A method for preparing a gelatin casing

Abstract

This invention provides a method for preparing gelatin sausage casings, relating to the field of sausage casing processing technology. The method includes the following steps: dissolving gelatin in water to obtain a gelatin solution; uniformly dispersing chitosan in an aqueous glacial acetic acid solution and stirring to obtain a chitosan solution; adjusting the temperature to 60-70℃, adding a mixed solution to the chitosan solution, mixing well to form a mixed solution, adding a gelatin solution at a volume ratio of 3-4:1 to the mixed solution, and stirring for 1-3 hours to obtain the prepared solution. This method, by adding cinnamaldehyde and hydrogen peroxide to the chitosan solution at a mass ratio of 2:1, significantly improves the tensile strength of the mixed solution. Compared to products prepared using only gelatin and chitosan solution as the main raw materials, the tensile strength is increased by 79.5%. Simultaneously, the 3-4:1 volume ratio of gelatin solution to the mixed solution effectively improves the boiling resistance of the finished product.

Description

Technical Field

[0001] This invention relates to the field of sausage casing processing technology, and specifically to a method for preparing gelatin sausage casings. Background Technology

[0002] In recent years, with the rapid development of science and technology and the rapid improvement of production levels, in order to adapt to large-scale mechanized production, improve production efficiency, reduce costs, and meet consumers' diversified product demands, artificial sausage casings have been rapidly developed and manufactured and entered the sausage meat product processing field. After continuous testing and improvement, they have finally been put into production.

[0003] Currently, the mature sausage casing categories are divided into natural sausage casings and artificial sausage casings. Natural sausage casings rely on animal digestive tract tissues and have problems such as limited resources, uneven specifications, and strict storage conditions. They are difficult to adapt to high-speed automated production and have high quality control risks. Artificial sausage casings, such as collagen sausage casings, have poor heat resistance and insufficient mechanical properties. Cellulose sausage casings are not edible, and plastic sausage casings pose a risk of contamination.

[0004] None of the above-mentioned artificial sausage casings can fully meet the requirements of high-end meat products for edibility, heat resistance, and excellent barrier properties. Therefore, a gelatin sausage casing with broad application prospects is proposed. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method for preparing gelatin casings, which can effectively alleviate the current situation where artificial casings cannot fully meet the requirements of high-end meat products for edibility, heat resistance, and excellent barrier properties.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A method for preparing gelatin casings includes the following steps: S1. Dissolve gelatin in water to obtain a gelatin solution; S2. Chitosan is uniformly dispersed in glacial acetic acid aqueous solution to obtain chitosan solution; S3. Adjust the temperature to 60-70℃, add the mixed liquid to the chitosan solution, mix well to form a mixed liquid, add gelatin solution with a volume ratio of 3-4:1 to the mixed liquid, stir for 1-3 hours to obtain the prepared solution; The mixture was obtained by mixing cinnamaldehyde and hydrogen peroxide at a mass ratio of 2:1. S4. Add glycerol and Tween-80 to the preparation solution, homogenize, and obtain the membrane solution; S5. Remove bubbles, shape, dry, demold, and obtain gelatin casings.

[0007] Preferably, the mass ratio of gelatin to water in step S2 is 1.5:1.

[0008] Preferably, in step S2, the mass ratio of chitosan to glacial acetic acid aqueous solution is 2:100, and the volume fraction of glacial acetic acid aqueous solution is 2%. The uniform dispersion is achieved by first magnetically stirring at 400-600 r / min at 40-50℃ for 3-4 hours, then adjusting the temperature to 20-30℃ at 5℃ / min and magnetically stirring at 800-1000 r / min for 7-9 hours.

[0009] Preferably, in step S3, the volume ratio of chitosan solution to mixture is 2-4:1, and the volume fraction of hydrogen peroxide is 2%.

[0010] Preferably, in step S4, the volume ratio of glycerol to the preparation solution is 1:0.20, and the volume ratio of Tween-80 to the preparation solution is 1:0.051.

[0011] Preferably, the homogenization rate in step S4 is 10000-12000 r / min, lasting for 8-12 min.

[0012] Preferably, in step S5, the molding process involves uniformly casting the film liquid onto the mold and controlling the film thickness to be 30-40 μm.

[0013] This invention provides a method for preparing gelatin casings, which has the following advantages compared with the prior art: This method significantly improves tensile strength by adding a mixture of cinnamaldehyde and hydrogen peroxide at a mass ratio of 2:1 to the chitosan solution. Compared with products prepared by mixing only gelatin and chitosan solution as the main raw materials, the tensile strength is increased by 79.5%. At the same time, mixing the gelatin solution and the mixture at a volume ratio of 3-4:1 can effectively improve the boiling resistance of the finished product. Detailed Implementation

[0014] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0015] Example 1 A method for preparing gelatin casings includes the following steps: S1. Dissolve gelatin in water at a mass ratio of 1.5:1 to obtain a gelatin solution; S2. Add chitosan to a 2% (v / v) glacial acetic acid aqueous solution with a mass ratio of 2:100. First, stir magnetically at 400 r / min for 3 hours at 40℃. Then, adjust the temperature to 20℃ at 5℃ / min and stir magnetically at 800 r / min for 7 hours to obtain a chitosan solution. S3. Adjust the temperature to 65℃, add the mixture (cinnamaldehyde and 2% (v / v) hydrogen peroxide mixed at a mass ratio of 2:1) to the chitosan solution at a volume ratio of 4:1, mix well to form a mixture, add gelatin solution at a volume ratio of 3:1 to the mixture, stir for 3 hours to obtain the prepared solution. S4. Add glycerol and Tween-80 to the preparation solution at a volume ratio of 1:0.20 and a volume ratio of 1:0.051. Homogenize at 10000 r / min for 12 min to obtain the membrane solution. S5. Remove bubbles, evenly cast the film solution onto the mold, control the film thickness at 30μm, let it air dry, demold, and obtain gelatin casing.

[0016] Example 2 A method for preparing gelatin casings includes the following steps: S1. Dissolve gelatin in water at a mass ratio of 1.5:1 to obtain a gelatin solution; S2. Add chitosan to a 2% (v / v) glacial acetic acid aqueous solution with a mass ratio of 2:100. First, stir magnetically at 50°C and 600 r / min for 4 hours. Then, adjust the temperature to 30°C at 5°C / min and stir magnetically at 1000 r / min for 9 hours to obtain a chitosan solution. S3. Adjust the temperature to 65℃, add cinnamaldehyde to the chitosan solution at a volume ratio of 2:1, mix well to form a mixture, add gelatin solution at a volume ratio of 1:4 to the mixture, stir for 1 hour to obtain the prepared solution. S4. Add glycerol and Tween-80 to the preparation solution at a volume ratio of 1:0.20 and a volume ratio of 1:0.051. Homogenize at 12000 r / min for 8 min to obtain the membrane solution. S5. Remove bubbles, evenly cast the film solution onto the mold, control the film thickness at 40μm, let it air dry, demold, and obtain gelatin casing.

[0017] Comparative Example 1 This comparative example follows the preparation method of Example 1, except for step S3, which is as follows: S3. Adjust the temperature to 30℃, add cinnamaldehyde to the chitosan solution at a volume ratio of 4:1, mix well to form a mixture, add gelatin solution at a volume ratio of 3:1 to the mixture, stir for 3 hours to obtain the prepared solution. Comparative Example 2 This comparative example follows the preparation method of Example 1, except for step S3, which is as follows: S3. Adjust the temperature to 30℃, add 2% (v / v) hydrogen peroxide to the chitosan solution at a volume ratio of 4:1, mix well to form a mixture, add gelatin solution at a volume ratio of 3:1 to the mixture, stir for 3 hours to obtain the prepared solution. Comparative Example 3 This comparative example follows the preparation method of Example 1, except for step S3, which is as follows: S3. Adjust the temperature to 30℃, add gelatin solution with a volume ratio of 3:1 to chitosan solution to chitosan solution, stir for 3 hours to obtain the prepared solution; Comparative Example 4 This comparative example follows the preparation method of Example 1, except for step S3, which is as follows: S3. Adjust the temperature to 30℃, add the mixture (cinnamaldehyde and 2% (v / v) hydrogen peroxide mixed at a mass ratio of 2:1) to the chitosan solution at a volume ratio of 4:1, mix well to form a mixture, add gelatin solution at a volume ratio of 1:1 to the mixture, stir for 3 hours to obtain the prepared solution. Comparative Example 5 This comparative example follows the preparation method of Example 1, except for step S3, which is as follows: S3. Adjust the temperature to 30℃, add the mixture (cinnamaldehyde and 2% (v / v) hydrogen peroxide mixed at a mass ratio of 2:1) to the chitosan solution at a volume ratio of 4:1, mix well to form a mixture, add gelatin solution at a volume ratio of 5:1 to the mixture, stir for 3 hours to obtain the prepared solution. Detection 1. Mechanical property testing; Following the test method of GB / T 1040.3-2006, the film was cut into strips of 150mm × 15mm. The thickness of the sample at different locations was measured using a micrometer-based thickness gauge, and the average value was calculated. The sample was clamped in a pneumatic fixture, ensuring the sample axis and fixture axis were aligned. The fixture spacing was 100mm, and the loading speed was 50mm / min. The sample was stretched until it broke, at which point the test was stopped. Tensile strength is the maximum stress experienced by the sample during the test. Elongation at break is the increment per unit length of the original gauge length. Specific results are shown in Table 1. Table 1 As shown in the table above, Example 1 exhibits the best tensile strength and elongation at break. Although the tensile strength of Example 2 is higher than that of Example 1, the elongation at break is reduced by 17.4%. Therefore, overall, Example 1 is better than Example 2. Furthermore, based on the data of elongation at break of Comparative Examples 2 and 3, although they are higher than those of Example 1, the tensile strength values ​​are significantly lower. This indicates that adding a mixture of cinnamaldehyde and hydrogen peroxide at a mass ratio of 2:1 to the chitosan solution, along with a gelatin solution at a volume ratio of 3:1 to the mixture, can achieve better results.

[0018] 2. Boiling resistance A 150mm × 15mm strip sample was placed in distilled water and boiled in an infrared heating furnace for 30 minutes. After removing the sample and drying the surface, its tensile properties were tested at a test speed of 10mm / min. The tensile properties were calculated according to formula (1): R(%)=σ A / σ B ×100 (1) Where: σ A - Tensile strength of the sample after boiling; σ B - Tensile strength of the unboiled sample.

[0019] The specific results are shown in Table 2: Table 2 As can be seen from the table above, Example 1 has the best boiling resistance.

[0020] 3. Determination of oil and grease barrier ability Add 5ml of olive oil to a test tube, seal it with the membrane to be tested, invert it onto filter paper, and leave it for 6-7 days. Weigh the change in mass of the filter paper and calculate according to formula (2): P0=△M×h / (s×t)(2) Where: △M - change in filter paper mass (g); h - thickness of the membrane to be tested (mm); s - area of ​​the test tube opening (m²) 2 ); t - test time (d).

[0021] The specific results are shown in Table 3: Table 3 As can be seen from the table above, Example 1 has the lowest oil permeability coefficient, meaning it has the strongest oil barrier ability.

[0022] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing gelatin sausage casings, characterized in that, The preparation method includes the following steps: S1. Dissolve gelatin in water to obtain a gelatin solution; S2. Chitosan is uniformly dispersed in glacial acetic acid aqueous solution to obtain chitosan solution; S3. Adjust the temperature to 60-70℃, add the mixed liquid to the chitosan solution, mix well to form a mixed liquid, add gelatin solution with a volume ratio of 3-4:1 to the mixed liquid, stir for 1-3 hours to obtain the prepared solution; The mixture was obtained by mixing cinnamaldehyde and hydrogen peroxide at a mass ratio of 2:

1. S4. Add glycerol and Tween-80 to the preparation solution, homogenize, and obtain the membrane solution; S5. Remove bubbles, shape, dry, demold, and obtain gelatin casings.

2. The preparation method according to claim 1, characterized in that, In step S1, the mass ratio of gelatin to water is 1.5:

1.

3. The preparation method according to claim 1, characterized in that, In step S2, the mass ratio of chitosan to glacial acetic acid aqueous solution is 2:100, and the volume fraction of glacial acetic acid aqueous solution is 2%. The uniform dispersion is achieved by first magnetically stirring at 400-600 r / min at 40-50℃ for 3-4 hours, then adjusting the temperature to 20-30℃ at 5℃ / min and magnetically stirring at 800-1000 r / min for 7-9 hours.

4. The preparation method according to claim 1, characterized in that, In step S3, the volume ratio of chitosan solution to mixed liquid is 2-4:1, and the volume fraction of hydrogen peroxide is 2%.

5. The preparation method according to claim 1, characterized in that, In step S4, the volume ratio of glycerol to the preparation solution is 1:0.20, and the volume ratio of Tween-80 to the preparation solution is 1:0.

051.

6. The preparation method according to claim 1, characterized in that, The homogenization rate in step S4 is 10000-12000 r / min, lasting for 8-12 min.

7. The preparation method according to claim 1, characterized in that, In step S5, the shaping process specifically involves uniformly casting the film liquid onto the mold and controlling the film thickness to be between 30-40 μm.

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