A method for preparing high-protein yogurt and yogurt
By processing milk through separation, enzymatic hydrolysis, fermentation, and mixing, the problem of water separation during the storage of Greek fermented yogurt was solved, resulting in a high-protein yogurt with stable texture and delicate taste.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- INNER MONGOLIA YILI IND GROUP CO LTD
- Filing Date
- 2024-11-26
- Publication Date
- 2026-05-26
AI Technical Summary
Existing Greek fermented yogurt is prone to water separation during storage, resulting in an unstable system and affecting the consumer experience.
By separating raw milk into skim milk and cream, the skim milk is sterilized, enzymatically hydrolyzed and fermented, and concentrated into a concentrated milk base, which is then mixed with whey. The cream and whey are homogenized and then mixed with the concentrated milk base. Dynamic mixing and double homogenization are used to form a stable yogurt system.
The prepared high-protein yogurt has a stable texture, is not prone to water separation during storage, has a smooth and delicate taste, and a stable system, which enhances the user experience.
Smart Images
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of yogurt technology, specifically relating to a method for preparing high-protein yogurt and the yogurt itself. Background Technology
[0002] Yogurt is an acidic dairy product made from cow's milk through fermentation with lactic acid bacteria, containing active lactic acid bacteria and possessing high nutritional value. Yogurt is a uniquely flavorful food, characterized by its high nutritional value, containing easily digestible high-quality protein and active probiotics beneficial to human gut health. With the improvement of people's living standards and consumers' pursuit of a healthy lifestyle, the demand for "protein-rich," "fat-free," and "low-calorie" yogurt is expanding. Therefore, low-calorie, high-protein yogurt is increasingly favored by consumers. Greek fermented yogurt, as a relatively new type of yogurt, is highly popular due to its high protein content. Currently, there are many Greek fermented yogurt products on the market, most of which are thick yogurts meant to be eaten with a spoon. During storage, these yogurts are prone to water separation, resulting in an unstable system that affects consumer use. Summary of the Invention
[0003] The purpose of this invention is to provide a method for preparing high-protein yogurt and the yogurt itself, in order to solve the problem of water separation and system instability that easily occurs in yogurt during storage.
[0004] In a first aspect, embodiments of the present invention provide a method for preparing high-protein yogurt, comprising:
[0005] Separate skim milk and cream from raw milk;
[0006] After sterilization, the skim milk is added to protease for enzymatic hydrolysis.
[0007] The skim milk after enzymatic hydrolysis is sterilized and then fermented to obtain milk base;
[0008] The milk base is concentrated to obtain concentrated milk base and whey;
[0009] The light cream and whey are mixed, homogenized, and sterilized to obtain a mixture.
[0010] Yogurt is obtained by mixing the concentrated milk base with the mixture.
[0011] Optionally, the enzymatic hydrolysis temperature is 45-55℃ and the enzymatic hydrolysis time is 40-80 min.
[0012] Optionally, the amount of protease added is 0.2-0.5‰ of the weight of skim milk.
[0013] Alternatively, the fermentation temperature is 40-45℃.
[0014] Optionally, before mixing the concentrated milk base with the mixture, the method further includes:
[0015] The concentrated milk base is placed at 4-8℃ for post-maturation, and the post-maturation lasts for 4-6 hours to break the emulsion. After the emulsion is broken, it is homogenized to obtain the pretreated concentrated milk base.
[0016] The step of mixing the concentrated milk base with the mixture to obtain yogurt includes:
[0017] Yogurt is obtained by mixing the pretreated concentrated milk base with the mixture.
[0018] Optionally, after demulsification, the primary homogenization pressure is 40-50 bar, and the secondary homogenization pressure is 180-200 bar.
[0019] Optionally, the amount of heavy cream is 30-50 parts by weight, and the amount of whey is 40-60 parts by weight.
[0020] Optionally, the concentrated milk base is 900-920 parts by weight, and the mixed feed is 80-100 parts by weight.
[0021] Optionally, the step of mixing the concentrated milk base with the mixture to obtain yogurt includes:
[0022] The concentrated milk base is mixed and homogenized with the mixture to obtain yogurt;
[0023] The primary homogenization pressure is 40-50 bar, and the secondary homogenization pressure is 180-200 bar.
[0024] Secondly, embodiments of the present invention provide a yogurt prepared using the preparation method described in the above embodiments.
[0025] In the method for preparing high-protein yogurt according to this invention, skim milk and light cream are separated from raw milk; the skim milk is sterilized and then hydrolyzed with protease; the hydrolyzed skim milk is sterilized and fermented to obtain a milk base; the milk base is concentrated to obtain a concentrated milk base and whey; the light cream and whey are mixed, homogenized, and sterilized to obtain a mixture; the concentrated milk base and the mixture are then mixed to obtain yogurt. The yogurt prepared by the above method is smooth and delicate, with a dense texture and stable structure. During storage, the yogurt is less prone to water separation, and the system remains stable. Detailed Implementation
[0026] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0027] The terms "first," "second," etc., used in the specification and claims of this invention are used to distinguish similar objects and are not used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention can be implemented in orders other than those described herein. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.
[0028] The method for preparing high-protein yogurt according to an embodiment of the present invention includes:
[0029] Separate skim milk and cream from raw milk;
[0030] After sterilization, the skim milk is added to protease for enzymatic hydrolysis.
[0031] The skim milk after enzymatic hydrolysis is sterilized and then fermented to obtain milk base;
[0032] The milk base is concentrated to obtain concentrated milk base and whey;
[0033] The light cream and whey are mixed, homogenized, and sterilized to obtain a mixture.
[0034] Yogurt is obtained by mixing the concentrated milk base with the mixture.
[0035] In the method for preparing high-protein yogurt according to this invention, skim milk and light cream are first separated from raw milk; the skim milk is sterilized and then hydrolyzed with protease; the hydrolyzed skim milk is then sterilized and fermented to obtain a milk base; the milk base is concentrated to obtain a concentrated milk base and whey; the light cream and whey are mixed, homogenized, and sterilized to obtain a mixture; the concentrated milk base and the mixture are then mixed to obtain yogurt. After enzymatic hydrolysis of the skim milk, the protein content is increased, preventing protein flocculation or precipitation, improving product stability, and preventing fat from rising. The mixing of light cream and whey improves product stability and prevents water separation. After dynamic mixing and simultaneous Y-tron refining and homogenization, the product is more delicate, stable during its shelf life, less prone to water separation, and has a delicate and creamy texture. The yogurt prepared by the above method is smooth and delicate, with a creamy texture, stable structure, and is less prone to water separation during storage, resulting in a stable system.
[0036] In some embodiments, the enzymatic hydrolysis temperature can be 45-55℃ and the enzymatic hydrolysis time can be 40-80 min. For example, the enzymatic hydrolysis temperature can be 45℃ and the enzymatic hydrolysis time can be 80 min; the enzymatic hydrolysis temperature can be 55℃ and the enzymatic hydrolysis time can be 40 min.
[0037] Optionally, the amount of protease added can be 0.2-0.5‰ of the weight of skim milk. For example, the amount of protease added can be 0.2‰ or 0.5‰ of the weight of skim milk.
[0038] Optionally, during the process of sterilizing and fermenting the enzymatically hydrolyzed skim milk to obtain milk base, the fermentation temperature can be 40-45℃, for example, 43℃.
[0039] In some embodiments of the present invention, before mixing the concentrated milk base with the mixture, the following may be included:
[0040] The concentrated milk base is placed at 4-8℃ for post-maturation, and the post-maturation lasts for 4-6 hours to break the emulsion. After the emulsion is broken, it is homogenized to obtain the pretreated concentrated milk base.
[0041] The step of mixing the concentrated milk base with the mixture to obtain yogurt includes:
[0042] Yogurt is obtained by mixing the pretreated concentrated milk base with the mixture.
[0043] For example, before mixing the concentrated milk base with the mixture, it may also include:
[0044] The concentrated milk base is placed at 4°C for post-fermentation and fermentation for 6 hours to break the emulsion. After the emulsion is broken, it is homogenized to obtain a pretreated concentrated milk base. The pretreated concentrated milk base is then mixed with the mixed materials to obtain yogurt.
[0045] In some embodiments, the primary homogenization pressure after demulsification can be 40-50 bar, and the secondary homogenization pressure can be 180-200 bar. For example, the concentrated milk base is placed at 4-8°C for post-fermentation, and demulsification is performed after 4-6 hours of post-fermentation. After demulsification, homogenization is performed, and the primary homogenization pressure after demulsification can be 40 bar, and the secondary homogenization pressure can be 200 bar.
[0046] Alternatively, the amount of whipping cream can be 30-50 parts by weight, and the amount of whey can be 40-60 parts by weight. For example, the amount of whipping cream can be 30 parts by weight and the amount of whey can be 60 parts by weight; or the amount of whipping cream can be 40 parts by weight and the amount of whey can be 50 parts by weight.
[0047] Optionally, the concentrated milk base can be 900-920 parts by weight, and the mixture can be 80-100 parts by weight. For example, the concentrated milk base can be 900 parts by weight, and the mixture can be 100 parts by weight; or the concentrated milk base can be 920 parts by weight, and the mixture can be 80 parts by weight.
[0048] Optionally, the step of mixing the concentrated milk base with the mixture to obtain yogurt may include:
[0049] The concentrated milk base is mixed and homogenized with the mixture to obtain yogurt;
[0050] The primary homogenization pressure is 40-50 bar, and the secondary homogenization pressure is 180-200 bar.
[0051] For example, yogurt is obtained by homogenizing concentrated milk base with mixed ingredients. The primary homogenization pressure can be 50 bar, and the secondary homogenization pressure can be 180 bar.
[0052] The method for preparing high-protein yogurt in this invention can be as follows:
[0053] (1) Milk fat separation: Use a milk fat separator to separate the milk fat from the raw milk, separating skim milk and light cream. The light cream has a fat content of 40% to 45%.
[0054] (2) Skim milk treatment: Skim milk is sterilized by passing it through a sterilization separator. Skim milk can then enter the MF membrane system for physical sterilization. Then, protease is added for enzymatic hydrolysis. The hydrolysis temperature can be 45-55℃, the hydrolysis time can be 40-80min, and the amount of protease added can be 0.2-0.5‰ of the mass of skim milk.
[0055] (3) Skim milk sterilization: Enzymatically skim milk is homogenized and then sterilized at 95°C for 300 seconds before being put into a fermentation tank;
[0056] (4) Skim milk fermentation: Add fermentation starter, fermentation can be carried out at 43℃, and fermentation can be stopped when pH<4.8;
[0057] (5) Concentration: Fermented skim milk is heated to 50-55°C by a hot plate and then concentrated in a whey separator to obtain concentrated milk base. The protein concentration in the concentrated milk base can be increased by more than 2.5 times, and the protein quality can be 7.2-7.5% of the concentrated milk base quality.
[0058] (6) Concentrated milk base treatment: The concentrated milk base is refrigerated at 4-8℃ for post-ripening. After 4-6 hours of post-ripening, it is demulsified. After demulsification, it is homogenized in a homogenizer. The pressure of the first homogenization can be 40-50 bar, and the pressure of the second homogenization can be 180-200 bar.
[0059] (7) Whipping cream treatment: 30-50 parts by weight of whipping cream and 40-60 parts by weight of whey are mixed and homogenized to obtain a mixture. The homogenization temperature can be 55°C and the homogenization pressure can be 40-50 bar. The mixture is sterilized at 121°C for 4 seconds.
[0060] (8) Online mixing: 900-920 parts by weight of concentrated milk base and 80-100 parts by weight of mixed material are mixed online through a dynamic mixer and refined by Y-tron, and then homogenized online through a homogenizer. The homogenization conditions are: the first homogenization pressure is 40-50 bar, and the second homogenization pressure can be 180-200 bar.
[0061] (9) Preparing for filling: Cool the mixed milk base to 15°C and put it into the filling tank;
[0062] (10) Filling: Fill at 15-20℃;
[0063] The yogurt of this invention is prepared using the preparation method described in the above embodiments. The yogurt prepared by the above method is smooth and delicate, with a dense texture and stable quality. During storage, the yogurt is not prone to water separation, and the system remains stable.
[0064] The present invention will be further described below through some specific embodiments.
[0065] Example 1
[0066] Yogurt preparation method:
[0067] (1) Milk fat separation: Use a milk fat separator to separate the milk fat from the raw milk, separating skim milk and light cream. The light cream has a fat content of 40% to 45%.
[0068] (2) Skim milk treatment: Skim milk is sterilized by passing it through a sterilization separator. Skim milk enters the MF membrane system for physical sterilization. Then, protease is added for enzymatic hydrolysis. The hydrolysis temperature can be 50℃, the hydrolysis time can be 60min, and the amount of protease added can be 0.5‰ of the mass of skim milk.
[0069] (3) Skim milk sterilization: Enzymatically skim milk is homogenized and then sterilized at 95°C for 300 seconds before being put into a fermentation tank;
[0070] (4) Skim milk fermentation: Add fermentation starter, fermentation can be carried out at 43℃, and fermentation can be stopped when pH<4.8;
[0071] (5) Concentration: Fermented skim milk is heated to 50-55°C by a hot plate and then concentrated in a whey separator to obtain concentrated milk base and whey. The protein concentration in the concentrated milk base can be increased by more than 2.5 times, and the protein quality can be 7.2-7.5% of the concentrated milk base quality.
[0072] (6) Concentrated milk base treatment: The concentrated milk base is refrigerated at 4-8℃ for post-ripening. After 4-6 hours of post-ripening, it is demulsified. After demulsification, it is homogenized in a homogenizer. The pressure of the first homogenization can be 40-50 bar, and the pressure of the second homogenization can be 180-200 bar.
[0073] (7) Whipping cream processing: 40 parts by weight of whipping cream and 60 parts by weight of whey are mixed and homogenized to obtain a mixture. The homogenization temperature can be 55℃ and the homogenization pressure can be 40-50 bar. The mixture is sterilized at 121℃ for 4 seconds.
[0074] (8) Online mixing: 900 parts by weight of concentrated milk base and 100 parts by weight of mixed material are mixed online through a dynamic mixer and refined by Y-tron, and then homogenized online through a homogenizer. The homogenization conditions are: the first homogenization pressure is 50 bar, and the second homogenization pressure can be 200 bar.
[0075] (9) Preparing for filling: Cool the mixed milk base to 15°C and put it into the filling tank;
[0076] (10) Filling: Fill at 15-20℃;
[0077] Example 2
[0078] Yogurt preparation method:
[0079] (1) Milk fat separation: Use a milk fat separator to separate the milk fat from the raw milk, separating skim milk and light cream. The light cream has a fat content of 40% to 45%.
[0080] (2) Skim milk treatment: Skim milk is sterilized by passing it through a sterilization separator. Skim milk enters the MF membrane system for physical sterilization. Then, protease is added for enzymatic hydrolysis. The hydrolysis temperature can be 45℃, the hydrolysis time can be 80min, and the amount of protease added can be 0.3‰ of the mass of skim milk.
[0081] (3) Skim milk sterilization: Enzymatically skim milk is homogenized and then sterilized at 95°C for 300 seconds before being put into a fermentation tank;
[0082] (4) Skim milk fermentation: Add fermentation starter, fermentation can be carried out at 43℃, and fermentation can be stopped when pH<4.8;
[0083] (5) Concentration: Fermented skim milk is heated to 50-55°C by a hot plate and then concentrated in a whey separator to obtain concentrated milk base and whey. The protein concentration in the concentrated milk base can be increased by more than 2.5 times, and the protein quality can be 7.2-7.5% of the concentrated milk base quality.
[0084] (6) Concentrated milk base treatment: The concentrated milk base is refrigerated at 4-8℃ for post-ripening. After 4-6 hours of post-ripening, it is demulsified. After demulsification, it is homogenized in a homogenizer. The pressure of the first homogenization can be 40-50 bar, and the pressure of the second homogenization can be 180-200 bar.
[0085] (7) Whipping cream processing: 50 parts by weight of whipping cream and 40 parts by weight of whey are mixed and homogenized to obtain a mixture. The homogenization temperature can be 55℃ and the homogenization pressure can be 40-50 bar. The mixture is sterilized at 121℃ for 4 seconds.
[0086] (8) Online mixing: 910 parts by weight of concentrated milk base and 90 parts by weight of mixed material are mixed online through a dynamic mixer and refined by Y-tron, and then homogenized online through a homogenizer. The homogenization conditions are: the first homogenization pressure is 50 bar, and the second homogenization pressure can be 200 bar.
[0087] (9) Preparing for filling: Cool the mixed milk base to 15°C and put it into the filling tank;
[0088] (10) Filling: Fill at 15-20℃;
[0089] Example 3
[0090] Yogurt preparation method:
[0091] (1) Milk fat separation: Use a milk fat separator to separate the milk fat from the raw milk, separating skim milk and light cream. The light cream has a fat content of 40% to 45%.
[0092] (2) Skim milk treatment: Skim milk is sterilized by passing it through a sterilization separator. Skim milk enters the MF membrane system for physical sterilization. Then, protease is added for enzymatic hydrolysis. The hydrolysis temperature can be 55℃, the hydrolysis time can be 40min, and the amount of protease added can be 0.2‰ of the mass of skim milk.
[0093] (3) Skim milk sterilization: Enzymatically skim milk is homogenized and then sterilized at 95°C for 300 seconds before being put into a fermentation tank;
[0094] (4) Skim milk fermentation: Add fermentation starter, fermentation can be carried out at 43℃, and fermentation can be stopped when pH<4.8;
[0095] (5) Concentration: Fermented skim milk is heated to 50-55°C by a hot plate and then concentrated in a whey separator to obtain concentrated milk base and whey. The protein concentration in the concentrated milk base can be increased by more than 2.5 times, and the protein quality can be 7.2-7.5% of the concentrated milk base quality.
[0096] (6) Concentrated milk base treatment: The concentrated milk base is refrigerated at 4-8℃ for post-ripening. After 4-6 hours of post-ripening, it is demulsified. After demulsification, it is homogenized in a homogenizer. The pressure of the first homogenization can be 40-50 bar, and the pressure of the second homogenization can be 180-200 bar.
[0097] (7) Whipping cream processing: 30 parts by weight of whipping cream and 40 parts by weight of whey are mixed and homogenized to obtain a mixture. The homogenization temperature can be 55℃ and the homogenization pressure can be 40-50 bar. The mixture is sterilized at 121℃ for 4 seconds.
[0098] (8) Online mixing: 920 parts by weight of concentrated milk base and 80 parts by weight of mixed material are mixed online through a dynamic mixer and refined by Y-tron, and then homogenized online through a homogenizer. The homogenization conditions are: the first homogenization pressure is 50 bar, and the second homogenization pressure can be 200 bar.
[0099] (9) Preparing for filling: Cool the mixed milk base to 15°C and put it into the filling tank;
[0100] (10) Filling: Fill at 15-20℃;
[0101] Comparative Example 1
[0102] Yogurt preparation method:
[0103] (1) Milk fat separation: Use a milk fat separator to separate the milk fat from the raw milk, separating skim milk and light cream. The light cream has a fat content of 40% to 45%.
[0104] (2) Skim milk treatment: Skim milk is sterilized by passing it through a sterilization separator. Skim milk enters the MF membrane system for physical sterilization. Then, protease is added for enzymatic hydrolysis. The hydrolysis temperature can be 40℃, the hydrolysis time can be 80min, and the amount of protease added can be 0.1‰ of the mass of skim milk.
[0105] (3) Skim milk sterilization: Enzymatically skim milk is homogenized and then sterilized at 95°C for 300 seconds before being put into a fermentation tank;
[0106] (4) Skim milk fermentation: Add fermentation starter, fermentation can be carried out at 43℃, and fermentation can be stopped when pH<4.8;
[0107] (5) Concentration: Fermented skim milk is heated to 50-55°C by a hot plate and then concentrated in a whey separator to obtain concentrated milk base and whey. The protein concentration in the concentrated milk base can be increased by more than 2.5 times, and the protein quality can be 7.2-7.5% of the concentrated milk base quality.
[0108] (6) Concentrated milk base treatment: The concentrated milk base is refrigerated at 4-8℃ for post-ripening. After 4-6 hours of post-ripening, it is demulsified. After demulsification, it is homogenized in a homogenizer. The pressure of the first homogenization can be 40-50 bar, and the pressure of the second homogenization can be 180-200 bar.
[0109] (7) Whipping cream processing: 40 parts by weight of whipping cream and 60 parts by weight of whey are mixed and homogenized to obtain a mixture. The homogenization temperature can be 55℃ and the homogenization pressure can be 40-50 bar. The mixture is sterilized at 121℃ for 4 seconds.
[0110] (8) Online mixing: 900 parts by weight of concentrated milk base and 100 parts by weight of mixed material are mixed online through a dynamic mixer and refined by Y-tron, and then homogenized online through a homogenizer. The homogenization conditions are: the first homogenization pressure is 50 bar, and the second homogenization pressure can be 200 bar.
[0111] (9) Preparing for filling: Cool the mixed milk base to 15°C and put it into the filling tank;
[0112] (10) Filling: Fill at 15-20℃;
[0113] Comparative Example 2
[0114] Yogurt preparation method:
[0115] (1) Milk fat separation: Use a milk fat separator to separate the milk fat from the raw milk, separating skim milk and light cream. The light cream has a fat content of 40% to 45%.
[0116] (2) Skim milk treatment: Skim milk is sterilized by passing it through a sterilization separator and then enters the MF membrane system for physical sterilization;
[0117] (3) Skim milk sterilization: After homogenization, skim milk is sterilized at 95°C for 300 seconds and then put into the fermentation tank;
[0118] (4) Skim milk fermentation: Add fermentation starter, fermentation can be carried out at 43℃, and fermentation can be stopped when pH<4.8;
[0119] (5) Concentration: Fermented skim milk is heated to 50-55°C by a hot plate and then concentrated in a whey separator to obtain concentrated milk base and whey. The protein concentration in the concentrated milk base can be increased by more than 2.5 times, and the protein quality can be 7.2-7.5% of the concentrated milk base quality.
[0120] (6) Concentrated milk base treatment: The concentrated milk base is refrigerated at 4-8℃ for post-ripening. After 4-6 hours of post-ripening, it is demulsified. After demulsification, it is homogenized in a homogenizer. The pressure of the first homogenization can be 40-50 bar, and the pressure of the second homogenization can be 180-200 bar.
[0121] (7) Whipping cream processing: 50 parts by weight of whipping cream and 40 parts by weight of whey are mixed and homogenized to obtain a mixture. The homogenization temperature can be 55℃ and the homogenization pressure can be 40-50 bar. The mixture is sterilized at 121℃ for 4 seconds.
[0122] (8) Online mixing: 910 parts by weight of concentrated milk base and 90 parts by weight of mixed material are mixed online through a dynamic mixer and refined by Y-tron, and then homogenized online through a homogenizer. The homogenization conditions are: the first homogenization pressure is 50 bar, and the second homogenization pressure can be 200 bar.
[0123] (9) Preparing for filling: Cool the mixed milk base to 15°C and put it into the filling tank;
[0124] (10) Filling: Fill at 15-20℃;
[0125] Comparative Example 3
[0126] Yogurt preparation method:
[0127] (1) Milk fat separation: Use a milk fat separator to separate the milk fat from the raw milk, separating skim milk and light cream. The light cream has a fat content of 40% to 45%.
[0128] (2) Skim milk treatment: Skim milk is sterilized by passing it through a sterilization separator. Skim milk enters the MF membrane system for physical sterilization. Then, protease is added for enzymatic hydrolysis. The hydrolysis temperature can be 45℃, the hydrolysis time can be 80min, and the amount of protease added can be 0.3‰ of the mass of skim milk.
[0129] (3) Skim milk sterilization: Enzymatically skim milk is homogenized and then sterilized at 95°C for 300 seconds before being put into a fermentation tank;
[0130] (4) Skim milk fermentation: Add fermentation starter, fermentation can be carried out at 43℃, and fermentation can be stopped when pH<4.8;
[0131] (5) Concentration: Fermented skim milk is heated to 50-55°C by a hot plate and then concentrated in a whey separator to obtain concentrated milk base and whey. The protein concentration in the concentrated milk base can be increased by more than 2.5 times, and the protein quality can be 7.2-7.5% of the concentrated milk base quality.
[0132] (6) Whipping cream processing: 50 parts by weight of whipping cream and 40 parts by weight of whey are mixed and homogenized to obtain a mixture. The homogenization temperature can be 55℃ and the homogenization pressure can be 40-50 bar. The mixture is sterilized at 121℃ for 4 seconds.
[0133] (7) Online mixing: 910 parts by weight of concentrated milk base and 90 parts by weight of mixed material are mixed online through a dynamic mixer and refined by Y-tron, and then homogenized online through a homogenizer. The homogenization conditions are: the first homogenization pressure is 50 bar, and the second homogenization pressure can be 200 bar.
[0134] (8) Preparing for filling: Cool the mixed milk base to 15°C and put it into the filling tank;
[0135] (9) Filling: Fill at 15-20℃;
[0136] Comparative Example 4
[0137] Yogurt preparation method:
[0138] (1) Milk fat separation: Use a milk fat separator to separate the milk fat from the raw milk, separating skim milk and light cream. The light cream has a fat content of 40% to 45%.
[0139] (2) Skim milk treatment: Skim milk is sterilized by passing it through a sterilization separator. Skim milk enters the MF membrane system for physical sterilization. Then, protease is added for enzymatic hydrolysis. The hydrolysis temperature can be 45℃, the hydrolysis time can be 80min, and the amount of protease added can be 0.3‰ of the mass of skim milk.
[0140] (3) Skim milk sterilization: Enzymatically skim milk is homogenized and then sterilized at 95°C for 300 seconds before being put into a fermentation tank;
[0141] (4) Skim milk fermentation: Add fermentation starter, fermentation can be carried out at 43℃, and fermentation can be stopped when pH<4.8;
[0142] (5) Concentration: Fermented skim milk is heated to 50-55°C by a hot plate and then concentrated in a whey separator to obtain concentrated milk base and whey. The protein concentration in the concentrated milk base can be increased by more than 2.5 times, and the protein quality can be 7.2-7.5% of the concentrated milk base quality.
[0143] (6) Concentrated milk base treatment: The concentrated milk base is refrigerated at 4-8℃ for post-ripening. After 4-6 hours of post-ripening, it is demulsified. After demulsification, it is homogenized in a homogenizer. The pressure of the first homogenization can be 40-50 bar, and the pressure of the second homogenization can be 180-200 bar.
[0144] (7) Whipping cream treatment: 50 parts by weight of whipping cream are homogenized at a temperature of 55°C and a pressure of 40-50 bar, and then sterilized at 121°C for 4 seconds.
[0145] (8) Online mixing: 910 parts by weight of concentrated milk base and 50 parts by weight of light cream are mixed online through a dynamic mixer and refined by Y-tron, and then homogenized online through a homogenizer. The homogenization conditions are: the first homogenization pressure is 50 bar, and the second homogenization pressure can be 200 bar.
[0146] (9) Preparing for filling: Cool the mixed milk base to 15°C and put it into the filling tank;
[0147] (10) Filling: Fill at 15-20℃;
[0148] Comparative Example 5
[0149] Yogurt preparation method:
[0150] (1) Milk fat separation: Use a milk fat separator to separate the milk fat from the raw milk, separating skim milk and light cream. The light cream has a fat content of 40% to 45%.
[0151] (2) Skim milk treatment: Skim milk is sterilized by passing it through a sterilization separator. Skim milk enters the MF membrane system for physical sterilization. Then, protease is added for enzymatic hydrolysis. The hydrolysis temperature can be 45℃, the hydrolysis time can be 80min, and the amount of protease added can be 0.3‰ of the mass of skim milk.
[0152] (3) Skim milk sterilization: Enzymatically skim milk is homogenized and then sterilized at 95°C for 300 seconds before being put into a fermentation tank;
[0153] (4) Skim milk fermentation: Add fermentation starter, fermentation can be carried out at 43℃, and fermentation can be stopped when pH<4.8;
[0154] (5) Concentration: Fermented skim milk is heated to 50-55°C by a hot plate and then concentrated in a whey separator to obtain concentrated milk base and whey. The protein concentration in the concentrated milk base can be increased by more than 2.5 times, and the protein quality can be 7.2-7.5% of the concentrated milk base quality.
[0155] (6) Concentrated milk base treatment: The concentrated milk base is refrigerated at 4-8℃ for post-ripening. After 4-6 hours of post-ripening, it is demulsified. After demulsification, it is homogenized in a homogenizer. The pressure of the first homogenization can be 40-50 bar, and the pressure of the second homogenization can be 180-200 bar.
[0156] (7) 40 parts by weight of whey were homogenized at a temperature of 55°C and a pressure of 40-50 bar, and sterilized at 121°C for 4 seconds.
[0157] (8) Online mixing: 910 parts by weight of concentrated milk base and 40 parts by weight of whey are mixed online through a dynamic mixer and refined by Y-tron, and then homogenized online through a homogenizer. The homogenization conditions are: the first homogenization pressure is 50 bar, and the second homogenization pressure can be 200 bar.
[0158] (9) Preparing for filling: Cool the mixed milk base to 15°C and put it into the filling tank;
[0159] (10) Filling: Fill at 15-20℃;
[0160] Comparative Example 6
[0161] Yogurt preparation method:
[0162] (1) Milk fat separation: Use a milk fat separator to separate the milk fat from the raw milk, separating skim milk and light cream. The light cream has a fat content of 40% to 45%.
[0163] (2) Skim milk treatment: Skim milk is sterilized by passing it through a sterilization separator. Skim milk enters the MF membrane system for physical sterilization. Then, protease is added for enzymatic hydrolysis. The hydrolysis temperature can be 45℃, the hydrolysis time can be 80min, and the amount of protease added can be 0.3‰ of the mass of skim milk.
[0164] (3) Skim milk sterilization: Enzymatically skim milk is homogenized and then sterilized at 95°C for 300 seconds before being put into a fermentation tank;
[0165] (4) Skim milk fermentation: Add fermentation starter, fermentation can be carried out at 43℃, and fermentation can be stopped when pH<4.8;
[0166] (5) Concentration: Fermented skim milk is heated to 50-55°C by a hot plate and then concentrated in a whey separator to obtain concentrated milk base and whey. The protein concentration in the concentrated milk base can be increased by more than 2.5 times, and the protein quality can be 7.2-7.5% of the concentrated milk base quality.
[0167] (6) Whipping cream processing: 50 parts by weight of whipping cream and 40 parts by weight of whey are mixed and homogenized to obtain a mixture. The homogenization temperature can be 55℃ and the homogenization pressure can be 40-50 bar. The mixture is sterilized at 121℃ for 4 seconds.
[0168] (7) Online mixing: 910 parts by weight of concentrated milk base and 90 parts by weight of mixed material are mixed online through a dynamic mixer and refined by Y-tron;
[0169] (8) Preparing for filling: Cool the mixed milk base to 15°C and put it into the filling tank;
[0170] (9) Filling: Fill at 15-20℃;
[0171] Performance tests were conducted on the yogurts used in the above embodiments and comparative examples.
[0172] (1) Sensory evaluation of the taste and flavor of the yogurts prepared in Examples 1-3 and Comparative Examples 1-6 was conducted. The main evaluation items included: texture (whey separation, viscosity, smoothness, and consistency), color, flavor, and mouthfeel. A total of 45 people participated in the experiment and conducted sensory evaluations of the yogurt products of Examples 1-3 and Comparative Examples 1-6. The sensory scoring criteria are shown in Table 1, and the experimental results are summarized in Table 2.
[0173] Table 1 Sensory Evaluation Criteria
[0174]
[0175] Table 2 Sensory evaluation results
[0176]
[0177] As shown in Table 2, the sensory evaluation of product preference was conducted based on the test samples of Examples 1-3 and Comparative Examples 1-6. The products of the Examples 1-3 had a delicate and mellow taste, stable texture, rich flavor, and a smooth drinking experience. The products of Comparative Examples 1-6 had particles, a less delicate taste, and insufficient flavor release.
[0178] (2) Viscosity of yogurt products
[0179] After the yogurt product was refrigerated at 4-8℃ for 4 hours, a sample was taken for viscosity testing. An Anton Paar MCR302 rheometer was used, with a constant shear rate of 50 1 / s and data points collected at 60 s 1 / s. The temperature was controlled at 20℃.
[0180] Table 3 Viscosity of Yogurt Products
[0181] name Viscosity (mPa·s) Example 1 645 Example 2 633 Example 3 652 Comparative Example 1 735 Comparative Example 2 849 Comparative Example 3 1176 Comparative Example 4 721 Comparative Example 5 765 Comparative Example 6 1475
[0182] As shown in Table 3, based on Examples 1-3 and Comparative Examples 1-6, the viscosity of the samples in the examples was lower than that of the comparative examples. After treatment with protease, the product viscosity decreased and the smoothness improved. Homogenization after the concentrated yogurt has finished ripening ensures reduced product viscosity and a smooth and delicate texture. After two homogenization processes and one Y-tron refinement treatment, the product is guaranteed to be free of protein agglomerates.
[0183] (3) Changes in product condition during shelf life
[0184] The product was stored in a refrigerator at 4°C. The product condition was observed every 7 days to check for water separation and to determine the whey separation rate, as shown in Table 4.
[0185] Whey separation rate (%) = (mass of separated whey / total mass) * 100%
[0186] Table 4. Whey separation rate at different times
[0187]
[0188] As shown in Table 4, based on the sampling and testing observations of Examples 1-3 and Comparative Examples 1-6, the products in the Examples remained stable during their shelf life with virtually no water separation, indicating good product stability. In contrast, the products in the Comparative Examples all exhibited varying degrees of water separation.
[0189] The present invention has been described above in conjunction with embodiments thereof. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of the present invention.
Claims
1. A method for preparing high-protein yogurt, characterized in that, include: Separate skim milk and cream from raw milk; After sterilization, the skim milk is added to protease for enzymatic hydrolysis. The skim milk after enzymatic hydrolysis is sterilized and then fermented to obtain milk base; The milk base is concentrated to obtain concentrated milk base and whey; The light cream and whey are mixed, homogenized, and sterilized to obtain a mixture. Yogurt is obtained by mixing the concentrated milk base with the mixture.
2. The preparation method according to claim 1, characterized in that, The enzymatic hydrolysis temperature is 45-55℃, and the enzymatic hydrolysis time is 40-80 min.
3. The preparation method according to claim 1, characterized in that, The amount of protease added is 0.2-0.5‰ of the weight of skim milk.
4. The preparation method according to claim 1, characterized in that, The fermentation temperature is 40-45℃.
5. The preparation method according to claim 1, characterized in that, Before mixing the concentrated milk base with the mixture, the method further includes: The concentrated milk base is placed at 4-8℃ for post-maturation, and the post-maturation lasts for 4-6 hours to break the emulsion. After the emulsion is broken, it is homogenized to obtain the pretreated concentrated milk base. The step of mixing the concentrated milk base with the mixture to obtain yogurt includes: Yogurt is obtained by mixing the pretreated concentrated milk base with the mixture.
6. The preparation method according to claim 5, characterized in that, After demulsification, the primary homogenization pressure is 40-50 bar, and the secondary homogenization pressure is 180-200 bar.
7. The preparation method according to claim 1, characterized in that, The amount of heavy cream is 30-50 parts by weight, and the amount of whey is 40-60 parts by weight.
8. The preparation method according to claim 1, characterized in that, The concentrated milk base is 900-920 parts by weight, and the mixed feed is 80-100 parts by weight.
9. The preparation method according to claim 1, characterized in that, The step of mixing the concentrated milk base with the mixture to obtain yogurt includes: The concentrated milk base is mixed and homogenized with the mixture to obtain yogurt; The primary homogenization pressure is 40-50 bar, and the secondary homogenization pressure is 180-200 bar.
10. A type of yogurt, characterized in that, Prepared using the preparation method according to any one of claims 1-9.