Production method of imitated natural casing

Abstract

The invention relates to a production method of imitated natural casings. The production method comprises the following steps: selecting high-quality cow belly and cow back split leather and leftover materials of natural casings; the split leather is treated with alkaline protease in a rotating hub, ammonium sulfate and citric acid are used for decalcification treatment after treatment, and citric acid and sodium citrate are used for buffering; fully cleaning; aging and fully swelling; mixing split leather and natural casing leftover materials, and circularly grinding to obtain collagen pulp; mixing the mucilage and acid water; the colloid is fully swelled; homogenizing by a homogenizer, and filtering to obtain collagen colloid; and extruding the imitated natural collagen casing. The method has the advantages that split leather is screened, the casing is softer and more stable in quality, the raw materials comprise leftover materials of natural casings, and the performance of the casing is guaranteed; high-speed extrusion is adopted, so that the strength during filling is ensured, and the casing can be brighter; drying is rapid, so that the casing has enough brittleness; and a gradual traction mode is used, so that the softness similar to that of natural casings is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of casing production, and in particular to a method for producing an imitation natural casing. Background Art

[0002] In the prior art, Chinese patent CN112493291A discloses a method for preparing natural casing collagen, which comprises the following steps: first, a two-layer or three-layer cowhide which is pickled and shaped with lime and caustic soda in a certain proportion is rinsed, acidified, and rinsed again to form a transparent swollen block leather material, which is then pelletized, chopped, and defibrated into sheet-like collagen fibers of a certain thickness, which are then kneaded and sheared into clumping collagen fiber clusters in a kneading machine, and finally filtered and combed through a filter plate of a filter press to form round strip-like fiber bundles to obtain casing collagen.

[0003] However, the properties of the second layer of cowhide from different parts are different. If they are not distinguished, the product will be unstable. The second or third layer of cowhide only contains type I and III bovine collagen, while natural casings also contain other types of proteins, generally from pigs and sheep, which has an impact on the performance of casings. In addition, the products made from natural casings have the characteristics of being transparent, crisp and soft, which cannot be achieved by only using colloids and thinning, and is also related to the production process. A production method for imitating natural casings is required to develop a transparent, crisp and soft imitating natural collagen casing. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a method for producing imitation natural casings, which can solve the problems in the prior art of not distinguishing between the two layers of cowhide at different parts, resulting in unstable products, a single protein component of the casing affecting performance, and the casing being not transparent, brittle, and soft enough.

[0005] In order to solve the above technical problems, the technical solution of the present invention is: comprising the following steps: S1. Select high-quality raw materials: Select high-quality beef belly and back split hides and natural casing scraps; S2, hub treatment: Use alkaline protease to treat the split leather in the hub, decalcify with ammonium sulfate and citric acid, and then use citric acid and sodium citrate for buffering; S3. Hub cleaning: Use process chilled water to fully clean, control the conductivity <200u, and cool the cowhide; S4, acid skin aging: take out the acid skin and age it in a cold storage to make it fully swell; S5. Preparation of collagen slurry: Split skin and natural casing scraps are mixed, wherein the split skin accounts for 70-90%, and diced into 8-10 mm pieces, and then subjected to multiple cycles of grinding to obtain collagen slurry; S6. Preparation of collagen colloid: mixing glue and HCl acid water with a pH of 2 in a volume ratio of 1:1 to obtain a crude collagen colloid; S7, colloid aging: let the colloid stand for aging during filling to allow it to fully swell; S8, homogenization and filtration: homogenize by a homogenizer, then pass through a filter to finally obtain a uniform and stable collagen colloid; S9, extrusion casing: set the extrusion speed to above 6000m / h, the dry bulb temperature to 78℃, and gradually stretch and dry, the extrusion speed / winding speed = 1 / 1.5, extrude and dry the casing to obtain the final natural-simulated collagen casing.

[0006] Furthermore, in step S2, the alkaline protease liquid ratio is 100%, the alkaline protease is Novo protease, the addition ratio to the weight of cowhide is 0.8-1L / 1000kg, and the processing time is 24h.

[0007] Furthermore, in step S2, during the decalcification treatment, water is added to a liquid ratio of 60%, ammonium sulfate is added at 0.4-0.6% by weight of the cowhide, and citric acid is added at 0.4-0.6% by weight to reduce the pH value from 12 to 9. The treatment time is 12-24 hours.

[0008] Furthermore, in step S2, when citric acid and sodium citrate are used as buffers, the liquid ratio is 100%, 0.6-0.8% citric acid and 0.6-0.8% sodium citrate are added to the weight of the cowhide, the pH value is controlled to be 5, and the processing time is 12-24 hours.

[0009] The advantages of the present invention are: by screening the split hides, only the belly hide and the back hide are taken, which are softer and more stable in quality than the head hide and the shoulder hide, and the raw materials also contain the leftovers of natural casings, which can make up for the lack of other types of proteins in the split hides and ensure the casing performance; High-speed extrusion is used, with a speed of more than 6000m / h. The casing extruded at such a high speed will make the collagen fiber orientation highly consistent, which can not only ensure the strength during filling but also make the casing more transparent; Use high temperature to dry the casing quickly, with a dry bulb temperature of 78°C and a wet bulb temperature of 30°C, to ensure that the casing has sufficient brittleness; Combining high-quality raw materials and sufficiently thin casing production, using a step-by-step traction method, extrusion speed / winding speed = 1 / 1.5, to ensure that the softness is similar to that of natural casings. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic diagram of the sensory evaluation results of pure meat sausage application of casings produced in the examples and comparative examples of the present invention. DETAILED DESCRIPTION

[0011] In order to make the purpose, technical solution and advantages of the present invention more clear, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. The following embodiments can enable technicians in this field to understand the present invention more comprehensively, but the present invention is not limited to the scope of the embodiments.

[0012] This specific implementation adopts the following technical solution: a method for producing imitation natural casings, comprising the following steps: S1. Select high-quality raw materials: Select high-quality beef belly and back split hides and natural casing scraps; S2. Hub treatment: Use alkaline protease to treat the second layer of leather in the hub, the alkaline protease liquid ratio is 100%, the alkaline protease is Novo protease, the addition ratio is 0.8-1L / 1000kg for the weight of cowhide, the treatment time is 24h, after the treatment, use ammonium sulfate and citric acid for decalcification, add water to 60% liquid ratio, add 0.4-0.6% ammonium sulfate and 0.4-0.6% citric acid to the weight of cowhide, so that the pH value drops from 12 to 9, the treatment time is 12-24h, and then use citric acid and sodium citrate for buffering, the liquid ratio is 100%, add 0.6-0.8% citric acid and 0.6-0.8% sodium citrate to the weight of cowhide, control the pH value to 5, and the treatment time is 12-24h.

[0013] S3. Hub cleaning: Use process chilled water to fully clean, control the conductivity <200u, and cool the cowhide; S4, acid skin aging: take out the acid skin and age it in a cold storage to make it fully swell; S5. Preparation of collagen slurry: Split skin and natural casing scraps are mixed, wherein the split skin accounts for 70-90%, and diced into 8-10 mm pieces, and then subjected to multiple cycles of grinding to obtain collagen slurry; S6. Preparation of collagen colloid: mixing glue and HCl acid water with a pH of 2 in a volume ratio of 1:1 to obtain a crude collagen colloid; S7, colloid aging: let the colloid stand for aging during filling to allow it to fully swell; S8, homogenization and filtration: homogenize by a homogenizer, then pass through a filter to finally obtain a uniform and stable collagen colloid; S9, extrusion casing: set the extrusion speed to above 6000m / h, the dry bulb temperature to 78℃, and gradually stretch and dry, the extrusion speed / winding speed = 1 / 1.5, extrude and dry the casing to obtain the final natural-simulated collagen casing.

[0014] Example 1: According to the above method, the natural collagen casing is prepared. In step S2, the alkaline protease is added at a ratio of 1L / 1000kg to the weight of the cowhide; decalcification treatment is performed by adding 0.6% ammonium sulfate and 0.6% citric acid to the weight of the cowhide, and the treatment time is 24 hours; citric acid and sodium citrate are used as buffers, and 0.8% citric acid and 0.8% sodium citrate are added to the weight of the cowhide, and the treatment time is 24 hours; in step S5, the mixing ratio of the second layer of leather and the natural casing scraps is 70:30, and the pieces are cut into 8 mm.

[0015] Example 2: The preparation steps of Example 2 are the same as those of Example 1, except that the mixing ratio of split skin and natural casing scraps is 80:20.

[0016] Example 3: The preparation steps of Example 3 are the same as those of Example 1, except that the mixing ratio of split skin and natural casing scraps is 90:10.

[0017] Comparative Example 1: Natural casing.

[0018] Comparative Example 2: Conventional production process, basic speed 3000m / h.

[0019] The casings produced in Examples 1-3 and Comparative Examples 1-2 were tested for application in pure meat sausages. The application results are shown in Table 1.

[0020] Table 1: Filling and cooking test results of pure meat sausages prepared from casings produced in Examples 1-3 and Comparative Examples 1-2 The casings produced in Examples 1-3 and Comparative Examples 1-2 were used in pure meat sausages. The sensory evaluation results were as follows: Figure 1 As shown, there were 20 participants in the sensory evaluation, with scores ranging from 1 to 10, and the higher the score, the better the performance.

[0021] The casings produced in Examples 1-3 and Comparative Examples 1-2 were tested for performance, and the results are shown in Table 2.

[0022] Table 2: Performance test texture analyzer data of casings produced in Examples 1-3 and Comparative Examples 1-2 From the above test results, it can be seen that: for filling and cooking properties, Example 1 is slightly worse, while the others meet normal production requirements. After texture analyzer and sensory evaluation analysis, the transparency, brittleness, softness and texture analyzer data brittleness, rupture force, rupture distance and chewiness of the imitation natural casings produced in Examples 1-3 are closer to the natural casings in Comparative Example 1, and are significantly better than the casings processed by the prior art in Comparative Example 2. In addition, Example 2 is closest to the taste of natural casings, and is significantly better than conventionally produced casings, and is the best embodiment.

[0023] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for producing a natural casing, characterized in that: The following steps are involved: S1. Select high-quality raw materials: Select high-quality beef belly and back split hides and natural casing scraps; S2, hub treatment: Use alkaline protease to treat the split leather in the hub, decalcify with ammonium sulfate and citric acid, and then use citric acid and sodium citrate for buffering; S3. Hub cleaning: Use process chilled water to fully clean, control the conductivity <200u, and cool the cowhide; S4, acid skin aging: take out the acid skin and age it in a cold storage to make it fully swell; S5. Preparation of collagen slurry: Split skin and natural casing scraps are mixed, wherein the split skin accounts for 70-90%, and diced into 8-10 mm pieces, and then subjected to multiple cycles of grinding to obtain collagen slurry; S6. Preparation of collagen colloid: mixing glue and HCl acid water with a pH of 2 in a volume ratio of 1:1 to obtain a crude collagen colloid; S7, colloid aging: let the colloid stand for aging during filling to allow it to fully swell; S8, homogenization and filtration: homogenize by a homogenizer, then pass through a filter to finally obtain a uniform and stable collagen colloid; S9, extrusion casing: set the extrusion speed to above 6000m / h, dry bulb temperature to 78℃, wet bulb temperature to 30℃, and gradually stretch and dry, extrusion speed / winding speed = 1 / 1.5, extrude and dry the casing to obtain the final natural collagen casing.

2. The method for producing a natural casing according to claim 1, characterized in that: In the step S2, the alkaline protease liquid ratio is 100%, the alkaline protease is Novo protease, the addition ratio to the weight of the cowhide is 0.8-1L / 1000kg, and the processing time is 24h.

3. The method for producing a natural casing according to claim 1, characterized in that: In step S2, during the decalcification treatment, water is added to a liquid ratio of 60%, ammonium sulfate is added at 0.4-0.6% of the weight of the cowhide, and citric acid is added at 0.4-0.6% to reduce the pH value from 12 to 9. The treatment time is 12-24 hours.

4. The method for producing a natural-like casing according to claim 1, characterized in that: In step S2, when citric acid and sodium citrate are used as buffer, the liquid ratio is 100%, 0.6-0.8% citric acid and 0.6-0.8% sodium citrate are added to the weight of the cowhide, the pH value is controlled to be 5, and the processing time is 12-24 hours.

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