Method for improving stability of crystal duck jelly through combination of potassium chloride and high-ester pectin

Abstract

The invention discloses a method for improving the stability of crystal duck jelly through combination of potassium chloride and high-ester pectin in the technical field of food deep processing and manufacturing. The method comprises the following steps: removing redundant fat from fresh cow leather, cleaning, cutting into blocks, mixing and heating the cow leather, water and high-ester pectin according to a certain proportion, removing the cow leather, and taking supernate; and cooking duck breast meat, cutting the cooked duck breast meat into shreds or small blocks, adding the shreds or small blocks into the cow leather supernatant, adding a proper amount of potassium chloride, uniformly mixing, standing at room temperature for a period of time, and cooling in a refrigerator to obtain the crystal duck jelly. A small amount of high-ester pectin and potassium chloride are added, so that the cow leather supernatant, the high-ester pectin and the potassium chloride fully interact to form a stable gel system, and the crystal duck jelly prepared under the system is good in finished product elasticity, glittering and translucent in appearance and smooth in taste. And the device is suitable for mass production of the crystal duck jelly.

Description

Technical Field

[0001] The invention relates to the technical field of food deep processing and production, and in particular to a method for improving the stability of crystal duck jelly by combining potassium chloride and high-ester pectin. Background Art

[0002] Meat jelly is a traditional Chinese cold cut meat product and a salad dish with a long history of consumption in my country. Examples include the world-renowned Yaorou from Zhenjiang, Jiangsu Province, and Miao fish jelly from Guizhou Province. The production process is simple, typically using ingredients such as pig skin, pig's trotters, cowhide, and fish skin. Seasonings such as salt are added, and it can also be used to preserve fruits and vegetables, enriching their appearance and edible value. Once cooled and cut into plates, it is ready to eat. Its appearance is crystal clear and beautiful, its flavor is alluring, its meaty aroma is rich, its texture is smooth, and its texture is tender. It is also low in fat, calories, and high in protein. Research has shown that meat jelly products are rich in collagen and various active peptides, demonstrating various benefits, including wrinkle reduction, anti-aging, hematopoietic stimulation, and antioxidant properties.

[0003] Crystal duck jelly is a dish from Huaiyang cuisine. The ingredients include Daguang duck, pork, pig skin, soy sauce, salt, and spices. The traditional preparation involves boiling the ingredients to remove the blood, then simmering them over a low heat until tender. The broth is then drained, the duck meat is deboned and placed in the broth, cooled and jellyed, and finally cut into pieces for consumption. Duck meat is high in protein, with a moderate and evenly distributed fat content. It also contains calcium, phosphorus, iron, niacin, and vitamins B1 and B2. Its sweet and cooling properties enter the lung, stomach, and kidney meridians, providing nourishment, stomach support, kidney tonification, edema reduction, fever relief, diarrhea relief, cough relief, and phlegm reduction. Crystal duck jelly, created by combining duck meat with the skin jelly, offers excellent flavor and high nutritional value.

[0004] In existing production processes, aspic made from raw materials such as pig skin, pig's trotters, cowhide, and fish skin has a low melting point and is prone to deformation and collapse at room temperature. Improving product stability by adding a certain amount of edible colloids has become a major improvement method in the industry. For example, the addition of sodium alginate, konjac flour, carrageenan, xanthan gum, agar polysaccharide, and tremella polysaccharide can all improve the product's thermal stability. However, the addition of too many colloids not only causes the product texture to become harder and the taste to deteriorate, but also increases costs and causes consumer rejection. Summary of the Invention

[0005] The purpose of the present invention is to overcome the defects in the prior art and provide a method for improving the stability of crystal duck jelly by combining potassium chloride and high-ester pectin. By adding a small amount of hydrophilic colloid, the problems of poor thermal stability, poor elasticity and hard taste of existing crystal duck jelly products are solved, thereby improving the edible taste of crystal duck jelly.

[0006] The objective of the present invention is achieved as follows: a method for improving the stability of crystal duck jelly by combining potassium chloride and high-ester pectin, comprising the following steps: removing excess fat from fresh cowhide, cleaning and cutting into pieces, mixing the cowhide, water, and high-ester pectin in a certain proportion and heating, removing the cowhide, and taking the supernatant; steaming and cooking duck breast meat thoroughly, cutting it into thin strips or small pieces, adding it to the cowhide supernatant, and then adding an appropriate amount of potassium chloride, mixing evenly, leaving it at room temperature for a period of time, and then cooling it in a refrigerator to obtain crystal duck jelly, wherein the high-ester pectin has an esterification degree DE greater than 50%.

[0007] When the present invention works, by adding a small amount of high-ester pectin and potassium chloride, the cowhide supernatant-high-ester pectin-potassium chloride fully interacts with each other, and the potassium ion can coordinate with the carboxyl group of the galacturonic acid on the pectin molecule to form a structure similar to "bridge", connecting adjacent pectin molecules together, helping to enhance the stability of the gel network, and finally forming a stable gel system. Potassium chloride has potassium ions similar to sodium ions, which can replace part of the sodium ions to increase the freshness of food. The mouthfeel is similar to sodium chloride, which improves the saltiness, making the finished product crystal duck jelly more delicious and rich in taste. The crystal duck jelly made under this system has good elasticity, crystal clear appearance, and smooth mouthfeel. The addition of potassium chloride can improve the thermodynamic properties of high-ester pectin, reduce the formation temperature of the gel, make the gel easier to form when cooling, and increase the melting temperature. The gel system is difficult to be destroyed when heated, thereby improving the thermal stability of the finished product (>50°C). The preparation method of the present invention is simple, the materials are simple, and it is suitable for use in batch production of crystal duck jelly.

[0008] Furthermore, the fresh cowhide is soaked in a sodium carbonate solution with a mass concentration of 0.5% to 1% for 20 minutes to remove excess fat, the mass ratio of the fresh cowhide to the sodium carbonate solution is 1:3, and the size of the fresh cowhide cut into pieces is 1 cm×1 cm×1 cm.

[0009] Furthermore, the mass ratio of the cowhide, water and high-ester pectin is 1:(2.5-4.0):(0.02-0.06), the heating temperature is 95° C.-100° C., and the heating time is 120 min-150 min.

[0010] Furthermore, the added amount of the duck breast is 10% to 25% of the total mass of the cowhide supernatant.

[0011] Furthermore, the potassium chloride is food-grade potassium chloride, and the added amount of potassium chloride is 0.02% to 0.08% of the total mass of the cowhide supernatant.

[0012] Furthermore, the room temperature placement time is 30 minutes, the refrigerator cooling temperature is 4°C, and the cooling time is 4 hours.

[0013] Crystal duck jelly is prepared by a method of improving the stability of crystal duck jelly by combining potassium chloride and high-ester pectin. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Graph showing the changes in moisture distribution of Examples 1 to 5 of the present invention and Comparative Examples 1 to 5.

[0015] Figure 2 The low-field nuclear magnetic resonance transverse relaxation spectra of Example 5 of the present invention and Comparative Example 1 are shown. DETAILED DESCRIPTION

[0016] Example 1:

[0017] A method for improving the stability of crystal duck jelly by combining potassium chloride and high-ester pectin, comprising the following steps:

[0018] (1) Fresh cowhide was soaked in a sodium carbonate solution with a mass concentration of 0.5% for 20 minutes to remove excess fat. The mass ratio of fresh cowhide to sodium carbonate solution was 1:3. After cleaning, the cowhide was cut into 1 cm × 1 cm × 1 cm blocks. The cowhide, water, and high ester pectin were mixed in a mass ratio of 1:3:0.02 and heated at a temperature of 95°C to 100°C for 150 minutes. After heating, the supernatant was collected.

[0019] (2) After the duck breast is steamed and cooked thoroughly, cut into thin strips or small pieces, and added to the cowhide supernatant. The amount of duck breast added is 10% of the total mass of the cowhide supernatant. Then, potassium chloride accounting for 0.02% of the total mass of the cowhide supernatant is added and mixed evenly. The mixture is placed at room temperature for 30 minutes, and then placed in a refrigerator at 4°C for 4 hours to obtain crystal duck jelly.

[0020] Example 2:

[0021] A method for improving the stability of crystal duck jelly by combining potassium chloride and high-ester pectin, comprising the following steps:

[0022] (1) Fresh cowhide was soaked in a sodium carbonate solution with a mass concentration of 0.5% for 20 minutes to remove excess fat. The mass ratio of fresh cowhide to sodium carbonate solution was 1:3. After cleaning, the cowhide was cut into 1 cm × 1 cm × 1 cm blocks. The cowhide, water, and high ester pectin were mixed in a mass ratio of 1:3:0.02 and heated at a temperature of 95°C to 100°C for 150 minutes. After heating, the supernatant was collected.

[0023] (2) After the duck breast is steamed and cooked thoroughly, cut into thin strips or small pieces, and added to the cowhide supernatant. The amount of duck breast added is 10% of the total mass of the cowhide supernatant. Then, potassium chloride accounting for 0.05% of the total mass of the cowhide supernatant is added and mixed evenly. The mixture is placed at room temperature for 30 minutes, and then placed in a refrigerator at 4°C for 4 hours to obtain crystal duck jelly.

[0024] Example 3:

[0025] A method for improving the stability of crystal duck jelly by combining potassium chloride and high-ester pectin, comprising the following steps:

[0026] (1) Fresh cowhide was soaked in a sodium carbonate solution with a mass concentration of 0.5% for 20 minutes to remove excess fat. The mass ratio of fresh cowhide to sodium carbonate solution was 1:3. After cleaning, the cowhide was cut into 1 cm × 1 cm × 1 cm blocks. The cowhide, water, and high ester pectin were mixed in a mass ratio of 1:3:0.02 and heated at a temperature of 95°C to 100°C for 150 minutes. After heating, the supernatant was collected.

[0027] (2) After the duck breast is steamed and cooked thoroughly, cut into thin strips or small pieces, and added to the cowhide supernatant. The amount of duck breast added is 10% of the total mass of the cowhide supernatant. Then, potassium chloride accounting for 0.08% of the total mass of the cowhide supernatant is added and mixed evenly. The mixture is placed at room temperature for 30 minutes, and then placed in a refrigerator at 4°C for 4 hours to obtain crystal duck jelly.

[0028] Example 4:

[0029] A method for improving the stability of crystal duck jelly by combining potassium chloride and high-ester pectin, comprising the following steps:

[0030] (1) Fresh cowhide was soaked in a sodium carbonate solution with a mass concentration of 0.5% for 20 minutes to remove excess fat. The mass ratio of fresh cowhide to sodium carbonate solution was 1:3. After cleaning, the cowhide was cut into 1 cm × 1 cm × 1 cm blocks. The cowhide, water, and high ester pectin were mixed in a mass ratio of 1:3:0.06 and heated at a temperature of 95°C to 100°C for 150 minutes. After heating, the supernatant was collected.

[0031] (2) After the duck breast is steamed and cooked thoroughly, cut into thin strips or small pieces, and added to the cowhide supernatant. The amount of duck breast added is 10% of the total mass of the cowhide supernatant. Then, potassium chloride accounting for 0.02% of the total mass of the cowhide supernatant is added and mixed evenly. The mixture is placed at room temperature for 30 minutes, and then placed in a refrigerator at 4°C for 4 hours to obtain crystal duck jelly.

[0032] Example 5:

[0033] A method for improving the stability of crystal duck jelly by combining potassium chloride and high-ester pectin, comprising the following steps:

[0034] (1) Fresh cowhide was soaked in a sodium carbonate solution with a mass concentration of 0.5% for 20 minutes to remove excess fat. The mass ratio of fresh cowhide to sodium carbonate solution was 1:3. After cleaning, the cowhide was cut into 1 cm × 1 cm × 1 cm blocks. The cowhide, water, and high ester pectin were mixed in a mass ratio of 1:3:0.06 and heated at a temperature of 95°C to 100°C for 150 minutes. After heating, the supernatant was collected.

[0035] (2) After the duck breast is steamed and cooked thoroughly, cut into thin strips or small pieces, and added to the cowhide supernatant. The amount of duck breast added is 10% of the total mass of the cowhide supernatant. Then, potassium chloride accounting for 0.05% of the total mass of the cowhide supernatant is added and mixed evenly. The mixture is placed at room temperature for 30 minutes, and then placed in a refrigerator at 4°C for 4 hours to obtain crystal duck jelly.

[0036] Example 6:

[0037] A method for improving the stability of crystal duck jelly by combining potassium chloride and high-ester pectin, comprising the following steps:

[0038] (1) Fresh cowhide was soaked in a sodium carbonate solution with a mass concentration of 0.5% for 20 minutes to remove excess fat. The mass ratio of fresh cowhide to sodium carbonate solution was 1:3. After cleaning, the cowhide was cut into 1 cm × 1 cm × 1 cm blocks. The cowhide, water, and high ester pectin were mixed in a mass ratio of 1:3:0.06 and heated at a temperature of 95°C to 100°C for 150 minutes. After heating, the supernatant was collected.

[0039] (2) After the duck breast is steamed and cooked thoroughly, cut into thin strips or small pieces, and added to the cowhide supernatant. The amount of duck breast added is 10% of the total mass of the cowhide supernatant. Then, potassium chloride accounting for 0.08% of the total mass of the cowhide supernatant is added and mixed evenly. The mixture is placed at room temperature for 30 minutes, and then placed in a refrigerator at 4°C for 4 hours to obtain crystal duck jelly.

[0040] Comparative Example 1:

[0041] The specific steps are the same as those in Example 5, except that: high-ester pectin and potassium chloride are not added, cowhide and water are mixed in a mass ratio of 1:3 and heated at a temperature of 95°C to 100°C for 150 minutes, and the supernatant is collected after the heating is completed;

[0042] The duck breast is steamed and cooked thoroughly, cut into thin strips or small pieces, and added to the cowhide supernatant. The amount of duck breast added is 10% of the total mass of the cowhide supernatant. The duck breast is placed at room temperature for 30 minutes and then placed in a 4°C refrigerator for 4 hours to obtain crystal duck jelly.

[0043] Comparative Example 2:

[0044] The specific steps are the same as those in Example 5, except that: potassium chloride is not added to prepare the crystal duck jelly.

[0045] Comparative Example 3:

[0046] The specific steps are the same as those in Example 5, except that no high-ester pectin is added to prepare the crystal duck jelly.

[0047] Comparative Example 4:

[0048] The specific steps are the same as those in Example 5, except that sodium chloride is used instead of potassium chloride, and the amount of potassium chloride added is 0.05% of the total mass of the cowhide supernatant to prepare crystal duck jelly.

[0049] Comparative Example 5:

[0050] The specific steps are the same as those in Example 5, except that calcium chloride is used instead of potassium chloride, and the added amount of potassium chloride is 0.05% of the total mass of the cowhide supernatant to prepare crystal duck jelly.

[0051] Performance measurement:

[0052] The melting points of the crystal duck jellies obtained in Examples 1 to 6 and Comparative Examples 1 to 5 were determined using a rheometer equipped with a plate with a diameter of 40 mm. About 1 mL of the sample solution was transferred to the sample stage of the rheometer, and the temperature was set to 4°C. Then, the plate gap was set to 1 mm, and low-density silicone oil was applied to the periphery of the plate to prevent evaporation of sample moisture. A heating program was then performed from 4°C to 60°C at 5°C / min. The melting point was defined as the intersection of G' and G" during the heating process. The strain was fixed at 1.0% (within the linear viscoelastic range) and the frequency was 1 Hz.

[0053] The gel strength of the products of Examples 1 to 6 and Comparative Examples 1 to 5 was measured using a TA.XT Plus physical property tester equipped with a P / 0.5R probe. The measurement parameters were: a descending speed of 1.5 mm / s before measurement, a test speed of 1.0 mm / s, an ascending speed of 1.0 mm / s after measurement, a compression depth of 4 mm, an automatic trigger type, a trigger force of 5 g, and the force value when the test probe touched 4 mm into the aspic gel was recorded as the gel strength.

[0054] The texture characteristics of the samples were determined using a TA.XT Plus physical property tester. The measurement conditions were: TPA mode, P50 probe, descending speed 2.0 mm / s before measurement, measuring speed 1.0 mm / s, rising speed 1.0 mm / s after measurement, compression ratio 30%, automatic trigger type, trigger force 5 g, and dwell time 5 s in secondary compression.

[0055] The results of melting point, gel strength and texture properties are shown in Table 1.

[0056] Table 1 Changes in melting point, gel strength and texture characteristics of the products of Examples and Comparative Examples

[0057] Grouping Melting point (℃) Gel strength (g) Elasticity (mm) Chewing properties (mj) Resilience Example 1 57.19±1.62 140.22±3.08 0.91±0.01 365.17±12.06 0.59±0.04 Example 2 54.14±2.49 132.79±4.17 0.93±0.04 377.52±10.12 0.58±0.02 Example 3 52.77±1.85 127.62±3.46 0.92±0.02 380.39±17.43 0.61±0.05 Example 4 >60.00 271.48±4.95 0.95±0.01 423.85±15.47 0.58±0.04 Example 5 >60.00 262.15±3.77 0.98±0.05 455.14±19.26 0.61±0.02 Example 6 >60.00 255.76±4.14 0.96±0.04 461.32±14.13 0.62±0.02 Comparative Example 1 24.31±1.38 87.99±3.43 0.87±0.04 237.09±11.85 0.56±0.03 Comparative Example 2 39.60±1.22 202.14±4.32 0.84±0.04 392.11±13.42 0.49±0.04 Comparative Example 3 28.62±0.76 98.15±3.74 0.89±0.02 286.62±15.74 0.57±0.02 Comparative Example 4 53.17±1.17 217.35±3.82 0.87±0.04 405.22±11.37 0.55±0.01 Comparative Example 5 51.63±1.46 221.07±4.34 0.88±0.02 389.48±14.19 0.53±0.02

[0058] After refrigerating the samples of Examples 1 to 6 and Comparative Examples 1 to 5 at 4°C for 24 hours, about 2 g of gel sample was placed in a nuclear magnetic tube (15 mm in diameter) and the water distribution of the sample was determined using the T2 spectrum of a low-field nuclear magnetic resonance instrument. T21, T22, and T23 represent bound water, non-mobile water, and free water, respectively. The measurement parameters were set as follows: the test algorithm was the CPMG pulse sequence (Carr-Purcell-Meiboom-Gill), the measurement temperature was 32°C, the continuous scanning interval TW was 5000ms, the echo time TE was 0.4ms, the number of echoes NECH was 18000 times, and the number of scans NS was 4 times. The exponential decay graph was obtained by inversion, and the fluidity and distribution of water were analyzed by the relaxation time value and the peak area percentage. The results are as follows: Figure 1 、 2 shown.

[0059] From Table 1, Figures 1-2 The results show that:

[0060] (1) Compared with Examples 1 to 6, the crystal duck jelly product obtained in Comparative Example 1 does not contain high-ester pectin and potassium chloride, and its melting point is 24.31°C, which is much lower than the melting point of the crystal duck jelly products obtained in Examples 1 to 6. The gel strength, elasticity, chewiness, and recovery are also lower than those in Examples 1 to 6. The ratio of bound water T21 is increased, indicating that the addition of high-ester pectin and potassium chloride can significantly improve the stability of crystal duck jelly.

[0061] (2) Compared with Example 5, potassium chloride was not added to the finished crystal duck jelly prepared in Comparative Example 2, and high-ester pectin was not added to the finished crystal duck jelly prepared in Comparative Example 3. The melting point, gel strength, elasticity, chewiness, and recovery of the finished products of Comparative Examples 2 and 3 were all lower than those of Example 5, and the bound water ratio was lower than that of Example 5, indicating that potassium chloride and high-ester pectin have a certain synergistic effect in enhancing the stability of crystal duck jelly.

[0062] (3) Compared with Example 5, sodium chloride was used instead of potassium chloride in Comparative Example 4, and calcium chloride was used instead of potassium chloride in Comparative Example 4. The melting point, gel strength, elasticity, chewiness, resilience, bound water ratio and other indicators of the finished products of Comparative Examples 4 and 5 were all lower than those of Example 5, indicating that the interaction effect of potassium chloride with high-ester pectin was better than that of other salts (sodium chloride, calcium chloride, etc.).

[0063] Comparative Example 6: Treating cowhide by changing the concentration of sodium carbonate

[0064] When the concentration of sodium carbonate is too high (>1.2%), it is easy to cause excessive expansion or deformation of the collagen on the cowhide, which damages the quality of the cowhide itself and affects the texture of the gel. The final product of crystal duck jelly has a hard texture and a bitter taste, which is not edible.

[0065] When the mass concentration of sodium carbonate is too low (less than 0.3%), the fat removal effect on the cowhide is poor, and it is not easy to condense and form during the cooling process. Excessive fat interferes with the hydrogen bonds and hydrophobic interactions between the colloid molecules, affecting the formation of the gel. The surface color of the formed gel is turbid, resulting in a decrease in the appearance of the finished crystal duck jelly, and the finished crystal duck jelly has a greasy taste and a poor flavor.

[0066] Using a sodium carbonate solution with a mass concentration in the range of 0.5% to 1% can effectively remove the fat attached to the cowhide. It is easy to condense and form during the cooling process. The gel formed has a clear and translucent appearance. The finished crystal duck jelly is beautiful and tastes smooth and not greasy.

[0067] The present invention is not limited to the above-mentioned embodiments. On the basis of the technical solutions disclosed in the present invention, those skilled in the art can make some substitutions and modifications to some of the technical features therein according to the disclosed technical content without creative labor, and these substitutions and modifications are all within the protection scope of the present invention.

Claims

1. A method for improving the stability of crystal duck jelly by combining potassium chloride and high-ester pectin, characterized in that: The following steps are involved: Excess fat is removed from fresh cowhide, which is then cleaned and cut into pieces. The cowhide, water, and high-ester pectin are mixed in a certain proportion and heated. The cowhide is removed and the supernatant is collected. Duck breast is steamed and cooked thoroughly, cut into thin strips or small pieces, added to the cowhide supernatant, and then an appropriate amount of potassium chloride is added. The mixture is evenly mixed, left at room temperature for a period of time, and then cooled in a refrigerator to obtain crystal duck jelly, wherein the high-ester pectin has an esterification degree DE greater than 50%.

2. The method for improving the stability of crystal duck jelly by combining potassium chloride and high-ester pectin according to claim 1, characterized in that: The fresh cowhide is soaked in a sodium carbonate solution with a mass concentration of 0.5% to 1% for 20 minutes to remove excess fat. The mass ratio of the fresh cowhide to the sodium carbonate solution is 1:3, and the size of the fresh cowhide cut into pieces is 1 cm × 1 cm × 1 cm.

3. The method for improving the stability of crystal duck jelly by combining potassium chloride and high-ester pectin according to claim 1, characterized in that: The cowhide, water and high ester pectin are mixed in a mass ratio of 1: (2.5-4.0): (0.02-0.06), the heating temperature is 95-100° C., and the heating time is 120-150 min.

4. The method for improving the stability of crystal duck jelly by combining potassium chloride and high-ester pectin according to claim 1, characterized in that: The added amount of the duck breast is 10% to 25% of the total mass of the cowhide supernatant.

5. The method for improving the stability of crystal duck jelly by combining potassium chloride and high-ester pectin according to claim 1, characterized in that: The potassium chloride is food grade potassium chloride, and the amount of potassium chloride added is 0.02% to 0.08% of the total mass of the cowhide supernatant.

6. The method for improving the stability of crystal duck jelly by combining potassium chloride and high-ester pectin according to claim 1, characterized in that: The room temperature placement time is 30 min, the refrigerator cooling temperature is 4°C, and the cooling time is 4 h.

7. Crystal duck jelly prepared by the method for improving the stability of crystal duck jelly by combining potassium chloride and high-ester pectin according to any one of claims 1 to 6.

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