, whey precipitation, protein granulation, etc., and the loss of vitamins and some immune active substances is relatively small.

[0042] After the sampling, rapid freezing, cold chain transportation, low-temperature temporary storage and slow thawing operations of the present invention, the colostrum raw material sample finally obtained is in a uniform state, without undesirable conditions such as fat floating, whey precipitation, protein granulation, etc., and the retention rate of nutrients in the obtained colostrum raw material is high, which can provide high-quality raw materials for further in-depth research and processing applications of bovine colostrum.

[0043] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] The endpoints and any values ​​of the ranges disclosed in this specification are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0045] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "specific implementations", or "some specific implementations" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0046] In the examples provided in this specification, if no specific techniques or conditions are specified, the techniques or conditions described in the literature in this field or the product instructions are used. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased through regular channels.

[0047] Example 1

[0048] This embodiment provides a method for improving the nutritional retention rate of bovine colostrum, comprising the following steps.

[0049] (1) Collection of fresh colostrum. Use vacuum milking equipment to collect fresh colostrum separately, adjust the appropriate milking speed to milk evenly, and complete the process for a single cow within 15 minutes. Clean the milking machine before each milking, sterilize and dry the milking bucket at high temperature to reduce contamination during the milking process. During milking, strictly follow the standard milking specifications, and the processes such as pre-disinfection, drug bath, discarding the first three handfuls of milk, wiping, cupping, cup inspection, cup removal, and post-dip bathing must be standardized. During milking, the milk bucket is placed in a refrigeration-type external circulation thermostat with the temperature set to 4°C, and the milk is collected and cooled at the same time. At the end of milking, the temperature of the milk sample in the milking bucket is 4°C.

[0050] (2) Rapid freezing. After milking, quickly fill the milk in the milk bucket into a sterile milk storage bag in a clean environment and seal it tightly. The milk storage bag specification is 1000ml. Put the milk storage bag into a mixture of dry ice and ethanol to quickly freeze the sample for 10 minutes.

[0051] (3) Frozen storage and cold chain transportation. After quick freezing, the samples are quickly transferred to a -20℃ refrigerator or cold storage for storage. When used, they need to be transported to the processing factory through the cold chain without being refrigerated during the whole process.

[0052] (4) Thaw the sample slowly. Take it out of the -20℃ refrigerator or cold storage and first perform low-frequency ultrasonic treatment to shorten the thawing time and improve the thawing uniformity. The ultrasonic frequency is 50kHz and the intensity is 0.3W / cm 2, ultrasonic time 10min. Then put it in a 4℃ refrigerator for 12h. After taking it out, put it in a water bath to thaw for 1.0h, the water bath temperature is 30℃, and the sample is completely dissolved and mixed evenly before use.

[0053] The sample sections of this embodiment before thawing are uniform without large ice crystals, and the sample states after thawing are uniform without undesirable states such as fat floating, whey precipitation, and protein granulation.

[0054] (5) Sample testing and processing application: The completely thawed samples are mixed evenly before testing and processing application.

[0055] Example 2

[0056] This embodiment provides a method for improving the nutritional retention rate of bovine colostrum, comprising the following steps.

[0057] (1) Collection of fresh colostrum. Use vacuum milking equipment to collect fresh colostrum separately, adjust the appropriate milking speed to milk evenly, and complete the process for a single cow within 15 minutes. Clean the milking machine before each milking, sterilize and dry the milking bucket at high temperature to reduce contamination during the milking process. During milking, strictly follow the standard milking specifications, and the processes such as pre-disinfection, drug bath, discarding the first three handfuls of milk, wiping, cupping, cup inspection, cup removal, and post-dip bathing must be standardized. During milking, the milk bucket is placed in a refrigerated external circulation thermostat with the temperature set to 4°C, and the milk is collected and cooled at the same time. At the end of milking, the temperature of the milk sample in the milking bucket is 6°C.

[0058] (2) Rapid freezing. After milking, quickly fill the milk in the milk bucket into a sterile milk storage bag in a clean environment and seal it tightly. The milk storage bag specification is 1000ml. Put the milk storage bag into a mixture of dry ice and ethanol to quickly freeze the sample for 20 minutes.

[0059] (3) Frozen storage and cold chain transportation. After quick freezing, the samples are quickly transferred to a -20℃ refrigerator or cold storage for storage. When used, they need to be transported to the processing factory through the cold chain without being refrigerated during the whole process.

[0060] (4) Thaw the sample slowly. Take it out of the -20℃ refrigerator or cold storage and first perform low-frequency ultrasonic treatment to shorten the thawing time and improve the thawing uniformity. The ultrasonic frequency is 150kHz and the intensity is 0.4W / cm 2 , ultrasonic time 30min. Then put it in a 4℃ refrigerator for 6h. After taking it out, put it in a water bath to thaw for 1.5h, the water bath temperature is 15℃, and the sample is completely dissolved and mixed evenly before use.

[0061] The sample sections of this embodiment before thawing are uniform without large ice crystals, and the sample states after thawing are uniform without undesirable states such as fat floating, whey precipitation, and protein granulation.

[0062] (5) Sample testing and processing application: The completely thawed samples are mixed evenly before testing and processing application.

[0063] Example 3

[0064] This embodiment provides a method for improving the nutritional retention rate of bovine colostrum, comprising the following steps.

[0065] (1) Collection of fresh colostrum. Use vacuum milking equipment to collect fresh colostrum separately, adjust the appropriate milking speed to milk evenly, and complete the process for a single cow within 15 minutes. Clean the milking machine before each milking, sterilize and dry the milking bucket at high temperature to reduce contamination during the milking process. During milking, strictly follow the standard milking specifications, and the processes such as pre-disinfection, drug bath, discarding the first three handfuls of milk, wiping, cupping, cup inspection, cup removal, and post-dip bathing must be standardized. During milking, the milk bucket is placed in a refrigerated external circulation thermostat with the temperature set to 4°C, and the milk is collected and cooled at the same time. At the end of milking, the temperature of the milk sample in the milking bucket is 8°C.

[0066] (2) Rapid freezing. After milking, quickly fill the milk in the milk bucket into a sterile milk storage bag in a clean environment and seal it tightly. The milk storage bag specification is 1000ml. Put the milk storage bag into a mixture of dry ice and ethanol to quickly freeze the sample for 40 minutes.

[0067] (3) Frozen storage and cold chain transportation. After quick freezing, the samples are quickly transferred to a -20℃ refrigerator or cold storage for storage. When used, they need to be transported to the processing factory through the cold chain without being refrigerated during the whole process.

[0068] (4) Thaw the sample slowly. Take it out of the -20℃ refrigerator or cold storage and first perform low-frequency ultrasonic treatment to shorten the thawing time and improve the thawing uniformity. The ultrasonic frequency is 100kHz and the intensity is 0.2W / cm 2 , ultrasonic time 20min. Then put it in a 4℃ refrigerator for 8h. After taking it out, put it in a water bath to thaw for 3.0h, the water bath temperature is 10℃, and the sample is completely dissolved and mixed evenly before use.

[0069] The sample sections of this embodiment before thawing are uniform without large ice crystals, and the sample states after thawing are uniform without undesirable states such as fat floating, whey precipitation, and protein granulation.

[0070] (5) Sample testing and processing application: The completely thawed samples are mixed evenly before testing and processing application.

[0071] Comparative Example 1

[0072] The only difference between this comparative example and Example 2 is that the quick freezing is not performed, but the samples are directly placed in a -20°C refrigerator for slow freezing.

[0073] The cross section of the sample in this comparative example was not uniform before thawing, no large ice crystals were formed, but there was obvious fat accumulation. The state of the sample after thawing was not uniform, with fat floating, slight whey precipitation, protein granulation and other undesirable conditions.

[0074] Comparative Example 2

[0075] The only difference between this comparative example and Example 2 is that no ultrasonic wave is performed.

[0076] The cross section of the sample before thawing in this comparative example was uniform, and no large ice crystals were formed. The state of the sample after thawing was not uniform, with fat floating, slight whey precipitation, protein granulation and other undesirable conditions.

[0077] Comparative Example 3

[0078] The only difference between this comparative example and Example 1 is that the quick freezing time is 5 minutes.

[0079] The cross section of the sample before thawing in this comparative example was uniform, and no large ice crystals were formed. The state of the sample after thawing was not uniform, with fat floating, slight whey precipitation, protein granulation and other undesirable conditions.

[0080] Comparative Example 4

[0081] The only difference between this comparative example and Example 2 is that the ultrasonic time is 60 min.

[0082] The cross section of the sample in this comparative example was uniform before thawing, and no large ice crystals were formed. The state of the sample after thawing was uneven, with fat floating, slight fat floating and whey precipitation.

[0083] Comparative Example 5

[0084] The only difference between this comparative example and Example 3 is that after ultrasonic treatment, the product is not placed in a 4° C. environment but is directly put into a water bath for thawing.

[0085] The cross section of the sample before thawing in this comparative example was uniform, and no large ice crystals were formed. The state of the sample after thawing was not uniform, with fat floating, slight whey precipitation, protein granulation and other undesirable conditions.

[0086] Comparative Example 6

[0087] The only difference between this comparative example and Example 1 is that the thawing temperature in the water bath is 45°C.

[0088] The cross section of the sample in this comparative example was uniform before thawing, and no large ice crystals were formed. The state of the sample after thawing was not uniform, with serious fat floating, obvious whey precipitation, protein granulation and other undesirable conditions.

[0089] The nutritional preservation effects of the samples after thawing of Examples 1-3 and Comparative Examples 1-6 are shown in Table 1.

[0090] Table 1

[0091]

[0092] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for improving the nutritional retention rate of bovine colostrum, characterized in that: After the colostrum is collected, it is sequentially subjected to low-temperature bath quick freezing, storage and thawing treatments; wherein the low-temperature bath uses ethanol as the conducting medium, the quick freezing agent is dry ice, and the quick freezing time is 10-40 minutes; the storage temperature is -20±5°C; the thawing steps include: using ultrasonic treatment to treat the sample to be thawed at a temperature of -20±5°C, the ultrasonic frequency is 50-150kHz, and the intensity is 0.2-0.4W / cm 2 , time is 10-30min; then place the ultrasonically treated sample in a 4±2℃ environment for 6-12h; normal temperature water bath, the water bath temperature is 10-30℃, time is 1-3h.

2. The method for improving the nutritional retention rate of bovine colostrum according to claim 1, characterized in that: The colostrum collection speed is 5-15min / head; the colostrum collection tool maintains a temperature of 4±2℃, and the colostrum temperature before quick freezing is 4-8℃.

3. The method for improving the nutritional retention rate of bovine colostrum according to claim 1, characterized in that: The temperature of the cryotherapy bath was -72±5°C.

4. The method for improving the nutritional retention rate of bovine colostrum according to any one of claims 1 to 3, characterized in that: The steps include: (1) Use vacuum milking equipment to collect fresh colostrum. After milking, fill the colostrum in the milk bucket into a sterile milk storage bag and seal it; (2) Place the sealed milk storage bag in a mixture of dry ice and ethanol for quick freezing; (3) Transfer the quick-frozen samples to -20±5℃ for storage; (4) Treat the sample to be thawed with ultrasound, then place it in an environment of 4±2℃ for 6-12h, and finally thaw it in a water bath at room temperature.

5. The method for improving the nutritional retention rate of bovine colostrum according to claim 4, characterized in that: Step (3) is: transferring the quick-frozen samples to a -20±5°C environment for storage and transportation.

6. A bovine colostrum raw material product, characterized in that: Obtained by the method according to any one of claims 1 to 5.

7. Use of the bovine colostrum raw material product obtained by the method according to any one of claims 1 to 5, or the bovine colostrum raw material product according to claim 6 in the preparation of milk-containing food or medicine.

8. The use according to claim 7, characterized in that: The milk-containing food includes health products.

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