A method to delay the hardening of meat chunks during the storage period of zongzi (sticky rice dumplings).

Abstract

This invention discloses a method for delaying the hardening of pork chunks during the storage period of zongzi (sticky rice dumplings), belonging to the field of food processing technology. This invention involves injecting a mixture of xanthan gum and gelatin into pork, followed by ultrasonic injection and soaking in a natural preservative solution to obtain pork chunks suitable for preparing vacuum-packed zongzi. The resulting zongzi retain good texture, flavor, and moisture content even under long-term vacuum packaging. This invention breaks through traditional process bottlenecks, comprehensively overcoming the problem of pork chunk hardening during the storage period of zongzi through structural optimization of raw material pretreatment, scientific application of natural preservatives, and precise control of the processing flow, effectively meeting the market's urgent demand for high-quality, long-shelf-life zongzi.

Description

Technical Field

[0001] This invention relates to a method for delaying the hardening of meat chunks during the storage period of zongzi (sticky rice dumplings), belonging to the field of food processing technology. Background Technology

[0002] Meat-filled rice dumplings (zongzi) are a popular traditional food with a wide consumer base. However, existing zongzi-making techniques have many flaws. During storage, due to environmental factors and the characteristics of their own composition, the meat is prone to hardening.

[0003] Traditional processing methods involve simple initial treatment of meat chunks, lacking effective moisture retention and tenderization measures. This results in significant moisture loss and muscle fiber contraction during subsequent processing and long-term storage, leading to a poorer texture and greater difficulty in chewing. Furthermore, the lack of targeted antioxidant and antibacterial measures allows fat oxidation and microbial growth to accelerate the deterioration of meat quality, further exacerbating hardening and severely shortening the shelf life of the meat dumplings. This limits their commercial promotion and market competitiveness, making it difficult to meet consumer demand for high-quality, long-shelf-life meat dumpling products.

[0004] In today's food market, zongzi (sticky rice dumplings), as a traditional delicacy with a long history and wide appeal, has always maintained a certain market share. However, a key problem that has long plagued the development of the zongzi industry—the hardening of the meat during storage—severely restricts its quality improvement and market expansion. Traditional zongzi-making techniques are inadequate in addressing this problem. Because of the high water activity of the meat itself, water easily flows to the relatively less active glutinous rice, causing the meat's moisture content to drop rapidly. Under these conditions, the muscle fibers contract and aggregate, leading to rapid hardening and a deterioration in texture. Current conventional methods for processing meat products, such as enzymatic treatment, phosphate treatment, sous-vide cooking, and physical field intervention, can improve water retention and tenderness in the short term after treatment. However, enzymatic treatment can lead to a decrease in the water-holding capacity of meat products, which can actually accelerate water loss. Phosphate treatment is difficult to apply to traditional foods in today's environment that promotes green food. Sous-vide cooking and physical field intervention improve meat quality by altering the denaturation of muscle proteins. However, during long-term storage, these methods are unlikely to improve the binding capacity of meat protein to water and thus inhibit water migration and improve quality.

[0005] Therefore, developing a method to maintain the water content, good texture, and flavor of the meat inside the zongzi (sticky rice dumpling) for a long time under vacuum packaging has extremely high practical and economic value. Summary of the Invention

[0006] To address the aforementioned problems, this invention involves compounding xanthan gum and gelatin, then injecting ultrasonically into pork and soaking it in a natural preservative solution to obtain pork chunks suitable for preparing vacuum-packed zongzi (sticky rice dumplings). This allows the pork chunks to maintain good texture, flavor, and moisture content even after long-term storage in vacuum packaging. This invention breaks through traditional process bottlenecks, comprehensively overcoming the problem of pork chunk hardening during zongzi storage through structural optimization of raw material pretreatment, scientific application of natural preservatives, and precise control of the processing flow. This effectively meets the market's urgent demand for high-quality, long-shelf-life zongzi.

[0007] The first objective of this invention is to provide a method for processing pork for vacuum-packed meat dumplings, comprising the following steps:

[0008] (1) Dissolve xanthan gum and gelatin in water, mix well, and prepare a mixed glue solution; inject the mixed glue solution into pork chunks, place the injected pork chunks in a self-sealing bag, and sonicate to obtain sonicated pork chunks.

[0009] (2) Dissolve tea polyphenols and rosemary extract in water, mix well, and prepare a natural preservative solution; place the ultrasonically treated meat pieces in the natural preservative solution for soaking, and after soaking, take them out and drain them to obtain pork for vacuum packaging meat dumplings.

[0010] In one embodiment, the concentration of xanthan gum in the mixed gum solution of step (1) is 0.001 to 0.002 g / mL, and the concentration of gelatin is 0.001 to 0.002 g / mL.

[0011] In one embodiment, in step (1), the injection volume of the mixed adhesive solution is 0.05-0.08 mL / g pork;

[0012] Optionally, the injection volume of the mixed gel solution is 0.05 mL / g pork.

[0013] In one embodiment, in step (1), the ultrasound is performed at 300-400W, 35-40KHz, and 35-37℃ for 5-10 minutes.

[0014] In one embodiment, the concentration of tea polyphenols in the natural preservative solution of step (2) is 0.004-0.006 g / mL, and the concentration of rosemary extract is 0.002-0.004 g / mL.

[0015] In one embodiment, the ultrasonically treated meat pieces in step (2) are soaked in a natural preservative solution for 25 to 40 minutes.

[0016] The second objective of this invention is to provide a method for simultaneously improving the water retention, flavor, textural properties, and sensory quality of pork in vacuum-packed zongzi (sticky rice dumplings), comprising the following steps:

[0017] (1) Dissolve xanthan gum and gelatin in water, mix well, and prepare a mixed glue solution; inject the mixed glue solution into pork chunks, place the injected pork chunks in a self-sealing bag, and sonicate to obtain sonicated pork chunks.

[0018] (2) Dissolve tea polyphenols and rosemary extract in water, mix well, and prepare a natural preservative solution; place the ultrasonically treated meat pieces in the natural preservative solution for soaking, and after soaking, take them out and drain them to obtain pork for vacuum packaging meat dumplings.

[0019] In one embodiment, in the mixed gum solution of step (1), the concentration of xanthan gum is 0.001-0.002 g / mL, and the concentration of gelatin is 0.001-0.002 g / mL;

[0020] Optionally, in step (1), the injection volume of the mixed gel solution is 0.05 to 0.08 mL / g pork;

[0021] Optionally, in step (1), the ultrasound is performed at 300-400W, 35-40KHz, and 35-37℃ for 5-10 minutes.

[0022] Optionally, in the natural preservative solution of step (2), the concentration of tea polyphenols is 0.004-0.006 g / mL, and the concentration of rosemary extract is 0.002-0.004 g / mL;

[0023] Optionally, the ultrasonically treated meat pieces in step (2) are soaked in a natural preservative solution for 25 to 40 minutes.

[0024] A third object of the present invention is to provide a meat dumpling prepared by any of the above-described methods. A fourth object of the present invention is to provide the application of any of the above-described methods in the preparation of meat dumplings.

[0025] Beneficial effects of the present invention

[0026] This invention combines xanthan gum and gelatin to form a protein-polysaccharide gel network structure in meat chunks, which greatly enhances the ability to retain water, effectively improves the water retention of meat chunks in zongzi (sticky rice dumplings), delays the protein denaturation process caused by water loss, optimizes the textural properties of meat chunks in zongzi, and allows the meat chunks to maintain a good taste even after long-term storage. This solves the problems of poor taste and difficulty in chewing caused by processing and storage of meat chunks in traditional processes.

[0027] Secondly, this invention uses ultrasound-assisted hydrophilic colloid treatment of meat blocks, combined with physical methods to improve the muscle fiber structure of the meat blocks, promote the uniform distribution of the mixed colloid in the meat blocks, enhance the binding strength between colloid molecules and meat proteins, and further restrict the flow of water in the meat blocks, so as to improve the texture of the meat blocks during storage and extend the shelf life.

[0028] The addition of natural preservatives can further improve the edible quality of the meat. Tea polyphenols and rosemary extracts effectively enhance the flavor score of the meat during heat processing and delay the darkening and discoloration caused by oxidation, significantly increasing consumer acceptance. Furthermore, their antioxidant capacity also slows down the deterioration and hardening of the meat, extending its shelf life and better preserving its flavor, thus meeting consumer demand for high-quality meat dumplings. Attached Figure Description

[0029] Figure 1 The results show the moisture distribution of Examples 1, 2 and Comparative Examples 1 to 13; where A to O represent Examples 1, 2 and Comparative Examples 1 to 13, respectively. Detailed Implementation

[0030] The preferred embodiments of the present invention are described below. It should be understood that the embodiments are for better explanation of the present invention and are not intended to limit the present invention.

[0031] Raw materials used in the examples:

[0032] Xanthan gum (food grade) was purchased from Henan Wanbang Chemical Technology Co., Ltd.

[0033] Gelatin (food grade) was purchased from Henan Wanbang Chemical Technology Co., Ltd.

[0034] Tea polyphenols (food grade) were purchased from Henan Wanbang Industrial Co., Ltd.

[0035] Rosemary extract (food grade) was purchased from Shengfa Biotechnology Co., Ltd.

[0036] The lean pork hind leg was purchased from Yimeijia Food Store in Binhu District, Wuxi City, Jiangsu Province.

[0037] Test method:

[0038] 1. Method for detecting cooking loss

[0039] Accurately weigh the processed meat chunks as m1. After wrapping, steaming, and storage, remove the meat chunks from the zongzi. After removing any residual glutinous rice from the surface, accurately weigh them as m2. The water holding capacity is calculated using the following formula:

[0040]

[0041] Moisture content

[0042] After storage, the meat chunks are removed from the zongzi (sticky rice dumplings), the surface residue of glutinous rice is removed, and the meat is chopped. The meat is then evenly spread in an aluminum box and placed in a 105℃ oven to dry until constant weight. The mass of the sample before drying (m1) and after drying (m2) is accurately measured. The difference is the moisture loss. The moisture content is expressed as the percentage of moisture loss to the weight of the fresh sample.

[0043]

[0044] 2. Moisture distribution

[0045] After storage, the meat pieces were removed from the zongzi (sticky rice dumplings), and residual glutinous rice was removed from the surface. Two grams of meat were then wrapped in raw material and the moisture distribution in the sample was characterized using a low-field nuclear magnetic resonance (NMR) analyzer. Hydrogen proton density imaging was obtained using an MSE imaging sequence. Measurement conditions were: center frequency 23.319 MHz, repetition time 3000 ms, echo time 20 ms, field of view: 50 mm longitudinally and 50 mm laterally. Laméer's law was used, and three layers of meat were selected as the imaging layers. After image acquisition, the signal-to-noise ratio (SNR) was adjusted through filtering, and pseudo-coloring was applied to the final image.

[0046] 3. Texture testing methods

[0047] After storage, the meat pieces were removed from the zongzi (sticky rice dumplings), and any remaining glutinous rice was removed from the surface. The pieces were then cut into cubes with dimensions of 1.5 cm in length, width, and height. The hardness of the samples was measured using a texture analyzer. A P36 / R cylindrical probe was used for full texture profile analysis (TPA). The initial speed was 3 mm / s, the testing speed was 1 mm / s, and the post-test speed was 5 mm / s. The test type was compression, the target mode was deformation, the target value was 30%, the contact force was 5 g, and the operation mode was two repeated tests. Three parallel experiments were conducted for each sample group, and the average value was taken.

[0048] 4. Color detection method

[0049] After removing the stored meat from the zongzi and removing any residual glutinous rice, the internal light was calibrated before using a colorimeter to measure the brightness value (L) near the center of each surface of the sample. * ), redness value (a * ) and yellowness value (b * ).

[0050] 5. Sensory evaluation methods

[0051] After storing the meat pieces, remove them from the rice dumplings, remove any remaining glutinous rice, and label the samples with random letters. Place them in a white container at room temperature. Eight judges (4 men and 4 women) with more than one year of sensory analysis experience are invited to participate. The samples are cut into uniform sizes for sensory evaluation. The scoring criteria are shown in Table 1.

[0052] Table 1 Sensory Evaluation Scoring Criteria

[0053]

[0054]

[0055] Example 1

[0056] A method for processing pork chunks in vacuum-packed zongzi (sticky rice dumplings), comprising the following steps:

[0057] (1) Dissolve 0.15g xanthan gum and 0.15g gelatin in 100mL of water, mix well, and prepare a mixed gel solution; inject 1mL of the mixed gel solution into a piece of lean pork (cube with a side length of 2.5cm and a mass of 20g), place the injected pork piece in a self-sealing bag, and sonicate at 300W, 40KHz, and 37℃ for 10min.

[0058] (2) Dissolve 0.5g of tea polyphenols and 0.3g of rosemary extract in 100mL of water, mix well, and prepare a natural preservative solution; after sonication, soak the meat pieces in the natural preservative solution for 10min, take them out and drain them to obtain the processed pork pieces.

[0059] Example 2

[0060] A method for processing pork chunks in vacuum-packed zongzi (sticky rice dumplings), comprising the following steps:

[0061] (1) Dissolve 0.15g xanthan gum and 0.15g gelatin in 100mL of water, mix well, and prepare a mixed gel solution; inject 1mL of the mixed gel solution into a piece of lean pork (cube with a side length of 2.5cm and a mass of 20g), place the injected pork piece in a self-sealing bag, and sonicate at 400W, 40KHz, and 37℃ for 5min.

[0062] (2) Dissolve 0.5g of tea polyphenols and 0.3g of rosemary extract in 100mL of water, mix well, and prepare a natural preservative solution; after sonication, soak the meat pieces in the natural preservative solution for 10min, take them out and drain them to obtain the processed pork pieces.

[0063] Comparative Example 1

[0064] Based on Example 1, step (1) is omitted, and the remaining steps are the same as in Example 1, to prepare the processed pork chunks.

[0065] Comparative Example 2

[0066] Based on Example 1, step (2) is omitted, and the remaining steps are the same as in Example 1, to prepare the processed pork chunks.

[0067] Comparative Example 3

[0068] Based on Example 1, the xanthan gum and gelatin in step (1) were changed to equal amounts of xanthan gum, and the remaining steps were the same as in Example 1, to prepare the treated pork chunks.

[0069] Comparative Example 4

[0070] Based on Example 1, the xanthan gum and gelatin in step (1) were changed to equal amounts of gelatin, and the remaining steps were the same as in Example 1, to prepare the treated pork chunks.

[0071] Comparative Example 5

[0072] Based on Example 1, the xanthan gum and gelatin in step (1) are changed to equal amounts of carrageenan and xanthan gum (e.g., xanthan gum and carrageenan, which are commonly used in the prior art).

[0073] Comparative Example 6

[0074] Based on Example 1, the amount of xanthan gum and gelatin in step (1) was changed to 0.1g and 0.2g respectively, and the remaining steps were the same as in Example 1, to prepare the treated pork chunks.

[0075] Comparative Example 7

[0076] Based on Example 1, the amounts of xanthan gum and gelatin in step (1) were changed to 0.2g and 0.1g respectively, while the remaining steps were the same as in Example 1, and the treated pork chunks were prepared.

[0077] Comparative Example 8

[0078] Based on Example 1, the injection volume of the mixed glue solution in step (2) was changed to 0.5 mL, and the remaining steps were the same as in Example 1, to prepare the treated pork chunks.

[0079] Comparative Example 9

[0080] Based on Example 1, the injection volume of the mixed glue solution in step (2) was changed to 1.5 mL, and the remaining steps were the same as in Example 1, to prepare the treated pork chunks.

[0081] Comparative Example 10

[0082] Based on Example 1, the ultrasonic frequency in step (1) was changed to 30KHz, and the remaining steps were the same as in Example 1, to prepare the processed pork chunks.

[0083] Comparative Example 11

[0084] Based on Example 1, the ultrasonic frequency in step (1) was changed to 50KHz, while the remaining steps were the same as in Example 1, and the processed pork chunks were prepared.

[0085] Comparative Example 12

[0086] Based on Example 1, the ultrasonic temperature in step (1) was changed to 25°C, while the remaining steps were the same as in Example 1, and the processed pork chunks were prepared.

[0087] Comparative Example 13

[0088] Based on Example 1, the ultrasonic temperature in step (1) was changed to 50°C, while the remaining steps were the same as in Example 1, and the processed pork chunks were prepared.

[0089] Example 3

[0090] 1. Making meat dumplings

[0091] Take the treated pork chunks obtained from Examples 1 and 2, and Comparative Examples 1-13, as well as the untreated pork chunks, to prepare meat dumplings. The steps are as follows:

[0092] (1) Soak glutinous rice and water in a 1:1 mass ratio for 2 hours, and drain the water after soaking; add seasoning (weight ratio: 100 parts glutinous rice, 5 parts salt, 5 parts light soy sauce, 3 parts five-spice powder, 1 part oyster sauce; marinate for 30 minutes), stir well so that the seasoning is evenly absorbed into the rice grains;

[0093] (2) The processed pork chunks are seasoned with marinade (by weight: 20 parts pork chunks, 2 parts salt, 2 parts dark soy sauce, 0.5 parts MSG, 1.5 parts chicken bouillon, and 3 parts cooking wine; marinate for 30 minutes).

[0094] (3) The marinated glutinous rice and marinated pork chunks are wrapped in a mass ratio of 130:20 (the type of bamboo leaves is reed leaves); after wrapping, heat treatment is carried out at 0.6MPa pressure for 60min, and then pressure is stopped and heat treatment is carried out for 60min; the prepared meat dumplings are vacuum-packed.

[0095] 2. Properties of pork chunks in meat dumplings

[0096] Take the meat dumplings made from pork chunks treated in step 1, and test the properties of the meat chunks in the dumplings after 10 days of storage.

[0097] (1) Moisture distribution

[0098] The results of cooking loss, moisture content, and moisture distribution are shown in Table 2. Figure 1 As shown.

[0099] Table 2 Results of cooking loss and moisture content in Examples 1, 2 and Comparative Examples 1-13

[0100] Cooking loss (%) Moisture content (%) Example 1 55.33 51.16 Example 2 55.23 50.34 Comparative Example 1 56.34 48.61 Comparative Example 2 56.17 48.57 Comparative Example 3 56.77 48.7 Comparative Example 4 57.34 46.34 Comparative Example 5 56.21 48.99 Comparative Example 6 56.45 47.04 Comparative Example 7 55.3 51.82 Comparative Example 8 57.3 48.32 Comparative Example 9 55.3 51.2 Comparative Example 10 56.91 50.53 Comparative Example 11 55.98 50.51 Comparative Example 12 56.32 49.23 Comparative Example 13 57.3 48.12

[0101] Combining Examples 1 and 2 with Comparative Examples 1, 10-13, it can be found that the ultrasonic step significantly affects the cooking loss, water content and moisture distribution of the meat samples. Comparative Example 1 shows the characteristics of high cooking loss and low water content, indicating that the ultrasonic step can effectively improve the water retention capacity of the meat. This is mainly due to its ability to destroy the structure of muscle fibers to a certain extent and promote the binding of proteins and colloidal molecules.

[0102] The water bath temperature and frequency of ultrasound also have a certain impact on the quality of meat. Comparative Examples 10 and 11 showed lower cooking losses than Examples 1 and 2. This is because excessively high ultrasound frequencies can damage the original structure of muscle fibers, leading to a decrease in water retention capacity, while excessively low frequencies can affect the binding speed and strength of colloids and protein molecules.

[0103] Examples 1 and 2, along with Comparative Example 2, demonstrate that the addition of natural preservatives enhances the water-holding capacity of meat chunks. Examples 1 and 2, and Comparative Examples 3-9, show that only when xanthan gum and gelatin are blended in a 1:1 ratio to a concentration exceeding 0.3% (mass fraction) does a significant improvement in the water-holding capacity and moisture content of the meat chunks occur. When xanthan gum or gelatin is used alone, cooking losses increase by 2.6% and 3.6%, respectively, compared to Example 1. Furthermore, changing the blending system (currently, the most commonly studied blend is xanthan gum and carrageenan) does not significantly improve the effect. A higher proportion of xanthan gum in the formula results in better water retention. However, when the proportion of gelatin is too high, its poor thermal stability causes it to easily dissolve back into the water from its protein-bound state at high temperatures, leading to a poor improvement effect.

[0104] Therefore, when the amount of water-retaining agent added is less than 1 mL, the water-retaining effect is not significantly improved. This is because a small number of colloidal molecules cannot form a three-dimensional gel network structure with strong water-retaining capacity in the protein. In summary, the results indicate that only by using a 1:1 mixture of xanthan gum and gelatin to a concentration of 0.3%, and injecting it into the meat at a dosage of 0.05 g / mL, combined with ultrasonic treatment and synergistic treatment with preservatives, can the meat achieve optimal water retention.

[0105] Hydrogen proton density image as follows Figure 1 As shown, the distribution of moisture within the sample is clearly visualized, with red areas representing high moisture content and blue areas representing low moisture content. It is evident that... Figure 1The moisture distribution results shown are consistent with the moisture content changes in Table 2. After the combined treatment with improver, preservative and ultrasound, Examples 1 and 2 and Comparative Examples 9 to 13 all showed higher hydrogen proton density, which further confirms the effect of this method on improving the water retention of meat.

[0106] (2) Texture test results

[0107] The results of the texture analysis are shown in Table 3.

[0108] Table 3. Texture determination results of Examples 1 and 2 and Comparative Examples 1–13

[0109]

[0110]

[0111] Texture is an important indicator of meat product quality, which greatly affects the product's edibility and consumers' eating experience. Hardness, adhesiveness, and chewiness are direct indicators of sample texture, with chewiness referring to the energy required to chew solid food.

[0112] Combined with Examples 1 and 2, and Comparative Examples 1, 10-13, it can be demonstrated that ultrasound parameters have a certain influence on the texture of meat. This is related to the fact that ultrasound frequency itself can affect changes in muscle fiber structure, and also to its involvement in affecting the moisture distribution of meat. Studies have shown that water content and moisture distribution are significantly correlated with texture, and that excessively high or low ultrasound frequencies also affect the texture of meat.

[0113] Combined with Examples 1 and 2 and Comparative Examples 1 and 2, it can be seen that although the effect of adding preservatives on meat quality is not as significant as that of the ultrasonic step, it can still reduce the hardness by 10.28%, the adhesiveness by 22.8%, and the chewiness by 33.7%. This is because the antioxidant properties of tea polyphenols and rosemary extract in the natural preservatives inhibit the oxidation rate of meat protein to a certain extent.

[0114] Combining Examples 1 and 2 with Comparative Examples 3–9, it can be observed that the improver formulation has a significant impact on texture. The xanthan gum and gelatin systems alone cannot provide sufficient improvement because gelatin and xanthan gum can form a stable protein gel network structure during dissolution. This structure, under ultrasound, further binds to the meat protein, further restricting the flow of water in the meat and reducing moisture loss during storage, thus affecting the texture of the meat. Although carrageenan is also widely used in improving the quality of meat products, the higher binding degree between gelatin and protein is more beneficial for the improver's ability to restrict water flow in meat products.

[0115] (3) Appearance and color

[0116] The color of the meat chunks is shown in Table 4.

[0117] Table 4. Color detection results of Examples 1 and 2 and Comparative Examples 1-13

[0118]

[0119]

[0120] Combining Examples 1 and 2 with Comparative Examples 1-13, it can be found that the preservative is effective in increasing the brightness value (L) of meat pieces. * The preservative has a significant effect because the tea polyphenols and rosemary extract in the preservative are commonly used antioxidants in food. The color change of meat pieces mainly depends on the type and denaturation of myoglobin in the muscle. Myoglobin denatures at high temperatures to form methemoglobin and ferrous hemoglobin. During heating and storage, a large number of free radicals and secondary oxidation products will oxidize ferrous hemoglobin to methemoglobin, causing the meat pieces to darken in color. * The color value decreases. The antioxidants in the preservative effectively weaken this process and have a good effect on improving the color of meat products.

[0121] (4) Sensory evaluation

[0122] The sensory evaluation results of the meat chunks are shown in Table 5.

[0123] Table 5. Sensory evaluation results of Examples 1 and 2 and Comparative Examples 1-13

[0124] color taste Flavor texture Overall acceptability Example 1 7.61 7.71 7.47 7.65 7.67 Example 2 7.64 7.75 7.42 7.66 7.64 Comparative Example 1 7.56 7.62 7.34 7.32 7.24 Comparative Example 2 7.3 7.57 7.01 7.54 7.45 Comparative Example 3 7.71 7.53 7.4 7.6 7.57 Comparative Example 4 7.56 7.3 7.31 7.2 7.16 Comparative Example 5 7.45 7.47 7.32 7.54 7.44 Comparative Example 6 7.44 7.36 7.23 7.44 7.12 Comparative Example 7 7.53 7.42 7.43 7.64 7.67 Comparative Example 8 7.53 7.4 7.32 7.31 7.16 Comparative Example 9 7.64 7.51 7.4 7.64 7.58 Comparative Example 10 7.44 7.5 7.34 7.61 7.46 Comparative Example 11 7.66 7.51 7.37 7.64 7.59 Comparative Example 12 7.56 7.48 7.26 7.68 7.36 Comparative Example 13 7.62 7.56 7.36 7.63 7.42

[0125] The sensory evaluation results are shown in Table 5. Combining Examples 1 and 2 with Comparative Examples 1, 10-13, it can be found that the ultrasonic step has a significant impact on the photosensitive evaluation of meat quality. Examples 1 and 2 and Comparative Examples 10-13, which are combined with ultrasonic treatment, have higher scores in texture and overall acceptability than Comparative Example 1. Furthermore, the lower ultrasonic frequency and unsuitable water bath temperature also have an impact on the sensory evaluation of the meat pieces.

[0126] Comparative Example 2 shows that the addition of preservatives has a certain effect on improving the color and flavor of the meat chunks, which is consistent with the color test results. Furthermore, combined with Comparative Examples 3-9, it indicates that neither xanthan gum nor gelatin alone, nor a combination of xanthan gum and carrageenan, is sufficient to improve the hardening of meat chunks during storage. This is because these hydrophilic gum systems struggle to maintain good water retention in this food (meat chunks in zongzi). The ratio and amount of the mixed gum solution also significantly affect the improvement effect. When the xanthan gum content in the solution reaches 50%, the overall acceptability score is 7.67, while when it reaches 33.3%, the overall acceptability score is only 7.12. Further increasing the xanthan gum ratio does not significantly improve the photosensitive evaluation score. In addition, the amount of the mixed gum solution added shows a similar trend to the ratio; too low an amount is insufficient to achieve satisfactory results, while the best improvement effect is obtained when the amount added is greater than 0.05 mL / g.

[0127] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Anyone skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the claims.

Claims

1. A method for simultaneously improving the water retention, flavor, textural properties, and appearance of pork in vacuum-packed zongzi (sticky rice dumplings), characterized in that, Including the following steps: (1) Dissolve xanthan gum and gelatin in water, mix well, and prepare a mixed glue solution; inject the mixed glue solution into pork chunks, place the injected meat chunks in a self-sealing bag, and sonicate to obtain sonicated meat chunks; (2) Dissolve tea polyphenols and rosemary extract in water, mix well, and prepare a natural preservative solution; place the ultrasonically treated meat pieces in the natural preservative solution for soaking, and after soaking, take them out and drain them to obtain pork for vacuum packaging of meat dumplings; In step (1), the concentration of xanthan gum in the mixed gelatin solution is 0.001~0.002 g / mL, the concentration of gelatin is 0.001~0.002 g / mL, and the injection volume of the mixed gelatin solution is 0.05~0.08 mL / g pork. In step (1), the ultrasound treatment is performed at 300~400 W, 35~40 KHz, and 35~37 ℃ for 5~10 min; In the natural preservative solution of step (2), the concentration of tea polyphenols is 0.004~0.006 g / mL and the concentration of rosemary extract is 0.002~0.004 g / mL.

2. The method according to claim 1, characterized in that, In step (2), the ultrasonically treated meat pieces are soaked in a natural preservative solution for 25-40 minutes.

3. The application of the method according to any one of claims 1 to 2 in the preparation of zongzi (sticky rice dumplings).

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