Method for preparing yogurt and yogurt

Abstract

The application provides a yogurt preparation method and yogurt, wherein the preparation method comprises the following steps: mixing yogurt raw materials, homogenizing, hydrating, degassing, homogenizing, and then performing first ultrahigh pressure sterilization to obtain a base material; performing fermentation treatment and demulsification on the base material, adding jam to the demulsified base material and uniformly mixing to obtain a mixed material; wherein the jam is obtained by performing ultrahigh pressure sterilization on fruit puree rich in anthocyanins; and performing second ultrahigh pressure sterilization on the mixed material. The application adopts ultrahigh pressure sterilization, can effectively protect heat-sensitive nutrients in the yogurt under the condition of meeting sterilization indexes, and obtains high-nutrition yogurt. The ultrahigh pressure sterilization does not need to add preservatives in the yogurt, and can obtain healthy yogurt. In addition, the jam is obtained by performing ultrahigh pressure sterilization on fruit puree rich in anthocyanins, and the yogurt with fruit flavor and containing anthocyanins can be obtained.

Description

Technical Field

[0001] This invention relates to the field of food processing technology, and in particular to a method for preparing yogurt and the yogurt itself. Background Technology

[0002] Yogurt is a dairy product made from cow's milk, goat's milk, or other milk through processes such as sterilization and fermentation. Yogurt not only has a rich taste but also offers health benefits such as aiding digestion, providing nutrition, and boosting immunity, making it very popular with consumers.

[0003] Existing yogurt products mostly use high-temperature sterilization methods during the preparation process to meet the sterilization standards for market launch. However, this causes a large amount of heat-sensitive nutrients in the yogurt to be destroyed, resulting in a reduction in the nutritional value of the yogurt. Summary of the Invention

[0004] This invention provides a method for preparing yogurt and yogurt in general, to address the problem that existing yogurt products often use high-temperature sterilization methods during preparation to meet sterilization standards for market release, which results in the destruction of a large amount of heat-sensitive nutrients in the yogurt, leading to a reduction in its nutritional value.

[0005] To solve the above-mentioned technical problems, the present invention is implemented as follows:

[0006] In a first aspect, embodiments of the present invention provide a method for preparing yogurt, comprising:

[0007] Step S1: Mix the yogurt ingredients, dissolve, hydrate, deaerate, homogenize, and then perform the first ultra-high pressure sterilization to obtain the base material;

[0008] Step S2: Ferment and demulsify the base material, add jam to the demulsified base material and mix evenly to obtain a mixture; wherein, the jam is obtained by sterilizing fruit puree rich in anthocyanins under ultra-high pressure;

[0009] Step S3: Perform a second ultra-high pressure sterilization on the mixture.

[0010] Optionally, the first ultra-high pressure sterilization step includes:

[0011] Add the homogenized yogurt ingredients to an ultra-high pressure sterilizer and sterilize at the first pressure for 3-7 minutes;

[0012] Increase the pressure from the first pressure to the second pressure, sterilize at the second pressure for 3-7 minutes, and then release the pressure to atmospheric pressure.

[0013] The first pressure is 300-400 MPa, and the second pressure is 500-600 MPa.

[0014] Optionally, step S3 includes:

[0015] The mixture is added to an ultra-high pressure sterilization device and sterilized under the third pressure for 8-12 minutes;

[0016] Increase the pressure from the third pressure to the fourth pressure, sterilize at the fourth pressure for 8-12 minutes, and then release the pressure to atmospheric pressure.

[0017] The third pressure is 300-500 MPa, and the fourth pressure is 550-650 MPa.

[0018] Optionally, the method for preparing the jam includes:

[0019] The fruit puree is added to an ultra-high pressure sterilization device and sterilized at the fifth pressure for 8-12 minutes;

[0020] Increase the pressure from the fifth pressure to the sixth pressure, sterilize at the sixth pressure for 8-12 minutes, and then release the pressure to atmospheric pressure;

[0021] The fifth pressure is 180-220 MPa, and the sixth pressure is 300-400 MPa.

[0022] Optionally, the method for preparing the fruit puree includes:

[0023] Heat the juice to 35-40℃, add sweetener, citrus fiber, and fruit pieces, and stir well.

[0024] The juice is prepared from at least one of the following fruits: blueberries, blackberries, cherries, raspberries, grapes, mulberries; and / or

[0025] The sweetener comprises granulated sugar and / or a sugar substitute, wherein the sugar substitute comprises at least one of aspartame, saccharin, xylitol, erythritol, threose, sifidin, and maltitol; and / or

[0026] The length L, width M, and height N of the fruit granules satisfy the following conditions: 1mm≤L≤3mm, 1mm≤M≤3mm, and 1mm≤N≤3mm.

[0027] Optionally, the yogurt ingredients include milk;

[0028] The yogurt ingredients also include at least one of sweeteners, inulin, anthocyanins, vitamin A, vitamin B1, vitamin B2, and vitamin C; and / or

[0029] The sweetener includes white sugar and / or a sugar substitute, wherein the sugar substitute includes at least one of aspartame, saccharin, xylitol, erythritol, threose, sifidin, and maltitol.

[0030] Optionally, the step of fermenting the substrate includes:

[0031] Heat the base material to 40-45℃, add the fermentation agent, and cool it down to 2-6℃ after the fermentation endpoint is reached.

[0032] The starter culture includes at least one of Lactobacillus delbrueckii subsp. bulgaricus, Streptococcus salivarius subsp. thermophilus, Lactococcus lactis subsp. lactis, Lactococcus fat, Bifidobacterium animalis subsp. lactis, and Lactobacillus acidophilus.

[0033] The fermentation endpoint was pH = 4.50-4.55.

[0034] Optionally, the melting temperature is 50-55℃, the melting time is 20-40 min, the demulsification frequency is 75-85%, and the demulsification time is 7-13 min.

[0035] Optionally, step S3 is followed by:

[0036] Step S4: Fill the mixture after ultra-high pressure sterilization.

[0037] Secondly, embodiments of the present invention provide a yogurt prepared using the yogurt preparation method described in any one of the first aspects.

[0038] In this embodiment of the invention, step S1 involves mixing yogurt ingredients, dissolving and homogenizing them, followed by a first ultra-high pressure sterilization to obtain a base material; step S2 involves fermenting and demulsifying the base material, adding jam to the demulsified base material and mixing evenly to obtain a mixture; wherein the jam is obtained by ultra-high pressure sterilization of anthocyanin-rich fruit puree; step S3 involves a second ultra-high pressure sterilization of the mixture. Ultra-high pressure sterilization, while meeting sterilization standards, effectively protects heat-sensitive nutrients in the yogurt, resulting in highly nutritious yogurt. Ultra-high pressure sterilization eliminates the need for preservatives in the yogurt, leading to healthier yogurt. Furthermore, the jam, obtained by ultra-high pressure sterilization of anthocyanin-rich fruit puree, provides a yogurt with a fruity flavor and anthocyanin content. Attached Figure Description

[0039] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0040] Figure 1 This is a schematic flowchart of the yogurt preparation method according to an embodiment of the present invention. Detailed Implementation

[0041] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. 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.

[0042] The terms "first," "second," etc., used in this embodiment of the invention are used to distinguish similar objects, not to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that embodiments of the invention can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first" and "second" are generally of the same class, without limiting the number of objects; for example, the first object can be one or more. Furthermore, in this embodiment of the invention, "or" indicates at least one of the connected objects. For example, "A or B" covers three scenarios: Scenario 1: includes A but does not include B; Scenario 2: includes B but does not include A; Scenario 3: includes both A and B. The character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0043] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0044] It should be noted that all raw materials used in the embodiments of the present invention can be obtained commercially available. Any range described in the embodiments of the present invention includes the end value and any value between the end values, as well as any sub-range formed by the end value or any value between the end values.

[0045] This invention provides a method for preparing yogurt, see [link to relevant documentation]. Figure 1 As shown, Figure 1 This is a schematic flowchart of a yogurt preparation method according to an embodiment of the present invention. The yogurt preparation method includes:

[0046] Step S1: Mix the yogurt ingredients, dissolve, hydrate, deaerate, homogenize, and then perform the first ultra-high pressure sterilization to obtain the base material;

[0047] Step S2: Ferment and demulsify the base material, add jam to the demulsified base material and mix evenly to obtain a mixture; wherein, the jam is obtained by sterilizing fruit puree rich in anthocyanins under ultra-high pressure;

[0048] Step S3: Perform a second ultra-high pressure sterilization on the mixture.

[0049] Ultra-high pressure sterilization (UHP) is a method of killing microorganisms in food using a high-pressure environment. Its principle is to destroy the cell membrane, proteins, and nucleic acids of bacteria by applying extremely high pressure, thereby achieving a sterilization effect.

[0050] Jam is made from fruit puree rich in anthocyanins through ultra-high pressure sterilization, giving yogurt a variety of health benefits such as anti-oxidation, anti-inflammation, and protection of cardiovascular health.

[0051] In this embodiment of the invention, step S1 involves mixing yogurt ingredients, dissolving and homogenizing them, followed by a first ultra-high pressure sterilization to obtain a base material; step S2 involves fermenting and demulsifying the base material, adding jam to the demulsified base material and mixing evenly to obtain a mixture; wherein the jam is obtained by ultra-high pressure sterilization of anthocyanin-rich fruit puree; step S3 involves a second ultra-high pressure sterilization of the mixture. Ultra-high pressure sterilization, while meeting sterilization standards, effectively protects heat-sensitive nutrients in the yogurt, resulting in highly nutritious yogurt. Ultra-high pressure sterilization eliminates the need for preservatives in the yogurt, leading to healthier yogurt. Furthermore, the jam, obtained by ultra-high pressure sterilization of anthocyanin-rich fruit puree, provides a yogurt with a fruity flavor and anthocyanin content.

[0052] In some embodiments of the present invention, optionally, the first ultra-high pressure sterilization step includes:

[0053] Add the homogenized yogurt ingredients to an ultra-high pressure sterilizer and sterilize at the first pressure for 3-7 minutes;

[0054] Increase the pressure from the first pressure to the second pressure, sterilize at the second pressure for 3-7 minutes, and then release the pressure to atmospheric pressure.

[0055] The first pressure is 300-400 MPa, and the second pressure is 500-600 MPa.

[0056] In this embodiment of the invention, the above process steps can achieve a high sterilization rate, avoid interference from miscellaneous bacteria in subsequent fermentation treatment, improve the fermentation success rate, and effectively protect the heat-sensitive nutrients in the yogurt raw materials, ensuring that highly nutritious yogurt is obtained.

[0057] In some embodiments of the present invention, step S3 may optionally include:

[0058] Add the mixture to the ultra-high pressure sterilization equipment and sterilize it under the third pressure for 8-12 minutes;

[0059] Increase the pressure from the third pressure to the fourth pressure, sterilize at the fourth pressure for 8-12 minutes, and then release the pressure to atmospheric pressure.

[0060] The third pressure is 300-500 MPa, and the fourth pressure is 550-650 MPa.

[0061] In this embodiment of the invention, the above process steps can kill lactic acid bacteria in the mixture and any remaining bacteria, spoilage bacteria and pathogens in the fruit puree, extend the shelf life of the yogurt, and effectively protect the heat-sensitive nutrients in the mixture, ensuring that a highly nutritious yogurt is obtained.

[0062] In some embodiments of the present invention, optionally, the method for preparing jam includes:

[0063] Add the fruit puree to the ultra-high pressure sterilization equipment and sterilize it at the fifth pressure for 8-12 minutes;

[0064] Increase the pressure from the fifth pressure to the sixth pressure, sterilize at the sixth pressure for 8-12 minutes, and then release the pressure to atmospheric pressure.

[0065] The fifth pressure is 180-220 MPa, and the sixth pressure is 300-400 MPa.

[0066] In this embodiment of the invention, the above-described process steps can eliminate unwanted bacteria, spoilage bacteria, and pathogenic bacteria in the fruit puree, extend the shelf life of the yogurt, and effectively protect the heat-sensitive nutrients in the fruit puree, ensuring that a highly nutritious yogurt is obtained.

[0067] In some embodiments of the present invention, optionally, the method for preparing fruit puree includes:

[0068] Heat the juice to 35-40℃, add sweetener, citrus fiber, and fruit pieces, and stir well.

[0069] The juice is made from at least one of the following fruits: blueberries, blackberries, cherries, raspberries, grapes, mulberries; and / or

[0070] Sweeteners include white sugar and / or artificial sweeteners, wherein the artificial sweeteners include at least one of aspartame, saccharin, xylitol, erythritol, threose, sifidin, and maltitol; and / or

[0071] The length L, width M, and height N of the fruit satisfy the following conditions: 1mm≤L≤3mm, 1mm≤M≤3mm, 1mm≤N≤3mm.

[0072] Blueberries, blackberries, cherries, raspberries, grapes, and mulberries are all fruits rich in anthocyanins. Juices made from at least one of these fruits are rich in anthocyanins. The juice is preferably not-from-concentrate, obtained by fruit pressing. Furthermore, after pressing, the juice is preferably pasteurized using NFC (Not From Concentrate) or cold pasteurization processes.

[0073] It should be noted that sweeteners were added during the preparation of the fruit puree to enhance its flavor. The addition of citrus fiber increased the dietary fiber content and improved the puree's consistency.

[0074] Adding fruit pieces allows consumers to not only sip the yogurt but also chew on the fruit pulp, enriching its texture. In some embodiments, the fruit pieces are preferably from the same variety of fruit used to prepare the juice. In some embodiments, the juice is preferably prepared from multiple fruits, forming a compound juice. The fruit pieces include pieces from the aforementioned multiple fruits.

[0075] The length L, width M, and height N of the fruit pieces must satisfy the following conditions: 1mm≤L≤3mm, 1mm≤M≤3mm, and 1mm≤N≤3mm. This results in a delicate texture and reduces the risk of children choking on the fruit pieces.

[0076] Sweeteners added during the preparation of fruit puree can be sugar substitutes, which reduce calorie intake when consuming yogurt and do not significantly affect the blood sugar level of consumers after consumption.

[0077] In some embodiments of the present invention, the yogurt ingredients may optionally include milk;

[0078] Yogurt ingredients also include at least one of the following: sweeteners, inulin, anthocyanins, vitamin A, vitamin B1, vitamin B2, and vitamin C; and / or

[0079] Sweeteners include white sugar and / or sugar substitutes, and sugar substitutes include at least one of aspartame, saccharin, xylitol, erythritol, threose, sifidin, and maltitol.

[0080] In some embodiments, the yogurt ingredients may include a sweetener. The sweetener may be a sugar substitute, which reduces calorie intake when consuming the yogurt and does not significantly affect the consumer's blood sugar levels after consumption.

[0081] Inulin is a natural water-soluble dietary fiber supplement, the main component of which is inulin polysaccharide (composed of fructose molecular chains). In some embodiments, inulin may be included in yogurt ingredients, enabling the yogurt to regulate the balance of intestinal flora and improve digestion.

[0082] In some embodiments, the yogurt ingredients may include anthocyanins to supplement the anthocyanins in the jam, thereby increasing the anthocyanin content in the yogurt and giving it various health benefits such as antioxidant, anti-inflammatory, and cardiovascular health protection.

[0083] In some embodiments, the yogurt ingredients may include at least one of vitamin A, vitamin B1, vitamin B2, and vitamin C, thereby improving the nutritional value of the yogurt.

[0084] In some embodiments of the present invention, optionally, the step of fermenting the substrate includes:

[0085] Heat the base material to 40-45℃, add the fermentation agent, and cool it down to 2-6℃ after the fermentation endpoint is reached.

[0086] The starter culture includes at least one of Lactobacillus delbrueckii subsp. bulgaricus, Streptococcus salivarius subsp. thermophilus, Lactococcus lactis subsp. lactis, Lactococcus fat, Bifidobacterium animalis subsp. lactis, and Lactobacillus acidophilus.

[0087] The fermentation endpoint was pH = 4.50-4.55.

[0088] Adding a starter culture to the substrate at 40-45℃ can achieve high fermentation efficiency. After the fermentation endpoint, cool the temperature to 2-6℃ to terminate fermentation and avoid over-fermentation.

[0089] In some embodiments of the present invention, optionally, the melting temperature is 50-55°C, the melting time is 20-40 min, the demulsification frequency is 75-85%, and the demulsification time is 7-13 min.

[0090] The melting temperature is 50-55℃, and the melting time is 20-40 minutes, which is conducive to the full melting of yogurt raw materials in the melting tank. The demulsification frequency is 75-85%, and the demulsification time is 7-13 minutes, which eliminates the stabilization conditions of the emulsion obtained from melting, causes the dispersed droplets to aggregate and separate, and improves the effect of subsequent mixing with jam.

[0091] In some embodiments of the present invention, optionally, step S3 is followed by:

[0092] Step S4: The mixture after ultra-high pressure sterilization is filled to obtain the final yogurt product. Ultra-high pressure sterilization of the mixture before filling results in a long shelf life for the final yogurt product.

[0093] In some embodiments of the present invention, the homogenization temperature is optionally room temperature, and the homogenization conditions are 30 / 180 bar, with the aim of breaking down fat globules in the liquid and preventing fat globules from floating to the surface during subsequent processing and shelf life, which would have a negative impact on the flavor and appearance of the yogurt product.

[0094] This invention also provides a yogurt prepared using the yogurt preparation method described in any one of the embodiments of this invention.

[0095] The following description is based on specific embodiments.

[0096] Example 1

[0097] The steps for preparing yogurt include:

[0098] Milk, white sugar, anthocyanins, vitamin A, vitamin B1, vitamin B2 and vitamin C are mixed, thawed at 50°C for 20 minutes, hydrated, degassed and homogenized, and then added to an ultra-high pressure sterilization device for sterilization at 400MPa for 5 minutes. After that, the pressure is increased to 600MPa and sterilized for 5 minutes, and then the pressure is released to atmospheric pressure.

[0099] The raw materials sterilized by ultra-high pressure were heated to 40°C, and a fermentation agent was added. After the pH reached 4.50, the temperature was lowered to 4°C to terminate the fermentation.

[0100] The fermented liquid was demulsified at a frequency of 75% for 7 minutes. After demulsification, jam was added and mixed evenly. Then, it was added to an ultra-high pressure sterilization device and sterilized at 500 MPa for 10 minutes. After that, the pressure was increased to 600 MPa and sterilized for 10 minutes. The pressure was then released to atmospheric pressure.

[0101] The steps for preparing the jam are as follows:

[0102] Heat the mixed juice of blueberries, blackberries, cherries, raspberries, grapes, and mulberries to 35-40℃, add white sugar, citrus fiber, and fruit pieces (blueberries, blackberries, cherries, raspberries, grapes, and mulberries), stir well to get a fruit puree;

[0103] Add the fruit puree to the ultra-high pressure sterilization equipment and sterilize at 200MPa for 5 minutes. Then, increase the pressure to 300MPa and sterilize for 5 minutes. Finally, release the pressure to atmospheric pressure.

[0104] Example 2

[0105] The steps for preparing yogurt include:

[0106] Milk, white sugar, anthocyanins, vitamin A, vitamin B1, vitamin B2 and vitamin C are mixed, thawed at 50°C for 20 minutes, hydrated, degassed and homogenized, and then added to an ultra-high pressure sterilization device for sterilization at 400MPa for 5 minutes. After that, the pressure is increased to 600MPa and sterilized for 5 minutes, and then the pressure is released to atmospheric pressure.

[0107] The raw materials sterilized by ultra-high pressure were heated to 40°C, and a fermentation agent was added. After the pH reached 4.50, the temperature was lowered to 4°C to terminate the fermentation.

[0108] The fermented liquid was demulsified at a frequency of 75% for 7 minutes. After demulsification, jam was added and mixed evenly. Then, it was added to an ultra-high pressure sterilization device and sterilized at 500 MPa for 10 minutes. After that, the pressure was increased to 600 MPa and sterilized for 10 minutes. The pressure was then released to atmospheric pressure.

[0109] The steps for preparing the jam are as follows:

[0110] Heat the mixed juice of blueberries, blackberries, cherries, raspberries, grapes, and mulberries to 35-40℃, add white sugar, citrus fiber, and fruit pieces (blueberries, blackberries, cherries, raspberries, grapes, and mulberries), stir well to get a fruit puree;

[0111] Add the fruit puree to the ultra-high pressure sterilization equipment and sterilize at 200MPa for 5 minutes. Then, increase the pressure to 400MPa and sterilize for 5 minutes. Finally, release the pressure to atmospheric pressure.

[0112] Example 3

[0113] The steps for preparing yogurt include:

[0114] Milk, white sugar, anthocyanins, vitamin A, vitamin B1, vitamin B2 and vitamin C are mixed, thawed at 50°C for 20 minutes, hydrated, degassed and homogenized, and then added to an ultra-high pressure sterilization device for sterilization at 300MPa for 5 minutes. After that, the pressure is increased to 600MPa and sterilized for 5 minutes, and then the pressure is released to atmospheric pressure.

[0115] The raw materials sterilized by ultra-high pressure were heated to 40°C, and a fermentation agent was added. After the pH reached 4.50, the temperature was lowered to 4°C to terminate the fermentation.

[0116] The fermented liquid was demulsified at a frequency of 75% for 7 minutes. After demulsification, jam was added and mixed evenly. Then, it was added to an ultra-high pressure sterilization device and sterilized at 400 MPa for 10 minutes. After that, the pressure was increased to 600 MPa and sterilized for 10 minutes. The pressure was then released to atmospheric pressure.

[0117] The steps for preparing the jam are as follows:

[0118] Heat the mixed juice of blueberries, blackberries, cherries, raspberries, grapes, and mulberries to 35-40℃, add white sugar, citrus fiber, and fruit pieces (blueberries, blackberries, cherries, raspberries, grapes, and mulberries), stir well to get a fruit puree;

[0119] Add the fruit puree to the ultra-high pressure sterilization equipment and sterilize at 200MPa for 5 minutes. Then, increase the pressure to 300MPa and sterilize for 5 minutes. Finally, release the pressure to atmospheric pressure.

[0120] Example 4

[0121] The steps for preparing yogurt include:

[0122] Milk, white sugar, anthocyanins, vitamin A, vitamin B1, vitamin B2 and vitamin C are mixed, thawed at 50°C for 20 minutes, hydrated, degassed and homogenized, and then added to an ultra-high pressure sterilization device for sterilization at 300MPa for 5 minutes. After that, the pressure is increased to 600MPa and sterilized for 5 minutes, and then the pressure is released to atmospheric pressure.

[0123] The raw materials sterilized by ultra-high pressure were heated to 40°C, and a fermentation agent was added. After the pH reached 4.50, the temperature was lowered to 4°C to terminate the fermentation.

[0124] The fermented liquid was demulsified at a frequency of 75% for 7 minutes. After demulsification, jam was added and mixed evenly. Then, it was added to an ultra-high pressure sterilization device and sterilized at 400 MPa for 10 minutes. After that, the pressure was increased to 600 MPa and sterilized for 10 minutes. The pressure was then released to atmospheric pressure.

[0125] The steps for preparing the jam are as follows:

[0126] Heat the mixed juice of blueberries, blackberries, cherries, raspberries, grapes, and mulberries to 35-40℃, add white sugar, citrus fiber, and fruit pieces (blueberries, blackberries, cherries, raspberries, grapes, and mulberries), stir well to get a fruit puree;

[0127] Add the fruit puree to the ultra-high pressure sterilization equipment and sterilize at 200MPa for 5 minutes. Then, increase the pressure to 400MPa and sterilize for 5 minutes. Finally, release the pressure to atmospheric pressure.

[0128] Example 5

[0129] The steps for preparing yogurt include:

[0130] Milk, white sugar, anthocyanins, vitamin A, vitamin B1, vitamin B2 and vitamin C are mixed, thawed at 50°C for 20 minutes, hydrated, degassed and homogenized, and then added to an ultra-high pressure sterilization device for sterilization at 300MPa for 5 minutes. After that, the pressure is increased to 500MPa and sterilized for 5 minutes, and then the pressure is released to atmospheric pressure.

[0131] The raw materials sterilized by ultra-high pressure were heated to 40°C, and a fermentation agent was added. After the pH reached 4.50, the temperature was lowered to 4°C to terminate the fermentation.

[0132] The fermented liquid was demulsified at a frequency of 75% for 7 minutes. After demulsification, jam was added and mixed evenly. Then, it was added to an ultra-high pressure sterilization device and sterilized at 300 MPa for 10 minutes. After that, the pressure was increased to 600 MPa and sterilized for 10 minutes. The pressure was then released to atmospheric pressure.

[0133] The steps for preparing the jam are as follows:

[0134] Heat the mixed juice of blueberries, blackberries, cherries, raspberries, grapes, and mulberries to 35-40℃, add white sugar, citrus fiber, and fruit pieces (blueberries, blackberries, cherries, raspberries, grapes, and mulberries), stir well to get a fruit puree;

[0135] Add the fruit puree to the ultra-high pressure sterilization equipment and sterilize at 200MPa for 5 minutes. Then, increase the pressure to 300MPa and sterilize for 5 minutes. Finally, release the pressure to atmospheric pressure.

[0136] Example 6

[0137] The steps for preparing yogurt include:

[0138] Milk, white sugar, anthocyanins, vitamin A, vitamin B1, vitamin B2 and vitamin C are mixed, thawed at 50°C for 20 minutes, hydrated, degassed and homogenized, and then added to an ultra-high pressure sterilization device for sterilization at 300MPa for 5 minutes. After that, the pressure is increased to 500MPa and sterilized for 5 minutes, and then the pressure is released to atmospheric pressure.

[0139] The raw materials sterilized by ultra-high pressure were heated to 40°C, and a fermentation agent was added. After the pH reached 4.50, the temperature was lowered to 4°C to terminate the fermentation.

[0140] The fermented liquid was demulsified at a frequency of 75% for 7 minutes. After demulsification, jam was added and mixed evenly. Then, it was added to an ultra-high pressure sterilization device and sterilized at 300 MPa for 10 minutes. After that, the pressure was increased to 600 MPa and sterilized for 10 minutes. The pressure was then released to atmospheric pressure.

[0141] The steps for preparing the jam are as follows:

[0142] Heat the mixed juice of blueberries, blackberries, cherries, raspberries, grapes, and mulberries to 35-40℃, add white sugar, citrus fiber, and fruit pieces (blueberries, blackberries, cherries, raspberries, grapes, and mulberries), stir well to get a fruit puree;

[0143] Add the fruit puree to the ultra-high pressure sterilization equipment and sterilize at 200MPa for 5 minutes. Then, increase the pressure to 400MPa and sterilize for 5 minutes. Finally, release the pressure to atmospheric pressure.

[0144] Example 7

[0145] The steps for preparing yogurt include:

[0146] Milk, white sugar, anthocyanins, vitamin A, vitamin B1, vitamin B2 and vitamin C are mixed, thawed at 55°C for 40 minutes, hydrated, degassed and homogenized, and then added to an ultra-high pressure sterilization device for sterilization at 400MPa for 3 minutes. After that, the pressure is increased to 600MPa and sterilized for 7 minutes, and then the pressure is released to atmospheric pressure.

[0147] The raw materials sterilized by ultra-high pressure were heated to 40°C, and a fermentation agent was added. After the pH reached 4.55, the temperature was lowered to 6°C to terminate the fermentation.

[0148] The fermented liquid was demulsified at a frequency of 75% for 13 minutes. After demulsification, jam was added and mixed evenly. Then, it was added to an ultra-high pressure sterilization device and sterilized at 500 MPa for 10 minutes. After that, the pressure was increased to 550 MPa and sterilized for 8 minutes. The pressure was then released to atmospheric pressure.

[0149] The steps for preparing the jam are as follows:

[0150] Heat the mixed juice of blueberries, blackberries, cherries, raspberries, grapes, and mulberries to 35-40℃, add white sugar, citrus fiber, and fruit pieces (blueberries, blackberries, cherries, raspberries, grapes, and mulberries), stir well to get a fruit puree;

[0151] Add the fruit puree to the ultra-high pressure sterilization equipment and sterilize at 180MPa for 8 minutes. Then, increase the pressure to 300MPa and sterilize for 12 minutes. Finally, release the pressure to atmospheric pressure.

[0152] Example 8

[0153] The steps for preparing yogurt include:

[0154] Milk, white sugar, anthocyanins, vitamin A, vitamin B1, vitamin B2 and vitamin C are mixed, thawed at 55°C for 20 minutes, hydrated, degassed and homogenized, and then added to an ultra-high pressure sterilization device for sterilization at 400MPa for 7 minutes. After that, the pressure is increased to 600MPa and sterilized for 3 minutes, and then the pressure is released to atmospheric pressure.

[0155] The raw materials sterilized by ultra-high pressure were heated to 40°C, and a fermentation agent was added. After the pH reached 4.50, the temperature was lowered to 6°C to terminate the fermentation.

[0156] The fermented liquid was demulsified at a frequency of 85% for 13 minutes. After demulsification, jam was added and mixed evenly. Then, it was added to an ultra-high pressure sterilization device and sterilized at 500 MPa for 10 minutes. After that, the pressure was increased to 650 MPa and sterilized for 12 minutes. The pressure was then released to atmospheric pressure.

[0157] The steps for preparing the jam are as follows:

[0158] Heat the mixed juice of blueberries, blackberries, cherries, raspberries, grapes, and mulberries to 35-40℃, add white sugar, citrus fiber, and fruit pieces (blueberries, blackberries, cherries, raspberries, grapes, and mulberries), stir well to get a fruit puree;

[0159] Add the fruit puree to the ultra-high pressure sterilization equipment and sterilize at 220MPa for 12 minutes. Then, increase the pressure to 300MPa and sterilize for 8 minutes, then release the pressure to atmospheric pressure.

[0160] Example 9

[0161] The steps for preparing yogurt include:

[0162] Milk, white sugar, anthocyanins, vitamin A, vitamin B1, vitamin B2 and vitamin C are mixed, thawed at 50°C for 40 minutes, hydrated, degassed and homogenized, and then added to an ultra-high pressure sterilization device for sterilization at 400MPa for 7 minutes. After that, the pressure is increased to 600MPa and sterilized for 7 minutes, and then the pressure is released to atmospheric pressure.

[0163] The raw materials sterilized by ultra-high pressure were heated to 40°C, and a fermentation agent was added. After the pH reached 4.55, the temperature was lowered to 4°C to terminate the fermentation.

[0164] The fermented liquid was demulsified at a frequency of 85% for 13 minutes. After demulsification, jam was added and mixed evenly. Then, it was added to an ultra-high pressure sterilization device and sterilized at 500 MPa for 10 minutes. After that, the pressure was increased to 650 MPa and sterilized for 8 minutes. The pressure was then released to atmospheric pressure.

[0165] The steps for preparing the jam are as follows:

[0166] Heat the mixed juice of blueberries, blackberries, cherries, raspberries, grapes, and mulberries to 35-40℃, add white sugar, citrus fiber, and fruit pieces (blueberries, blackberries, cherries, raspberries, grapes, and mulberries), stir well to get a fruit puree;

[0167] Add the fruit puree to the ultra-high pressure sterilization equipment and sterilize at 220MPa for 8 minutes. Then, increase the pressure to 300MPa and sterilize for 12 minutes. Finally, release the pressure to atmospheric pressure.

[0168] Comparative Example 1

[0169] The steps for preparing yogurt include:

[0170] Milk, white sugar, anthocyanins, vitamin A, vitamin B1, vitamin B2 and vitamin C are mixed, thawed at 50°C for 20 minutes, hydrated, degassed and homogenized, and then added to an ultra-high pressure sterilization device for sterilization at 400MPa for 5 minutes. After that, the pressure is increased to 600MPa and sterilized for 5 minutes, and then the pressure is released to atmospheric pressure.

[0171] The raw materials sterilized by ultra-high pressure were heated to 40°C, and a fermentation agent was added. After the pH reached 4.50, the temperature was lowered to 4°C to terminate the fermentation.

[0172] The fermented liquid was demulsified at a frequency of 75% for 7 minutes. After demulsification, jam was added and mixed evenly. Then, it was added to an ultra-high pressure sterilization device and sterilized at 400 MPa for 10 minutes. After that, the pressure was increased to 600 MPa and sterilized for 10 minutes. The pressure was then released to atmospheric pressure.

[0173] The steps for preparing the jam are as follows:

[0174] Heat the mixed juice of blueberries, blackberries, cherries, raspberries, grapes, and mulberries to 35-40℃, add white sugar, citrus fiber, and fruit pieces (blueberries, blackberries, cherries, raspberries, grapes, and mulberries), and stir well.

[0175] Comparative Example 2

[0176] The steps for preparing yogurt include:

[0177] Mix milk, white sugar, anthocyanins, vitamin A, vitamin B1, vitamin B2 and vitamin C, melt at 50℃ for 20 minutes, hydrate, deaerate and homogenize;

[0178] Heat the homogenized raw materials to 40°C, add the fermenting agent, and then cool to 4°C after the pH reaches 4.50 to terminate the fermentation.

[0179] The fermented liquid was demulsified at a frequency of 75% for 7 minutes. After demulsification, jam was added and mixed evenly. Then, it was added to an ultra-high pressure sterilization device and sterilized at 400 MPa for 10 minutes. After that, the pressure was increased to 600 MPa and sterilized for 10 minutes. The pressure was then released to atmospheric pressure.

[0180] The steps for preparing the jam are as follows:

[0181] Heat the mixed juice of blueberries, blackberries, cherries, raspberries, grapes, and mulberries to 35-40℃, add white sugar, citrus fiber, and fruit pieces (blueberries, blackberries, cherries, raspberries, grapes, and mulberries), stir well to get a fruit puree;

[0182] Add the fruit puree to the ultra-high pressure sterilization equipment and sterilize at 100MPa for 5 minutes. Then, increase the pressure to 300MPa and sterilize for 5 minutes. Finally, release the pressure to atmospheric pressure.

[0183] Comparative Example 3

[0184] The steps for preparing yogurt include:

[0185] Milk, white sugar, anthocyanins, vitamin A, vitamin B1, vitamin B2 and vitamin C are mixed, thawed at 50°C for 20 minutes, hydrated, degassed and homogenized, and then added to an ultra-high pressure sterilization device for sterilization at 400MPa for 10 minutes. After that, the pressure is increased to 600MPa and sterilized for 10 minutes, and then the pressure is released to atmospheric pressure.

[0186] The raw materials sterilized by ultra-high pressure were heated to 40°C, and a fermentation agent was added. After the pH reached 4.50, the temperature was lowered to 4°C to terminate the fermentation.

[0187] Demulsify the fermented liquid at a frequency of 75% for 7 minutes. After demulsification, add jam and mix well.

[0188] The steps for preparing the jam are as follows:

[0189] Heat the mixed juice of blueberries, blackberries, cherries, raspberries, grapes, and mulberries to 35-40℃, add white sugar, citrus fiber, and fruit pieces (blueberries, blackberries, cherries, raspberries, grapes, and mulberries), stir well to get a fruit puree;

[0190] Add the fruit puree to the ultra-high pressure sterilization equipment and sterilize at 100MPa for 10 minutes. Then, increase the pressure to 300MPa and sterilize for 10 minutes, and then release the pressure to atmospheric pressure.

[0191] Comparative Example 4

[0192] The steps for preparing yogurt include:

[0193] Milk, white sugar, anthocyanins, vitamin A, vitamin B1, vitamin B2 and vitamin C are mixed, thawed at 50°C for 20 minutes, hydrated, degassed and homogenized, and then added to an ultra-high pressure sterilization device for sterilization at 400MPa for 2 minutes. After that, the pressure is increased to 600MPa and sterilized for 2 minutes, and then the pressure is released to atmospheric pressure.

[0194] The raw materials sterilized by ultra-high pressure were heated to 40°C, and a fermentation agent was added. After the pH reached 4.50, the temperature was lowered to 4°C to terminate the fermentation.

[0195] The fermented liquid was demulsified at a frequency of 75% for 7 minutes. After demulsification, jam was added and mixed evenly. Then, it was added to an ultra-high pressure sterilization device and sterilized at 400 MPa for 5 minutes. After that, the pressure was increased to 600 MPa and sterilized for 5 minutes. The pressure was then released to atmospheric pressure.

[0196] The steps for preparing the jam are as follows:

[0197] Heat the mixed juice of blueberries, blackberries, cherries, raspberries, grapes, and mulberries to 35-40℃, add white sugar, citrus fiber, and fruit pieces (blueberries, blackberries, cherries, raspberries, grapes, and mulberries), stir well to get a fruit puree;

[0198] Add the fruit puree to the ultra-high pressure sterilization equipment and sterilize at 200MPa for 2 minutes. Then, increase the pressure to 300MPa and sterilize for 2 minutes. Finally, release the pressure to atmospheric pressure.

[0199] Comparative Example 5

[0200] The steps for preparing yogurt include:

[0201] Milk, white sugar, anthocyanins, vitamin A, vitamin B1, vitamin B2 and vitamin C are mixed, thawed at 50°C for 20 minutes, hydrated, degassed and homogenized, and then pasteurized (75°C for 30 seconds).

[0202] The above-mentioned pasteurized raw materials were heated to 40°C, and a fermentation agent was added. After the pH reached 4.50, the temperature was lowered to 4°C to terminate the fermentation.

[0203] The fermented liquid was demulsified at a frequency of 75% for 7 minutes. After demulsification, jam was added and mixed evenly, and then pasteurized (75°C for 30 seconds).

[0204] The steps for preparing the jam are as follows:

[0205] Heat the mixed juice of blueberries, blackberries, cherries, raspberries, grapes, and mulberries to 35-40℃, add white sugar, citrus fiber, and fruit pieces (blueberries, blackberries, cherries, raspberries, grapes, and mulberries), stir well to get a fruit puree;

[0206] The fruit puree was pasteurized (75°C for 30 seconds).

[0207] Comparative Example 6

[0208] The steps for preparing yogurt include:

[0209] Milk, white sugar, anthocyanins, vitamin A, vitamin B1, vitamin B2 and vitamin C are mixed, thawed at 50°C for 20 minutes, hydrated, degassed and homogenized, and then added to an ultra-high pressure sterilization device for sterilization at 400MPa for 10 minutes. After that, the pressure is increased to 600MPa and sterilized for 10 minutes, and then the pressure is released to atmospheric pressure.

[0210] The raw materials sterilized by ultra-high pressure were heated to 40°C, and a fermentation agent was added. After the pH reached 4.50, the temperature was lowered to 4°C to terminate the fermentation.

[0211] The fermented liquid was demulsified at a frequency of 75% for 7 minutes. After demulsification, jam was added and mixed evenly. Then, it was added to an ultra-high pressure sterilization device and sterilized at 400 MPa for 15 minutes. After that, the pressure was increased to 600 MPa and sterilized for 15 minutes. The pressure was then released to atmospheric pressure.

[0212] The steps for preparing the jam are as follows:

[0213] Heat the mixed juice of blueberries, blackberries, cherries, raspberries, grapes, and mulberries to 35-40℃, add white sugar, citrus fiber, and fruit pieces (blueberries, blackberries, cherries, raspberries, grapes, and mulberries), stir well to get a fruit puree;

[0214] Add the fruit puree to the ultra-high pressure sterilization equipment and sterilize at 200MPa for 10 minutes. Then, increase the pressure to 300MPa and sterilize for 10 minutes. Finally, release the pressure to atmospheric pressure.

[0215] Comparative Example 7

[0216] The steps for preparing yogurt include:

[0217] Milk, white sugar, anthocyanins, vitamin A, vitamin B1, vitamin B2 and vitamin C are mixed, thawed at 50°C for 20 minutes, hydrated, degassed and homogenized, and then added to an ultra-high pressure sterilization device for sterilization at 400MPa for 5 minutes. After that, the pressure is increased to 600MPa and sterilized for 5 minutes, and then the pressure is released to atmospheric pressure.

[0218] The raw materials sterilized by ultra-high pressure were heated to 40°C, and a fermentation agent was added. After the pH reached 4.50, the temperature was lowered to 4°C to terminate the fermentation.

[0219] The fermented liquid was demulsified at a frequency of 75% for 7 minutes. After demulsification, jam was added and mixed evenly. Then, it was added to an ultra-high pressure sterilization device and sterilized at 500 MPa for 10 minutes. After that, the pressure was increased to 600 MPa and sterilized for 10 minutes. The pressure was then released to atmospheric pressure.

[0220] The steps for preparing the jam are as follows:

[0221] Heat the mixed juice of blueberries, blackberries, cherries, raspberries, grapes, and mulberries to 35-40℃, add white sugar, citrus fiber, and fruit pieces (blueberries, blackberries, cherries, raspberries, grapes, and mulberries), stir well to get a fruit puree;

[0222] The fruit puree is sterilized at ultra-high temperature (135℃ for 30 seconds).

[0223] The above embodiments and comparative examples were tested.

[0224] The method for detecting anthocyanins was as follows: Yogurt products were diluted 10-fold with water as the dilution solution, extracted by ultrasonic vibration for 30 min, then brought to a final volume of 50 ml, centrifuged at 14000 r / min for 5 min, and the supernatant was collected after filtration through an aqueous filter membrane. The mobile phase was set as A (5% phosphoric acid solution)-B (methanol), and the elution conditions were: 0–10.5 min, B 23%; 10.5–29.1 min, B 23–26%; 29.1 min–40.0 min, B 26%–60%. The anthocyanin content in unsterilized jam was determined as X, and the anthocyanin content in the product was determined as Y. The degree of denaturation was calculated as (XY) / X.

[0225] The method for obtaining the sensory evaluation scores of the products was as follows: Thirty male volunteers aged 18-35 and 30 female volunteers aged 18-35 were recruited. In a bright room with the room temperature controlled at 25±2℃, the volunteers tasted the samples from the example and comparative examples in turn, and filled out questionnaires, rating the products' refreshing taste, sweet-sour ratio, aroma, clarity, and color. A 20-point scale was used for scoring, with 1 point being extremely poor, 10 points being average, and 20 points being extremely excellent, and all categories were scored equally.

[0226] The total bacterial count in the samples from the examples and comparative examples was tested.

[0227] Furthermore, the shelf life of the examples and comparative examples was tested, with the number of lactic acid bacteria in the yogurt at 25°C being greater than or equal to 10. 6 The number of days the product is stored is its shelf life.

[0228] Shelf life testing method: The test shall be conducted in accordance with the method of GB 4789.35.

[0229] The test results are shown in Table 1:

[0230] Table 1 Test Results

[0231]

[0232] Table 1 shows that Comparative Example 1 did not sterilize the fruit puree, resulting in residual bacteria that multiplied as the packaging time increased. Although it was subsequently sterilized together with the yogurt, these bacteria were difficult to completely eliminate, leading to a short shelf life and low sensory score. Comparative Example 2 did not sterilize the milk, resulting in excessive bacteria that prevented fermentation from completing. Comparative Example 3 did not use ultra-high pressure sterilization for the yogurt, resulting in a shorter shelf life, but the absence of a sterilization step led to a higher sensory score. Comparative Example 4 shortened the sterilization time for all steps, resulting in poor sterilization at each step, thus extending the sterilization time and shortening the shelf life. Comparative Example 5 used heat sterilization, achieving a shelf life comparable to ultra-high pressure sterilization, but the sensory score was poor. Comparative Example 6 extended the ultra-high pressure sterilization time, enhancing the elimination of bacteria and extending the shelf life, but the sensory score was low.

[0233] In summary, the preparation method of this invention employs ultra-high pressure sterilization, which effectively protects heat-sensitive nutrients in yogurt while meeting sterilization standards, resulting in highly nutritious yogurt. Ultra-high pressure sterilization eliminates the need for preservatives, leading to healthier yogurt. Furthermore, the jam, obtained from anthocyanin-rich fruit puree through ultra-high pressure sterilization, yields yogurt with a fruity flavor and containing anthocyanins.

[0234] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0235] The embodiments of the present invention have been described above with reference to the accompanying drawings. 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 yogurt, characterized in that, include: Step S1: Mix the yogurt ingredients, dissolve, hydrate, deaerate, homogenize, and then perform the first ultra-high pressure sterilization to obtain the base material; Step S2: Ferment and demulsify the base material, add jam to the demulsified base material and mix evenly to obtain a mixture; wherein, the jam is obtained by sterilizing fruit puree rich in anthocyanins under ultra-high pressure; Step S3: Perform a second ultra-high pressure sterilization on the mixture.

2. The method for preparing yogurt according to claim 1, characterized in that, The steps for the first ultra-high pressure sterilization include: Add the homogenized yogurt ingredients to an ultra-high pressure sterilizer and sterilize at the first pressure for 3-7 minutes; Increase the pressure from the first pressure to the second pressure, sterilize at the second pressure for 3-7 minutes, and then release the pressure to atmospheric pressure. The first pressure is 300-400 MPa, and the second pressure is 500-600 MPa.

3. The method for preparing yogurt according to claim 1, characterized in that, Step S3 includes: The mixture is added to an ultra-high pressure sterilization device and sterilized under the third pressure for 8-12 minutes; Increase the pressure from the third pressure to the fourth pressure, sterilize at the fourth pressure for 8-12 minutes, and then release the pressure to atmospheric pressure. The third pressure is 300-500 MPa, and the fourth pressure is 550-650 MPa.

4. The method for preparing yogurt according to claim 1, characterized in that, The method for preparing the jam includes: The fruit puree is added to an ultra-high pressure sterilization device and sterilized at the fifth pressure for 8-12 minutes; Increase the pressure from the fifth pressure to the sixth pressure, sterilize at the sixth pressure for 8-12 minutes, and then release the pressure to atmospheric pressure; The fifth pressure is 180-220 MPa, and the sixth pressure is 300-400 MPa.

5. The method for preparing yogurt according to claim 1 or 4, characterized in that, The method for preparing the fruit puree includes: Heat the juice to 35-40℃, add sweetener, citrus fiber, and fruit pieces, and stir well. The juice is prepared from at least one of the following fruits: blueberries, blackberries, cherries, raspberries, grapes, mulberries; and / or The sweetener comprises granulated sugar and / or a sugar substitute, wherein the sugar substitute comprises at least one of aspartame, saccharin, xylitol, erythritol, threose, sifidin, and maltitol; and / or The length L, width M, and height N of the fruit granules satisfy the following conditions: 1mm≤L≤3mm, 1mm≤M≤3mm, and 1mm≤N≤3mm.

6. The method for preparing yogurt according to claim 1, characterized in that, The yogurt ingredients include cow's milk; The yogurt ingredients also include at least one of sweeteners, inulin, anthocyanins, vitamin A, vitamin B1, vitamin B2, and vitamin C; and / or The sweetener includes white sugar and / or a sugar substitute, wherein the sugar substitute includes at least one of aspartame, saccharin, xylitol, erythritol, threose, sifidin, and maltitol.

7. The method for preparing yogurt according to claim 1, characterized in that, The step of fermenting the base material includes: Heat the base material to 40-45℃, add the fermentation agent, and cool it down to 2-6℃ after the fermentation endpoint is reached. The starter culture includes at least one of Lactobacillus delbrueckii subsp. bulgaricus, Streptococcus salivarius subsp. thermophilus, Lactococcus lactis subsp. lactis, Lactococcus fat, Bifidobacterium animalis subsp. lactis, and Lactobacillus acidophilus. The fermentation endpoint was pH = 4.50-4.

55.

8. The method for preparing yogurt according to claim 1, characterized in that, The melting temperature is 50-55℃, the melting time is 20-40 min, the demulsification frequency is 75-85%, and the demulsification time is 7-13 min.

9. The method for preparing yogurt according to claim 1, characterized in that, Step S3 is followed by: Step S4: Fill the mixture after ultra-high pressure sterilization.

10. A type of yogurt, characterized in that, The yogurt is prepared using the method described in any one of claims 1 to 9.

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