Novel cheese production method

Abstract

The invention belongs to the field of food processing and production, and particularly relates to a novel production method of cheese. Cow milk is used as a raw material, a microfiltration treatment technology is combined, and casein interception liquid and fat are mixed in proportion to prepare the cheese. The embodiment of the invention shows that compared with the prior art, the cheese produced by mixing the microfiltration trapped fluid with 10% or 20% of fat has no significant difference in sensory analysis, functional characteristics and the like, and the cheese produced by mixing the microfiltration trapped fluid with 40% of fat has good water-holding capacity, relatively strong melting property and relatively high oil separation property. According to the optimized novel cheese production method, the gelation rate can be increased, the preparation time is saved, and the production efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of food processing, and in particular relates to a novel production method of cheese. Background Art

[0002] With the improvement of consumers' living conditions and the increase of food nutrition demand, the dietary structure of dairy products has changed from "drinking milk" to "eating milk". Cheese is made by concentrating cow's milk 10 times, with high nutritional value, rich in high-quality protein, fat, vitamin A, calcium and phosphorus and other nutrients. Under the action of fermentation agent and rennet, most of the whey is discharged from the curd. In this process, the protein is enzymatically hydrolyzed into small molecules such as amino acids and peptides, which is conducive to digestion and absorption. The addition of fermentation agent and salt can hydrolyze fat and produce rich flavor substances. In addition, most of the lactose is discharged with the whey or is decomposed and fermented. Cheese is suitable for consumers with lactose intolerance and can meet consumers' requirements for food sensory properties and nutritional properties. Therefore, my country's cheese market has strong development potential.

[0003] Ultrafiltration technology (UF) has been widely used to make various types of cheese. Compared with traditional processes, cheese produced by ultrafiltration technology has higher nutritional value and higher content of whey protein, calcium and vitamins. Some studies have used ultrafiltration technology to process milk to make cheese, but because ultrafiltration will cause whey protein to be retained in the retentate, the incorporation of whey protein causes semi-hard and hard cheeses to show texture and functional defects.

[0004] Therefore, in order to prepare cheese with excellent texture and good functional properties, the process of cheese production still needs to be further improved. Summary of the invention

[0005] The object of the present invention is to provide a novel method for producing cheese, which can not only effectively separate casein and whey protein, but also increase the gelation rate, save time, and improve production efficiency.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] The present invention provides a cheese, which is prepared from casein retentate;

[0008] The casein retentate is obtained by membrane separation of skim milk.

[0009] Preferably, the cheese is prepared by mixing casein intercept and fat obtained from skimmed milk.

[0010] The present invention also provides a method for preparing cheese, which specifically comprises the following steps:

[0011] S1, heating raw milk and skimming it to obtain fat and skimmed milk;

[0012] S2, performing membrane separation on the skim milk in step S1 to obtain a casein interception liquid;

[0013] S3, mixing the casein intercepted liquid with the fat in step S1, adding rennet and incubating to obtain curd;

[0014] S4, cutting the curd in step S3 into particles and removing whey, and keeping warm and brewing;

[0015] S5. Add salt to the curd particles in step S4, stir evenly, press, blanch and store.

[0016] Preferably, the degreasing process in step S1 is to heat the milk to 60° C., keep it warm for 30 minutes, and perform degreasing process with a disc centrifuge.

[0017] Preferably, the membrane separation experiment process in step S2 is to add the skim milk in step S1 into a circulation tank of a separation device, and perform a membrane separation experiment using a 100 nm ceramic membrane.

[0018] More preferably, the transmembrane pressure difference in the membrane separation experiment is set to 80 kPa, the feed liquid temperature is controlled at 50-55° C. during the separation process, and the concentration multiple is 3.

[0019] Preferably, 0.04 g / L chymosin is added to the mixed product in step S3 and incubated at 32° C. for 45 min.

[0020] Preferably, step S4 further comprises cutting the curd into 1 cm 3 After the particles have stood for 5 minutes, the temperature was raised to 42°C and kept warm for 40 minutes. The whey was removed and the brewing was continued.

[0021] Preferably, in step S5, the amount of salt added to the curd particles is 1%, and the curd particles are pressed at 0.5 MPa for 30 minutes.

[0022] Preferably, the blanching process in step S5 is to place the pressed curd into the whey discharged in step S4 at 95° C. for 1 hour, and then store it at 4° C. after cooling.

[0023] Beneficial effects of the present invention:

[0024] 1. The raw materials used for the cheese of the present invention are simple, and no additives, thickeners or colloids are used, so the cheese is more nutritious and healthy.

[0025] 2. The present invention uses microfiltration technology to effectively separate casein and whey protein. The microfiltration technology can separate and obtain a retentate that is more suitable for producing semi-hard or hard cheese than concentrated milk or ultrafiltration retentate.

[0026] 3. The present invention adopts ceramic membrane to carry out membrane separation experiment, which has higher removal rate of whey protein and lower cost.

[0027] 4. The skim milk of the present invention is subjected to microfiltration to obtain a retentate, and the permeate obtained after ultrafiltration is mixed with fat as raw materials to produce cheese with excellent texture and functional properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0029] Figure 1 For comparison of protein content determination results;

[0030] Figure 2 For comparison of fat content determination results;

[0031] Figure 3 For comparison of moisture content determination results;

[0032] Figure 4 For comparison of ash content determination results;

[0033] Figure 5 For comparison of hardness test results;

[0034] Figure 6 For comparison of melting test results;

[0035] Figure 7 For comparison of oil separation test results;

[0036] Figure 8 For comparison of water holding capacity determination results;

[0037] Fig. 9 This is the result of electronic nose analysis;

[0038] Fig.10 For electronic nose data,information analysis results comparison;

[0039] Fig.11 To compare the results of cheese appearance analysis;

[0040] Fig.12 Comparison of cheese sensory evaluation data and information analysis results; DETAILED DESCRIPTION

[0041] The invention provides a cheese prepared by taking milk, rennet and salt as raw materials. The cheese contains no chemical components, has simple and safe ingredients and is high in nutritional value.

[0042] The invention provides a novel method for producing cheese, which uses milk as raw material, performs skimming treatment on the milk, adds the skimmed milk obtained into a membrane separation device, performs membrane separation experiment using a ceramic membrane, separates casein and whey protein, and collects the retentate after membrane separation. The retentate and the fat separated by the skimming treatment are mixed in proportion to prepare cheese.

[0043] The membrane separation process, namely the ultrafiltration process, uses a ceramic membrane with a pore size of 100 nm and a transmembrane pressure difference of 80 kPa. During the separation process, the feed liquid temperature is controlled at 50-55°C, the concentration factor is 3, and the retentate is collected for standby use.

[0044] The intercepted liquid collected in the membrane separation experiment during the preparation process of the present invention is respectively mixed with 0%, 2%, 4%, 6%, 8%, 10%, 20% and 40% of fat in proportion, and 0.04g / L rennet is added for incubation. The incubated curd is cut into particles, whey is removed, and the curd is kept warm for brewing, so as to inhibit the growth of gas-producing spoilage bacteria, promote the increase of acidity of curd, kill Escherichia coli, change the internal structure of curd, control the moisture content of cheese and form a unique texture.

[0045] 1% salt is added to the curd particles after heat preservation and brewing, and they are pressed at 0.5MPa. The curd blocks are immersed in hot whey or hot salt water, kneaded and stretched, so that the curd blocks gradually become smooth and elastic. Through the heating and stretching steps, the casein, which was originally in a grid shape, will be rearranged into a strip-like structure along the stretching direction. Some fat globules and water will be embedded in the gaps of the protein strips, so that the cheese will form a fibrous structure with a more compact texture. The subsequent cooling and molding process further fixes and retains this structure and texture, thus forming the unique stringy characteristics of the cheese.

[0046] In order to further illustrate the present invention, the technical solution provided by the present invention is described in detail below in conjunction with the accompanying drawings and embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0047] The production processes, experimental methods or detection methods involved in the embodiments of the present invention, unless otherwise specified, are all conventional methods in the prior art, and their names and / or abbreviations are all conventional names in the field. The various instruments, equipment, raw materials or reagents used in the embodiments of the present invention have no special restrictions on the sources, are all conventional products that can be purchased through regular commercial channels, and can also be prepared according to conventional methods well known to those skilled in the art.

[0048] Example 1 Cheese Preparation

[0049] The raw milk was heated to 60°C for 30 min and skimmed using a disc centrifuge (FT15-A, Armfield, UK) to obtain fat and skimmed milk.

[0050] The separated fat was cooled to room temperature for later use, and the skim milk was added to the circulation tank of a membrane separation device (Keysino plantscale, Shanghai Kaixin Separation Technology Co., Ltd.), and a membrane separation experiment was carried out using a 100 nm ceramic membrane.

[0051] In the membrane separation experiment, the transmembrane pressure difference was set to 80 kPa, the feed liquid temperature was controlled at 50-55°C during the separation process, the concentration factor was 3, and the retentate was collected for later use.

[0052] The fat was mixed with the retentate at a ratio of 0%, 2%, 4%, 6%, 8%, 10%, 20%, and 40%, and the protein and fat contents in the reconstituted samples were determined. The temperature was adjusted to 32°C, 0.04 g / L rennet was added to the reconstituted samples, and incubated for 45 min.

[0053] Then, cut the curd into 1cm 3 After the particles have stood for 5 minutes, the temperature was raised to 42°C and kept warm for 40 minutes. The whey was removed and the brewing was continued.

[0054] Add 1% salt to the curd particles and stir evenly. Press the curd particles at 0.5 MPa for 30 minutes. Put the pressed curd into 95℃ whey for 1 hour, cool the curd to room temperature, package and store at 4℃ for further measurement.

[0055] Comparative Example 1

[0056] The protein and fat content of cow milk was measured using cow milk as a control group. The temperature was adjusted to 32°C. 0.1 g / L rennet was added to the milk and incubated for 45 min. Then, the curd was cut into 1 cm 3 After 5 minutes of standing, the temperature was raised to 42°C, kept warm for 40 minutes, whey was removed, and the curd was kept warm. 1% salt was added to the curd particles and stirred evenly. The curd particles were pressed at 0.5MPa for 30 minutes. The pressed curd was placed in 95°C whey and blanched for 1 hour. The curd was removed and cooled to room temperature, packaged and stored at 4°C for further measurement.

[0057] Example 2 Determination of fat content and protein content

[0058] The fat and protein contents in the comparative example and reconstituted samples were determined according to the Mojonnier method and the Kjeldahl method. Figure 1-2 shown.

[0059] The moisture content was measured by drying method. Figure 3 shown.

[0060] 1g of cheese is kept at 105℃ for 5h until constant weight. 1g of sample (m1) is weighed in a constant weight crucible (m0), carbonized with a low fire and kept at 550℃ for 5h, cooled to room temperature and weighed m2, ash content (%) = (m2-m0) / m1×100, the result is as follows Figure 4 shown.

[0061] The results showed that the fat content of the control group was 25.05%, and the fat content of the cheese prepared by casein micelle retentate ranged from 2.83% to 44.30%, which increased with the increase of fat addition. Among them, the fat content of the cheese prepared by casein micelle retentate and 20% fat reconstituted samples was closest to that of the control group. The protein content of the control group was 20.39%, and the protein content of the cheese prepared by casein micelle retentate was 36.14%-16.58%, which decreased with the increase of fat addition. The moisture content decreased with the increase of fat content, and the ash content decreased with the increase of fat content. There was no significant difference in the protein content, fat content, ash content and moisture content of the cheese prepared by casein micelle retentate and 20% fat reconstituted samples compared with the cheese components of the control group.

[0062] Example 3 Determination of texture characteristics

[0063] Cut the cheese into 1cm pieces 3 The texture characteristics of cheese were determined by a texture analyzer (TA.HDplus, Stable Micro Systems, Surrey, UK). The P / 36R round probe was selected for the full texture analysis (TPA) test. The probe descent speed was set to 2 mm / s before and after the test. The speed was set to 1 mm / s during the test. The trigger force was set to 5 g and the deformation was 40% to determine the hardness of the sample.

[0064] The results are as follows Figure 5 As shown, there are significant differences in the textural properties between the different samples. The casein micellar retentate has a higher total solid content and calcium content, which leads to an increase in colloidal calcium, so the samples prepared from the microfiltration retentate (fat content 0-8%) have a higher hardness compared with the control cheese. With the increase in fat content, the hardness of the cheese shows a trend of first increasing and then decreasing. There is no significant difference in the hardness of the cheese prepared from the casein micellar retentate and 20% fat reconstituted samples and the control cheese.

[0065] Example 4 Functional property determination

[0066] 4.1 Determination of solubility and oil separation

[0067] Cut the cheese into cylinders with a diameter of 1.2 cm and a height of 1.0 cm. Then, place them on filter paper with a diameter of 9 cm and keep them at 105°C for 1 hour. After cooling to 25°C, measure the height of the cylinder to indicate the melting property of the cheese. After heating, an oil ring is formed on the filter paper. Measure the diameter of the oil ring from four directions and take the average value to represent the oil separation property of the cheese.

[0068] Cheese melting results Figure 6 As shown. The melting properties of cheese are related to the interaction between proteins. The higher the height value, the worse the sample's solubility. The height of the control group sample was 0.83 cm, and the height range of the cheese prepared by recombining the microfiltration retentate with fat was 0.23-0.98 cm. With the increase of fat content in the recombinant sample, the melting properties of the cheese first decreased and then increased, and the MF-40% sample had the highest solubility. This is because the MF-40% sample has the least retentate content, and the protein content and calcium content are reduced, resulting in reduced protein cross-linking, reduced interactions between proteins, and increased solubility.

[0069] The results of cheese oil separation are as follows Figure 7 As shown. The larger the diameter of the oil ring, the stronger the oil separation. The diameter of the oil ring of the control sample is 6.48cm. The oil separation of MF-0%, MF-2%, and MF-4% is close to zero because the fat content in these samples is very low. With the increase of fat content in the recombinant samples, the diameter of the oil ring increases significantly, indicating that the oil separation of cheese is enhanced, and MF-40% has the highest oil separation. Comprehensively considering all samples, the functional characteristics of MF-20% are closest to those of the control group, with no significant difference.

[0070] 4.2 Determination of water holding capacity

[0071] Weigh 5g of sample and centrifuge at 10000rpm for 30min at 25℃. Let the sample stand at 4℃ for 1h to solidify the fat, discard the water, and weigh the remaining sample (m2). The water holding capacity (WHC) is calculated according to the following formula: WHC (%) = m2 / m1×100.

[0072] The results of cheese water holding capacity are as follows Figure 8 As shown. The water holding capacity of the control sample was 87.26%, the highest water holding capacity of the cheese prepared by recombining the microfiltration retentate with 40% fat was 97.75%, and the lowest water holding capacity of the cheese prepared by recombining the microfiltration retentate with 10% fat was 86.04%. The water holding capacity first decreased and then increased with the increase of fat content in the recombined samples. There was no significant difference in the water holding capacity of the cheese prepared by recombining the microfiltration retentate with 10% or 20% fat and the control group, and the water holding capacity of the other samples was significantly higher than that of the control group. The results show that the cheese prepared by recombining the microfiltration retentate with fat has good water holding capacity.

[0073] 4.3 Electronic Nose and Electronic Eye Detection

[0074] For electronic nose detection, the samples were chopped and placed in a sample bottle for enrichment for 30 min. An electronic nose (PEN 3.5, AIRSENSE, Germany) was used to collect data and analyze the differences in flavor between different samples.

[0075] Electronic eye inspection, cut the cheese into cheese blocks of the same size, use a colorimeter (Verivide, UK) to analyze, and measure 6 points for each sample. Measure the L*, a*, and b* values ​​of the samples. The L* value represents brightness, ranging from 0-100, and close to 100 represents white. a* represents green (-) to red (+), and b* represents blue (+) to yellow (-).

[0076] The results are as follows Figure 9-10 As shown, except for the MF-40% sample, there was no significant difference in flavor between the other samples and the control group. Appearance is an important factor of the product and directly affects consumer acceptance. The results are shown in Table 1. Compared with the control group, the lightness value (L*) of the cheese prepared by the microfiltration retentate was significantly reduced. As the fat content in the reconstituted sample increased, the L* of the cheese prepared by the microfiltration retentate and fat reconstitution increased. The control sample had the lowest b*, and the cheese prepared by the retentate had a higher b*, which tended to decrease with the increase of the fat content in the reconstituted sample. This result shows that the microfiltration process leads to a decrease in whiteness and yellowness. This is because during the blanching process of the cheese, the lactose and protein in the cheese undergo a Maillard reaction, and the Maillard product causes the cheese to turn black. There was no significant difference in the appearance of the MF-10% and MF-20% samples from the control group.

[0077] Table 1 Effect of microfiltration retentate and fat content on cheese appearance

[0078]

[0079]

[0080] 4.4 Sensory evaluation

[0081] Each cheese sample was evaluated for appearance (shiny and dull), texture (chewy, rubbery, firm, crumbly, and grainy), flavor (flat, creamy, sweet, salty, rancid, and acidic), and overall acceptability using a descriptive scorecard with a 10-point intensity rating, from 1 as the lowest intensity to 10 as the highest, with higher scores representing more favorable cheese samples. All ratings were averaged.

[0082] The sensory evaluation results are as follows Figure 11-12As shown, the appearance score ranged from 5.83 to 8.08, with the control group having a higher score of 7.67, the MF-40% sample having the lowest score, and the MF-20% sample having the highest score. Similar results were found in the texture and flavor scores, with MF-40% having the lowest score, 4.75 and 5.00, respectively; MF-10% samples had the highest texture score (7.58 points), and MF-20% samples had the highest flavor score (7.25 points); the texture and flavor scores of the control group were 6.92 and 7.08, respectively. Compared with the control group (7.42 points), the overall acceptability score of cheese prepared with low fat content (0%-8%) was lower (5.33-6.50 points), and as the fat content increased to 10% and 20%, the overall acceptability score increased to 7.33 and 7.25, which were significantly higher than other cheeses. The addition of fat can increase the sensory score of cheese, and the MF-10% sample had the highest overall acceptability score, close to the control group.

[0083] In this experiment, cheese made from cow's milk was used as the control group, and cheese made from microfiltration retentate and fat reconstituted samples was used as the experimental group to compare the differences between the two groups of samples. The results showed that the cheese produced from microfiltration retentate and 10% or 20% fat had no significant differences in composition, appearance, texture, flavor and functional properties from the control group, and the cheese produced by this method had higher nutritional value and production efficiency.

[0084] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A cheese, characterized in that: The cheese is prepared from casein retentate; The casein retentate is obtained by membrane separation of skim milk.

2. The cheese according to claim 1, characterized in that The cheese is prepared by mixing casein interception liquid and fat obtained by skimming milk.

3. A method for preparing cheese, characterized in that: The specific steps include: S1, heating raw milk and skimming it to obtain fat and skimmed milk; S2, performing membrane separation on the skim milk in step S1 to obtain a casein interception liquid; S3, mixing the casein intercepted liquid with the fat in step S1, adding rennet and incubating to obtain curd; S4, cutting the curd in step S3 into particles and removing whey, and keeping warm and brewing; S5. Add salt to the curd particles in step S4, stir evenly, press, blanch and store.

4. The preparation method according to claim 3, characterized in that: The degreasing process in step S1 is to heat the milk to 60° C., keep the temperature for 30 minutes, and perform degreasing in a disc centrifuge.

5. The preparation method according to claim 3, characterized in that: The membrane separation experiment process in step S2 is to add the skim milk in step S1 into the circulation tank of the separation equipment, and use a 100 nm ceramic membrane to perform a membrane separation experiment.

6. The preparation method according to claim 5, characterized in that: The transmembrane pressure difference in the membrane separation experiment was set to 80 kPa, the feed liquid temperature was controlled at 50-55° C. during the separation process, and the concentration factor was 3.

7. The preparation method according to claim 3, characterized in that: In step S3, 0.04 g / L of chymosin is added to the mixed product, and the incubation condition is 45 min at 32°C.

8. The preparation method according to claim 3, characterized in that: Step S4 also includes cutting the curd into 1 cm 3 After the particles have stood for 5 minutes, the temperature was raised to 42°C and kept warm for 40 minutes. The whey was removed and the brewing was continued.

9. The preparation method according to claim 3, characterized in that: In step S5, the amount of salt added to the curd particles is 1%, and the curd particles are pressed at 0.5 MPa for 30 minutes.

10. The preparation method according to claim 3, characterized in that: The blanching process in step S5 is to place the pressed curd into the whey discharged in step S4 at 95° C. for 1 hour, and store it at 4° C. after cooling.

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