Low-fat high-protein stretched cheese and method for preparing the same

Abstract

The application relates to the field of food, and discloses a low-fat high-protein stretch type cheese and a preparation method thereof. The preparation method comprises the following steps: subjecting raw milk to standardization treatment to obtain a standardized liquid; subjecting the standardized liquid to sterilization treatment to obtain a sterilized product; uniformly mixing the sterilized product with konjac glucomannan after cooling to obtain a mixture; adjusting the pH value of the mixture to 5.8-6.0 by using an acidifying agent to obtain an acidified liquid; inoculating the acidified liquid with a starter to perform pre-fermentation treatment to obtain a pre-fermented product; performing curd formation treatment, whey discharge treatment, heap fermentation treatment, salting treatment, hot stretching treatment and ripening treatment on the pre-fermented product to obtain the low-fat high-protein stretch type cheese. The stretch type cheese disclosed by the application not only has low fat content and high protein content, but also has excellent melting property, stretchability and flavor taste, is comparable to traditional high-fat cheese, and meets the needs of consumers.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of food. Specifically, the present application relates to a low-fat high-protein stretch cheese and a preparation method thereof. BACKGROUND

[0002] Stretch cheese is a very popular dairy product, whose consumption has increased dramatically in the past few decades. Stretch cheese, commercially known as pizza cheese, is a semi-hard unripened cheese, white or yellow, smooth and elastic in surface, containing 20-30% of milk fat. Stretch cheese has become a high-consumption soft cheese, and 70% of it is used as an ingredient in the process of making pizza worldwide. However, it has been reported that food often containing saturated dairy fat can cause chronic obesity, cardiovascular disease, gastrointestinal and neurodegenerative disease, and other chronic diseases. Over time, consumers are increasingly aware of the consequences of high-fat foods and are becoming healthier, so the demand for low-fat cheese formulations has increased significantly. Today, dairy products, especially cheese, with reduced saturated fat and high protein content, play an important role in the intake of a balanced diet. This trend has led to an increased demand for the production of stretch cheese with less milk fat and high sensory properties.

[0003] Proper melting of cheese is an essential attribute of stretch cheese, so it has functionality on baked pizza. Fat in the stretch cheese system provides dynamic properties such as color, flavor, meltability, stretchability, spreadability, and lubricity, and the reduction of fat has a negative impact on the functionality and rheological properties of stretch cheese, and the reduction of fat makes stretch cheese less meltable, mainly because the lubrication between fat and protein globules is reduced. The meltability of cheese is also affected by the total calcium content and protein-bound calcium, the degree and type of protein hydrolysis, and the baking conditions. It has been reported that the meltable increased 2.6-fold as the calcium content decreased from 0.65% to 0.35%.

[0004] Therefore, the current low-fat high-protein stretch cheese and the preparation method thereof still need to be researched. SUMMARY

[0005] The present application aims to at least partially solve the technical problems existing in the prior art. To this end, the present application proposes a low-fat high-protein stretch cheese and a preparation method thereof, which not only has a low-fat content and a high-protein content, but also has excellent meltability, stretchability, and flavor and taste, comparable to traditional high-fat cheese, meeting the needs of consumers.

[0006] In one aspect of the present application, a method for preparing a low-fat high-protein stretch cheese is provided. According to an embodiment of the present application, the method comprises: subjecting raw milk to standardization to obtain a standardized liquid; subjecting the standardized liquid to sterilization to obtain a sterilized product; mixing the sterilized product with konjac glucomannan after cooling to obtain a mixture; adjusting the pH value of the mixture to 5.8-6.0 using an acidifying agent to obtain an acidified liquid; inoculating the acidified liquid with a starter culture to perform pre-fermentation to obtain a pre-fermented product; subjecting the pre-fermented product to curd formation, whey separation, heap fermentation, salting, hot stretching and maturation to obtain the low-fat high-protein stretch cheese; and the low-fat high-protein stretch cheese has a fat content of 5-6% by mass and a protein content of 24-26% by mass.

[0007] The protein content of traditional fermented stretch cheese is usually between 23%-27%, the fat content is between 18%-25%, and the ratio of casein to fat is close to 1:1. Using the traditional preparation process, cheese with good texture, flavor and taste can be obtained. In order to obtain low-fat cheese, the casein content needs to be maintained. Casein not only provides protein and improves nutritional value, but also improves the stretchability of cheese to some extent, making up for the decrease in stretchability caused by low fat. However, high-protein low-fat cheese still has problems such as poor melting, stretchability and flavor and taste.

[0008] In order to solve these problems, the present application adopts a unique acidification process, i.e. combining acidification of acidifying agent with acidification of starter culture. Specifically, since the decrease in fat content causes insufficient melting of cheese, the calcium content of the system can be reduced to improve the melting of cheese, which can be achieved by acidification of the acidifying agent. The acidifying agent can easily combine with calcium ions in the casein micelles to form calcium salt, which is discharged with whey, thereby rapidly and effectively reducing the calcium content of the cheese and significantly improving its melting. Further, the termination pH value of the acidification of the acidifying agent is controlled to be 5.8-6.0. If the pH value exceeds 6.0, the final product has too high calcium content, poor melting and poor stretchability. If the pH value is less than 5.8, the calcium content is too low, the melting is excessive, the stretchability is weak, and even there is almost no stretchability. However, the cheese treated only by the acidifying agent has poor flavor and taste, and the melting and stretchability cannot reach a high level. Therefore, the present application further combines the acidification of the starter culture on the basis of the acidification of the acidifying agent to enhance the flavor and taste of the cheese.

[0009] The raw milk is standardized to obtain a low-fat high-protein standardized liquid, which is then subjected to sterilization treatment. Due to the low fat content in the cheese, the stability of the cheese is significantly reduced. Therefore, konjac glucomannan (KGM) is added after sterilization treatment. KGM is a natural polysaccharide extracted from konjac tubers, which has the characteristics of solubility, stability, and high molecular weight. These characteristics endow KGM with excellent thickening properties, gelation behavior, water holding capacity, and biocompatibility. It can disperse in hot or cold water and form higher viscosity than guar gum and locust bean gum. By adding KGM, part of the fat content in traditional cheese is replaced, thereby reducing the fat content while retaining the flexibility and elasticity of the cheese and improving its overall sensory quality. After sterilization and cooling, KGM is added to the same acidification agent to acidify and better gel-forming ability, and the prepared cheese has good texture and flavor taste. If KGM is added after the acidification of the acidification agent, such as during the pre-fermentation process, KGM quickly gels in an acidic environment, competing with casein for cross-linking and resulting in uneven cheese texture and rubber-like hard lumps. KGM gel blocks the extension of casein fibers, reducing the stretchability, and absorbs flavor molecules, hindering their release, resulting in reduced milk aroma. If KGM is added before sterilization treatment, due to the high sterilization temperature, KGM will undergo irreversible uncoiling of molecular chains at temperatures > 60°C, resulting in the breaking of β-1,4 glycosidic bonds and a loss of viscosity, and a decrease in gel-forming ability. In addition, due to the high temperature of the liquid after sterilization, the addition of konjac glucomannan after cooling can maintain the properties of konjac glucomannan. Specifically, it can be cooled to 40-45°C or directly cooled to the temperature of the acidification agent addition, 10-15°C.

[0010] After acidification treatment, the fermentation product enters the subsequent processing steps, including curd, whey separation, stacking, salting, hot stretching, and maturation treatment, to further improve the flavor and texture of the cheese.

[0011] Therefore, the stretch cheese prepared according to the method of the present application not only has a low fat content and a high protein content, but also has excellent melting, stretchability, and flavor taste, comparable to traditional high-fat cheese, meeting the needs of consumers.

[0012] According to the embodiments of the present application, the above method for preparing low-fat high-protein stretch cheese can also have the following additional technical features:

[0013] According to the embodiments of the present application, the mass ratio of casein and fat in the standardized feed liquid is (5-20):1, for example, 5:1, 6:1, 8:1, 10:1, 12:1, 14:1, 15:1, 16:1, 18:1, 20:1. After conventional standardization, the contents of casein and fat are close to 1:1. By controlling the casein and fat in the standardized feed liquid to meet the above conditions, combined with the improvement of the preparation process, a low-fat high-protein cheese with good stretchability, melting property, stability and flavor taste can be obtained. For example, fat and skimmed milk can be obtained by centrifugal treatment, and then the fat and skimmed milk are mixed according to the ratio of casein and fat to obtain the standardized feed liquid.

[0014] According to the embodiments of the present application, the concentration of konjac glucomannan in the mixture is 1.1-1.3 g / 100 mL, that is, the addition amount of konjac glucomannan is 1.1-1.3 g based on 100 mL of the mixture. For example, the concentration of konjac glucomannan in the mixture is 1.1 g / 100 mL, 1.12 g / 100 mL, 1.15 g / 100 mL, 1.16 g / 100 mL, 1.18 g / 100 mL, 1.2 g / 100 mL, 1.22 g / 100 mL, 1.24 g / 100 mL, 1.25 g / 100 mL, 1.26 g / 100 mL, 1.28 g / 100 mL, 1.3 g / 100 mL. In this way, the cheese has better stretchability and melting property, the oil is appropriately separated after baking, the cheese silk is completely melted and does not flow, and the chewing taste is good.

[0015] According to the embodiments of the present application, the acidifying agent includes one or more of citric acid, lactic acid, glacial acetic acid, and tartaric acid.

[0016] According to the embodiments of the present application, the temperature of the sterilization treatment is 72-74°C, and the time is 14-16 s. In this way, it is beneficial to fully kill the miscellaneous bacteria and reduce the loss of nutritional ingredients.

[0017] According to the embodiments of the present application, before the pH value of the mixture is adjusted by the acidifying agent, the mixture is cooled to 10-15°C, for example, 10°C, 11°C, 12°C, 13°C, 14°C, 15°C. In this way, it is beneficial to chelate the acidifying agent with calcium ions to form calcium salt precipitate.

[0018] According to the embodiments of the present application, based on 100 kg of the acidified feed liquid, the addition amount of the ferment is 1-3 g, for example, 1 g, 1.5 g, 2 g, 2.5 g, 3 g. In this way, it is beneficial to enhance the flavor of the product, and the stretchability and melting property of the product are excellent.

[0019] According to the embodiments of the present application, the pre-fermentation treatment time is 25-35 min, for example, 25 min, 26 min, 28 min, 30 min, 32 min, 34 min, 35 min. Thus, the cheese curd effect is optimized, the whey discharge is beneficial, and the flavor substance release is facilitated, thereby improving the cheese flavor.

[0020] According to the embodiments of the present application, the fermenting agent comprises one or more of Lactobacillus bulgaricus, Streptococcus thermophilus, Lactobacillus helveticus, Lactobacillus casei, or Lactococcus lactis.

[0021] According to the embodiments of the present application, the curd treatment comprises: adding rennet to the pre-fermentation product, stirring and standing, and cutting into blocks; the final enzyme activity of the rennet in the pre-fermentation product is 40-60 IMCU / L; the standing time is 25-35 min; after cutting into blocks, standing for 5-10 min. Thus, the cheese flavor taste is good, and the melting and stretching properties are good.

[0022] According to the embodiments of the present application, the method further comprises: mixing the brine treatment liquid with cream, and then performing the hot stretching treatment. Thus, the cream is added to meet the fat content requirements of the cheese.

[0023] According to the embodiments of the present application, the cream comprises butter, whipping cream, and / or anhydrous cream. The whipping cream has a slightly lower milk flavor after mixing, the anhydrous cream has a harsh flavor, and the butter has a better effect. The amount of cream added is calculated based on the fat content in the final cheese.

[0024] According to the embodiments of the present application, the amount of salt used in the brine treatment is 1-2% by mass of the heap fermentation treatment liquid, preferably 1.5-1.7% by mass. Thus, the cheese flavor taste and texture are better.

[0025] According to the embodiments of the present application, the temperature of the whey discharge is 40-41℃, and the stirring time is 20-25 min. Thus, the cheese flavor taste and texture are better.

[0026] According to the embodiments of the present application, the heap fermentation treatment comprises: continuing to ferment the curd after the whey discharge at 40-41℃ until the pH value is 5.0-5.2. Thus, the cheese flavor taste and texture are better.

[0027] According to the embodiments of the present application, the temperature of the hot stretching is 82-87℃, the time is 10-15 min, and the stretching is performed in a 3-6% by mass salt water. Thus, the cheese has good melting and stretching properties.

[0028] According to the embodiments of the present application, the temperature of the ripening treatment is 2-6℃, and the time is 13-15 days. Thus, the release of flavor substances is facilitated.

[0029] In another aspect of the present application, the present application provides a low-fat high-protein stretched cheese. According to the embodiments of the present application, the low-fat high-protein stretched cheese is obtained by the method for preparing a low-fat high-protein stretched cheese described above. Thus, the stretched cheese of the present application not only has a low fat content and a high protein content, but also has excellent melting, stretchability and flavor taste, which is comparable to traditional high-fat cheese, and meets the needs of consumers.

[0030] Additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter. DETAILED DESCRIPTION

[0031] The embodiments of the present application are described in detail below. The embodiments described below are exemplary only, and are intended to explain the present application, and should not be understood as a limitation of the present application.

[0032] It should be noted that the terms "first", "second" are used only for the purpose of description, and should not be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Thus, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. Further, in the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0033] The endpoints of the ranges and any values disclosed herein are not limited to the precise values stated. The ranges or values should be construed to be approximations that allow for significant variation. Various ranges of values are stated in terms of being between about one value and another. When such ranges are used, they always include the values that are expressly recited as endpoints. Many embodiments are presented in terms of mathematical expressions of the present application over a range of values. At the very least, and also by applying the teachings of the present application, one of ordinary skill in the art will appreciate that embodiments can be implemented over a range of values. At the very least, and also by applying the teachings of the present application, one of ordinary skill in the art will appreciate that embodiments can be implemented over a range of values.

[0034] In this document, the terms "comprise" or "include" are open-ended, i.e. they include what is recited in the present application, but do not exclude other aspects.

[0035] The present application provides a method for preparing a low-fat high-protein stretched cheese, comprising:

[0036] 1. Standardization: standardize the milk to a casein-fat ratio of (5-20): 1.

[0037] 2. Sterilization: pasteurize at 72-74℃ for 14-16 s, and then cool to 40-45℃.

[0038] 3. Add Konjac Glucomannan: Add Konjac Glucomannan to the pasteurized milk until the final concentration is 1.1-1.3 g / 100 mL, and mix well by slow stirring.

[0039] 4. Cool and acidify: Cool the mixture obtained in the previous step to 10-15 °C, and acidify to pH 5.8-6.0 by adding acidifying agent, while keeping slow stirring.

[0040] 5. Add starter culture: Warm the mixture obtained in the previous step to 33-37 °C and inoculate with a starter culture consisting of Streptococcus thermophilus STI-13 (Chr. Hansen) at a dosage of 1-3 g / 100 kg, and wait for 25-35 minutes for pre-fermentation.

[0041] 6. Coagulate: Add rennet (CHY-MAX™ PLUS, Chr. Hansen) previously diluted with chlorine-free cold water to the mixture obtained in the previous step until the final activity is 40-60 IMCU / L, and gently stir, then let stand for 25-35 minutes, cut into 1 cm cubes using a 1 cm wire knife, and let stand for 5-10 minutes.

[0042] 7. Drain whey: Slowly warm the milk to 40-41 °C, and gently stir for 20-25 minutes during the warming period to avoid the fusion of the freshly cut curd pieces and to promote whey drainage, and finally drain all the whey.

[0043] 8. Salting: Place the curd pieces in a salting tunnel at 40-41 °C for continued fermentation until pH 5.0-5.2, weigh the curd, and add salt at a level of 1-2 % (w / w), then add melted butterfat and mix well.

[0044] 9. Hot stretching: Stretch the salted curd in hot water at 82-87 °C containing 3-6 % salt using a double screw device for 10-15 minutes until the surface is smooth and delicate.

[0045] 10. Packaging: Package the cheese into blocks using a mold, vacuum package each block into a barrier bag using a vacuum packaging machine, and then store at 2-6 °C.

[0046] The solutions of the present application will be explained in connection with the following examples. Those skilled in the art will understand that the following examples are intended to be illustrative only and are not intended to limit the scope of the present application. Unless otherwise indicated, the techniques or conditions described in the examples are those that would be described in the literature or according to the manufacturer’s instructions. Unless otherwise indicated, the reagents or instruments used are conventional products that can be obtained commercially.

[0047] Examples 1-4

[0048] A low-fat high-protein stretched cheese was prepared according to the following method:

[0049] 1. Standardization: Standardize the milk to a casein-fat ratio of A, resulting in 100 kg of standardized milk.

[0050] 2. Pasteurization: Pasteurize the milk at B°C for C s.

[0051] 3. Addition of Konjac Glucomannan: Add Konjac Glucomannan to the pasteurized milk to a final concentration of E g / 100 mL, and mix thoroughly with slow stirring.

[0052] 4. Cooling and acidification: Cool the mixture to D°C, and acidify to pH F by adding an acidifying agent, while maintaining slow stirring.

[0053] 5. Addition of starter culture: Warm the mixture to 37°C and inoculate with a starter culture consisting of STI-13 starter culture (Chr. Hansen) to a level of 2 g / 100 kg, and pre-ferment for 30 minutes.

[0054] 6. Curdling: Add rennet (CHY-MAX™ PLUS, Chr. Hansen) previously diluted with non-chlorinated cold water to a final activity of 60 IMCU / L, and mix gently. Let stand for 30 minutes, cut into 1 cm cubes using a 1 cm wire knife, and let stand for 10 minutes.

[0055] 7. Whey draining: Slowly warm the milk to G°C, and mix gently for H minutes during the warming period to avoid fusion of the freshly cut curd and to promote whey drainage. Finally, drain the whey completely.

[0056] 8. Cheddaring: Place the curd in a cheddaring tunnel at I°C for further fermentation until pH J. Weigh the curd and salt to a level of K % (w / w), and then add O g / kg of melted, grated butter and mix thoroughly.

[0057] 9. Hot-washing and stretching: Stretch the salted curd in L°C hot water containing 4% salt using a double-screw apparatus for M minutes until the surface is smooth and delicate.

[0058] 10. Packaging and maturation: Package the cheese into blocks using a mould, vacuum-pack each block into a barrier bag using a vacuum-packing machine, and store at 4°C for N days.

[0059] Table 1 Process parameters for Examples 1-4

[0060]

[0061] Example 5

[0062] A low-fat, high-protein stretched cheese was prepared according to the method of Example 1, except that in step 3, the final concentration of Konjac Glucomannan was 0.9 g / 100 mL.

[0063] Example 6

[0064] Low-fat high-protein stretch cheese was prepared according to the method of Example 1, except that in Step 3, the final concentration of konjac glucomannan was 1.5 g / 100 mL.

[0065] Example 7

[0066] Low-fat high-protein stretch cheese was prepared according to the method of Example 3, except that butter was replaced by anhydrous butter (fat content 99.8%), and the amount of addition was 24 g / kg curd.

[0067] Example 8

[0068] Low-fat high-protein stretch cheese was prepared according to the method of Example 4, except that the amount of butter added was 37 g / kg curd.

[0069] Comparative Example 1

[0070] Low-fat high-protein stretch cheese was prepared according to the method of Example 1, except that Step 4 was not included, and the mixture obtained in Step 3 was directly subjected to Step 5.

[0071] Comparative Example 2

[0072] Low-fat high-protein stretch cheese was prepared according to the method of Example 1, except that in Step 4, the acidifier was added to acidify to a pH of 5.2, and then Step 5 was not performed, and Step 6 was directly performed.

[0073] Comparative Example 3

[0074] Low-fat high-protein stretch cheese was prepared according to the method of Example 1, except that Step 3 was not included, and the pasteurized milk obtained in Step 2 was directly subjected to Step 4.

[0075] Comparative Example 4

[0076] Low-fat high-protein stretch cheese was prepared according to the method of Example 1, except that Step 3 was not included;

[0077] Step 4: Temperature reduction and acidification: The pasteurized mixture from the previous step was cooled to 10°C, and an acidifier was added to acidify to a pH of 5.9, while maintaining slow stirring during the process;

[0078] Step 5: Addition of starter culture: The mixture obtained in the previous step was warmed to 33-37°C and inoculated with a starter culture consisting of STI-13 starter culture (Chr. Hansen) of Streptococcus thermophilus, with an addition amount of 2 g / 100 kg, and konjac glucomannan was added to a final concentration of 1.1 g / 100 mL, and pre-fermentation was performed for 30 minutes.

[0079] Comparative Example 5

[0080] A low-fat high-protein stretched cheese was prepared according to the method of example 1, except that in step 4, the pH F of the acidification was 5.6.

[0081] Comparative example 6

[0082] A low-fat high-protein stretched cheese was prepared according to the method of example 1, except that in step 4, the pH F of the acidification was 6.1.

[0083] Comparative example 7

[0084] A high-fat high-protein stretched cheese was prepared according to the following method:

[0085] Milk was standardized to a casein-fat ratio of 1 : 1, pasteurized at 72°C for 15 s, cooled to 33°C and inoculated with a starter culture of Streptococcus thermophilus consisting of STI-13 (Chr Hansen) at a dose of 2 g / 100 kg, and left for 30 min. Chymosin (CHY-MAX™ PLUS, Chr Hansen) was added, previously diluted with non-chlorinated cold water, to a final activity of 60 IMCU / L, and gently stirred. The milk was left to rest for 30 min, cut into 1 cm cubes using a 1 cm wire knife, and left to rest for 10 min. The milk was slowly warmed to 41°C, and gently stirred for 25 min during the warming period to avoid the fusion of the freshly cut curd pieces and to promote whey expulsion. Finally, the whey was completely expelled, and the curd pieces were placed in a 41°C cheese tunnel for further fermentation until pH 5.2. The curd was weighed and salted at a level of 1.5% (w / w), and stretched in 6% salted hot water at 85°C using a twin-screw apparatus for 15 min until the surface was smooth and delicate. The cheese was packed in blocks using a former, vacuum-packed in isolation bags using a vacuum-packing machine, and stored at 4°C for 15 days.

[0086] Comparative example 8

[0087] A low-fat high-protein stretched cheese was prepared according to the method of example 1, except that inulin was used instead of konjac glucomannan.

[0088] Test example

[0089] 1. The composition of the low-fat high-protein stretched cheese of examples 1-8 and comparative examples 1-8 was determined, respectively, according to the following methods:

[0090] Protein, fat, moisture, calcium and sodium content: determined according to GB 5009.5-2016, GB 5009.6-2016, GB 5009.3-2016, GB 5009.92-2016 and GB 5009.91-2017, respectively.

[0091] Table 2 Cheese composition

[0092]

[0093] 2. Sensory evaluation was performed on the low-fat high-protein stretched cheese of Examples 1-8 and Comparative Examples 1-8, respectively, in the following manner: 100 g of the cheese product was cut into pieces and evenly placed on a 9-inch pizza. The pizza was baked in a track oven at 250°C for 300 s, and cooled for 120 s or until the sample temperature reached 75°C. The pizza was then cut into 8 pieces and the prepared sample was used for evaluation. Ten professional sensory evaluators were selected and the evaluation was performed as follows:

[0094] Stretchability: One piece of the sample was observed for stretchability.

[0095] Melting: The melting of the surface of the cheese was observed under light, and the pizza was observed for flowability.

[0096] Spot size: The spot size and uniformity were measured using a ruler under light.

[0097] Spot color: The color of the cheese was observed under light.

[0098] Spot area: The spot area of the cheese was observed and estimated under light.

[0099] Oiliness: The surface of the cheese was pressed using a knife and fork or the pizza was tilted and observed under light.

[0100] Taste and odor: One piece of the sample was used to smell the odor, then the mouth was rinsed with warm water, and the taste was then tasted.

[0101] Texture: One piece of the sample was used to rinse the mouth with warm water, and the texture was then tasted.

[0102] The taste and odor score sheet is shown in Table 3.

[0103] Table 3. Taste and odor score sheet

[0104]

[0105] The results are shown in Table 4. It can be seen that the cheese prepared in Examples 1-4 has better stretchability, melting, baking state, and flavor and taste.

[0106] As can be seen from Example 1 and Comparative Example 1, without acidification using an acidulant, the stretchability is significantly weakened, most of the shredded cheese does not completely melt, almost no oil is separated, there is a wax feeling when chewing, the spot diameter is large, and the color is dark.

[0107] As can be seen from Example 1 and Comparative Example 2, directly acidifying to a low pH value using an acidulant without pre-fermentation of the starter, the stretchability is weak, the chewing is loose, there is a feeling of broken slag, and the milk flavor is obviously insufficient.

[0108] As can be seen from Example 1 and Comparative Example 3, no konjac glucomannan is added, the stringiness is stronger, easy to break, almost no stringing, the cut silk is almost not melted, large area of focal spot, almost no oil separation, lower sensory score.

[0109] As can be seen from Example 1 and Comparative Example 4, konjac glucomannan is added during pre-fermentation, the stringiness is stronger, easy to break, the cut silk is almost not melted, no oil separation, surface drying, larger focal spot diameter, dark brown and higher coverage, lower sensory score.

[0110] As can be seen from Example 1 and Comparative Example 5, the pH value of the acidification end point of the acidifying agent is too low, the stringiness is weaker, the cut silk is over-melted in a flowing state, there is a sense of debris when chewing, and the sensory score is lower.

[0111] As can be seen from Example 1 and Comparative Example 6, the pH value of the acidification end point of the acidifying agent is too high, the stringiness is stronger and easy to break, a small part of the cut silk is not completely melted, almost no oil separation and lower sensory score.

[0112] As can be seen from Example 1 and Comparative Example 7, Comparative Example 7 produces a high-fat high-protein cheese, and the method of the present application can obtain a low-fat high-protein cheese with comparable quality to the high-fat high-protein cheese of Comparative Example 7.

[0113] As can be seen from Example 1 and Comparative Example 8, the konjac glucomannan is replaced by inulin, the stringiness is slightly weaker, the focal spot diameter is slightly larger, there is a slight sense of debris when chewing, and the sensory score is slightly lower.

[0114] Table 4 Sensory evaluation results

[0115]

[0116] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.​

Claims

1. A method of preparing a low-fat, high-protein, stretchy cheese, characterized in that, The application relates to a method for preparing a low-fat high-protein stretched cheese. The method comprises the following steps: standardizing raw milk to obtain a standardized liquid; sterilizing the standardized liquid to obtain a sterilized product; mixing the sterilized product with konjac glucomannan after cooling to obtain a mixture; adjusting the pH value of the mixture to 5.8-6.0 by using an acidifying agent to obtain an acidified liquid; inoculating the acidified liquid with a starter to perform pre-fermentation to obtain a pre-fermented product; performing curd formation, whey separation, heap fermentation, salting, hot stretching and ripening on the pre-fermented product to obtain the low-fat high-protein stretched cheese; the low-fat high-protein stretched cheese has a fat content of 5.5-6% by mass and a protein content of 24-26% by mass; in the standardized liquid, the mass ratio of casein to fat is (5-20):1; the method further comprises mixing the liquid obtained through the salting with butter and then performing the hot stretching; 2. The method of claim 1, wherein, the butter comprises yellow butter.

3. The method according to claim 1 or 2, characterized in that, The concentration of konjac glucomannan in the mixture is 1.1-1.3 g / 100 mL. The acidifying agent comprises one or more of citric acid, lactic acid, glacial acetic acid and tartaric acid; before adjusting the pH value of the mixture by using the acidifying agent, the mixture is cooled to 10-15 DEG C; 4. The method of claim 1, wherein, the sterilization is performed at a temperature of 72-74 DEG C for 14-16 s. based on 100 kg of the acidified liquid, the amount of the starter added is 1-3 g, and the pre-fermentation is performed for 25-35 min at a temperature of 33-37 DEG C; 5. The method of claim 1, wherein, the starter comprises one or more of Lactobacillus bulgaricus, Streptococcus thermophilus, Lactobacillus helveticus, Lactobacillus casei and Lactococcus lactis. the curd formation comprises adding rennet to the pre-fermented product, stirring and then standing, and cutting into blocks; the final enzyme activity of the rennet in the pre-fermented product is 40-60 IMCU / L; the standing time is 25-35 min; 6. The method of claim 1, wherein, after the cutting into blocks, the standing time is 5-10 min.

7. The method of claim 1, wherein, the amount of salt used in the salting is 1-2% by mass of the liquid obtained through the heap fermentation. the temperature of the whey separation is 40-41 DEG C, and the stirring time is 20-25 min; the heap fermentation comprises continuing the fermentation of the curd block obtained through the whey separation at a temperature of 40-41 DEG C until the pH value is 5.0-5.2; the hot stretching is performed at a temperature of 82-87 DEG C for 10-15 min in 3-6% salt water; 8. A low-fat, high-protein, stretched cheese, characterized in that, the ripening is performed at a temperature of 2-6 DEG C for 13-15 days. The low-fat high-protein stretched cheese is obtained by the method for preparing a low-fat high-protein stretched cheese according to any one of claims 1-7.

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