Additive-free solidified cocoa layered low-sugar yoghourt and preparation method thereof

Abstract

The invention discloses a preparation method of additive-free solidified cocoa layered low-sugar yoghourt. In the preparation process of the additive-free solidification type layered low-sugar cocoa yoghurt, the part added with the cocoa powder is not homogenized, so that the prepared layered low-sugar cocoa yoghurt is coordinated in flavor while the content of white granulated sugar is less than 6.5%, the bitter taste of the cocoa powder does not appear in the product, and the layered low-sugar cocoa yoghurt has the unique fragrance of cocoa and the unique nutrition of yoghurt; meanwhile, the cocoa layered low-sugar yoghourt prepared according to the preparation method has obvious layering, and a thick cocoa coating can be formed.

Description

Technical Field

[0001] The invention relates to the technical field of fermented foods, and in particular to an additive-free solidified cocoa layered low-sugar yogurt and a preparation method thereof. Background Art

[0002] Yogurt is a popular fermented dairy product with a unique flavor and rich nutrition. The active lactic acid bacteria it contains also have health benefits. As a sweet and sour milk drink, it is made from milk, which is pasteurized and then added with beneficial bacteria (fermentation agent), and then cooled and bottled after fermentation.

[0003] Chocolate has a unique taste and is rich in various nutrients. It has the functions of regulating mood, relieving stress, anti-oxidation and anti-cancer. It is one of the most popular snacks. With the change of dietary concepts, people pay more and more attention to dietary health. Developing "healthy + sustainable" chocolate products with new flavors has become the main direction of new product research.

[0004] Yogurt is rich in nutrition and easy to digest and absorb, and is deeply loved by consumers. Combining cocoa and yogurt can enrich the flavor of yogurt and increase the nutritional content of cocoa. Due to the low melting point and high fat content of chocolate raw materials, the combination of chocolate and yogurt has certain technical difficulties. In the prior art "A Chocolate Yogurt", liquid cocoa yogurt is prepared by adding multiple food additives to the formula; in the prior art "Response Surface Method Optimization of Cocoa-Type Solidified Yogurt Formula", the amount of white sugar added in the optimal formula screened by BBD design is 10.31%. The cocoa-type yogurt prepared in the prior art usually contains a large amount of food additives, and usually needs to add more than 6.5% of white sugar to reduce the bitterness brought by cocoa powder, which does not meet the concept of health of modern people.

[0005] Therefore, a cocoa-type yogurt without adding food additives and with lower added amount of white granulated sugar is urgently needed. Summary of the invention

[0006] The purpose of the present invention is to overcome the above-mentioned shortcomings of the prior art and provide a non-additive solidified cocoa layered low-sugar yogurt and a preparation method thereof.

[0007] The first object of the present invention is to provide a method for preparing a non-additive solidified cocoa layered low-sugar yogurt.

[0008] The second object of the present invention is to provide cocoa layered low-sugar yogurt prepared by the above preparation method.

[0009] In order to achieve the above object, the present invention is implemented by the following scheme:

[0010] The present invention claims a method for preparing a non-additive solidified cocoa layered low-sugar yogurt, which comprises the following steps, measured by weight:

[0011] S1. 450 to 490 parts of milk are heated to 45 to 55° C., 10 to 50 parts of sweetener are added, and the mixture is thoroughly mixed to obtain material A;

[0012] Heat 475-495 parts of milk to 45-55° C., add 5-25 parts of cocoa powder and mix thoroughly to obtain material B;

[0013] S2. Homogenize the material A obtained in step S1 to obtain a homogenous material C;

[0014] S3. The homogenized material C obtained in step S2 and the material B are mixed and sterilized to obtain material D;

[0015] S4. The temperature of the material D obtained in step S3 is controlled to be 38 to 40°C, and 0.02 to 0.2 parts of the fermentation bacteria are added thereto to obtain a fermentation substrate E;

[0016] The fermentation bacteria are Lactococcus cremoris, Lactococcus lactis subsp. lactis and / or Streptococcus salivarius subsp. thermophilus;

[0017] S5. The fermentation substrate E obtained in step S4 is fully fermented to obtain yogurt F; the yogurt F is refrigerated and then ripened to obtain cocoa layered low-sugar yogurt.

[0018] Preferably, the milk in step S1 is raw milk.

[0019] Preferably, the sweetener in step S1 is white sugar.

[0020] Preferably, the homogenization in step S2 is: homogenizing at a homogenization temperature of 60 to 70° C. and controlling the homogenization pressure to 25 to 30 MPa.

[0021] More preferably, the homogenization in step S2 is: homogenizing at a homogenization temperature of 65° C. and controlling the homogenization pressure to 25 MPa.

[0022] Preferably, the sterilization in step S3 is specifically: sterilization at 90-95° C. for 15-300 s.

[0023] More preferably, the sterilization in step S3 is specifically: sterilization at 95° C. for 300 s.

[0024] Preferably, the fermentation bacteria in step S4 are Lactococcus cremoris, Lactococcus lactis subsp. lactis and Streptococcus salivarius subsp. thermophilus in a mass ratio of 1-6:1-6:1-8.

[0025] More preferably, the fermentation bacteria in step S4 are Lactococcus cremoris, Lactococcus lactis subsp. lactis and Streptococcus salivarius subsp. thermophilus in a mass ratio of 3:3:4.

[0026] Further preferably, the fermentation bacteria is XPL-40 starter culture, purchased from Chr. Hansen (Beijing) Trading Co., Ltd. with product number 709680.

[0027] Preferably, the sufficient fermentation in step S5 is specifically: fermenting at 38-40° C. for 6-8 hours.

[0028] More preferably, the sufficient fermentation in step S5 is specifically: fermentation at 38° C. for 7.5 hours.

[0029] Preferably, the refrigeration in step S5 is refrigeration at 4°C.

[0030] Preferably, the post-ripening in step S5 is for 12 to 24 hours.

[0031] The present invention also claims protection for the cocoa layered low-sugar yogurt prepared by the preparation method.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The present invention provides a method for preparing a non-additive coagulated cocoa layered low-sugar yogurt. In the preparation process of the non-additive coagulated cocoa layered low-sugar yogurt, the part to which cocoa powder is added is not homogenized, so that the prepared cocoa layered low-sugar yogurt has a harmonious flavor while ensuring that the white sugar content is less than 6.5%, and the product has no bitter taste of cocoa powder and has both the unique aroma of cocoa and the unique nutrition of yogurt; at the same time, the cocoa layered low-sugar yogurt prepared according to the preparation method has obvious layers and can form a thick cocoa coating. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a diagram of the layered observation results of cocoa layered low-sugar yogurt 1, cocoa layered low-sugar yogurt 2, cocoa layered low-sugar yogurt 3, cocoa yogurt 1 and cocoa yogurt 2 in Test Example 1. DETAILED DESCRIPTION

[0035] The present invention is further described in detail below in conjunction with the accompanying drawings and specific examples of the specification. The examples are only used to explain the present invention and are not used to limit the scope of the present invention. The test methods used in the following examples are conventional methods unless otherwise specified; the materials and reagents used are reagents and materials that can be obtained from commercial channels unless otherwise specified.

[0036] The raw milk used in the embodiments of the present invention was purchased from Pucheng Dairy Chengde Co., Ltd.;

[0037] The fermentation strain used in the embodiment of the present invention is XPL-40 starter, purchased from Chr. Hansen (Beijing) Trading Co., Ltd., with item number 709680, which contains Lactococcus cremoris, Lactococcus lactis subsp. lactis and Streptococcus salivarius subsp. thermophilus in a mass ratio of 3:3:4.

[0038] Example 1 A non-additive cocoa layered low-sugar yogurt

[0039] 1. Components of Cocoa Layered Low-Sugar Yogurt 1

[0040] A non-additive solidified cocoa layered low-sugar yogurt 1, comprising: 960g of raw milk, 10g of natural cocoa powder, 30g of white sugar and 0.1g of fermentation bacteria.

[0041] 2. Preparation method of cocoa layered low-sugar yogurt 1

[0042] The preparation method of cocoa layered low-sugar yogurt 1 comprises the following steps:

[0043] S1. Heat 470g of raw milk to 45-55°C, add 30g of white sugar, mix well and keep warm for 45-60 minutes to obtain material A. 1 ;

[0044] Next, 490 g of raw milk was heated to 45-55°C, 10 g of natural cocoa powder was added thereto, the mixture was fully mixed and kept warm for 45-60 minutes to obtain material B. 1 ;

[0045] S2. Material A obtained in step S1 1 The mixture was homogenized under the conditions of 65°C and 25 MPa to obtain homogenous material C. 1 ;

[0046] S3. The homogenized material C obtained in step S2 1 and material B obtained in step S1 1 After mixing evenly, sterilize at 95℃ for 300s to obtain material D 1 ;

[0047] S4. The material D obtained in step S3 1 The temperature was controlled to 38°C, and 0.1 g of fermentation bacteria was added to obtain fermentation substrate E. 1 ;

[0048] S5. The fermentation substrate E obtained in step S4 1 Fill the container and place it in a 38°C incubator for fermentation for 7.5 hours to obtain yogurt F. 1 ;

[0049] Yogurt F 1 The mixture is stored in a refrigerator at 4°C and ripened for 12 to 24 hours to obtain cocoa layered low-sugar yogurt 1.

[0050] Example 2 A non-additive cocoa layered low-sugar yogurt

[0051] 1. Components of Cocoa Layered Low-Sugar Yogurt 2

[0052] A non-additive solidified cocoa layered low-sugar yogurt 2, comprising: 955g of raw milk, 15g of natural cocoa powder, 30g of white sugar and 0.1g of fermentation bacteria.

[0053] 2. Preparation method of cocoa layered low-sugar yogurt 2

[0054] The preparation method of cocoa layered low-sugar yogurt 2 comprises the following steps:

[0055] S1. Heat 470g of raw milk to 45-55°C, add 30g of white sugar, mix well and keep warm for 45-60 minutes to obtain material A. 2 ;

[0056] Next, 485 g of raw milk was heated to 45-55°C, and 15 g of natural cocoa powder was added thereto. The mixture was fully mixed and kept warm for 45-60 minutes to obtain material B. 2 ;

[0057] S2. Material A obtained in step S1 2 The mixture was homogenized under the conditions of 65°C and 25 MPa to obtain homogenous material C. 2 ;

[0058] S3. The homogenized material C obtained in step S2 2 and material B obtained in step S1 2 After mixing evenly, sterilize at 95℃ for 300s to obtain material D 2 ;

[0059] S4. The material D obtained in step S3 2 The temperature was controlled to 38°C, and 0.1 g of fermentation bacteria was added to obtain fermentation substrate E. 2 ;

[0060] S5. The fermentation substrate E obtained in step S4 2 Fill the container and place it in a 38°C incubator for fermentation for 7.5 hours to obtain yogurt F.2 ;

[0061] Yogurt F 2 The mixture is stored in a refrigerator at 4°C and after ripening for 12 to 24 hours, cocoa layered low-sugar yogurt 2 is obtained.

[0062] Example 3 A non-additive cocoa layered low-sugar yogurt

[0063] 1. Components of Cocoa Layered Low-Sugar Yogurt 3

[0064] A non-additive solidified cocoa layered low-sugar yogurt 3, comprising: 970g of raw milk, 10g of natural cocoa powder, 20g of white sugar and 0.1g of fermentation bacteria.

[0065] 2. Preparation method of cocoa layered low-sugar yogurt 3

[0066] The preparation method of cocoa layered low-sugar yogurt 3 comprises the following steps:

[0067] S1. Heat 480g of raw milk to 45-55°C, add 20g of white sugar, mix thoroughly and keep warm for 45-60 minutes to obtain material A. 3 ;

[0068] Next, 490 g of raw milk was heated to 45-55°C, 10 g of natural cocoa powder was added thereto, the mixture was fully mixed and kept warm for 45-60 minutes to obtain material B. 3 ;

[0069] S2. Material A obtained in step S1 3 The mixture was homogenized under the conditions of 65°C and 25 MPa to obtain homogenous material C. 3 ;

[0070] S3. The homogeneous material C obtained in step S2 3 and material B obtained in step S1 3 After mixing evenly, sterilize at 95℃ for 300s to obtain material D 3 ;

[0071] S4. The material D obtained in step S3 3 The temperature was controlled to 38°C, and 0.1 g of fermentation bacteria was added to obtain fermentation substrate E. 3 ;

[0072] S5. The fermentation substrate E obtained in step S4 3 Fill the container and place it in a 38°C incubator for fermentation for 7.5 hours to obtain yogurt F. 3 ;

[0073] Yogurt F 3The mixture is stored in a refrigerator at 4°C and ripened for 12 to 24 hours to obtain cocoa layered low-sugar yogurt 3.

[0074] Comparative Example 1: a cocoa yogurt

[0075] 1. Components of Cocoa Yogurt 1

[0076] A cocoa yogurt 1 comprises: 960g of raw milk, 10g of natural cocoa powder, 30g of white sugar and 0.1g of fermentation bacteria.

[0077] 2. Preparation method of cocoa yogurt 1

[0078] The preparation method of cocoa yogurt 1 comprises the following steps:

[0079] S1. After heating 960g of raw milk to 45-55°C, add 30g of white sugar and 10g of natural cocoa powder, mix well, and keep warm for 45-60 minutes to obtain material A. 4 ;

[0080] S2. The material A obtained in step S1 is fully homogenized under the homogenization conditions of 65°C and 25MPa to obtain a homogenous material B. 4 ;

[0081] S3. The homogeneous material B obtained in step S2 4 After sterilization at 95℃ for 300s, material C was obtained. 4 ;

[0082] S4. The material C obtained in step S3 4 The temperature was controlled to 38°C, and 0.1 g of fermentation bacteria was added to obtain fermentation substrate D 4 ;

[0083] S5. The fermentation substrate D obtained in step S4 4 Fill the container and place it in a 38°C incubator for fermentation for 7.5 hours to obtain yogurt E. 4 ;

[0084] Yogurt E 4 The mixture was stored in a refrigerator at 4° C. and after ripening for 12 to 24 hours, cocoa yogurt 1 was obtained.

[0085] Comparative Example 2: a cocoa yogurt

[0086] 1. Components of Cocoa Yogurt 2

[0087] A cocoa yogurt 2, comprising: 910g of raw milk, 10g of natural cocoa powder, 80g of white sugar and 0.1g of fermentation bacteria.

[0088] 2. Preparation method of cocoa yogurt 2

[0089] The preparation method of cocoa yogurt 2 comprises the following steps:

[0090] S1. After heating 910g of raw milk to 45-55°C, add 80g of white sugar and 10g of natural cocoa powder, mix well and keep warm for 45-60 minutes to obtain material A. 5 ;

[0091] S2. Material A obtained in step S1 5 Homogenize thoroughly at 65°C and 25MPa to obtain homogenous material B. 5 ;

[0092] S3. The homogeneous material B obtained in step S2 5 After sterilization at 95℃ for 300s, material C was obtained. 5 ;

[0093] S4. The material C obtained in step S3 5 The temperature was controlled to 38°C, and 0.1 g of fermentation bacteria was added to obtain fermentation substrate D 5 ;

[0094] S5. The fermentation substrate D obtained in step S4 5 Fill the container and place it in a 38°C incubator for fermentation for 7.5 hours to obtain yogurt E. 5 ;

[0095] Yogurt E 5 The mixture was stored in a refrigerator at 4° C. and after ripening for 12 to 24 hours, cocoa yogurt 2 was obtained.

[0096] Test Example 1: Test of Cocoa Yogurt

[0097] 1. Experimental Methods

[0098] 1. pH and acidity testing

[0099] The pH values ​​of the cocoa layered low-sugar yogurt 1 prepared in Example 1, the cocoa layered low-sugar yogurt 2 prepared in Example 2, the cocoa layered low-sugar yogurt 3 prepared in Example 3, the cocoa yogurt 1 prepared in Comparative Example 1, and the cocoa yogurt 2 prepared in Comparative Example 2 were measured using a pH meter, and the acidity of the yogurt was measured according to the national standard GB 5009.239-2016.

[0100] 2. Sensory evaluation test

[0101] 30 people were randomly selected as testers, and sensory evaluation was performed on the cocoa layered low-sugar yogurt 1 prepared in Example 1, the cocoa layered low-sugar yogurt 2 prepared in Example 2, the cocoa layered low-sugar yogurt 3 prepared in Example 3, the cocoa yogurt 1 prepared in Comparative Example 1, and the cocoa yogurt 2 prepared in Comparative Example 2 for texture (fineness and freshness) and taste and flavor (base sweet and sour ratio and bitterness); 2 hours before the sensory evaluation test, the testers did not eat spicy or overly strong-flavored foods, and also avoided smoking cigarettes, and rinsed their mouths with clean water before tasting different yogurts; the sensory evaluation test method is shown in Table 1.

[0102] Table 1 Sensory evaluation test methods

[0103]

[0104] Note: The sensory evaluation score can be a decimal, such as 5.6.

[0105] The evaluation results of all testers on the same sensory evaluation index of the same yogurt were summed up and the average value was taken as the sensory evaluation result.

[0106] 3. Layered Observation Test

[0107] The cocoa layered low-sugar yogurt 1 prepared in Example 1, the cocoa layered low-sugar yogurt 2 prepared in Example 2, the cocoa layered low-sugar yogurt 3 prepared in Example 3, the cocoa yogurt 1 prepared in Comparative Example 1, and the cocoa yogurt 2 prepared in Comparative Example 2 were respectively placed in a refrigerator at 4° C. for 12 hours and photographed for observation.

[0108] 2. Experimental Results

[0109] 1. pH and acidity test results

[0110] The pH value and acidity test results of yogurt are shown in Table 1.

[0111] Table 1 pH value and acidity test results

[0112]

[0113] The results showed that there was basically no significant difference in acidity and pH value among the cocoa layered low-sugar yogurt 1 prepared in Example 1, the cocoa layered low-sugar yogurt 2 prepared in Example 2, the cocoa layered low-sugar yogurt 3 prepared in Example 3, the cocoa yogurt 1 prepared in Comparative Example 1, and the cocoa yogurt 2 prepared in Comparative Example 2, indicating that homogenizing and inhomogenizing the raw materials will not affect the acidity of the yogurt.

[0114] 2. Sensory evaluation test results

[0115] The sensory evaluation test results of cocoa layered low-sugar yogurt 1, cocoa layered low-sugar yogurt 2, cocoa layered low-sugar yogurt 3, cocoa yogurt 1 and cocoa yogurt 2 are shown in Table 2.

[0116] Table 2 Sensory evaluation results

[0117]

[0118] The results showed that the fineness of cocoa layered low-sugar yogurt 1, cocoa layered low-sugar yogurt 2, cocoa layered low-sugar yogurt 3, cocoa yogurt 1 and cocoa yogurt 2 was basically the same; as for the freshness, bitterness, sweet-sour ratio and overall evaluation, because the amount of white sugar added in the preparation of cocoa yogurt 2 in Comparative Example 2 reached 8% (w / w), they all showed a trend of cocoa yogurt 2>cocoa layered low-sugar yogurt 1>cocoa layered low-sugar yogurt 2=cocoa layered low-sugar yogurt 3>cocoa yogurt 1; and the cocoa layered low-sugar yogurt prepared in Example 1 had a better sweet-sour ratio and weaker bitterness under the same pH and acidity (compared with cocoa yogurt 1), indicating that under low-sugar conditions (the amount of white sugar added was 3%), the sensory evaluation of the yogurt prepared according to the method shown in Example 1 was better.

[0119] 3. Layered observation test results

[0120] The stratified observation results of cocoa layered low-sugar yogurt 1, cocoa layered low-sugar yogurt 2, cocoa layered low-sugar yogurt 3, cocoa yogurt 1 and cocoa yogurt 2 are shown in the figure. Figure 1 As shown, a is cocoa yogurt 1, b is cocoa yogurt 2, c is cocoa layered low-sugar yogurt 1, d is cocoa layered low-sugar yogurt 2, and e is cocoa layered low-sugar yogurt 3. The results show that under the same formula, the cocoa yogurts 1 and 2 prepared in Comparative Examples 1 and 2 will not produce stratification. Only by following the methods shown in Examples 1, 2, and 3 can cocoa layered low-sugar yogurts with stratification effect be prepared, and a thick cocoa coating is formed on the lower layer, so that the yogurt has the taste of both yogurt and cocoa sauce.

[0121] 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 the protection scope of the present invention. For ordinary technicians in this field, other different forms of changes or modifications can be made based on the above descriptions and ideas. It is not necessary and impossible to list all the implementation methods here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A method for preparing a non-additive cocoa layered low-sugar yogurt, characterized in that: Calculated by weight, the process comprises the following steps: S1. 450 to 490 parts of milk are heated to 45 to 55° C., 10 to 50 parts of sweetener are added, and the mixture is thoroughly mixed to obtain material A; Heat 475-495 parts of milk to 45-55° C., add 5-25 parts of cocoa powder and mix thoroughly to obtain material B; S2. Homogenize the material A obtained in step S1 to obtain a homogenous material C; S3. The homogenized material C obtained in step S2 and the material B are mixed and sterilized to obtain material D; S4. The temperature of the material D obtained in step S3 is controlled to be 38 to 40°C, and 0.02 to 0.2 parts of the fermentation bacteria are added thereto to obtain a fermentation substrate E; The fermentation bacteria are Lactococcus cremoris, Lactococcus lactis subsp. lactis and / or Streptococcus salivarius subsp. thermophilus; S5. The fermentation substrate E obtained in step S4 is fully fermented to obtain yogurt F; the yogurt F is refrigerated and then ripened to obtain cocoa layered low-sugar yogurt.

2. The preparation method according to claim 1, characterized in that: The homogenization in step S2 is: homogenizing at a homogenization temperature of 60 to 70° C. and controlling the homogenization pressure to 25 to 30 MPa.

3. The preparation method according to claim 2, characterized in that: The homogenization in step S2 is: homogenization is performed at a homogenization temperature of 65° C. and a homogenization pressure of 25 MPa.

4. The preparation method according to claim 1, characterized in that: The sterilization in step S3 is specifically: sterilization at 90-95° C. for 15-300 seconds.

5. The preparation method according to claim 4, characterized in that: The sterilization in step S3 is specifically: sterilization at 95° C. for 300 seconds.

6. The preparation method according to claim 1, characterized in that: The fermentation bacteria in step S4 are Lactococcus cremoris, Lactococcus lactis subsp. lactis and Streptococcus salivarius subsp. thermophilus in a mass ratio of 1-6:1-6:1-8.

7. The preparation method according to claim 6, characterized in that: The fermentation bacteria in step S4 are Lactococcus cremoris, Lactococcus lactis subsp. lactis and Streptococcus salivarius subsp. thermophilus in a mass ratio of 3:3:

4.

8. The preparation method according to claim 1, characterized in that: The sufficient fermentation in step S5 specifically includes: fermenting at 38-40° C. for 6-8 hours.

9. The preparation method according to claim 8, characterized in that: The sufficient fermentation in step S5 specifically includes: fermenting at 38° C. for 7.5 hours.

10. Cocoa layered low-sugar yogurt prepared by the preparation method according to any one of claims 1 to 9.

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