Bovine colostrum ice cream base, preparation method thereof and ice cream containing bovine colostrum ice cream base

Abstract

The invention provides a bovine colostrum ice cream milk base and a preparation method thereof, and ice cream containing the bovine colostrum ice cream milk base comprises the following components in percentage by mass: 25-35% of bovine colostrum, 25-35% of single cream, 5-10% of milk powder, 10-20% of a sweetening agent and 0.05-0.2% of a stabilizer. Heating the bovine colostrum to 35-45 DEG C, adding the single cream, the milk powder, the sweetening agent and the stabilizer, continuously stirring until the raw materials are completely melted, and sterilizing a semi-finished product by adopting a low-temperature pasteurization process; and sterilizing and homogenizing to obtain the bovine coloctrum ice cream milk base. According to the bovine coloctrum ice cream base prepared by the preparation method disclosed by the invention, the total number of bacterial colonies can be ensured to be lower than 8000 CFU / mL, meanwhile, the activity retention rate of immune globulin in bovine coloctrum can be ensured to be higher than 90%, and the immune globulin in the bovine coloctrum is reserved to a great extent.

Description

Technical Field

[0001] The present invention relates to the technical field of ice cream, and particularly relates to a bovine colostrum ice cream milk base, a preparation method thereof, and an ice cream containing the same. Background Art

[0002] Ice cream is pleasant in taste, delicate, smooth, cool and sweet, and is deeply loved by people. With the increasing popularity of functional foods, it has become an irresistible trend to develop ice cream with healthy elements to meet consumers' demand for health. Bovine colostrum is known as "milk platinum" and is rich in functional substances such as immunoglobulins, taurine, and growth factors, which can effectively promote gastrointestinal motility in the human body, improve human immunity, and promote the growth and development of the body. However, the immunoglobulins in bovine colostrum are extremely prone to denaturation and inactivation under high-temperature conditions, which poses a great obstacle to the production of most foods that require high-temperature sterilization, resulting in few healthy foods containing bovine colostrum on the market. Therefore, developing a bovine colostrum ice cream with high protein activity has broad market prospects. Summary of the Invention

[0003] In view of this, the present invention provides a bovine colostrum ice cream and a preparation method thereof, which solve the problems of poor heat resistance and easy denaturation and inactivation of immunoglobulins during the high-temperature sterilization process of bovine colostrum.

[0004] In order to solve the technical problems proposed in the background art, the present invention adopts the following technical solutions:

[0005] In the first aspect, the present invention provides a preparation method of a bovine colostrum ice cream milk base, which includes the following raw materials by mass percentage:

[0006] 25% - 35% of bovine colostrum, 25% - 35% of light cream, 5% - 10% of milk powder, 10% - 20% of sweetener, 0.05% - 0.2% of stabilizer, and the remaining mass is made up with pure water;

[0007] The preparation method includes: heating the bovine colostrum to 35°C - 45°C, then adding the light cream, milk powder, sweetener, and stabilizer, continuously stirring until all the raw materials are melted, and sterilizing the semi-finished product using a low-temperature pasteurization process, where the sterilization temperature is 63 - 67°C and the sterilization time is 25 - 35 min; after sterilization, homogenization treatment is carried out to obtain the bovine colostrum ice cream milk base.

[0008] Further, the bovine colostrum ice cream milk base further includes a heat protection agent with an addition amount of 3% - 5.5 wt%, and the heat protection agent includes maltitol.

[0009] Further, the heat protection agent further includes freeze-dried powder of Lactobacillus paracasei PC-01; and the mass ratio of the freeze-dried powder of Lactobacillus paracasei PC-01 to the maltitol is (1:4) - (4:1).

[0010] Further, the colostrum ice cream milk base further includes condensed milk with an addition amount of 4% - 8 wt%; and / or

[0011] also includes concentrated milk with an addition amount of 2% - 6 wt%; and / or

[0012] also includes egg yolk with an addition amount of 2% - 6 wt%.

[0013] Further, the milk powder includes whole milk powder and skim milk powder, and the mass ratio of the whole milk powder to the skim milk powder is (1:2) - (2:1).

[0014] Further, the sweetener includes at least one of granulated sugar, trehalose, polydextrose, acesulfame potassium, xylitol, aspartame, maltose, and sorbitol.

[0015] Further, the stabilizer includes at least one of sodium alginate, sodium carboxymethyl cellulose, and monoglyceride.

[0016] Further, the conditions for the homogenization treatment are: the secondary pressure is 25 - 30 Bar, and the total pressure is 90 - 110 Bar.

[0017] In a second aspect, the present invention provides a colostrum ice cream milk base, which is prepared by the preparation method as described above.

[0018] In a third aspect, the present invention provides an ice cream, which contains the colostrum ice cream milk base as described above.

[0019] The beneficial effects of the above technical solutions of the present invention are as follows:

[0020] The present invention provides a preparation method for a colostrum ice cream milk base. The colostrum ice cream milk base prepared by the preparation method of the present invention can not only ensure that the total number of colonies is less than 8000 CFU / mL, but also ensure that the retention rate of the immunoglobulin activity in the colostrum can reach more than 80%, and can exceed 90% at most, greatly retaining the immunoglobulin activity in the colostrum. Further, the preparation method provided by the present invention has simple steps and low cost, and has broad market application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is the IgG activity retention rate curve at different sterilization times at a sterilization temperature of 65°C;

[0022] Figure 2 It is the IgG activity retention rate curve at different sterilization times at a sterilization temperature of 63°C;

[0023] Figure 3It is the IgG activity retention rate curve at different sterilization times under the sterilization temperature of 67°C;

[0024] Figure 4 It is the IgG activity retention rate curve at different sterilization times under the sterilization temperature of 60°C;

[0025] Figure 5 It is the IgG activity retention rate curve at different sterilization times under the sterilization temperature of 70°C;

[0026] Figure 6 It is the IgG activity retention rate in Example 2;

[0027] Figure 7 It is the IgG activity retention rate in Example 3;

[0028] Figure 8 It is the IgG activity retention rate in Comparative Example 3. Detailed implementation manners

[0029] To further understand the present invention, the preferred implementation manners of the present invention will be described below in conjunction with examples. However, it should be understood that these descriptions are only for further explaining the features and advantages of the present invention, rather than limiting the present invention.

[0030] First aspect, the present invention provides a preparation method of a bovine colostrum ice cream base, which includes the following raw materials by mass percentage:

[0031] 25% - 35% of bovine colostrum, 25% - 35% of light cream, 5% - 10% of milk powder, 10% - 20% of sweetener, 0.05% - 0.2% of stabilizer, and the remaining mass is made up with pure water;

[0032] The preparation method includes: heating the bovine colostrum to 35°C - 45°C, then adding the light cream, milk powder, sweetener and stabilizer, continuously stirring until all the raw materials are melted, and sterilizing the semi-finished product by low-temperature pasteurization process, the sterilization temperature is 63 - 67°C, and the sterilization time is 25 - 35 min; after sterilization, homogenization treatment is carried out to obtain the bovine colostrum ice cream base.

[0033] According to some embodiments of the present invention, the bovine colostrum ice cream base further includes a thermal protectant with an addition amount of 3% - 5.5 wt%, and the thermal protectant includes maltitol.

[0034] According to some embodiments of the present invention, the thermal protectant further includes freeze-dried powder of Lactobacillus paracasei PC-01; and the mass ratio of the freeze-dried powder of Lactobacillus paracasei PC-01 to the maltitol is (1:4) - (4:1).

[0035] The present invention provides a colostrum ice cream milk base. The colostrum ice cream milk base contains 25% - 35wt% of colostrum. Colostrum is rich in immunoglobulins, which can effectively promote gastrointestinal motility in the human body and improve human immunity. However, the immunoglobulins in colostrum are extremely prone to denaturation and inactivation under high-temperature conditions. To address this problem, in the present invention, by controlling different sterilization temperatures and times, adding a composite thermal protection agent of Lactobacillus paracasei PC-01 freeze-dried powder and maltitol in different mass ratios and addition amounts to the product formula, and taking the immunoglobulins and total colony count in colostrum as the main evaluation indicators, the optimal preparation method for maintaining the high protein activity of colostrum is found from two aspects: optimizing the production process and improving the product formula. The preferred preparation method in the present invention is as follows: after heating the colostrum to 35°C - 45°C, add the light cream, milk powder, sweetener, stabilizer, and composite thermal protection agent, continuously stir until all the raw materials are melted, and use the low-temperature pasteurization process to sterilize the semi-finished product. The sterilization temperature is 65°C, and the sterilization time is 30 minutes; after sterilization, carry out homogenization treatment to obtain the colostrum ice cream milk base. The colostrum ice cream milk base prepared by this preparation method can not only ensure that the total colony count is lower than 8000 CFU / mL, but also ensure that the retention rate of immunoglobulin activity in colostrum can reach more than 80%, and the highest can exceed 90%, greatly retaining the immunoglobulin activity in colostrum. Further, the preparation method provided in the present invention has simple steps and low cost, and has broad market application prospects.

[0036] Preferably, the mass ratio of the Lactobacillus paracasei PC-01 freeze-dried powder to the maltitol is 3:2.

[0037] When the inventor of the present invention added maltitol alone as a thermal protection agent, the retention rate of immunoglobulin activity increased to a certain extent. When adding Lactobacillus paracasei PC-01 freeze-dried powder alone as a thermal protection agent, there was no significant effect on the retention rate of immunoglobulin activity. On this basis, when the Lactobacillus paracasei PC-01 freeze-dried powder and the maltitol were compounded as a thermal protection agent, an unexpected technical effect was achieved. According to the following experimental results, when the mass ratio of the added Lactobacillus paracasei PC-01 freeze-dried powder to the maltitol is 3:2 and the addition amount range is 4.5% - 5%, the retention rate of immunoglobulin activity can be retained with the highest efficiency, and the retention rate of immunoglobulin activity can reach more than 80%, and the highest can exceed 90%.

[0038] According to some embodiments of the present invention, the colostrum ice cream milk base further includes condensed milk with an addition amount of 4% - 8wt%; and / or further includes concentrated milk with an addition amount of 2% - 6wt%; and / or further includes egg yolk with an addition amount of 2% - 6wt%.

[0039] In the present invention, by adding substances such as condensed milk, concentrated milk, and egg yolk to the colostrum ice cream milk base, the taste and texture of the milk base can be further optimized, and the smoothness of the product can be improved.

[0040] According to some embodiments of the present invention, the milk powder includes whole milk powder and skim milk powder, and the mass ratio of the whole milk powder to the skim milk powder is (1:2) to (2:1). Preferably, the mass ratio of the whole milk powder to the skim milk powder is 1:1. Adding both whole milk powder and skim milk powder can ensure the taste and flavor of the product while controlling the fat content of the product.

[0041] According to some embodiments of the present invention, the sweetener includes at least one of granulated sugar, trehalose, polydextrose, acesulfame potassium, xylitol, aspartame, maltose, and sorbitol.

[0042] According to some embodiments of the present invention, the stabilizer includes at least one of sodium alginate, sodium carboxymethyl cellulose, and monoglyceride.

[0043] According to some embodiments of the present invention, the conditions for the homogenization treatment are: the secondary pressure is 25 - 30 Bar, and the total pressure is 90 - 110 Bar.

[0044] In a second aspect, the present invention provides a colostrum ice cream milk base, which is prepared by the preparation method as described above.

[0045] In a third aspect, the present invention provides an ice cream, which contains the colostrum ice cream milk base as described above.

[0046] Colostrum naturally contains a large number of active functional components, and the most important one is immunoglobulin (IgG), which can significantly improve the human immune function and has an inhibitory effect on many pathogenic microorganisms and viruses. However, the immunoglobulin in colostrum is extremely prone to denaturation and inactivation under high-temperature conditions. The present invention provides a colostrum ice cream, in which the retention rate of immunoglobulin activity can reach more than 80%, and it is a colostrum ice cream with high protein activity, which has broad market prospects.

[0047] The following further illustrates the present invention through some specific embodiments.

[0048] The concentrated milk used in the following examples and comparative examples is concentrated milk for the food industry, and the manufacturer is Ningxia Yimei Biotechnology Co., Ltd.

[0049] The influence of sterilization conditions on the number of colonies and IgG activity

[0050] Example 1:

[0051] (1) Formula of 1 kg of colostrum ice cream:

[0052] By mass percentage, it includes: 30% of colostrum, 3% of granulated sugar, 4% of whole milk powder, 6% of condensed milk, 4% of skim milk powder, 4% of frozen egg yolk, 30% of light cream, 4% of concentrated milk, 5% of trehalose, 4% of polydextrose, 1‰ of sodium alginate, and the remaining mass is made up to volume with pure water;

[0053] (2) Preparation process:

[0054] After heating the colostrum to 40 °C, successively add granulated sugar, skim milk powder, whole milk powder, condensed milk, frozen egg yolk, light cream, concentrated milk, trehalose, polydextrose, and sodium alginate, ensure the temperature is between 40 - 45 °C, continuously stir until all the dry matter raw materials are melted, sterilize the semi-finished product using the low-temperature pasteurization process (65 °C, 30 min), and after sterilization, homogenize it (secondary pressure 30 Bar, total pressure 110 Bar) to obtain the finished colostrum ice cream milk base. Sterilize and can the finished product, and pour it into a transparent sterile bottle as the experimental sample.

[0055] Furthermore, in this embodiment, while keeping other conditions unchanged, at a sterilization temperature of 65 °C, set the sterilization times to 0, 5, 10, 15, 20, 25, 30, 35, 40 min respectively, and take the IgG immunoglobulin activity retention rate and total number of colonies as the main evaluation indicators to explore the effects of different sterilization times at 65 °C on the number of colonies and IgG activity.

[0056] Furthermore, in this embodiment, while keeping other conditions unchanged, change the low-temperature pasteurization process at a sterilization temperature of 63 °C, set the sterilization times to 0, 5, 10, 15, 20, 25, 30, 35, 40 min respectively; change the low-temperature pasteurization process at a sterilization temperature of 67 °C, set the sterilization times to 0, 5, 10, 15, 20, 25, 30, 35, 40 min respectively.

[0057] The calculation method of the IgG immunoglobulin retention rate is to use the enzyme-linked immunosorbent assay method. Taking the IgG mass concentration as the abscissa and the absorbance (OD value) as the ordinate, draw the IgG mass concentration standard curve. The calculation formula for the IgG activity retention rate is as follows:

[0058] IgG activity retention rate (%) = a / b × 100;

[0059] In the formula, a: the final IgG mass concentration, μg / mL; b: the initial IgG mass concentration, μg / mL.

[0060] Total number of colonies: Refer to the method of "GB 4789.35 - 2016 National Food Safety Standard Microbiological Examination of Foods - Examination of Lactic Acid Bacteria" to determine the viable count of the strains.

[0061] Experimental results:

[0062] The results of each index of the experimental samples at different sterilization temperatures and different sterilization times are as Figures 1 to 3 shown in Table 1. As shown in Table 1, it can be seen that when bovine colostrum is sterilized at 65 °C, the retention rate of IgG activity shows an overall downward trend. When the sterilization time continues from 5 minutes to 10 minutes, the decline rate of IgG activity retention rate is the fastest, and then the decline rate slows down and continues to 30 minutes; when the sterilization temperature is maintained at 65 °C and the sterilization time continues to 30 minutes, the total number of colonies is less than 8000 CFU / mL, meeting the requirements for ice cream production.

[0063] Table 1

[0064]

[0065]

[0066] Comparative Example 1

[0067] (1) Formula of 1 kg of bovine colostrum ice cream:

[0068] By mass percentage, it includes: 30% bovine colostrum, 3% granulated sugar, 4% whole milk powder, 6% condensed milk, 4% skim milk powder, 4% ice egg yolk, 30% light cream, 4% concentrated milk, 5% trehalose, 4% polydextrose, 1‰ sodium alginate, and the remaining mass is made up with pure water;

[0069] (2) Preparation process:

[0070] After heating bovine colostrum to 40 °C, granulated sugar, skim milk powder, whole milk powder, condensed milk, ice egg yolk, light cream, concentrated milk, trehalose, polydextrose, and sodium alginate are added in sequence, ensuring the temperature is between 40 - 45 °C, and continuously stirred until all dry matter raw materials are melted. The semi-finished product is sterilized by low-temperature pasteurization process (60 °C, 30 min), and after sterilization, it is homogenized (secondary pressure 30 Bar, total pressure 110 Bar) to obtain the finished product of bovine colostrum ice cream milk base. The finished product is aseptically canned and filled into a transparent sterile bottle as the experimental sample.

[0071] Furthermore, in this comparative example, other conditions are kept unchanged. At a sterilization temperature of 60 °C, the sterilization times are set to 0, 5, 10, 15, 20, 25, 30, 35, 40 min respectively. Taking the retention rate of IgG immunoglobulin activity and the total number of colonies as the main evaluation indexes, the effects of different sterilization times at 60 °C on the number of colonies and the activity of IgG are explored.

[0072] The calculation method of the retention rate of IgG immunoglobulin and the method of colony counting are the same as those in Example 1.

[0073] Experimental results:

[0074] The results of each index of this comparative example sample at the same sterilization temperature and different sterilization times are as follows Figure 4 As shown in Figure and Table 2, it can be seen from the figure that the retention rate of IgG activity generally shows a downward trend, and the decline rate is the fastest in the early stage of sterilization, and then slows down. Finally, the retention rate of IgG activity exceeds 70% at the end of sterilization; however, it can be seen from Table 2 that at 60°C, when the sterilization time reaches 30 minutes, the total number of colonies exceeds 10000 CFU / mL, which does not meet the production requirements of ice cream products.

[0075] Table 2

[0076]

[0077] Comparative Example 2

[0078] (1) Formula of 1 kg of colostrum ice cream:

[0079] By mass percentage, it includes: 30% of colostrum, 3% of granulated sugar, 4% of whole milk powder, 6% of condensed milk, 4% of skim milk powder, 4% of ice egg yolk, 30% of light cream, 4% of concentrated milk, 5% of trehalose, 4% of polydextrose, 1‰ of sodium alginate, and the remaining mass is made up to volume with pure water;

[0080] (2) Preparation process:

[0081] After heating the colostrum to 40°C, granulated sugar, skim milk powder, whole milk powder, condensed milk, ice egg yolk, light cream, concentrated milk, trehalose, polydextrose, and sodium alginate are added in sequence, ensuring that the temperature is between 40 - 45°C, and continuously stirred until all the dry matter raw materials are melted. The semi-finished product is sterilized by low-temperature pasteurization process (70°C, 30 min), and after sterilization, it is homogenized (secondary pressure 30 Bar, total pressure 110 Bar) to obtain the finished colostrum ice cream milk base. The finished product is aseptically canned and filled into a transparent sterile bottle as the experimental sample.

[0082] Furthermore, in this comparative example, other conditions are kept unchanged. At the sterilization temperature of 70°C, the sterilization times are set to 0, 5, 10, 15, 20, 25, 30 min respectively. Taking the retention rate of IgG immunoglobulin activity and the total number of colonies as the main evaluation indicators, the effects of different sterilization times at 70°C on the colony number and IgG activity are explored.

[0083] The calculation method of the IgG immunoglobulin retention rate and the method of colony counting are the same as those in Example 1.

[0084] Experimental results:

[0085] The results of each index of this comparative example sample at the same sterilization temperature and different sterilization times are as follows Figure 5, as shown in Table 3, it can be seen from the figure that when the sterilization stage reaches 4 minutes, the IgG activity retention rate drops rapidly, below 30%. When the sterilization time continues to 10 minutes, the IgG activity retention rate is already below 20%. The activity retention rate is too low, and the subsequent time points are meaningless, so they are not measured and marked. It can be seen from Table 3 that when sterilizing at 70 °C, the total number of colonies is already below 10000 CFU / mL when the time reaches 20 minutes, and there are no colonies after sterilization for 30 minutes.

[0086] Table 3

[0087]

[0088] Effect of thermal protectant on the number of colonies and IgG activity

[0089] Example 2

[0090] (1) Formula of 1 kg of colostrum ice cream:

[0091] By mass percentage, it includes: 30% colostrum, 3% granulated sugar, 4% whole milk powder, 6% condensed milk, 4% non-fat milk powder, 4% frozen egg yolk, 30% light cream, 4% concentrated milk, 5% trehalose, 4% polydextrose, 1‰ sodium alginate, 4.5% thermal protectant (where the mass ratio of Lactobacillus paracasei PC-01 powder to maltitol is 3:2), and the remaining mass is made up to volume with pure water. The freeze-dried powder of Lactobacillus paracasei PC-01 is provided by the Lactic Acid Bacteria Collection Center (LABCC), Inner Mongolia Agricultural University.

[0092] (2) Preparation process:

[0093] After heating the colostrum to 40 °C, granulated sugar, non-fat milk powder, whole milk powder, condensed milk, frozen egg yolk, light cream, concentrated milk, trehalose, polydextrose, and sodium alginate are added in sequence, ensuring the temperature is between 40 - 45 °C, and continuously stirred until all the dry matter raw materials are melted. The semi-finished product is sterilized by low-temperature pasteurization (65 °C, 30 min), and after sterilization, it is homogenized (secondary pressure 30 Bar, total pressure 110 Bar) to obtain the finished product of colostrum ice cream milk base. The finished product is aseptically canned and filled into transparent sterile bottles as experimental samples.

[0094] Furthermore, in this embodiment, the production process conditions were kept unchanged, with a sterilization temperature of 65°C and a sterilization time of 30 min. Experiments were conducted on the composition and addition amount of the thermal protectant. Specifically, the addition amounts were set at 3%, 3.5%, 4%, 4.5%, 5% and 5.5% respectively, and under each addition amount, the mass ratios of Lactobacillus paracasei PC-01 freeze-dried powder to maltitol were set at 4:1, 2:3, 3:2, 1:4 respectively. Using the IgG immunoglobulin activity retention rate and the total number of colonies as the main evaluation indicators, the effects of different thermal protectants on the number of colonies and IgG activity were explored.

[0095] The calculation method of the IgG immunoglobulin retention rate and the method of colony counting are the same as those in Example 1.

[0096] Experimental results:

[0097] Under different mass ratio conditions of the experimental samples, the results of the total number of colonies and the IgG immunoglobulin activity retention rate are shown in Table 4 and Figure 6 as follows. It can be seen from the table of the total number of colonies that the protectants with different ratios and addition amounts have no significant effect on the total number of colonies; it can be seen from the figure of the IgG activity that the compound Lactobacillus paracasei PC-01 powder - maltitol thermal protectants with different mass ratios and different addition amounts have a significant effect on the immunoglobulin activity retention rate. When the mass ratio is 3:2 and the addition amount ranges from 4.5%, the immunoglobulin activity retention rate is the highest, exceeding 90%. The compound thermal protectants with other mass ratios and addition amounts basically maintain the immunoglobulin activity retention rate above 80%.

[0098] Table 4

[0099]

[0100]

[0101] Example 3

[0102] (1) Formula for 1 kg of bovine colostrum ice cream:

[0103] By mass percentage, it includes: 30% bovine colostrum, 3% granulated sugar, 4% whole milk powder, 6% condensed milk, 4% non-fat milk powder, 4% ice egg yolk, 30% light cream, 4% concentrated milk, 5% trehalose, 4% polydextrose, 1‰ sodium alginate, thermal protectant (selecting maltitol as the thermal protectant with an addition amount of 3%), and the remaining mass is made up to volume with pure water;

[0104] (2) Preparation process:

[0105] After heating colostrum to 40°C, add granulated sugar, skim milk powder, whole milk powder, condensed milk, frozen egg yolks, light cream, condensed milk, trehalose, polydextrose, and sodium alginate in sequence, ensuring the temperature is between 40 - 45°C, and continuously stir until all the dry matter raw materials are melted. Use the low-temperature pasteurization process (65°C, 30 min) to sterilize the semi-finished product. After sterilization, homogenize it (secondary pressure 30 Bar, total pressure 110 Bar) to obtain the finished colostrum ice cream base. Sterile can the finished product and fill it into transparent sterile bottles as experimental samples.

[0106] Furthermore, in this comparative example, the production process conditions were kept unchanged, with a sterilization temperature of 65°C and a sterilization time of 30 min, and experiments were conducted on the addition amount of the heat protection agent maltitol. Specifically, the addition amounts were set at 3.5%, 4%, 4.5%, 5%, and 5.5% respectively. Using the IgG immunoglobulin activity retention rate and the total number of colonies as the main evaluation indicators, explore the effects of the addition amount of the heat protection agent on the number of colonies and the IgG activity.

[0107] The calculation method of the IgG immunoglobulin retention rate and the method of colony counting are the same as in Example 1.

[0108] Experimental results:

[0109] Under different mass ratio conditions of the samples in this comparative example, the results of the total number of colonies and the IgG immunoglobulin activity retention rate are shown in Table 5 and Figure 7 as shown. It can be seen from Table 5 and Figure 7 that for the heat protection agent maltitol with the same addition amount, it has a significant impact on the immunoglobulin activity retention rate and an insignificant impact on the total number of colonies. When the addition amount ranges from 4.5%, the immunoglobulin activity retention rate is close to 90%. When the addition amount of maltitol is between 3% - 5.5%, the immunoglobulin activity retention rate can be maintained above 80%.

[0110] Table 5

[0111]

[0112] Comparative Example 3

[0113] (1) Formula for 1 kg of colostrum ice cream:

[0114] By mass percentage, it includes: 30% colostrum, 3% granulated sugar, 4% whole milk powder, 6% condensed milk, 4% skim milk powder, 4% frozen egg yolks, 30% light cream, 4% condensed milk, 5% trehalose, 4% polydextrose, 1‰ sodium alginate, heat protection agent (selecting Lactobacillus paracasei PC - 01 freeze-dried powder as the heat protection agent, with an addition amount of 3%), and the remaining mass is made up with pure water.

[0115] (2) Preparation process:

[0116] After heating the bovine colostrum to 40°C, add granulated sugar, non-fat milk powder, whole milk powder, condensed milk, frozen egg yolks, light cream, condensed milk, trehalose, polydextrose, and sodium alginate in sequence, ensuring the temperature is between 40 - 45°C, and continuously stir until all the dry matter raw materials are melted. Sterilize the semi-finished product using the low-temperature pasteurization process (65°C, 30 min), and after sterilization, homogenize it (secondary pressure 30 Bar, total pressure 110 Bar) to obtain the finished product of bovine colostrum ice cream base. Sterile canning of the finished product is carried out and filled into transparent sterile bottles as experimental samples.

[0117] Furthermore, in this comparative example, the production process conditions were kept unchanged, the sterilization temperature was 65°C, and the sterilization time was 30 min. Experiments were conducted on the addition amount of the heat protectant, Lactobacillus paracasei PC-01 freeze-dried powder. Specifically, the addition amounts were set at 3.5%, 4%, 4.5%, and 5.5% respectively. Using the IgG immunoglobulin activity retention rate and the total number of colonies as the main evaluation indicators, the effect of the addition amount of the heat protectant on the number of colonies and the IgG activity was explored.

[0118] The calculation method of the IgG immunoglobulin retention rate and the method of colony counting are the same as in Example 1.

[0119] Experimental results:

[0120] Under different mass ratio conditions of this experimental sample, the results of the total number of colonies and the IgG immunoglobulin activity retention rate are shown in Table 6 Figure 8 as shown. From Figure 8 it can be seen that different addition amounts of Lactobacillus paracasei PC-01 freeze-dried powder have little effect on the immunoglobulin activity retention rate, and the immunoglobulin activity retention rate remains at about 80%.

[0121] Table 6

[0122]

[0123] Analyze the experimental data in the above examples and comparative examples comprehensively:

[0124] When cold drinks and ice creams are produced in factories, strict control of microbial indicators is required. The total number of colonies is the main evaluation index, and generally, the total number of colonies needs to be controlled below 8000 CFU / mL. From the experimental results of the above examples and comparative examples, when the sterilization temperature is controlled between 65°C and 70°C and the sterilization time is controlled at 30 minutes, the production requirements of ice cream can be met; from the experimental results of the IgG activity retention rate, when the sterilization temperature is maintained at 65°C and the sterilization time is maintained at 30 minutes, the IgG activity retention rate inside the bovine colostrum ice cream is maintained above 80%. After confirming the sterilization process, two different components of heat protectants are added to the formula. According to the experimental results, when adding the Lactobacillus paracasei PC-01 freeze-dried powder-maltitol heat protectant with a mass ratio of 3:2 and an addition amount of 4.5%, the immunoglobulin activity retention rate can be retained with the highest efficiency. When the heat protectant maltitol is added alone, the immunoglobulin activity retention rate is slightly increased, while when the Lactobacillus paracasei PC-01 freeze-dried powder is added alone, there is no significant effect on the immunoglobulin activity retention rate. The reason may be that after the Lactobacillus paracasei PC-01 freeze-dried powder is inactivated, it will specifically adhere to maltitol, thereby indirectly enhancing the heat protection performance of maltitol.

[0125] The above is the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A preparation method of a bovine colostrum ice cream milk base, characterized in that, by mass percentage, it includes the following raw materials: 25% - 35% of bovine colostrum, 25% - 35% of light cream, 5% - 10% of milk powder, 10% - 20% of sweetener, 0.05% - 0.2% of stabilizer, and the remaining mass is made up to volume with pure water; The preparation method includes: heating the bovine colostrum to 35°C - 45°C, then adding the light cream, milk powder, sweetener and stabilizer, continuously stirring until all the raw materials are melted, and sterilizing the semi-finished product by low-temperature pasteurization process, the sterilization temperature is 63 - 67°C, and the sterilization time is 25 - 35 min; after sterilization, homogenization treatment is carried out to obtain the bovine colostrum ice cream milk base.

2. The preparation method according to claim 1, characterized in that, the bovine colostrum ice cream milk base further includes a thermal protectant with an addition amount of 3% - 5.5 wt%, and the thermal protectant includes maltitol.

3. The preparation method according to claim 2, characterized in that, the thermal protectant further includes freeze-dried powder of Lactobacillus paracasei PC-01; and the mass ratio of the freeze-dried powder of Lactobacillus paracasei PC-01 to the maltitol is (1:4) - (4:1).

4. The preparation method according to claim 1, characterized in that, the bovine colostrum ice cream milk base further includes condensed milk with an addition amount of 4% - 8 wt%; and / or further includes concentrated milk with an addition amount of 2% - 6 wt%; and / or further includes egg yolk with an addition amount of 2% - 6 wt%.

5. The preparation method according to claim 1, characterized in that, the milk powder includes whole milk powder and skim milk powder, and the mass ratio of the whole milk powder to the skim milk powder is (1:2) - (2:1).

6. The preparation method according to claim 1, characterized in that, the sweetener includes at least one of white granulated sugar, trehalose, polydextrose, acesulfame potassium, xylitol, aspartame, maltose and sorbitol.

7. The preparation method according to claim 1, characterized in that, the stabilizer includes at least one of sodium alginate, sodium carboxymethylcellulose and monoglyceride.

8. The preparation method according to claim 1, characterized in that, the conditions of the homogenization treatment are: the secondary pressure is 25 - 30 Bar, and the total pressure is 90 - 110 Bar.

9. A bovine colostrum ice cream milk base, characterized in that, the bovine colostrum ice cream milk base is prepared by the preparation method described in any one of claims 1 - 8.

10. An ice cream, characterized in that, the ice cream contains the bovine colostrum ice cream milk base described in claim 9.

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