Normal-temperature wiredrawing yoghurt and preparation method thereof

Abstract

The invention belongs to the technical field of preparation of wiredrawing yoghurt, and particularly relates to normal-temperature wiredrawing yoghurt and a preparation method thereof.The normal-temperature wiredrawing yoghurt is prepared from glutinous rice starch, cassava starch and carboxymethyl cellulose in a specific proportion, all the raw materials take effect synergistically, a multi-element stable system is constructed, and the wiredrawing structure of the yoghurt is achieved; the addition of various strains to contribute the exopolysaccharides is not needed. The wire drawing system formed by the scheme has heat resistance and shear resistance, can realize production of normal-temperature wire drawing yogurt products, is suitable for long-shelf-life storage and is very friendly to people who do not tolerate low-temperature foods. The problems of limited eating scene, process intolerance and the like of the traditional wiredrawing yoghurt are broken through, so that the yoghurt product can maintain good wiredrawing performance and stability under the condition of normal temperature.

Description

Technical Field

[0001] The invention belongs to the technical field of drawing yogurt preparation, and in particular relates to room-temperature drawing yogurt and a preparation method thereof. Background Art

[0002] Wiredrawn yogurt is a yogurt product with a long sticky structure. It has strong adhesion and good ductility. It is widely used in fruit salad, table sauces and baked fillings, and is deeply loved by consumers. At present, manufacturers of wiredrawn yogurt usually use lactic acid bacteria with high extracellular polysaccharide production to ferment the product. The metabolites produced during the microbial fermentation process produce large molecular extracellular polysaccharides to make the product obtain a longer wiredrawn structure. However, the use scenarios of this type of wiredrawn yogurt are very limited. First of all, the wiredrawn yogurt currently on the market is low-temperature yogurt, which needs to be stored at around 4°C. If the lactic acid bacteria continue to ferment and produce lactic acid after defrosting, the pH of the system will drop to around 3.4-4.0. The high-strength acid will seriously damage the extracellular polysaccharide structure, causing the wiredrawn yogurt structure to collapse and lose its wiredrawing performance. Secondly, the consumption temperature of low-temperature wiredrawn yogurt is low, which is not friendly to children and the elderly with delicate spleen and stomach, as well as special groups who are intolerant to low-temperature products, thus affecting the sales of the product. The extracellular polysaccharides produced by the final fermentation bacteria are usually large molecular polysaccharides with poor heat resistance. After high-temperature shearing, their wire drawing structure will be severely damaged and they cannot be heated and eaten.

[0003] For example, Chinese patent document CN114190434A discloses a private chef wire drawing yogurt and a preparation method thereof, wherein the method first filters raw milk through an RO membrane until the milk protein content is 4.0-4.8wt%, the obtained concentrated milk is homogenized at 0-200 bar, stirred, sterilized, and cooled in sequence, a fermentation agent is added, and fermented to a pH of 4.6-4.8, and then stirred and demulsified at a speed of 300-600 r / min, and the private chef wire drawing yogurt is obtained by post-ripening for more than 12 hours; wherein the fermentation agent is composed of thermophilic streptococcus and bulgaricus lactobacillus, and the dosage ratio of the thermophilic streptococcus to the bulgaricus lactobacillus is 1×10 11 CFU: 2.1×10 7 ~5.2×10 7 The prepared yogurt not only has excellent texture, taste, flavor and high extracellular polysaccharide content, but also has strong wire drawing properties.

[0004] Chinese patent document CN113678893A discloses a wire-drawn yogurt and a preparation method thereof, comprising the following steps: S1. fresh milk is centrifuged to separate the milk fat, and the remaining skim milk is sterilized, canned, and refrigerated; S2. the milk fat is preheated and then added into a mixture of white sugar and protein powder for the first material disintegration, after the first material disintegration, the milk fat is preheated for the first time, and then a dry mixture of white sugar and a stabilizer is added for the second material disintegration, after the second material disintegration, the milk fat is preheated for the second time, sweetened condensed milk and light cream are added for the third material disintegration after preheating, homogenized after the third material disintegration, and sterilized after homogenization; S3. the sterilized material is cooled and inoculated, stirring is started after inoculation, and filling is performed after stirring evenly; S4. the filling material is fermented, and the temperature is cooled and refrigerated after fermentation.

[0005] Chinese patent document CN116769673 discloses a strain of fermentative lactobacillus A51 that produces high extracellular polysaccharides, and its preservation number is CCTCC NO: M2023861. The strain can produce high extracellular polysaccharides, including fucose, galactose, glucose, mannose and galacturonic acid. The strain can be used to produce stringy yogurt and cheese-flavored stringy yogurt; the strain has weak post-acidification ability, and the acidity value after fermenting milk for 12 hours is 72T; in addition, the strain can significantly improve the viscosity value, water holding rate and adhesion properties of yogurt, improve the texture of yogurt, and give yogurt stringy properties. The strain and commercial starter are combined to prepare yogurt, and the resulting yogurt has a fine texture, high viscosity, good stringiness, a string length of 35-60 cm, and a strong cheese flavor.

[0006] Chinese patent document CN118374418A discloses a composition of Leuconostoc mesenteroides YM1 and Lactobacillus kefir NK1, and its application and a kind of drawing yogurt. By using Leuconostoc mesenteroides YM1 and Lactobacillus kefir NK1, a drawing yogurt with high water holding capacity, strong stability, uniform and delicate taste, rich aroma, moderate sourness and sweetness, and long drawing is prepared. The drawing yogurt preparation method is safe and green, and the prepared drawing yogurt has a high content of extracellular polysaccharides, is deeply loved by consumers, and has broad application prospects.

[0007] Chinese patent document CN116195634A provides a method for improving the stringiness of yogurt, comprising the following steps: mixing milk raw materials with polysaccharides, homogenizing and sterilizing, adding a fermentation agent for fermentation, and performing intermittent stirring during the fermentation process to obtain a high stringiness yogurt. Compared with the prior art, intermittent stirring and shearing during the fermentation process can avoid the influence of casein coagulation on the production of extracellular polysaccharides by the fermentation agent, and at the same time, adding polysaccharides to the fermentation system promotes the secretion of extracellular polysaccharides by the fermentation agent, and doubly improves the production of extracellular polysaccharides by the fermentation agent, so that the stringiness of yogurt can be improved when using conventional fermentation agents for fermentation, thereby making the obtained high stringiness yogurt thick and delicate, and the quality is more stable during the shelf life.

[0008] The above-mentioned drawn yogurts are all low-temperature drawn yogurts. How to break through the limitations of low-temperature storage and consumption of traditional drawn yogurts and provide a room-temperature drawn yogurt that maintains good stability and drawing performance under room temperature conditions is a technical problem that needs to be solved urgently in this field. Summary of the invention

[0009] To this end, the present invention aims to solve the defect that the existing wire drawing yogurt cannot maintain good wire drawing performance and stability under normal temperature conditions, and further provide a room temperature wire drawing yogurt and a preparation method thereof.

[0010] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows: The invention provides a room-temperature drawn yogurt, the raw materials of which include a stabilizer composition, a milk base and a starter; the stabilizer composition includes physically modified starch and carboxymethyl cellulose in a mass ratio of 15-23:1-4, the physically modified starch includes glutinous rice starch and cassava starch in a mass ratio of 10-15:4.5-8; the mass ratio of the milk base to the stabilizer composition is 883-916:16-27.

[0011] Further, the mass ratio of the physically modified starch to the carboxymethyl cellulose is 18-20:3; and / or the mass ratio of the glutinous rice starch to the cassava starch is 12:6-8; Furthermore, the mass ratio of the milk base to the stabilizer composition is 892.5-894.5:21-23; and / or, based on the mass of raw materials other than the starter in the room temperature wire drawing yogurt, the amount of the starter is 200-300 dcu / ton.

[0012] Furthermore, the milk base is selected from one or more of raw cow's milk, whole milk powder, skim milk powder and whey protein powder; and / or the starter is selected from one or more of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus.

[0013] Furthermore, based on the mass of raw materials other than the starter in the room temperature wire drawing yogurt, the starter includes 120-180 dcu / ton of Lactobacillus delbrueckii subsp. bulgaricus and 80-120 dcu / ton of Streptococcus salivarius subsp. thermophilus.

[0014] Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus were both commercially available conventional strains.

[0015] Furthermore, the raw materials of the room temperature wire drawing yogurt also include one or more of sweeteners, oils and fats, and egg yolk powder.

[0016] Furthermore, the sweetener is selected from one or more of white sugar, sucrose, glucose, lactose, maltose, fructose, fructose syrup, glucose syrup, maltose syrup, maltodextrin, sugar alcohol, cyclamate, aspartame, sucralose, honey, acesulfame potassium, and neotame; and / or the fat includes one or more of light cream, fermented light cream, and butter.

[0017] Furthermore, the mass ratio of the milk base to the sweetener is 883-916:30-60; and / or, the mass ratio of the milk base to the oil is 883-916:8-10; and / or, the mass ratio of the milk base to the egg yolk powder is 883-916:1-2.

[0018] The present invention also provides a method for preparing room temperature wire drawing yogurt, comprising the steps of mixing raw materials except a starter, homogenizing, sterilizing once, adding a starter to ferment, demulsifying, cooling, and sterilizing twice to obtain the yogurt.

[0019] Further, the homogenization temperature is 60-63°C, including primary homogenization and secondary homogenization, the pressure of the primary homogenization is 150-200 bar, and the pressure of the secondary homogenization is 50-70 bar; and / or, the sterilization temperature of the primary sterilization is 120-135°C, and the time is 3-5s; and / or, the fermentation temperature is 40-44°C; and / or, the demulsification speed is 80-100r / min, and the time is 5-8min; and / or, the sterilization temperature of the secondary sterilization is 75-80°C, and the time is 10-20s.

[0020] Furthermore, the milk base material further comprises a step of concentrating the milk base material to a protein content of 3.5-4.0% before mixing.

[0021] Compared with the prior art, the present invention has the following beneficial effects: (1) The room temperature drawn yogurt provided by the present invention comprises a stabilizer composition, a milk base and a fermentation agent; the stabilizer composition comprises physically modified starch and carboxymethyl cellulose in a mass ratio of 15-23:1-4, and the physically modified starch comprises glutinous rice starch and tapioca starch in a mass ratio of 10-15:4.5-8; the mass ratio of the milk base to the stabilizer composition is 883-916:16-27, and the stabilizer composition comprising glutinous rice starch, tapioca starch and carboxymethyl cellulose is added to other yogurt raw materials. Under the above-mentioned specific ratio, the raw materials are synergistically effective, and a multi-stabilization system is constructed to achieve the drawing structure of the yogurt, without adding a variety of bacteria to contribute extracellular polysaccharides. The drawing system formed by this scheme is heat-resistant and shear-resistant, and can realize the production of room temperature drawn yogurt products. It is suitable for long shelf life storage and is very friendly to people who are intolerant to low-temperature foods. It breaks through the problems of limited consumption scenarios of traditional drawn yogurt and process intolerance, so that the yogurt product can maintain good drawing performance and stability under room temperature conditions.

[0022] (2) The room temperature wire drawing yogurt provided by the present invention can better improve the wire drawing performance of the yogurt by controlling the mass ratio of the physically modified starch to the carboxymethyl cellulose to be 18-20:3; or the mass ratio of the glutinous rice starch to the tapioca starch to be 12:6-8.

[0023] (3) The room temperature wire drawing yogurt provided by the present invention can better improve the wire drawing performance of the yogurt by controlling the mass ratio of the milk base material to the stabilizer composition to 892.5-894.5:21-23. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the specific implementation methods or the description of the prior art. It is obvious that the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 This is a drawing effect display diagram of the room temperature drawing yogurt prepared in Example 1; Figure 2 is a schematic diagram of a yogurt stringing test device used in Experimental Example 1; 1. Liquid storage component; 2. Camera component; 3. Computer. DETAILED DESCRIPTION

[0026] The technical solution of the present invention is described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] Example 1 This embodiment provides a stabilizer composition, including: 12 kg of glutinous rice starch, 6 kg of cassava starch, and 3 kg of carboxymethyl cellulose.

[0028] The present embodiment provides a room temperature drawn yogurt and a preparation method thereof, wherein the raw materials include the following components: 894.5 kg of raw milk, 60 kg of white sugar, 21 kg of the stabilizer composition of the present embodiment, 8 kg of light cream, 1.5 kg of egg yolk powder, and 250 dcu of starter (150 dcu of Lactobacillus delbrueckii subsp. bulgaricus and 100 dcu of Streptococcus salivarius thermophilus).

[0029] The method for preparing the room temperature drawn yogurt comprises the following steps: (1) Raw milk concentration: Raw milk that has passed the antibiotic test is concentrated through an RO membrane to a protein content of 4.0%.

[0030] (2) Chemical ingredients: The concentrated raw milk is heated to 45°C on a hot plate and then directly beaten into a mixing tank. White sugar, glutinous rice starch, tapioca starch, carboxymethyl cellulose and egg yolk powder are mixed evenly and added to the mixing tank. The mixture is stirred at a speed of 500 rpm for 15 minutes, and then the cream is added to the mixture and stirred at the same speed for 10 minutes to obtain a mixed liquid.

[0031] (3) Homogenization: The mixed liquid in step (2) is heated to 62°C and then homogenized with a primary pressure of 200 bar and a secondary pressure of 50 bar.

[0032] (4) Sterilization and cooling: The homogenized mixed liquid is sterilized at 130°C for 5 seconds, and the liquid temperature is quickly reduced to 32°C through a cold water plate exchanger.

[0033] (5) Fermentation and demulsification: The fermentation agent was inoculated into the slurry of step (4) at a rate of 250 dcu / ton. The fermentation temperature was 43°C. The pH of the slurry was ≤ 4.3 and the acidity was > 75°T. Demulsification could be performed at the end of the fermentation. The demulsification speed was 100 rpm for 5 min, and the slurry temperature was lowered to 25°C.

[0034] (6) Secondary sterilization and canning: The demulsified liquid is heated at a speed of 120r / min and a temperature of 75°C for 15s, and then cooled to 25°C for canning. Figure 1 shown.

[0035] Example 2 This embodiment provides a stabilizer composition, including: 12 kg of glutinous rice starch, 8 kg of cassava starch, and 3 kg of carboxymethyl cellulose.

[0036] The present embodiment provides a room temperature drawn yogurt and a preparation method thereof, wherein the raw materials include the following components: 892.5 kg of raw milk, 60 kg of white sugar, 23 kg of the stabilizer composition of the present embodiment, 8 kg of light cream, 1.5 kg of egg yolk powder, and 250 dcu of starter (150 dcu of Lactobacillus delbrueckii subsp. bulgaricus and 100 dcu of Streptococcus salivarius thermophilus).

[0037] The method for preparing the room temperature drawn yogurt comprises the following steps: (1) Raw milk concentration: Raw milk that has passed the antibiotic test is concentrated through an RO membrane to a protein content of 4.0%.

[0038] (2) Chemical ingredients: The concentrated raw milk is heated to 45°C on a hot plate and then directly beaten into a mixing tank. White sugar, glutinous rice starch, tapioca starch, carboxymethyl cellulose and egg yolk powder are mixed evenly and added to the mixing tank. The mixture is stirred at a speed of 450 rpm for 12 minutes, and then the cream is added to the mixture and stirred at the same speed for 10 minutes to obtain a mixed liquid.

[0039] (3) Homogenization: The mixed liquid in step (2) is heated to 62°C and then homogenized with a primary pressure of 200 bar and a secondary pressure of 50 bar.

[0040] (4) Sterilization and cooling: The homogenized mixed liquid is sterilized at 135°C for 3s, and the liquid temperature is quickly reduced to 32°C through a cold water plate exchanger.

[0041] (5) Fermentation and demulsification: The fermentation agent was inoculated into the slurry of step (4) at a rate of 250 dcu / ton. The fermentation temperature was 42°C. The pH of the slurry was ≤ 4.3 and the acidity was > 75°T. Demulsification could be performed at the end of the fermentation. The demulsification speed was 90 rpm for 8 min, and the slurry temperature was lowered to 23°C.

[0042] (6) Secondary sterilization and canning: The demulsified liquid is heated at a speed of 110 rpm and a temperature of 80°C for 10 seconds, and then cooled to 22°C for canning.

[0043] Example 3 This embodiment provides a stabilizer composition, including: 10 kg of glutinous rice starch, 5 kg of cassava starch, and 2.5 kg of carboxymethyl cellulose.

[0044] This embodiment provides a room temperature wire drawing yogurt and a preparation method thereof, wherein the raw materials include the following components: 905 kg of raw milk, 17.5 kg of the stabilizer composition of this embodiment, and 250 dcu of starter (150 dcu of Lactobacillus delbrueckii subsp. bulgaricus and 100 dcu of Streptococcus salivarius subsp. thermophilus). The preparation method thereof is the same as that of Example 1.

[0045] Example 4 The present embodiment provides a stabilizer composition, room temperature wire drawing yogurt and a preparation method thereof, which are basically the same as those in Example 1, except that the amount of the stabilizer composition is different. The stabilizer composition in the present embodiment includes: 10 kg of glutinous rice starch, 5 kg of cassava starch and 2.5 kg of carboxymethyl cellulose.

[0046] This embodiment provides a room temperature drawing yogurt and a preparation method thereof, wherein the raw materials include the following components: 905 kg of raw milk, 60 kg of white sugar, 17.5 kg of the stabilizer composition of this embodiment, 8 kg of cream, 1.5 kg of egg yolk powder, and 250 dcu of starter (150 dcu of Lactobacillus delbrueckii subsp. bulgaricus and 100 dcu of Streptococcus salivarius thermophilus). The preparation method thereof is the same as that of Example 1.

[0047] Example 5 This embodiment provides a stabilizer composition, including: 15 kg of glutinous rice starch, 7.5 kg of cassava starch, and 3.75 kg of carboxymethyl cellulose.

[0048] This embodiment provides a room temperature drawing yogurt and a preparation method thereof, wherein the raw materials include the following components: 883 kg of raw milk, 60 kg of white sugar, 26.25 kg of the stabilizer composition of this embodiment, 8 kg of cream, 1.5 kg of egg yolk powder, and 250 dcu of starter (150 dcu of Lactobacillus delbrueckii subsp. bulgaricus and 100 dcu of Streptococcus salivarius thermophilus). The preparation method thereof is the same as that of Example 1.

[0049] Example 6 The present embodiment provides a stabilizer composition, room temperature wire drawing yogurt and a preparation method thereof, which are basically the same as those in Example 1, except that the amount of the stabilizer composition is different. The stabilizer composition in the present embodiment includes: 13.3 kg of glutinous rice starch, 6.7 kg of cassava starch and 1 kg of carboxymethyl cellulose.

[0050] Example 7 The present embodiment provides a stabilizer composition, room temperature drawn yogurt and a preparation method thereof, which are basically the same as those in Example 1, except that the amount of the stabilizer composition is different. The stabilizer composition in the present embodiment includes: 11.3 kg of glutinous rice starch, 5.7 kg of cassava starch and 4 kg of carboxymethyl cellulose.

[0051] Example 8 The present embodiment provides a stabilizer composition, room temperature wire drawing yogurt and a preparation method thereof, which are basically the same as those in Example 1, except that the amount of the stabilizer composition is different. The stabilizer composition in the present embodiment includes: 13.5 kg of glutinous rice starch, 4.5 kg of cassava starch and 3 kg of carboxymethyl cellulose.

[0052] Example 9 The present embodiment provides a stabilizer composition, room temperature wire drawing yogurt and a preparation method thereof, which are basically the same as those in Example 1, except that the amount of the stabilizer composition is different. The stabilizer composition in the present embodiment includes: 10 kg of glutinous rice starch, 8 kg of cassava starch and 3 kg of carboxymethyl cellulose.

[0053] Comparative Example 1 This comparative example provides a stabilizer composition, room temperature drawing yogurt and a preparation method thereof, which are basically the same as Example 1, except that the composition and amount of the stabilizer composition are different. The stabilizer composition in this example includes: 12 kg of glutinous rice starch and 6 kg of cassava starch. The amount of the stabilizer composition added to the room temperature drawing yogurt is 18 kg.

[0054] Comparative Example 2 This comparative example provides a stabilizer composition, room temperature wire drawing yogurt and a preparation method thereof, which are basically the same as Example 1, except that sodium carboxymethyl cellulose is used instead of carboxymethyl cellulose in the stabilizer composition.

[0055] Comparative Example 3 This comparative example provides a stabilizer composition, room temperature drawing yogurt and a preparation method thereof, which are basically the same as Example 1, except that the composition and amount of the stabilizer composition are different. The stabilizer composition in this example includes: 12 kg of glutinous rice starch and 3 kg of carboxymethyl cellulose. The amount of the stabilizer composition added to the room temperature drawing yogurt is 15 kg.

[0056] Comparative Example 4 This comparative example provides a stabilizer composition, room temperature drawing yogurt and a preparation method thereof, which are basically the same as Example 1, except that the composition and amount of the stabilizer composition are different. The stabilizer composition in this example includes: 6 kg of tapioca starch and 3 kg of carboxymethyl cellulose. The amount of the stabilizer composition added to the room temperature drawing yogurt is 9 kg.

[0057] Comparative Example 5 This embodiment provides a stabilizer composition, room temperature drawing yogurt and a preparation method thereof, which are basically the same as those in Example 1, except that the amount of components of the stabilizer composition and the amount of the stabilizer composition added to the room temperature drawing yogurt are different. The stabilizer composition in this embodiment includes: 16 kg of glutinous rice starch, 8 kg of cassava starch, and 4 kg of carboxymethyl cellulose. The amount of the stabilizer composition added to the room temperature drawing yogurt is 28 kg.

[0058] Comparative Example 6 This embodiment provides a stabilizer composition, room temperature drawing yogurt and a preparation method thereof, which are basically the same as Example 1, except that the amount of components of the stabilizer composition and the amount of the stabilizer composition added to the room temperature drawing yogurt are different. The stabilizer composition in this embodiment includes: glutinous rice starch: 4kg, tapioca starch: 2kg, carboxymethyl cellulose: 1kg. The amount of the stabilizer composition added to the room temperature drawing yogurt is 7kg.

[0059] Comparative Example 7 This comparative example provides a stabilizer composition, room temperature wire drawing yogurt and a preparation method thereof, which are basically the same as Example 1, except that the composition of the stabilizer composition is different. The stabilizer composition in this example includes: 12 kg of glutinous rice starch, 6 kg of tapioca starch, 2 kg of agar, 0.5 kg of pectin and 0.5 kg of gellan gum.

[0060] Comparative Example 8 This comparative example provides a stabilizer composition, room temperature wire drawing yogurt and a preparation method thereof, which are basically the same as Example 1, except that the composition of the stabilizer composition is different. The stabilizer composition in this example includes: chemically modified starch (hydroxypropyl starch): 18 kg, carboxymethyl cellulose: 3 kg.

[0061] Test Example 1 The room temperature drawn yogurts prepared in each embodiment and comparative example were placed at room temperature of 25° C. for 6 months, and the drawing performance of each group of room temperature drawn yogurts before and after placement was tested, the appearance of the room temperature drawn yogurts was observed, the clarity index during placement was tested, and the stability was evaluated.

[0062] The test is carried out using the yogurt drawing test device, see Figure 2As shown, the yogurt drawing test device includes a liquid storage component 1, a camera component 2 and a computer 3. The liquid storage component 1 is suitable for storing yogurt samples, and the liquid storage component 1 is provided with a liquid outlet, which is used to discharge the yogurt sample stored in the liquid storage component 1 and enable it to form yogurt drawing. The liquid storage component 1 can be a funnel. The funnel is provided with a funnel piston for blocking or opening the liquid outlet. The camera component 2 is arranged on one side of the liquid storage component 1, and there is a certain distance between the camera component 2 and the yogurt drawing, so that the entire process of yogurt drawing can be photographed by the camera component 2, so that the camera component 2 can obtain the image information of the yogurt sample discharged by the liquid storage component 1. The computer 3 is electrically connected to the camera component 2, and is suitable for generating the time and length information of the yogurt sample flowing out from the liquid outlet to the formation of the drawing breakpoint according to the image information of the yogurt sample discharged by the liquid storage component 1, and the drawing performance of the yogurt is evaluated by the obtained breakpoint appearance time and initial drawing length. By configuring the openCV image processing system in the computer 3, the present application can perform algorithm processing and fitting on the collected image data, can quickly identify the wire drawing breakpoint position and breakpoint time, and output them to the user through the computer, avoiding the risks of large system errors and strong subjectivity caused by relying entirely on human visual observation and manual operation, and quickly and scientifically giving experimental results, improving the accuracy of the data, and meeting the application needs in the product development process.

[0063] The method of use is as follows: pour 50 mL of yogurt sample into the funnel that comes with the device and let it stand for 3 minutes. After the sample structure is fully restored, open the funnel piston and turn on the camera device at the same time. At this time, the camera captures dynamic images of the yogurt filamentous structure flowing out of the funnel at a collection frequency of 150 times / s. When the yogurt sample in the funnel has flowed out, the photo test stops. The camera device automatically transmits the collected image information to the computer connected to the device. The image processing system openCV configured on the computer recognizes, processes, calculates and outputs the data values ​​of the fracture position (i.e., the drawing length) L (cm) and the fracture time T (s) when the yogurt sample is first drawn and broken. The results are shown in the table below.

[0064] Table 1 Wire drawing properties before and after placement

[0065] It can be seen from the above table that compared with the comparative examples, the room temperature yogurt obtained by adding appropriate proportions of glutinous rice starch, tapioca starch and carboxymethyl cellulose in the embodiments of the present invention has strong wire drawing performance, the wire drawing length is more than 18 cm, and the wire drawing duration is relatively long, indicating that the system constructed by this experimental scheme has good heat resistance and shear resistance.

[0066] Comparing Example 1 with Examples 4-5, it can be seen that Example 1 can further improve the drawing performance of the drawn yogurt by limiting the mass ratio of the milk base material to the stabilizer composition within the preferred range.

[0067] Comparing Example 1 with Examples 6-7, it can be seen that Example 1 can further improve the drawing performance of the drawn yogurt by limiting the mass ratio of the physically modified starch and the carboxymethyl cellulose to within the preferred range.

[0068] Comparing Example 1 with Examples 8-9, it can be seen that Example 1 can further improve the drawing performance of the drawn yogurt by limiting the mass ratio of glutinous rice starch to tapioca starch within the preferred range.

[0069] However, the comparative examples exhibited lower wire drawing ability due to the changes in the stabilizer composition or dosage.

[0070] Table 2 Product stability results

[0071] The clarification index is generally used to characterize the stability of the storage system during the shelf life of the product. The larger the value, the worse the system stability. In the evaluation of the room temperature yogurt system, a clarification index of ≤0.02 indicates that the product has good stability. This experimental example uses a specific ratio of glutinous rice starch and tapioca starch with a small amount of carboxymethyl cellulose to make the product shelf stable and reach the system stability formed by chemically modified starch and other compound combination colloids, indicating that the system constructed by this experimental scheme has good shelf life stability.

[0072] By comparing the example groups, it is found that the yogurt system constructed in Example 1 has strong wire drawing performance and can maintain a stable tissue state during the shelf life, which is the optimal solution of this solution.

[0073] Test Example 2 A panel of 9 professional sensory judges conducted a sensory evaluation of the samples described in this scheme according to the scoring table in Table 3 and gave corresponding scores.

[0074] Table 3 Sensory score table

[0075] Table 4 Sensory evaluation results

[0076] The sensory evaluation results show that the wire-drawn room-temperature yogurt obtained by using glutinous rice starch, tapioca starch and carboxymethyl cellulose in a specific ratio has a better taste and a higher comprehensive sensory score.

[0077] Obviously, the above embodiments are only examples for clear explanation, and are not intended to limit the implementation methods. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from them are still within the protection scope of the invention.

Claims

1. A room temperature drawing yogurt, characterized in that: Its raw materials include a stabilizer composition, a milk base and a starter; the stabilizer composition includes physically modified starch and carboxymethyl cellulose in a mass ratio of 15-23:1-4, and the physically modified starch includes glutinous rice starch and cassava starch in a mass ratio of 10-15:4.5-8; the mass ratio of the milk base to the stabilizer composition is 883-916:16-27.

2. The room temperature drawing yogurt according to claim 1, characterized in that: The mass ratio of the physically modified starch to the carboxymethyl cellulose is 18-20:3; and / or the mass ratio of the glutinous rice starch to the cassava starch is 12:6-8.

3. The room temperature drawing yogurt according to claim 1, characterized in that: The mass ratio of the milk base material to the stabilizer composition is 892.5-894.5:21-23; and / or, based on the mass of raw materials other than the starter in the room temperature wire drawing yogurt, the amount of the starter is 200-300 dcu / ton.

4. The room temperature drawing yogurt according to claim 1, characterized in that: The milk-based material is selected from one or more of raw cow's milk, whole milk powder, skimmed milk powder and whey protein powder; and / or, The fermentation agent is selected from one or more of Lactobacillus delbrueckii subspecies bulgaricus and Streptococcus salivarius subspecies thermophilic.

5. The room temperature drawing yogurt according to claim 1, characterized in that: The raw materials of the room temperature drawn yogurt also include one or more of sweeteners, oils and fats, and egg yolk powder.

6. The room temperature drawing yogurt according to claim 5, characterized in that: The sweetener is selected from one or more of white sugar, sucrose, glucose, lactose, maltose, fructose, fructose syrup, glucose syrup, maltose syrup, maltodextrin, sugar alcohol, sodium cyclamate, aspartame, sucralose, honey, acesulfame potassium, and neotame; and / or the fat includes one or more of light cream, fermented light cream, and butter.

7. The room temperature drawing yogurt according to claim 5, characterized in that: The mass ratio of the milk base to the sweetener is 883-916:30-60; and / or, the mass ratio of the milk base to the oil is 883-916:8-10; and / or, the mass ratio of the milk base to the egg yolk powder is 883-916:1-2.

8. A method for preparing the room temperature drawn yogurt according to any one of claims 1 to 7, characterized in that: The method comprises the steps of mixing raw materials except the leavening agent, homogenizing, sterilizing once, adding the leavening agent for fermentation, demulsifying, cooling and sterilizing twice to obtain the product.

9. The method for preparing room temperature wire drawing yogurt according to claim 8, characterized in that: The homogenization temperature is 60-63°C, including primary homogenization and secondary homogenization, the primary homogenization pressure is 150-200 bar, and the secondary homogenization pressure is 50-70 bar; and / or, The sterilization temperature of the primary sterilization is 120-135°C and the time is 3-5s; and / or, The fermentation temperature is 40-44°C; and / or, The demulsification speed is 80-100 rpm and the time is 5-8 min; and / or, The secondary sterilization temperature is 75-80°C and the time is 10-20s.

10. The method for preparing room temperature wire drawing yogurt according to claim 8 or 9, characterized in that: The milk base material further comprises a step of concentrating the milk base material to a protein content of 3.5-4.0% before mixing.

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