Cheese and preparation method thereof

Abstract

The invention relates to the field of food, and provides cheese and a preparation method thereof, and the cheese comprises the following raw materials: micellar casein liquid, single cream, carbohydrates, a leavening agent, chymosin, calcium salt, table salt and water. The cheese is good in stretching softness, easy to shape, good in baking performance, good in flavor and taste and high in stability, and can be stored for at least 9 months under the refrigeration condition.

Description

Technical Field

[0001] The present invention relates to the field of food, and more particularly to cheese and a method for preparing the same. Background Art

[0002] Cheese, also known as cottage cheese, is a dairy product made from raw milk, cream, skim milk or a mixture of these products, fermented and coagulated, and whey separated. It is known as the "king of dairy products" and is a high value-added product in the dairy industry. However, the current cheese preparation process has the following problems: in the process of using raw milk as the main raw material to prepare cheese, whey byproducts are directly discharged, resulting in a waste of resources; cheese prepared from skim milk and cream has a short shelf life under refrigerated storage conditions, and pizza cheese products have a low hardness, and the product is incomplete during grating, which is easy to produce crumbs.

[0003] Casein is one of the most important proteins in cow's milk, accounting for about 80% of the total amount of milk protein. It is a complex high-molecular protein composed of multiple amino acid residues with high solubility and stability. In cow's milk, casein is mainly composed of three subtypes: α-CN, β-CN and κ-CN, among which α-CN is composed of αs1-CN and αs2-CN. αS1-, αS2-, β- and κ-CN are four casein molecules that are similar in amino acid composition, molecular weight, content in cow's milk and global physicochemical properties, and their proportions in micelles are approximately 40%, 10%, 35% and 15% (w / w). These casein subtypes are more or less phosphorylated, which makes these proteins have a good ability to bind calcium phosphate. Casein micelle molecules form micelle structures through two types of interactions: protein-protein interactions (hydrophobicity, hydrogen bonds and electrostatic attraction) and calcium and phosphorus binding.

[0004] At present, the process of preparing cheese using micellar casein liquid as raw material still needs to be studied. Summary of the invention

[0005] The present application aims to solve the technical problems existing in the prior art at least to a certain extent. To this end, the present application proposes cheese and a preparation method thereof, wherein the cheese of the present application has good stretching softness, is easy to shape, has good baking performance, good flavor and taste, is strong in stability, and can be stored under refrigerated conditions for at least 9 months.

[0006] In one aspect of the present application, the present application proposes a cheese. According to an embodiment of the present application, the raw materials of the cheese include: micellar casein liquid, cream, sugar, leavening agent, rennet, calcium salt, salt and water; based on the total mass of the raw materials of the cheese, the content of the micellar casein liquid is 43% to 46%, the content of the cream is 6.3% to 6.8%, the content of the leavening agent is 0.0015% to 0.0025%, and the activity of the rennet is 5.8 IMCU % to 6.4 IMCU %.

[0007] The cheese according to the embodiment of the present application uses micellar casein liquid as the main raw material, and the cheese curd prepared is moderately hard and soft, has good tensile softness, is easy to shape, and has good baking performance, providing the cheese with protein network structure support characteristics. The addition of cream mainly provides fat for the cheese. The raw materials also contain carbohydrates and leavening agents to promote acid production during the fermentation process and form curds under the action of rennet. In addition, the addition of calcium salt during the fermentation process can increase the calcium ion concentration in the milk, which is conducive to the aggregation of micellar casein and the coagulation effect of rennet, and can also enhance the stretchability and solubility of the cheese. The addition of salt not only enhances the flavor of the cheese, but also helps the discharge of whey.

[0008] Compared with micellar casein powder, micellar casein liquid is able to maintain its original micellar network structure because it has not been subjected to high-temperature powder spraying and drying treatment. It can be subjected to hot blanching and stretching treatment, and the cheese finally obtained has better drawing and charring effects. During the baking process, it has uniform charring performance, appropriate oil precipitation, optimal viscosity, good flavor release, mellow taste, full flavor, high product yield, appropriate hardness, low viscosity, good surface smoothness, short molding time, and easy demoulding.

[0009] Micellar casein liquid, cream and starter content as well as rennet activity will affect the quality of cheese. When the above conditions are met, the obtained cheese has good tensile softness, is easy to shape, has good baking performance, good flavor and taste, is strong in stability, and can be stored under refrigerated conditions for at least 9 months.

[0010] According to the embodiments of the present application, the cheese may also have the following additional technical features: According to an embodiment of the present application, the micellar casein content in the micellar casein liquid is 6%~7%; based on the total mass of the raw materials of the cheese, the carbohydrate content is 4.8%~5.3%, the calcium salt content is 0.02%~0.03%, and the salt content is 0.2%~0.25%.

[0011] According to an embodiment of the present application, the carbohydrate substance includes lactose; the fermentation agent includes thermophilic Streptococcus; and the calcium salt includes calcium chloride.

[0012] According to an embodiment of the present application, the micellar casein solution is obtained by subjecting skim milk to microfiltration membrane treatment.

[0013] According to an embodiment of the present application, the microfiltration membrane treatment conditions include at least one of the following: the pore size of the microfiltration membrane is 0.1 μm~0.4 μm; the transmembrane pressure is 0.05 mPa~0.1 mPa; the temperature is 40℃~60℃; using the diafiltration method, the volume ratio of diafiltration water to skim milk is (0.5~1.5):1; the concentration coefficient is 1~3.

[0014] In another aspect of the present application, the present application proposes a method for preparing the cheese described above. According to an embodiment of the present application, the method comprises: fermenting the micellar casein solution, cream, sugar, calcium salt, starter and water to obtain a fermentation product; coagulating the fermentation product with rennet to obtain a curd; cutting, stirring, draining, salting, blanching, stretching and cooling the curd to obtain the cheese.

[0015] According to an embodiment of the present application, the method further comprises: sterilizing the micellar casein solution, cream and water to obtain a sterilized product; and fermenting the sterilized product, sugar substances, leavening agent and calcium salt.

[0016] According to an embodiment of the present application, the fermentation process includes a first fermentation stage and a second fermentation stage; the fermentation temperature of the first fermentation stage is lower than the fermentation temperature of the second fermentation stage.

[0017] According to an embodiment of the present application, the temperature of the first fermentation stage is 33°C~35°C, and the time is 30 min~60 min; the temperature of the second fermentation stage is 38°C~41°C, and the time is 60 min~90 min; the pH value of the fermentation product is 6.4~6.6.

[0018] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. DETAILED DESCRIPTION

[0019] The embodiments of the present invention are described in detail below. The embodiments described below are exemplary and are only used to explain the present invention, and should not be understood as limiting the present invention.

[0020] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. Further, in the description of the present invention, unless otherwise specified, the meaning of "plurality" is two or more.

[0021] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0022] In this document, the terms “include” or “comprising” are open expressions, that is, including the contents specified in the present invention but not excluding other contents.

[0023] As used herein, the terms "optionally", "optional" or "optionally" generally mean that the subsequently described event or circumstance may but need not occur, and that the description includes instances where the event or circumstance occurs and instances where it does not.

[0024] The present application proposes cheese and a method for preparing the same, which will be described in detail below.

[0025] cheese In one aspect of the present application, the present application provides a cheese. According to an embodiment of the present application, the raw materials of the cheese include: micellar casein liquid, cream, sugar substances, starter, rennet, calcium salt, salt and water.

[0026] The cheese according to the embodiment of the present application uses micellar casein liquid (MCC liquid) as the main raw material, and the cheese curd prepared is moderately hard and soft, has good tensile softness, is easy to shape, and has good baking performance, providing the cheese with protein network structure support characteristics. The addition of cream mainly provides fat for the cheese. The raw materials also contain carbohydrates and leavening agents to promote acid production during the fermentation process and form curds under the action of rennet. In addition, the addition of calcium salt during the fermentation process can increase the calcium ion concentration in the milk, which is conducive to the aggregation of micellar casein and the coagulation effect of rennet, and can also enhance the stretchability and solubility of the cheese. The addition of salt not only enhances the flavor of the cheese, but also helps the discharge of whey.

[0027] Compared with micellar casein powder, micellar casein liquid is able to maintain its original micellar network structure because it has not been subjected to high-temperature powder spraying and drying treatment. It can be subjected to hot blanching and stretching treatment, and the cheese finally obtained has better drawing and charring effects. During the baking process, it has uniform charring performance, appropriate oil precipitation, optimal viscosity, good flavor release, mellow taste, full flavor, high product yield, appropriate hardness, low viscosity, good surface smoothness, short molding time, and easy demoulding.

[0028] According to an embodiment of the present application, based on the total mass of the raw materials of the cheese, the micellar casein liquid has a content of 43% to 46%, such as 43%, 43.5%, 44%, 44.5%, 45%, 45.5%, and 46%. Thus, it is possible to provide abundant protein to improve the nutritional value of cheese, and to improve the flavor and taste of cheese, making it stretchable and having a suitable texture and hardness. In some embodiments, the micellar casein content in the micellar casein liquid is 6% to 7%.

[0029] According to an embodiment of the present application, based on the total weight of the raw materials of the cheese, the content of the cream is 6.3% to 6.8%, for example, 6.3%, 6.4%, 6.5%, 6.6%, 6.7%, and 6.8%. In this way, rich fat can be provided for the cheese, which not only enhances the flavor and taste of the cheese, making it more delicate and smooth, but also helps to improve the solubility and stretchability of the cheese. At the same time, it can avoid hindering fermentation, too greasy and soft texture, and low stretchability and structural stability due to excessive addition of cream.

[0030] According to an embodiment of the present application, based on the total mass of the raw materials of the cheese, the carbohydrate content is 4.8% to 5.3%, for example, 4.8%, 4.9%, 5.0%, 5.1%, 5.2%, and 5.3%. The carbohydrate provides a carbon source for fermentation, and the content meets the above conditions. The fermentation speed and pH value decrease appropriately, thereby making the flavor, taste and texture of the cheese better, and the stretchability and coke effect are good. At the same time, it provides sweetness to balance the acidity. It participates in the caramelization reaction during the baking process, bringing an ideal color and flavor to the surface of the cheese.

[0031] According to an embodiment of the present application, based on the total weight of the raw materials of the cheese, the fermentation agent content is 0.0015% to 0.0025%, for example, 0.0015%, 0.0018%, 0.0020%, 0.0022%, 0.0024%, 0.0025%. Thus, the fermentation speed and pH value decrease appropriately, thereby making the cheese have better flavor, taste and texture, and better stretchability and charring effect.

[0032] According to an embodiment of the present application, based on the total weight of the raw materials of the cheese, the rennet activity is 5.8 IMCU%~6.4 IMCU%, for example, 5.8 IMCU%, 5.9 IMCU%, 6.0 IMCU%, 6.1 IMCU%, 6.2 IMCU%, 6.3 IMCU%, 6.4 IMCU%. That is, in 100 parts by weight of the raw materials, the rennet activity is 5.8 IMCU~6.4 IMCU. Rennet is a key step in the coagulation process by specifically hydrolyzing the peptide bond between Phe105-Met106 of the κ-casein polypeptide chain in the milk, forming a stable para-κ-casein and a hydrophilic glycomacropeptide, which will cause the stability of the casein micelles to change, thereby promoting the formation of curd. The rennet content meets the above conditions, effectively promotes the formation of curd, and has a better coagulation effect, so that the texture of the cheese is better, and the stretchability and focal spot effect are good.

[0033] According to an embodiment of the present application, based on the total mass of the raw materials of the cheese, the calcium salt content is 0.02% to 0.03%, for example, 0.02%, 0.022%, 0.024%, 0.025%, 0.026%, 0.028%, 0.03%. Thus, an appropriate amount of calcium ions can be provided, which helps to promote the aggregation of casein micelles and enhance the stability and texture of curd. An appropriate amount of calcium salt can also improve the solubility and stretchability of cheese, help to form a uniform scorch spot, enhance the sensory properties of cheese, and promote the discharge of whey, reduce the moisture content of cheese, and thus extend the shelf life of cheese.

[0034] According to an embodiment of the present application, based on the total mass of the raw materials of the cheese, the salt content is 0.2% to 0.25%, for example, 0.2%, 0.21%, 0.22%, 0.23%, 0.24%, and 0.25%. Therefore, meeting the above salt content can not only enhance the flavor and improve the taste level of the cheese, but also inhibit the growth of microorganisms by reducing the water activity and prolong the shelf life. In addition, salt helps to adjust the pH value of the cheese, promote the discharge of emulsion, and improve the texture and structure of the cheese, making it more compact.

[0035] According to an embodiment of the present application, the carbohydrate substance includes lactose. The fermentation bacteria ferments the cheese by converting lactose into lactic acid, promoting the hydrolysis of protein and fat in the cheese, and playing an important role in the texture and flavor of the cheese. The lactic acid produced by lactose fermentation causes the pH value in the cheese to decrease, affecting the dehydration shrinkage of the cheese and the retention of calcium, which helps the formation of cheese curd and can inhibit the growth of undesirable microorganisms.

[0036] According to an embodiment of the present application, the fermentation agent includes thermophilic Streptococcus; and the calcium salt includes calcium chloride.

[0037] According to an embodiment of the present application, the micellar casein liquid is obtained by microfiltration membrane treatment of skim milk. The microfiltration membrane treatment can effectively separate whey protein and micellar casein. The micellar casein liquid can be stored frozen, and the raw material has a long shelf life.

[0038] According to an embodiment of the present application, the microfiltration membrane treatment conditions include at least one of the following: The pore size of the microfiltration membrane is 0.1 μm to 0.4 μm, for example, 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm; The transmembrane pressure is 0.05 mPa~0.1 mPa, for example, 0.05 mPa, 0.06 mPa, 0.07 mPa, 0.08 mPa, 0.09 mPa, 0.1 mPa; The temperature is 40°C to 60°C, for example, 40°C, 42°C, 45°C, 48°C, 50°C, 52°C, 55°C, 58°C, 60°C; When using the diafiltration method, the volume ratio of diafiltration water to skim milk is (0.5~1.5):1, for example, 0.5:1, 1:1, 1.5:1; The concentration factor is 1 to 3, for example 1, 2, 3.

[0039] Thus, the micellar casein in the skim milk can be separated efficiently with high purity and yield.

[0040] Cheese preparation method In another aspect of the present application, the present application proposes a method for preparing the cheese described above. According to an embodiment of the present application, the method comprises: fermenting the micellar casein solution, cream, sugar, calcium salt, starter and water to obtain a fermentation product; coagulating the fermentation product with rennet to obtain a curd; cutting, stirring, draining, salting, blanching, stretching and cooling the curd to obtain the cheese. Thus, the cheese prepared according to the method of the embodiment of the present application has good stretching softness, is easy to shape, has good baking performance, good flavor and taste, is stable, and can be stored under refrigerated conditions for at least 9 months.

[0041] According to an embodiment of the present application, the method further comprises: sterilizing the micellar casein solution, cream and water to obtain a sterilized product; and fermenting the sterilized product, sugar substances, fermentation agent and calcium salt, thereby killing bacteria and improving the shelf life of cheese.

[0042] According to an embodiment of the present application, the fermentation process includes a first fermentation stage and a second fermentation stage; the fermentation temperature of the first fermentation stage is lower than the fermentation temperature of the second fermentation stage. By adopting a variable temperature fermentation method, low-temperature fermentation and curdling in the early stage can reduce fat loss, thereby increasing the product yield, and high-temperature fermentation in the later stage is conducive to the reproduction of the strain, so that the strain enters the logarithmic phase faster, ferments lactose to convert lactic acid, and improves the texture and flavor of the cheese.

[0043] According to an embodiment of the present application, the temperature of the first fermentation stage is 33°C~35°C, for example, 33°C, 34°C, 35°C, and the time is 30 min~60 min, for example, 30 min, 35 min, 40 min, 45 min, 50 min, 55 min, 60 min; the temperature of the second fermentation stage is 38°C~41°C, for example, 38°C, 39°C, 40°C, 41°C, and the time is 60 min~90min, for example, 60 min, 65 min, 70 min, 75 min, 80 min, 85 min, 90 min; the pH value of the fermentation product is 6.4~6.6, for example, 6.4, 6.5, 6.6.

[0044] Using the above-mentioned low-temperature fermentation and coagulation in the early stage of fermentation can reduce fat loss and increase the product yield. Using the above-mentioned high-temperature fermentation in the later stage is conducive to the reproduction of the bacteria, allowing the bacteria to enter the logarithmic phase faster, ferment lactose to convert lactic acid, and improve the texture and flavor of the cheese.

[0045] Increasing the fermentation (pre-acidification) time helps to reduce the pH value, making the fermentation bacteria reproduce faster and enhancing the coagulation effect in the later stage. The state of colloidal calcium phosphate is closely related to the change of pH value. The coagulation speed increases with the decrease of pH value. This may be because the decrease of pH value leads to the increase of calcium ion activity, thereby accelerating the coagulation speed. When the pH value of the liquid is 6.4~6.6, the fermentation is ended.

[0046] According to an embodiment of the present application, the method includes: (1) Standardization: Standardize the micellar casein solution at a ratio of casein: fat = 1.0 ± 0.1, and then add lactose; (2) Sterilization: The standardized samples are pasteurized at a temperature of 72-75°C for 15-30 seconds, and then cooled to the fermentation temperature of 33-35°C; (3) Fermentation: Add a fermentation agent and perform temperature-variable fermentation. Add calcium chloride at the same time. Ferment at 33-35°C for 30-60 min, then adjust to 38-41°C for 60-90 min, so that the pH value of the fermentation liquid reaches 6.4-6.6. (4) Curing: Add microbial rennet, dilute with 5-10 times mL of pure water, shake well and then add; (5) Cutting: After 30-40 minutes of curdling, determine the curd strength. Cut the curd when the strength is appropriate and let it stand for 5-10 minutes. (6) Stirring: After standing, continue stirring for 20-30 min to promote liquid discharge. Slowly heat to 40-42 °C while stirring, and record the pH of the liquid. (7) Drainage: When the pH value of the liquid is 6.3-6.4, the liquid is discharged; (8) Heap fermentation: The curd is left to ferment for about 20-40 minutes, and the curd is turned over every 15 minutes. The pH value is constantly tested during this period. When the pH value is 5.2-5.4, the heap fermentation is completed. (9) Cutting: Cut the cheese curd into small pieces (5 cm × 10 cm), add 0.2-0.25% dry salt based on the total weight of the cheese raw materials, mix well, and salt for 25 minutes; (10) Hot boiling: Use hot water at 65-70℃ to blanch the cheese. Use a thermometer to measure the temperature at the center of the cheese. When the temperature of the cheese reaches 60-65℃, stretch it for 2-3 minutes. (11) Cooling: After stretching, immediately cool in cold water; (12) Storage: After the cheese has cooled, store it at -18°C or 4°C.

[0047] It should be noted that the characteristics and advantages described above for cheese are also applicable to this method and will not be repeated here.

[0048] The scheme of the present invention will be explained below in conjunction with the embodiments. It will be appreciated by those skilled in the art that the following embodiments are only used to illustrate the present invention and should not be considered as limiting the scope of the present invention. Where specific techniques or conditions are not indicated in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. The reagents or instruments used are not indicated by the manufacturer and are all conventional products that can be obtained commercially.

[0049] In the following examples, the preparation method of micellar casein solution is as follows: 1. Degreasing: Raw milk is degreased by centrifugation at a temperature of 50°C and a centrifugal speed of 5000 rpm, and the fat content is adjusted to 0.06%; 2. Pasteurization: pasteurize the skim milk at a temperature of 85°C and a pasteurization time of 30 seconds; 3. Microfiltration membrane separation: The pasteurized skim milk was separated by microfiltration membrane, and the separation parameters were: the microfiltration membrane used had a pore size of 0.2 μm, a transmembrane pressure of 0.075 mPa, a temperature of 50°C, a diafiltration process, a diafiltration water volume: skim milk volume = 1:1, a concentration factor VCF of 2, and micellar casein liquid was obtained. The composition of the micellar casein liquid was as follows: micellar casein content was 6.6%, fat content was 0.22%, and lactose content was 0.3%.

[0050] Example 1 In this example, cheese was prepared according to the following method: 1. Formulation Micellar casein liquid 45wt%, cream 6.5wt%, lactose 5.0wt%, thermophilic Streptococcus fermentation agent 0.0025wt%, anhydrous calcium chloride 0.02wt%, microbial rennet activity 6.0 IMCU%, edible salt 0.25wt%, sterile water to make up to 100%.

[0051] 2. Steps (1) Standardization: Standardize the micellar casein solution, sterile water, and cream at a ratio of casein: fat = 1.0 ± 0.1; (2) Sterilization: Add lactose to the liquid obtained in the previous step and pasteurize it at 72°C for 30 seconds, then cool it to 35°C.

[0052] (3) Fermentation: Add thermophilic Streptococcus fermentation agent and anhydrous calcium chloride to the fermentation liquid obtained in the previous step, ferment at 35°C for 30 min, adjust to 41°C for 60 min, and ferment until the pH value of the fermentation liquid reaches 6.5.

[0053] (4) Curing: dilute the microbial rennet with 5 times mL of purified water, shake well and add; (5) Cutting: Cut the curd after 40 minutes of curdling and let it stand for 10 minutes after cutting; (6) Stirring: After standing, continue stirring for 30 min, and slowly heat to 40°C while stirring; (7) Drainage: When the pH value of the liquid is 6.3, the liquid is discharged; (8) Heap fermentation: The curd is left to ferment for 20 min, and the curd is turned over every 15 min. The pH value of the curd is continuously tested during this period. When the pH value is 5.4, the heap fermentation is completed. (9) Cutting: Cut the cheese curd into small pieces (5 cm × 10 cm), add dry edible salt, mix well, and salt for 25 minutes; (10) Hot boiling: Use hot water at 70°C to blanch the cheese. Use a thermometer to measure the temperature of the center of the cheese. When the temperature of the cheese reaches 60°C, stretch it for 3 minutes. (11) Cooling: After stretching, immediately place in cold water to cool, then package and store.

[0054] Example 2 In this example, cheese was prepared according to the following method: 1. Formulation Micellar casein liquid 43wt%, cream 6.3wt%, lactose 4.8wt%, thermophilic Streptococcus fermentation agent 0.002wt%, anhydrous calcium chloride 0.025wt%, microbial rennet activity 5.8 IMCU%, edible salt 0.2wt%, sterile water to make up to 100%.

[0055] 2. Steps (1) Standardization: Standardize the micellar casein solution, sterile water, and cream at a ratio of casein: fat = 1.0 ± 0.1; (2) Sterilization: Add lactose to the liquid obtained in the previous step and pasteurize it at 74°C for 20 seconds, then cool it to 33°C.

[0056] (3) Fermentation: Add thermophilic Streptococcus fermentation agent and anhydrous calcium chloride to the fermentation liquid obtained in the previous step, ferment at 33°C for 60 min, adjust to 38°C for 90 min, and ferment until the pH value of the fermentation liquid reaches 6.6.

[0057] (4) Curing: dilute the microbial rennet with 7 times mL of purified water, shake well and add; (5) Cutting: Cut the curd after 30 minutes of curdling and let it stand for 5 minutes after cutting; (6) Stirring: After standing, continue stirring for 20 min, and slowly heat to 41°C while stirring; (7) Drainage: When the pH value of the liquid is 6.4, the liquid is discharged; (8) Composting: The curd is left to ferment for 40 min, and the curd is turned over every 15 min. The pH value of the curd is continuously tested during fermentation. When the pH value is 5.2, composting is completed. (9) Cutting: Cut the cheese curd into small pieces (5 cm × 10 cm), add dry edible salt, mix well, and salt for 25 minutes; (10) Hot boiling: Use hot water at 65°C to blanch the cheese. Use a thermometer to measure the temperature of the center of the cheese. When the temperature of the cheese reaches 65°C, stretch it for 2 minutes. (11) Cooling: After stretching, immediately place in cold water to cool, and then package and store.

[0058] Example 3 In this example, cheese was prepared according to the following method: 1. Formulation Micellar casein liquid 46wt%, cream 6.8wt%, lactose 5.2wt%, thermophilic Streptococcus fermentation agent 0.0018wt%, anhydrous calcium chloride 0.026wt%, microbial rennet activity 6.4 IMCU%, edible salt 0.24wt%, sterile water to make up to 100%.

[0059] 2. Steps (1) Standardization: Standardize the micellar casein solution, sterile water, and cream at a ratio of casein: fat = 1.0 ± 0.1; (2) Sterilization: Add lactose to the liquid obtained in the previous step and pasteurize it at 75°C for 15 seconds, then cool it to 34°C.

[0060] (3) Fermentation: Add thermophilic Streptococcus fermentation agent and anhydrous calcium chloride to the fermentation liquid obtained in the previous step, ferment at 34°C for 50 min, adjust to 39°C for 80 min, and ferment until the pH value of the fermentation liquid reaches 6.6.

[0061] (4) Curing: dilute the microbial rennet with 10 times mL of purified water, shake well and add; (5) Cutting: Cut the curd after 35 minutes of curdling and let it stand for 7 minutes after cutting; (6) Stirring: After standing, continue stirring for 25 min, and slowly heat to 42 °C while stirring; (7) Drainage: When the pH value of the liquid is 6.35, the liquid is discharged; (8) Heap fermentation: The curd is left to stand and ferment for 30 min, turning over every 15 min. The pH value of the curd is continuously tested during this period. When the pH value is 5.3, the heap fermentation is completed. (9) Cutting: Cut the cheese curd into small pieces (5 cm × 10 cm), add dry edible salt, mix well, and salt for 25 minutes; (10) Hot boiling: Use hot water at 67°C to blanch the cheese. Use a thermometer to measure the temperature of the center of the cheese. When the temperature of the cheese reaches 63°C, stretch it for 2.5 minutes. (11) Cooling: After stretching, immediately place in cold water to cool, then package and store.

[0062] Example 4 In this example, cheese was prepared according to the following method: 1. Formulation Micellar casein liquid 44wt%, cream 6.6wt%, lactose 5.3wt%, thermophilic Streptococcus fermentation agent 0.0024wt%, anhydrous calcium chloride 0.023wt%, microbial rennet activity 6.2 IMCU%, edible salt 0.22wt%, sterile water to make up to 100%.

[0063] 2. Steps (1) Standardization: Standardize the micellar casein solution, sterile water, and cream at a ratio of casein: fat = 1.0 ± 0.1; (2) Sterilization: Add lactose to the liquid obtained in the previous step and pasteurize it at 73°C for 25 seconds, then cool it to 35°C.

[0064] (3) Fermentation: Add thermophilic Streptococcus fermentation agent and anhydrous calcium chloride to the fermentation liquid obtained in the previous step, ferment at 35°C for 40 min, adjust to 40°C for 70 min, and ferment until the pH value of the fermentation liquid reaches 6.5.

[0065] (4) Curing: dilute the microbial rennet with 8 times mL of purified water, shake well and add; (5) Cutting: Cut the curd after 33 minutes of curdling and let it stand for 8 minutes after cutting; (6) Stirring: After standing, continue stirring for 22 minutes, and slowly heat to 40°C while stirring; (7) Drainage: When the pH value of the liquid is 6.36, the liquid is discharged; (8) Composting: The curd is left to ferment for 25 min, and the curd is turned over every 15 min. The pH value of the curd is continuously tested during fermentation. When the pH value is 5.25, the composting is completed. (9) Cutting: Cut the cheese curd into small pieces (5 cm × 10 cm), add dry edible salt, mix well, and salt for 25 minutes; (10) Hot boiling: Use hot water at 68°C to blanch the cheese. Use a thermometer to measure the temperature of the center of the cheese. When the temperature of the cheese reaches 64°C, stretch it for 2.7 min. (11) Cooling: After stretching, immediately place in cold water to cool, then package and store.

[0066] Example 5 In this example, cheese was prepared according to the following method: 1. Formulation Micellar casein liquid 43wt%, cream 6.7wt%, lactose 5.1wt%, thermophilic Streptococcus fermentation agent 0.0023wt%, anhydrous calcium chloride 0.022wt%, microbial rennet activity 6.3 IMCU%, edible salt 0.23wt%, sterile water to make up to 100%.

[0067] 2. Steps (1) Standardization: Standardize the micellar casein solution, sterile water, and cream at a ratio of casein: fat = 1.0 ± 0.1; (2) Sterilization: Add lactose to the liquid obtained in the previous step and pasteurize it at 75°C for 20 seconds, then cool it to 33°C.

[0068] (3) Fermentation: Add thermophilic Streptococcus fermentation agent and anhydrous calcium chloride to the fermentation liquid obtained in the previous step, ferment at 33°C for 45 min, adjust to 41°C for 75 min, and ferment until the pH value of the fermentation liquid reaches 6.4.

[0069] (4) Curing: dilute the microbial rennet with 6 times mL of purified water, shake well and add; (5) Cutting: Cut the curd after 37 minutes of curdling and let it stand for 9 minutes after cutting; (6) Stirring: After standing, continue stirring for 28 minutes, and slowly heat to 41°C while stirring; (7) Drainage: When the pH value of the liquid is 6.3, the liquid is discharged; (8) Composting: The curd is left to ferment for 35 min, and the curd is turned over every 15 min. The pH value of the curd is continuously tested during fermentation. When the pH value is 5.35, composting is completed. (9) Cutting: Cut the cheese curd into small pieces (5 cm × 10 cm), add dry edible salt, mix well, and salt for 25 minutes; (10) Hot boiling: Use hot water at 66°C to blanch the cheese. Use a thermometer to measure the temperature of the center of the cheese. When the temperature of the cheese reaches 62°C, stretch it for 2.3 min. (11) Cooling: After stretching, immediately place in cold water to cool, and then package and store.

[0070] Example 6 Cheese was prepared according to the method of Example 1, except that Step (2): Sterilization: Add lactose to the liquid obtained in the previous step and pasteurize at 72°C for 30 seconds, then cool to 38°C.

[0071] Step (3): Fermentation: Add thermophilic Streptococcus fermentation agent and anhydrous calcium chloride to the liquid obtained in the previous step, and ferment at 38°C for 90 min until the pH value of the fermentation liquid reaches 6.65.

[0072] Example 7 Cheese was prepared according to the method of Example 1, except that Step (3): Fermentation: Add thermophilic Streptococcus fermentation agent and anhydrous calcium chloride to the liquid obtained in the previous step, and ferment at 35°C for 90 min until the pH value of the fermentation liquid reaches 6.71.

[0073] Example 8 Cheese was prepared according to the method of Example 1, except that (2) Sterilization: Add lactose to the liquid obtained in the previous step and pasteurize it at 72°C for 30 seconds, then cool it to 41°C.

[0074] (3) Fermentation: Add thermophilic Streptococcus fermentation agent and anhydrous calcium chloride to the slurry obtained in the previous step, ferment at 41°C for 60 min, adjust to 35°C for 60 min, and ferment until the pH value of the fermentation slurry reaches 6.63.

[0075] Comparative Example 1 Cheese was prepared according to the method of Example 1, except that the micellar casein liquid was replaced with micellar casein powder.

[0076] Micellar casein powder is obtained by spray drying micellar casein liquid. The spray drying conditions are as follows: The micellar casein liquid obtained by microfiltration membrane separation was concentrated by reverse osmosis, and the concentration parameters were: reverse osmosis membrane flow channel was 31 mil, concentration pressure was 3 mPa, and concentration temperature was 10 °C to obtain micellar casein concentrate, which was then spray-dried, and the spray-drying parameters were: inlet air temperature was 180 °C, and outlet air temperature was 80 °C.

[0077] Comparative Example 2 Cheese was prepared according to the method of Example 1, except that the amount of micellar casein solution added was 35 wt %.

[0078] Comparative Example 3 Cheese was prepared according to the method of Example 1, except that the amount of micellar casein solution added was 50 wt %.

[0079] Comparative Example 4 Cheese was prepared according to the method of Example 1, except that the amount of the thermophilic Streptococcus starter added was 0.0005%.

[0080] Comparative Example 5 Cheese was prepared according to the method of Example 1, except that the amount of the thermophilic Streptococcus starter added was 0.0030%.

[0081] Comparative Example 6 Cheese was prepared according to the method of Example 1, except that the amount of cream added was 5.0%.

[0082] Comparative Example 7 Cheese was prepared according to the method of Example 1, except that the amount of cream added was 7.5%.

[0083] Comparative Example 8 Cheese was prepared according to the method of Example 1, except that the rennet activity was 4.5 IMCU%.

[0084] Comparative Example 9 Cheese was prepared according to the method of Example 1, except that the rennet activity was 7.0 IMCU%.

[0085] Test Case The cheeses prepared in Examples 1 to 8 and Comparative Examples 1 to 9 were subjected to quality tests respectively: Table 1 Product sensory and texture evaluation data

[0086] 1. Texture test (1) The test was performed using a texture analyzer with a 12.7 mm diameter spherical probe that was pressed down 6 mm and held for 30 seconds before being lifted off the sample.

[0087] Parameter settings: pre-test speed 30mm / min, test speed 30mm / min, test distance 6mm, hold time 30s, down force 0.1N.

[0088] Hardness: The maximum force during the pressing process is recorded as the cheese hardness, unit: Newton.

[0089] Elasticity: The percentage of the load at the end point of the deformation for 30 seconds to the load at the starting point is recorded as elasticity, unit: %.

[0090] Maximum adhesive force: The absolute value of the maximum negative peak-to-peak value in the process of the probe rising back from the sample is recorded as the maximum adhesive force, unit: Newton.

[0091] Adhesion energy: The energy consumed by the adhesion of the sample when the probe rises and separates from the sample is recorded as adhesion energy, unit: millijoule.

[0092] (2) Tensile test: Prepare 10g of sliced ​​pizza sample, bake it in a 250℃ oven for 90s, cool it to 55-60℃, and use cylindrical and hook-shaped probes for testing. The pull-up height is 180mm and the test speed is 100mm / min.

[0093] The cheese texture test results are shown in Table 2. It can be seen that the cheese texture prepared in Examples 1-8 is better than that in Comparative Examples 1-9.

[0094] In Comparative Example 1, micellar casein powder was used. During the preparation of the micellar casein powder, the micellar structure was destroyed due to the high powder spraying temperature, resulting in poor coagulation and inability to stretch during the cheese preparation process.

[0095] It can be seen from Example 1, Comparative Example 2 and Comparative Example 3 that the amount of micellar casein liquid added is too high, the protein index is too high, the toughness is strong, and the stretching effect is not good; the amount of micellar casein liquid added is too low, the protein index is too low, the product is soft, the toughness is weak, and the oil precipitates and can flow.

[0096] It can be seen from Example 1, Comparative Example 4 and Comparative Example 5 that when the amount of thermophilic Streptococcus fermentation agent added is too high, the fermentation rate is accelerated, the moisture content is increased, and the product is softer; when the amount of thermophilic Streptococcus fermentation agent added is too low, the fermentation rate is slowed down and the production time is increased.

[0097] It can be seen from Example 1, Comparative Example 6 and Comparative Example 7 that when the amount of cream added is too high, more fat is precipitated; when the amount of cream added is too low, the product has strong toughness, poor stretching effect, and only a small amount of fat is precipitated.

[0098] It can be seen from Example 1, Comparative Example 8 and Comparative Example 9 that when the activity of rennet is high, the fat loss is large, the coagulation speed is accelerated, and the product moisture is high; when the activity of rennet is low, the coagulation property is low.

[0099] It can be seen from Example 1 and Examples 6-8 that low-temperature fermentation and coagulation in the early stage can reduce fat loss and make the product taste smooth, and high-temperature fermentation in the later stage is conducive to the reproduction of the bacteria, so that the bacteria enter the logarithmic phase faster, ferment lactose to convert lactic acid, and improve the texture and flavor of the cheese.

[0100] Table 2 Cheese texture results of Examples and Comparative Examples

[0101] 2. Baking test Preheat the oven to 250°C, put in the pizza cheese, bake for 5 minutes, observe the product performance and measure the taste. Specifically, ask ten professionals to conduct sensory evaluation on the taste, milk flavor, melting property, and oil precipitation. The sensory evaluation rules are shown in Table 3.

[0102] Table 3 Sensory evaluation table

[0103] The sensory scores of cheese are shown in Table 4. It can be seen that the sensory evaluation of the cheese prepared in Examples 1-8 is better than that of Comparative Examples 1-9.

[0104] In Comparative Example 1, due to the use of micellar casein powder, the micellar structure was destroyed during the powder spraying process, resulting in poor coagulation during the cheese preparation process, and the curd was hard and could not be stretched.

[0105] It can be seen from Example 1, Comparative Example 2 and Comparative Example 3 that when the amount of micellar casein liquid added is too high, the cheese is too hard, the melting effect is not good, and the oil precipitation is poor; when the amount of micellar casein liquid added is too low, the oil precipitation is in a micro-flow state and the texture is too soft.

[0106] It can be seen from Example 1, Comparative Example 4 and Comparative Example 5 that when the amount of thermophilic Streptococcus fermentation agent added is too high, the fermentation rate is accelerated, the water is not easy to be discharged, the product is soft, and the flavor is poor; when the amount of thermophilic Streptococcus fermentation agent added is too low, the fermentation rate is slow and the flavor is poor.

[0107] It can be seen from Example 1, Comparative Example 6 and Comparative Example 7 that when the amount of cream added is too high, the cream completely melts, tends to be in a fluid state, is too soft, and has poor chewiness; when the amount of cream added is too low, the oil precipitation is poor and the flavor is poor.

[0108] It can be seen from Example 1, Comparative Example 8 and Comparative Example 9 that the activity of added rennet is too high, the milk flavor is insufficient, the product is soft, and the chewiness is poor; the activity of added rennet is too low, and the coagulation property is low.

[0109] It can be seen from Example 1 and Examples 6-8 that low-temperature fermentation and coagulation in the early stage can reduce fat loss and make the product taste smooth, and high-temperature fermentation in the later stage is conducive to the reproduction of the bacteria, so that the bacteria enter the logarithmic phase faster, and then ferment lactose to convert lactic acid, thereby improving the texture and flavor of the cheese.

[0110] Table 4 Sensory evaluation of cheese prepared in Examples and Comparative Examples

[0111] 3. The product of Example 1 was placed under refrigeration for different periods of time, and sensory evaluation and texture testing were performed for different periods of time, and the results are shown in Table 5. It can be seen that the cheese of the present application has a stable texture during the shelf life, and still has a good taste, texture, flavor, melting property, and oil precipitation property after being stored under refrigeration for 9 months.

[0112] Table 5 Evaluation results of refrigerated products

[0113] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A cheese, characterized in that: The raw materials of the cheese include: micellar casein liquid, cream, sugar, starter, rennet, calcium salt, salt and water; Based on the total mass of the raw materials of the cheese, the content of the micellar casein liquid is 43% to 46%, the content of the light cream is 6.3% to 6.8%, the content of the starter is 0.0015% to 0.0025%, and the activity of the rennet is 5.8 IMCU % to 6.4 IMCU %.

2. The cheese according to claim 1, characterized in that The micellar casein content in the micellar casein solution is 6% to 7%; Based on the total mass of the raw materials of the cheese, the carbohydrate content is 4.8% to 5.3%, the calcium salt content is 0.02% to 0.03%, and the salt content is 0.2% to 0.25%.

3. The cheese according to claim 1, characterized in that The sugar substance includes lactose; The fermentation agent includes Streptococcus thermophilus; The calcium salt includes calcium chloride.

4. The cheese according to claim 1, characterized in that The micellar casein solution is obtained by subjecting skimmed milk to microfiltration membrane treatment.

5. The cheese according to claim 4, characterized in that The conditions for the microfiltration membrane treatment include at least one of the following: The pore size of the microfiltration membrane is 0.1 μm~0.4 μm; The transmembrane pressure is 0.05 mPa~0.1 mPa; Temperature is 40℃~60℃; When using the diafiltration method, the volume ratio of diafiltration water to skim milk is (0.5~1.5):1; The concentration factor is 1~3.

6. A method for preparing the cheese according to any one of claims 1 to 5, characterized in that: include: Fermenting the micellar casein solution, cream, sugar, calcium salt, starter and water to obtain a fermentation product; The fermentation product is subjected to a coagulation treatment with rennet to obtain a curd; The curd is cut, stirred, drained, salted, blanched, stretched and cooled to obtain the cheese.

7. The method according to claim 6, characterized in that Further including: sterilizing the micellar casein solution, cream and water to obtain a sterilized product; The sterilization product, sugar substance, fermentation agent and calcium salt are subjected to the fermentation treatment.

8. The method according to claim 6, characterized in that The fermentation process includes a first fermentation stage and a second fermentation stage; The fermentation temperature of the first fermentation stage is lower than the fermentation temperature of the second fermentation stage.

9. The method according to claim 8, characterized in that The temperature of the first fermentation stage is 33°C to 35°C, and the time is 30 min to 60 min; The temperature of the second fermentation stage is 38°C to 41°C, and the time is 60 min to 90 min.

10. The method according to claim 6, characterized in that The pH value of the fermentation product is 6.4-6.6.

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