Normal-temperature yoghourt and preparation method thereof

Abstract

The invention provides normal-temperature yoghourt and a preparation method thereof. Emulsified sodium carboxymethyl cellulose is prepared by emulsifying sodium carboxymethyl cellulose and an emulsifier under specific conditions, and the emulsified sodium carboxymethyl cellulose and hydroxypropyl distarch phosphate and gelatin in a specific ratio are used for preparing the normal-temperature yoghourt. Through the synergistic effect of the emulsified sodium carboxymethyl cellulose and the hydroxypropyl distarch phosphate and the gelatin in a specific ratio, the stability of the normal-temperature yoghourt is remarkably improved, and the problem of whey precipitation of the normal-temperature yoghourt is avoided on the premise of avoiding the addition of a large amount of various stable substances.

Description

Technical Field

[0001] The present invention relates to a room-temperature yogurt, and particularly to a room-temperature yogurt and a preparation method thereof, belonging to the food field. Background Art

[0002] Room-temperature yogurt does not need to be refrigerated, is convenient to carry out, has a suitable temperature, does not stimulate the gastrointestinal tract, and is more suitable for children, the elderly and people with weak gastrointestinal functions to eat. At the same time, the nutritional components of room-temperature yogurt are stable and have a long shelf life, generally being able to be stored at room temperature for more than 6 months.

[0003] However, whey separation is likely to occur in room-temperature yogurt during the shelf life. Whey separation not only causes the loss of nutritional components of room-temperature yogurt, deteriorates the texture of the product, but also affects the flavor and taste, giving consumers an unfavorable sensory impression.

[0004] How to avoid the whey separation problem of room-temperature yogurt and further improve the stability of room-temperature yogurt is a research hotspot in this field. Summary of the Invention

[0005] The present invention provides a room-temperature yogurt which can be stored at room temperature for 6 months, has a relatively uniform state, a relatively homogeneous texture, a strong milk flavor, a harmonious aroma, a delicate, thick and smooth taste, a moderate sour and sweet taste, a uniform taste, a relatively high stability, and no whey separation.

[0006] The present invention also provides a preparation method of a room-temperature yogurt. Through this preparation method, a room-temperature yogurt with the above advantages can be obtained, and this preparation method is simple to operate and has a simple process.

[0007] The present invention provides a room-temperature yogurt, wherein the raw materials of the room-temperature yogurt include, by mass percentage: 1.5-2.5% of emulsified sodium carboxymethylcellulose, 0.5-0.8% of a stabilizer, 0.002%-0.004% of a starter, and the balance is raw milk;

[0008] Wherein, the stabilizer includes hydroxypropyl distarch phosphate and gelatin, and the weight ratio of hydroxypropyl distarch phosphate to gelatin is (3-5):(2-3);

[0009] The emulsified sodium carboxymethylcellulose is prepared by at least the following process: at 78-85°C, sodium carboxymethylcellulose and an emulsifier are mixed at 2500-3500 r / min, and the mass ratio of the sodium carboxymethylcellulose to the emulsifier is (15-18):(1-1.5) to obtain the emulsified sodium carboxymethylcellulose.

[0010] The room-temperature yogurt as described above, wherein the emulsified sodium carboxymethylcellulose is prepared by a method comprising at least the following process: at 80°C, the sodium carboxymethylcellulose and the emulsifier are mixed at 3000 r / min to obtain the emulsified sodium carboxymethylcellulose, wherein the mass ratio of the emulsified sodium carboxymethylcellulose to the emulsifier is 16:1.

[0011] The room-temperature yogurt as described above, wherein the mass percentage content of the emulsified sodium carboxymethylcellulose in the raw materials of the room-temperature yogurt is 2%.

[0012] The room-temperature yogurt as described above, wherein the mass percentage content of the stabilizer in the raw materials of the room-temperature yogurt is 0.6%.

[0013] The room-temperature yogurt as described above, wherein the weight ratio of the hydroxypropyl distarch phosphate to the gelatin is 2:1.

[0014] The room-temperature yogurt as described above, wherein the emulsifier comprises at least one of monoglyceride and diglyceride fatty acid esters and glycerol monolaurate.

[0015] The room-temperature yogurt as described above, wherein the raw materials of the room-temperature yogurt further comprise a sweetening substance.

[0016] The room-temperature yogurt as described above, wherein the sweetening substance comprises at least one of fructose, high fructose syrup, maltose, xylitol, acesulfame potassium, aspartame, sucralose and sodium cyclamate.

[0017] The present invention also provides a method for preparing the room-temperature yogurt according to any one of the above, which comprises the following steps:

[0018] 1) Mixing a raw material system comprising the raw milk with the emulsified sodium carboxymethylcellulose and the stabilizer to obtain a first material;

[0019] 2) Homogenizing and performing a first sterilization treatment on the first material to obtain a second material;

[0020] 3) Adding the starter to the second material and performing fermentation, and terminating the fermentation when the fermentation acidity is 70°T - 75°T to obtain a third material;

[0021] 4) Performing a second sterilization treatment on the third material to obtain the room-temperature yogurt.

[0022] The preparation method as described above, wherein the sterilization temperature of the second sterilization treatment is 90 - 95°C and the sterilization time is 30 - 35 min.

[0023] The room-temperature yogurt of the present invention is prepared by emulsifying sodium carboxymethylcellulose and an emulsifier under specific conditions to obtain emulsified sodium carboxymethylcellulose, and using the emulsified sodium carboxymethylcellulose, hydroxypropyl distarch phosphate and gelatin in a specific ratio to prepare the room-temperature yogurt. Through the synergistic effect of the emulsified sodium carboxymethylcellulose, hydroxypropyl distarch phosphate and gelatin in a specific ratio, the stability of the room-temperature yogurt is significantly improved. On the premise of avoiding the addition of a large amount of various stabilizing substances, the problem of whey separation in the room-temperature yogurt is avoided. Moreover, the room-temperature yogurt can be stored at room temperature for 6 months, with a relatively uniform state, relatively homogeneous texture, strong milk fragrance flavor, coordinated aroma, delicate and thick taste, moderate sweetness and sourness, uniform taste, and high stability. Detailed Embodiments

[0024] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0025] The present invention provides a room-temperature yogurt, and the raw materials of the room-temperature yogurt include, by mass percentage: 1.5-2.5% of emulsified sodium carboxymethylcellulose, 0.5-0.8% of a stabilizer, 0.002%-0.004% of a starter, and the balance is raw milk;

[0026] Among them, the stabilizer includes hydroxypropyl distarch phosphate and gelatin, and the weight ratio of hydroxypropyl distarch phosphate to gelatin is (3-5):(2-3);

[0027] The above emulsified sodium carboxymethylcellulose is prepared by a method that at least includes the following process: at 78-85°C, sodium carboxymethylcellulose and an emulsifier are mixed at 2500-3500 r / min, wherein the mass ratio of sodium carboxymethylcellulose to the emulsifier is (15-18):(1-1.5), to obtain emulsified sodium carboxymethylcellulose.

[0028] The present invention does not limit the types of the above raw milk and starter, and the commonly used types in the art can be used. For example, the raw milk can include at least one of raw cow milk, raw goat milk, raw camel milk, reconstituted milk, and whole milk; the starter can be a combination of one probiotic or multiple probiotics, preferably at least one of Streptococcus thermophilus, Lactobacillus bulgaricus, Bifidobacterium lactis, and Lactobacillus rhamnosus.

[0029] The above stabilizer is a compound stabilizer including hydroxypropyl distarch phosphate and gelatin, wherein the weight ratio of hydroxypropyl distarch phosphate to gelatin is (3-5):(2-3).

[0030] The inventors found that sodium carboxymethyl cellulose and an emulsifier are mixed at 2500-3500 r / min at 78-85° C., wherein the mass ratio of sodium carboxymethyl cellulose to the emulsifier is (15-18):(1-1.5), to obtain emulsified sodium carboxymethyl cellulose, and the emulsified sodium carboxymethyl cellulose is used together with hydroxypropyl distarch phosphate and gelatin to prepare room temperature yogurt, wherein the mass percentage of emulsified sodium carboxymethyl cellulose in the raw materials of the room temperature yogurt is 1.5-2.5%, the mass percentage of hydroxypropyl distarch phosphate and gelatin is 0.5-0.8%, and the weight ratio of hydroxypropyl distarch phosphate to gelatin is (3-5):(2-3), which is beneficial to significantly improve the stability of room temperature yogurt and avoid the problem of whey precipitation. A new solution is provided for solving the problem of whey precipitation in room temperature yogurt without requiring a large amount of additives, thereby making the room temperature yogurt raw materials more natural and healthy, and at the same time, it is beneficial to improve the organizational state, flavor and mouthfeel of the above-mentioned room temperature yogurt.

[0031] The present invention does not limit the mixing time. The end point is that the sodium carboxymethyl cellulose and the emulsifier are mixed evenly so that they can fully act. The mixing time can be adjusted according to the mass of the sodium carboxymethyl cellulose and the emulsifier. For example, when the mass of the sodium carboxymethyl cellulose is 5-40g, preferably 24g, and the mass of the emulsifier is 0.5-2g, preferably 1g, the mixing time is 8-10min, so that the sodium carboxymethyl cellulose and the emulsifier are fully mixed and acted.

[0032] The room-temperature yogurt provided by the present invention can be kept for 6 months at room temperature. The room-temperature yogurt has a simple raw material formula, does not contain a large amount of additives, and the raw material components are relatively natural and healthy. During the shelf life, the room-temperature yogurt is in a relatively uniform state and has a relatively uniform texture; it has a strong milky flavor and a harmonious aroma; it has a delicate and thick taste and a uniform taste; it has a relatively high stability and avoids the problem of whey precipitation.

[0033] Furthermore, the emulsified sodium carboxymethyl cellulose is prepared by at least the following process: sodium carboxymethyl cellulose and an emulsifier are mixed at 3000 r / min at 80°C to obtain emulsified sodium carboxymethyl cellulose, wherein the mass ratio of sodium carboxymethyl cellulose to the emulsifier is 16: 1. The emulsified sodium carboxymethyl cellulose, hydroxypropyl distarch phosphate and gelatin act synergistically, which is conducive to achieving a better level of the organizational state, flavor and taste of the room temperature yogurt during the shelf life, making the room temperature yogurt more stable and avoiding the problem of whey precipitation.

[0034] In some embodiments, the mass percentage of the above-mentioned emulsified sodium carboxymethyl cellulose in the raw materials of ambient temperature yogurt is 2%, which is more conducive to the synergistic effect of the emulsified sodium carboxymethyl cellulose, hydroxypropyl distarch phosphate and gelatin, further improving the stability of the ambient temperature yogurt, thereby ensuring that the problem of whey precipitation is avoided during the shelf life.

[0035] Similarly, when the mass percentage content of the above stabilizer in the raw materials of the ambient temperature yogurt is 0.6%, the synergistic effect of the emulsified sodium carboxymethylcellulose and the stabilizer is better, which is more conducive to improving the stability of the ambient temperature yogurt and preventing the problem of whey separation during the shelf life of the ambient temperature yogurt.

[0036] The inventors also found that by further defining the weight ratio of the above hydroxypropyl distarch phosphate and gelatin to be 2:1, the stability of the ambient temperature yogurt can also be improved, the problem of whey separation during the shelf life can be avoided, and it is beneficial to maintain the stability of the tissue state, flavor and taste of the ambient temperature yogurt.

[0037] The above emulsifier includes at least one of mono- and diglycerol fatty acid esters and glycerol monolaurate, which can enable the effective emulsification modification of sodium carboxymethylcellulose, thereby obtaining emulsified sodium carboxymethylcellulose with improved stability of ambient temperature yogurt. Stability.

[0038] To improve the sweet taste of the ambient temperature yogurt, the raw materials of the ambient temperature yogurt also include a sweetening substance. The mass percentage content of the sweetening substance in the raw materials of the ambient temperature yogurt is 0.3-1%, which is beneficial to make the taste of the ambient temperature yogurt moderately sour and sweet and the taste more uniform.

[0039] The above sweetening substance includes at least one of fructose, high fructose syrup, maltose, xylitol, acesulfame potassium, aspartame, sucralose and sodium cyclamate. When the sweetening substance includes sucralose and acesulfame potassium, the mass ratio of sucralose to acesulfame potassium is (0.05-1):(0.3-1.2), which is beneficial to make the sweetness of the ambient temperature yogurt controllable and the taste uniform.

[0040] The present invention also provides a method for preparing the above ambient temperature yogurt, which includes the following steps:

[0041] 1) Mix the raw material system including raw milk with emulsified sodium carboxymethylcellulose and a stabilizer to obtain a first material;

[0042] 2) Homogenize and perform a first sterilization treatment on the first material to obtain a second material;

[0043] 3) Add a starter to the second material and ferment. When the fermentation acidity reaches 70°T-75°T, terminate the fermentation to obtain a third material;

[0044] 4) Perform a second sterilization treatment on the third material to obtain the above ambient temperature yogurt.

[0045] In the above step 1), in order to give full play to the synergistic effect of the emulsified sodium carboxymethylcellulose and the stabilizer and fully mix with the raw milk, the temperature of the mixing system can be increased and stirred, for example, stirred at 55°C for 25 minutes.

[0046] The present invention does not particularly limit the conditions for the homogenization and the first sterilization treatment in the above step 2). For example, the homogenization pressure may be 30 / 180 bar, and the conditions for the first sterilization may be a sterilization temperature of 95° C. and a sterilization time of 300 s.

[0047] It is understandable that when the first sterilization in step 2) is heat sterilization, the fermentation agent needs to be added after cooling in advance to avoid inactivation of the fermentation agent at an inappropriately high temperature. For example, the fermentation agent can be added after cooling to 40-43°C.

[0048] In the above step 3), after the fermentation agent is added to the second material, it needs to be mixed evenly, which is conducive to the fermentation agent being evenly dispersed in the second material, so that the fermentation action in the second material is evenly carried out at all positions.

[0049] The present invention does not particularly limit the fermentation temperature. The optimum fermentation temperature can be determined according to the characteristics of the fermentation agent. For example, when the fermentation agent includes thermophilic Streptococcus and bulgaricus Lactobacillus, the fermentation temperature can be determined to be 43°C, which is beneficial to improving the activity of the fermentation agent, thereby improving the quality and efficiency of the fermentation.

[0050] When the fermented yogurt is at 70°T-75°T, the fermentation is terminated to obtain the third material.

[0051] The purpose of performing the second sterilization treatment on the third material in step 4) is to kill the microorganisms in the third material, including the leavening agent, so that the product can be kept at room temperature to avoid excessive fermentation of microorganisms causing product deterioration, thereby obtaining the room temperature yogurt of the present invention.

[0052] The room-temperature yogurt prepared by the preparation method can be kept for 6 months at room temperature. During the shelf life, the organizational state, flavor and taste of the room-temperature yogurt are all good, which are specifically manifested in that the state is relatively uniform, the texture is relatively uniform; the milky flavor is rich and the aroma is coordinated; the taste is delicate and thick, and the taste is uniform; the stability is relatively high, and there is no problem of whey precipitation.

[0053] In step 2), the material is generally degassed before homogenization to protect the homogenization equipment. The degassing conditions may be 65° C. and 18 MPa.

[0054] It is understood that in order to ensure that the fermentation process is carried out in a sterile environment, after the fermentation agent is added in the above step 3), the system can also be transferred into a fermentation tank filled with nitrogen through a sterile filtration device.

[0055] Generally, before the second sterilization treatment in step 4) above, the third material can be filled first.

[0056] During filling, the third material can be heated to 65°C before filling. A higher temperature is beneficial to avoid continuous fermentation of the leavening agent and contamination by bacteria, which is beneficial to maintaining high product quality.

[0057] The second sterilization treatment has a sterilization temperature of 90-95°C and a sterilization time of 30-35 minutes, which can effectively kill the microorganisms in the third material, ensure that the product has a thick texture and no granularity, and enable the product to be stored for 6 months at room temperature.

[0058] Hereinafter, the room temperature yogurt and the preparation method thereof of the present invention will be described in more detail through specific examples.

[0059] Example 1

[0060] A room temperature yogurt of the present embodiment includes the following raw materials in terms of total weight of 1000 g:

[0061] Emulsified sodium carboxymethyl cellulose 20g, Streptococcus thermophilus 0.01g, Lactobacillus bulgaricus 0.01g, hydroxypropyl distarch phosphate 3g, gelatin 2g, fructose syrup 30g, sucralose 0.05g, acesulfame potassium 0.3g, the balance is whole milk;

[0062] The method for preparing the room temperature yogurt comprises the following steps:

[0063] 1) At 78°C, 30 g of sodium carboxymethyl cellulose and 2 g of mono- and di-glycerol fatty acid esters were mixed at 2500 r / min for 8 min, with the mass ratio of sodium carboxymethyl cellulose to emulsifier being 15:1, to obtain emulsified sodium carboxymethyl cellulose;

[0064] 2) emulsified sodium carboxymethyl cellulose, hydroxypropyl distarch phosphate, gelatin, fructose syrup, sucralose, acesulfame potassium, and whole milk are mixed, and stirred at 55° C. for 25 minutes to obtain a first material;

[0065] 3) degassing the first material at 65° C. and 18 MPa, homogenizing at a pressure of 30 / 180 bar, and finally sterilizing at 95° C. for 300 s, and cooling to 40-43° C. to obtain a second material;

[0066] 4) adding thermophilic Streptococcus and Bulgarian Lactobacillus to the second material and fermenting, passing through a sterile filtration device into a fermentation tank filled with nitrogen, fermenting at 43° C., and terminating the fermentation when the fermentation acidity is 70° T-75° T to obtain a third material;

[0067] 5) The third material is heated to 65° C. for filling, and then sterilized at 90° C. for 30 min to obtain room temperature yogurt.

[0068] Example 2

[0069] This embodiment is basically the same as Embodiment 1, except that:

[0070] 5 g of hydroxypropyl distarch phosphate, 3 g of gelatin, and the balance is whole milk.

[0071] Example 3

[0072] This example is basically the same as Example 1, except that:

[0073] Step 5) of the preparation method is: heating the third material to 65 °C for filling, and then sterilizing at 95 °C for 35 min to obtain room-temperature yogurt.

[0074] Example 4

[0075] This example is basically the same as Example 1, except that:

[0076] The emulsified carboxymethyl cellulose sodium in the raw materials of room-temperature yogurt is 25 g;

[0077] Step 1) of the preparation method is: at 85 °C, mixing 30 g of carboxymethyl cellulose sodium and 2 g of mono- and diglycerol fatty acid esters at 3500 r / min for 8 min, and the mass ratio of carboxymethyl cellulose sodium to emulsifier is 15:1 to obtain emulsified carboxymethyl cellulose sodium.

[0078] Example 5

[0079] This example is basically the same as Example 1, except that:

[0080] Step 1) of the preparation method is: at 78 °C, mixing 24 g of carboxymethyl cellulose sodium and 2 g of mono- and diglycerol fatty acid esters at 2500 r / min for 8 min, and the mass ratio of carboxymethyl cellulose sodium to emulsifier is 18:1.5 to obtain emulsified carboxymethyl cellulose sodium.

[0081] Example 6

[0082] This example is basically the same as Example 1, except that:

[0083] Step 5) of the preparation method is: heating the third material to 65 °C for filling, and then sterilizing at 85 °C for 20 min to obtain room-temperature yogurt.

[0084] Example 7

[0085] This example is basically the same as Example 1, except that:

[0086] The mass of hydroxypropyl distarch phosphate in the product raw materials is 4 g, and the difference in raw materials is made up with whole milk;

[0087] Step 1) in the preparation method is adjusted to: at 80°C, mix 32 g of sodium carboxymethyl cellulose and 2 g of mono- and diglycerol fatty acid esters at 3000 r / min for 8 min. The mass ratio of sodium carboxymethyl cellulose to the emulsifier is 16:1 to obtain emulsified sodium carboxymethyl cellulose.

[0088] Comparative Example 1

[0089] This comparative example is basically the same as Example 1, with the difference that:

[0090] 2 g of hydroxypropyl distarch phosphate and 1 g of gelatin, with the balance being whole milk.

[0091] Comparative Example 2

[0092] This comparative example is basically the same as Example 1, with the difference that:

[0093] 6 g of hydroxypropyl distarch phosphate and 4 g of gelatin, with the balance being whole milk.

[0094] Comparative Example 3

[0095] This comparative example is basically the same as Example 5, with the difference that:

[0096] Step 1) of the preparation method is: at 73°C, mix 24 g of sodium carboxymethyl cellulose and 2 g of mono- and diglycerol fatty acid esters at 2000 r / min for 6 min. The mass ratio of sodium carboxymethyl cellulose to the emulsifier is 12:1 to obtain emulsified sodium carboxymethyl cellulose.

[0097] Comparative Example 4

[0098] This comparative example is basically the same as Example 1, with the difference that:

[0099] Step 1) of the preparation method is: at 78°C, mix 26 g of sodium carboxymethyl cellulose and 1 g of mono- and diglycerol fatty acid esters at 2500 r / min for 8 min. The mass ratio of sodium carboxymethyl cellulose to the emulsifier is 26:1 to obtain emulsified sodium carboxymethyl cellulose.

[0100] Comparative Example 5

[0101] This comparative example is basically the same as Example 1, with the difference that:

[0102] In the raw materials of the room temperature yogurt, 5 g of hydroxypropyl distarch phosphate is used to replace 3 g of hydroxypropyl distarch phosphate and 2 g of gelatin in Example 1; other conditions remain unchanged.

[0103] Comparative Example 6

[0104] This comparative example is basically the same as Example 1, with the difference that:

[0105] In the raw materials of the room-temperature yogurt, replace 3 g of hydroxypropyl distarch phosphate and 2 g of gelatin in Example 1 with 5 g of emulsifying sodium carboxymethylcellulose; other conditions remain unchanged.

[0106] Test Example

[0107] 1. Detect the following parameters of the products in the above examples and comparative examples:

[0108] 1) Sensory evaluation: Conduct a sensory evaluation of the products according to the sensory evaluation criteria in Table 1. The main evaluation items include tissue state and color, flavor, and taste. A total of 30 people participated in the evaluation. After scoring the three items of tissue state and color, flavor, and taste of the products respectively, the average value was taken for each item according to the evaluators, and then the average scores of the three items were added together as the sensory evaluation score of the product. The specific results are shown in Table 2;

[0109] 2) Whey separation height: After placing the product at 25 °C for 100 days, measure the whey separation height with 100 g of the product as the standard. By placing the product on a horizontal experimental bench and using a ruler to measure the height from the concave liquid surface of the separated whey to the milk base plane, which is the whey separation height. The specific results are shown in Table 3.

[0110] 2. Test results

[0111] Table 1 Sensory evaluation criteria

[0112]

[0113] Table 2 Sensory evaluation results of the products

[0114]

[0115]

[0116] It can be seen from the results in Table 2 that:

[0117] The products in each example have good tissue state, taste, and flavor. There is no whey separation in the products, the characteristic flavor is strong, the aroma is harmonious, the taste is delicate, thick, moderately sweet and sour, and the taste is uniform;

[0118] By comparing each example with each comparative example, it can be seen that the following factors can affect the sensory evaluation of the products:

[0119] 1. Mass ratio of hydroxypropyl distarch phosphate to gelatin: When the mass ratio of hydroxypropyl distarch phosphate to gelatin is (3 - 5):(2 - 3), the product has a strong flavor, harmonious aroma, no whey separation, delicate, thick taste, and moderately sweet and sour. If it exceeds this addition range, whey separation will occur in the final product, affecting the shelf-life stability of the product;

[0120] 2. Process conditions for secondary sterilization: When the conditions for secondary sterilization are a sterilization temperature of 90 - 95°C and 30 - 35 minutes, the product has a strong milk fragrance, harmonious aroma, no whey precipitation, no granular feeling in the product. The secondary sterilization temperature in Example 6 is slightly lower, which will affect the shortening of the product shelf life. If the secondary sterilization conditions exceed the above range, the final product state and flavor with the same shelf life will not meet the development requirements;

[0121] 3. Process conditions for sodium carboxymethyl cellulose emulsification: The emulsification temperature is 78 - 85°C, and the stirring frequency is 2500 - 3500 r / min. To fully emulsify sodium carboxymethyl cellulose, the product can have a strong milk fragrance, harmonious aroma, no whey precipitation, a delicate, thick and smooth texture, and a moderate sweet and sour taste. Further, when the mass of sodium carboxymethyl cellulose is 5 - 40 g and the mass of the emulsifier is 0.5 - 2 g, the mixing time of 8 - 10 minutes can fully emulsify sodium carboxymethyl cellulose and thus achieve the expected emulsification effect. In short, if it exceeds the range of the above emulsification process conditions, the final product state and flavor will not meet the development requirements;

[0122] 4. Difference in the ratio of sodium carboxymethyl cellulose to emulsifier: When sodium carboxymethyl cellulose: emulsifier is (15 - 18):(1 - 1.5), the product has a strong milk fragrance, harmonious aroma, no whey precipitation, a delicate, thick and smooth texture, and a moderate sweet and sour taste. If it exceeds this addition range, the final product state and flavor will not meet the development requirements;

[0123] 5. Synergistic effect of sodium carboxymethyl cellulose, hydroxypropyl distarch phosphate and gelatin: The synergistic effect of sodium carboxymethyl cellulose, hydroxypropyl distarch phosphate and gelatin can effectively avoid the whey precipitation in ambient temperature yogurt, and the effect is better than that of single or the combination of two of them.

[0124] Table 3 Whey precipitation height of the product

[0125]

[0126]

[0127] It can be seen from the results in Table 3 that: The synergistic effect of sodium carboxymethyl cellulose, hydroxypropyl distarch phosphate and gelatin can effectively avoid the whey precipitation in ambient temperature yogurt, improve the product stability, and thus is beneficial to enhancing the flavor and texture of the product, and has a better effect than single or the combination of two of them; When sodium carboxymethyl cellulose: emulsifier is (15 - 18):(1 - 1.5), the product has a strong milk fragrance and no whey precipitation problem. If the addition amount of related raw materials exceeds this range, the product will have a whey precipitation problem and does not meet the product development requirements.

[0128] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A room-temperature yogurt, characterized in that the raw materials of the room-temperature yogurt include, by mass percentage: 1.5-2.5% of emulsified sodium carboxymethyl cellulose, 0.5-0.8% of stabilizer, 0.002%-0.004% of fermenting agent, and the balance is raw milk; wherein, the stabilizer includes hydroxypropyl distarch phosphate and gelatin, and the weight ratio of hydroxypropyl distarch phosphate to gelatin is (3-5):(2-3); the emulsified sodium carboxymethyl cellulose is prepared by at least a method including the following process: at 78-85 °C, sodium carboxymethyl cellulose and an emulsifier are mixed at 2500-3500 r / min, and the mass ratio of the sodium carboxymethyl cellulose to the emulsifier is (15-18):(1-1.5) to obtain the emulsified sodium carboxymethyl cellulose.

2. The room-temperature yogurt according to claim 1, characterized in that the emulsified sodium carboxymethyl cellulose is prepared by at least a method including the following process: at 80 °C, the sodium carboxymethyl cellulose and the emulsifier are mixed at 3000 r / min to obtain the emulsified sodium carboxymethyl cellulose, wherein the mass ratio of the sodium carboxymethyl cellulose to the emulsifier is 16:

1.

3. The room-temperature yogurt according to claim 1 or 2, characterized in that the mass percentage of the emulsified sodium carboxymethyl cellulose in the raw materials of the room-temperature yogurt is 2%.

4. The room-temperature yogurt according to any one of claims 1-3, characterized in that the mass percentage of the stabilizer in the raw materials of the room-temperature yogurt is 0.6%.

5. The room-temperature yogurt according to any one of claims 1-4, characterized in that the weight ratio of the hydroxypropyl distarch phosphate to the gelatin is 2:

1.

6. The room-temperature yogurt according to any one of claims 1-5, characterized in that the emulsifier includes at least one of mono- and diglycerol fatty acid esters and glycerol monolaurate.

7. The room-temperature yogurt according to any one of claims 1-6, characterized in that the raw materials of the room-temperature yogurt further include a sweetening substance.

8. The room-temperature yogurt according to claim 7, characterized in that the sweetening substance includes at least one of fructose, high fructose syrup, maltose, xylitol, acesulfame potassium, aspartame, sucralose and sodium cyclamate.

9. A method for preparing a room-temperature yogurt according to any one of claims 1-8, characterized in that it includes the following steps: 1) Mixing a raw material system including the raw milk with the emulsified sodium carboxymethyl cellulose and the stabilizer to obtain a first material; 2) Homogenizing and performing a first sterilization treatment on the first material to obtain a second material; 3) Adding the fermenting agent to the second material and performing fermentation, and terminating the fermentation when the fermentation acidity is 70°T - 75°T to obtain a third material; 4) Performing a second sterilization treatment on the third material to obtain the room-temperature yogurt.

10. The preparation method according to claim 9, characterized in that the sterilization temperature of the above-mentioned second sterilization treatment is 90-95 °C, and the sterilization time is 30-35 min.

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