Sterilization process of high-power-density ultrasonic-assisted medium-temperature water bath poultry products

Abstract

The invention discloses a high-power-density ultrasonic-assisted medium-temperature water bath sterilization process for poultry products, and belongs to the technical field of food production processes, and the high-power-density ultrasonic-assisted medium-temperature water bath sterilization process comprises the steps of raw material pretreatment, pickling, marinating, clean goose marinating and boiling, finished product packaging and vacuum packaging product sterilization. The cavitation effect generated by high-power-density ultrasound can directly destroy the microbial cell membrane structure and efficiently inactivate pathogenic bacteria and putrefying bacteria, and the medium-temperature environment can assist in enhancing the sterilization effect of ultrasound, avoid severe heat damage caused by traditional high-temperature and high-pressure sterilization, reduce thermal decomposition of flavor substances and damage to the goose meat structure, slow down fat oxidation and improve the quality of the goose meat. Compared with low-temperature cold sterilization, the salted goose has the advantages that the shelf life of salted geese is prolonged, and the salted goose sterilization method is suitable for industrial production of salted geese and other poultry products.

Description

Technical Field

[0001] The present invention relates to the technical field of food production technology, and in particular to a sterilization process for poultry products using high-power density ultrasound in conjunction with a medium-temperature water bath. Background Art

[0002] Salted goose (commonly known as Yangzhou old goose) is a representative dish of Huaiyang cuisine. Its plump, tender, yet firm texture, and golden, golden hue are renowned for their delicious, salty flavor. Currently, salted goose is primarily sold through two channels: freshly prepared and sold at individual stalls, and vacuum-packed pre-made. Vacuum-packed goose is primarily marketed to tourists, but its flavor quality lags significantly behind that of local fresh retail products. Vacuum-packed goose products require sterilization after processing to extend their shelf life.

[0003] Commonly used sterilization technologies include high-temperature thermal sterilization and low-temperature cold sterilization. High-temperature thermal sterilization usually requires processing in a high-temperature environment (≥120°C). High temperatures can cause some proteins in goose meat products to denature, reduce umami substances (such as glutamate), cause muscle fiber dehydration and shrinkage, make the meat hard and tough, and increase fat oxidation, which may produce a steamed or burnt smell, resulting in a poor flavor of goose meat. In addition, high-temperature thermal sterilization uses an autoclave, and the heating, insulation, and cooling processes are time-consuming and require continuous consumption of steam or electricity, resulting in high energy costs.

[0004] Low-temperature cold sterilization technology refers to the killing of microorganisms through chemical, physical or combined methods under conditions lower than traditional high-temperature sterilization (usually ≤60°C). It has poor effect on killing spores and usually requires preservatives (such as sodium lactate) or cold chain (≤4°C) for preservation. The product shelf life is short, and due to the weak penetration of technologies such as ultrasound and ultraviolet rays, they are only suitable for thin-sheet products or only for surface sterilization. For whole-packaged goose meat and other poultry products, there is still the problem of incomplete sterilization; some cold sterilization technologies require extended processing time due to weak penetration. For example, ultraviolet sterilization requires multiple flipping and irradiation of whole-packaged poultry meat, and the time is extended from 5 minutes to more than 20 minutes. At the same time, multiple steps are required to coordinate, such as pre-cooling before ultra-high pressure treatment and cold chain after sterilization. Multiple links lead to superposition of energy consumption and increase overall energy consumption; in addition, technologies such as ultra-high pressure jet and low-temperature plasma used in conjunction with low-temperature cold sterilization require special equipment, and the initial investment and maintenance costs are high. Summary of the Invention

[0005] The purpose of the present invention is to overcome the defects in the prior art and provide a sterilization process for poultry products by combining high-power-density ultrasound with a medium-temperature water bath. The cavitation effect generated by high-power-density ultrasound destroys the microbial structure, and the medium-temperature water bath is combined to achieve efficient sterilization, thereby improving the sterilization efficiency, ensuring the quality of goose meat, and helping to extend the shelf life of goose products.

[0006] The object of the present invention is achieved as follows: a high-power density ultrasound-assisted medium-temperature water bath sterilization process for poultry products, comprising the following steps:

[0007] Step 1, raw material pretreatment: slaughtering the goose, removing the hair, opening the stomach, and soaking in blood-removing water to obtain a clean goose;

[0008] Step 2, marinating: based on the weight of water, add 1wt% Sichuan peppercorns, 1wt% salt, and 3wt% cooking wine to water at room temperature of 20-25°C. After the salt is fully dissolved, completely immerse the cleaned goose processed in step 1 in the marinade liquid to ensure that the entire cleaned goose, especially the abdominal cavity, is covered with the marinade liquid, and refrigerate at 4°C for 12-48 hours.

[0009] Step 3, preparing brine: taking the mass of water as 100 parts, add 1 part of ginger, 1.2 parts of shallots, 0.5 parts of onions, 0.3 parts of garlic, 7.5 parts of salt, 1.5 parts of rock sugar, 2 parts of cooking wine, 0.4 parts of peppercorns, 0.2 parts of star anise, 0.15 parts of cinnamon bark, 0.25 parts of angelica dahurica, 0.03 parts of cloves, 0.15 parts of tsaoko, 0.15 parts of bay leaves, 0.25 parts of cumin, 0.1 parts of white cardamom, 0.1 parts of dried tangerine peel, 1 part of light soy sauce, 0.5 parts of dark soy sauce, and 0.5 parts of monosodium glutamate to the water, stir thoroughly to dissolve the soluble materials, then heat to boiling and simmer for 0.5 to 1.5 hours to obtain brine;

[0010] Step 4, braising the goose: soak the clean goose marinated in step 2 in the brine of step 3, and braising, and then let it stand;

[0011] Step 5, finished product packaging: after the braising is completed, the goose is vacuum-packed to make a vacuum-packed poultry product;

[0012] Step 6, sterilization of vacuum-packed products: immerse the vacuum-packed goose products in a constant temperature water bath and apply ultrasonic treatment. After the sterilization treatment is completed, take out the products, wipe off the moisture on the surface of the packaging, and refrigerate them.

[0013] When the present invention is working, it sterilizes the vacuum-packed goose meat products by assisting high-power-density ultrasound in a medium-temperature environment. The cavitation effect generated by the high-power-density ultrasound breaks the tight connection between the goose meat muscle fibers, prompting the redistribution of water originally bound in the tissue gaps, and prompting the water to be more evenly retained in the muscle structure. At the same time, the medium-temperature environment prompts moderate denaturation of myosin. This mild denaturation does not cause excessive contraction of the protein, but instead prompts its hydrophobic groups to be exposed, thereby enhancing the protein's ability to bind to water. The redistribution of water and the protein's strong ability to retain water enable the muscle tissue of the goose meat product to release more water during chewing, thereby improving the juiciness of the goose meat product. Ultrasonic cavitation physically destroys the microbial cell membrane, and combined with the medium temperature's inhibition of microbial enzyme activity, ensures the efficient killing of pathogenic bacteria and spoilage bacteria. Compared with traditional high-temperature sterilization, the TBA value of goose meat products prepared by the sterilization process of the present invention is 0.215μg / g at 28 days, which is lower than high-temperature sterilization (0.223μg / g) and the industry threshold (0.25μg / g). Compared with high-temperature sterilization, it delays the oxidation process by 7 to 10 days and the shelf life can be extended by 10 to 17 days.

[0014] Furthermore, when the clean goose is stewed in brine in step 4, the mass ratio of the clean goose to the brine is 1:2.

[0015] Furthermore, the braising process in step 4 is to boil over high heat and then turn to low heat, maintain a slightly boiling state, and cook for 2 to 3 hours, turning and skimming the foam regularly until cooked through. After the goose meat is cooked, turn off the heat and leave the goose body to soak in the brine for more than 1 to 2 hours.

[0016] Furthermore, the constant temperature water bath temperature in step 6 is 65° C., the applied ultrasonic frequency is 40 kHz, the ultrasonic power is 100-400 W, and the ultrasonic time is 5-10 min. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a bar graph with error bars showing the analysis results of TBA (thiobarbituric acid) in goose products prepared in accordance with an embodiment of the present invention.

[0018] Figure 2 The figure is a comparison chart of the experimental determination results (28 days) of the total bacterial count of Examples 1 to 6 of the present invention and Comparative Examples 1 to 3. DETAILED DESCRIPTION

[0019] Example 1:

[0020] A high-power ultrasound-assisted medium-temperature water bath sterilization process for poultry products comprises the following steps:

[0021] Step 1, raw material pretreatment: slaughtering the goose, removing the hair, opening the stomach, and soaking in blood-removing water to obtain a clean goose;

[0022] Step 2, marinating: based on the weight of water, add 1wt% Sichuan peppercorns, 1wt% salt, and 3wt% cooking wine to water at room temperature of 20-25°C. After the salt is fully dissolved, completely immerse the cleaned goose processed in step 1 in the marinade liquid to ensure that the entire cleaned goose, especially the abdominal cavity, is covered with the marinade liquid, and refrigerate at 4°C for 12-48 hours.

[0023] Step 3, preparing brine: taking the mass of water as 100 parts, add 1 part of ginger, 1.2 parts of shallots, 0.5 parts of onions, 0.3 parts of garlic, 7.5 parts of salt, 1.5 parts of rock sugar, 2 parts of cooking wine, 0.4 parts of peppercorns, 0.2 parts of star anise, 0.15 parts of cinnamon bark, 0.25 parts of angelica dahurica, 0.03 parts of cloves, 0.15 parts of tsaoko, 0.15 parts of bay leaves, 0.25 parts of cumin, 0.1 parts of white cardamom, 0.1 parts of dried tangerine peel, 1 part of light soy sauce, 0.5 parts of dark soy sauce, and 0.5 parts of monosodium glutamate to the water, stir thoroughly to dissolve the soluble materials, then heat to boiling and simmer for 0.5 to 1.5 hours to obtain brine;

[0024] Step 4, braising the cleaned goose: soak the cleaned goose marinated in step 2 in the brine prepared in step 3, bring to a boil over high heat, then reduce heat to a low boil, and cook for 2-3 hours, stirring and skimming the foam regularly, until cooked through. Turn off the heat after the goose meat is cooked, and soak the goose body in the brine for more than 1-2 hours, then let it stand;

[0025] Step 5, finished product packaging: after the braising is completed, the goose is vacuum-packed to make a vacuum-packed poultry product;

[0026] Step 6, sterilization of vacuum-packed products: immerse the vacuum-packed goose product in a constant temperature water bath at 65°C and apply ultrasonic treatment with a high-power ultrasonic frequency of 40kHz and an ultrasonic power of 100W for 10 minutes. After the sterilization, wipe off the moisture on the surface of the package and refrigerate to obtain a goose meat product, which is recorded as E1.

[0027] Example 2:

[0028] A sterilization process for poultry products using high-power density ultrasound in conjunction with a medium-temperature water bath, wherein the specific operating steps are the same as those in Example 1, except that in step 6, the high-power density ultrasound frequency is 40 kHz, the ultrasound power is 200 W, the sterilization treatment is performed for 10 minutes, and after the sterilization, the surface moisture of the package is wiped dry and the product is refrigerated to obtain a goose meat product, which is recorded as E2.

[0029] Example 3:

[0030] A sterilization process for poultry products using high-power density ultrasound in conjunction with a medium-temperature water bath, wherein the specific operating steps are the same as those in Example 1, except that in step 6, the high-power density ultrasound frequency is 40 kHz, the ultrasound power is 300 W, the sterilization treatment is performed for 10 minutes, and after the sterilization, the surface moisture of the package is wiped dry and the product is refrigerated to obtain a goose meat product, which is recorded as E3.

[0031] Example 4:

[0032] A sterilization process for poultry products using high-power density ultrasound in conjunction with a medium-temperature water bath, wherein the specific operating steps are the same as those in Example 1, except that in step 6, the high-power density ultrasound frequency is 40 kHz, the ultrasound power is 200 W, the sterilization treatment is performed for 5 minutes, and after the sterilization, the surface moisture of the package is wiped dry and the product is refrigerated to obtain a goose meat product, which is recorded as E4.

[0033] Example 5:

[0034] A sterilization process for poultry products using high-power density ultrasound in conjunction with a medium-temperature water bath, wherein the specific operating steps are the same as those in Example 1, except that in step 6, the high-power density ultrasound frequency is 40 kHz, the ultrasound power is 300 W, the sterilization treatment is performed for 5 minutes, and after the sterilization, the surface moisture of the package is wiped dry and the product is refrigerated to obtain a goose meat product, which is recorded as E5.

[0035] Example 6:

[0036] A sterilization process for poultry products using high-power ultrasound combined with a medium-temperature water bath, wherein the specific operating steps are the same as those in Example 1, except that in step 6, the high-power ultrasound frequency is 40 kHz, the ultrasonic power is 400 W, the sterilization treatment is performed for 5 minutes, and after the sterilization, the surface moisture of the package is wiped dry and the product is refrigerated to obtain a goose meat product, which is recorded as E6.

[0037] Comparative Example 1:

[0038] The specific steps are the same as those in Example 1, except that in step 6, the high-power ultrasonic frequency is 40 kHz, the ultrasonic power is 200 W, and the sterilization treatment is carried out in a 25°C water bath for 5 minutes. After the sterilization, the surface of the package is wiped dry and refrigerated to obtain a goose meat product, which is recorded as C1.

[0039] Comparative Example 2:

[0040] The specific steps are the same as those in Example 1, except that in step 6, a 65° C. medium-temperature water bath is used for sterilization for 10 minutes. After the sterilization, the surface of the package is wiped dry and the package is refrigerated to obtain a goose meat product, which is recorded as C2.

[0041] Comparative Example 3:

[0042] The specific steps are the same as those in Example 1, except that in step 6, a high temperature of 121±0.5°C and a high pressure of 0.10-0.12 MPa (steam sterilizer) are used, and the processing time is 15 minutes. After the processing, the surface moisture of the package is wiped dry and the package is refrigerated to obtain a goose meat product, which is recorded as C3.

[0043] Result analysis:

[0044] Sensory and textural analysis of brine geese (E1-E6) prepared in Examples 1-6 and brine geese (C1-C3) prepared in Comparative Examples 1-3 was performed by four sensory panelists, who evaluated and scored the meat. The texture analysis method was as follows: brine goose breast meat was cut into 1.5 cm × 1.5 cm × 1.5 cm cubes. The goose meat's elasticity, chewiness, hardness, cohesion, stickiness, and adhesiveness were measured using a TMS-pro physical property analyzer. Measurement parameters: P / 50 cylindrical probe, pre-measurement speed of 2.0 mm / s, test speed of 1.5 mm / s, post-measurement speed of 1.0 mm / s, measurement interval of 5 seconds, and compression ratio of 70%.

[0045] The sensory evaluation criteria are shown in Table 1, the sensory evaluation results are shown in Table 2, and the texture analysis results are shown in Table 3.

[0046] Table 1 Sensory evaluation standards

[0047]

[0048] Table 2 Sensory evaluation results

[0049] Color fragrance texture Organizational form Total score E1 11.00 17.00 18.75 18.25 65.00 E2 12.00 17.30 16.25 17.00 62.50 E3 13.30 16.25 16.75 17.00 63.25 E4 13.50 14.50 13.25 14.50 55.75 E5 16.80 18.00 19.50 19.50 73.75 E6 15.80 16.50 15.00 12.50 59.75 C1 15.50 17.25 15.25 14.25 62.25 C2 16.80 15.75 18.00 15.00 65.50 C3 13.80 14.50 13.75 14.50 56.50

[0050] The sensory evaluation results in Table 2 show that the salted goose treated with high-power ultrasound combined with a moderate-temperature waterbath sterilization process was preferred by the sensory panelists. This is because, under the same braising conditions, the ultrasound-assisted moderate-temperature waterbath sterilization process creates cavitation in the liquid, breaking down the tight connections between goose muscle fibers. This redistributes water previously trapped in the interstitial spaces, allowing it to be more evenly retained within the muscle structure. Simultaneously, the moderate temperature environment induces moderate denaturation of myosin. This mild denaturation does not lead to excessive protein contraction, but rather exposes its hydrophobic groups, thereby enhancing the protein's ability to bind water. This water redistribution, combined with the protein's strong water retention, allows the goose's muscle tissue to release more water during chewing, enhancing its juiciness. Ultrasonic cavitation physically disrupts microbial cell membranes, and combined with the moderate temperature's inhibition of microbial enzyme activity, ensures the efficient elimination of pathogenic and spoilage bacteria.

[0051] Table 3 Texture analysis results

[0052] Hardness (gf) Elasticity (cm) Adhesion Toughness (mj) Recoverability E1 3010.72±78.00 0.55±0.03 0.55±0.03 68.58±0.49 0.33±0.01 E2 2823.76±28.06 0.56±0.05 0.53±0.03 67.20±1.28 0.31±0.002 E3 2943.08±66.85 0.53±0.03 0.59±0.05 62.93±2.61 0.37±0.08 E4 2842.61±94.70 0.73±0.04 0.52±0.002 61.40±1.71 0.31±0.03 E5 2731.76±119.45 0.81±0.01 0.54±0.04 60.24±0.53 0.25±0.01 E6 2933.65±107.18 0.67±0.05 0.54±0.03 66.24±2.72 0.32±0.02 C1 3769.69±135.64 0.70±0.04 0.58±0.02 57.31±1.00 0.32±0.01 C2 2862.22±205.52 0.71±0.19 0.55±0.04 64.95±4.45 0.3±0.03 C3 2026±87.76 37±0.02 0.48±0.04 51.32±2.01 0.18±0.02

[0053] Table 3 shows the texture test results (hardness, elasticity, adhesion, toughness and recoverability). Comparison of the ultrasonic treatment groups (E1-E6) and the control groups (C1-C3) shows that the control group C1 used a room temperature water bath synergistically with ultrasonic sterilization, and the goose meat hardness reached 3769.69±135.64, which was much higher than the goose meat hardness of all ultrasonic treatment groups E1-E6 and the goose meat hardness of the non-ultrasonic treatment control groups C2 and C3, indicating that the 65℃ water bath environment is more conducive to the cavitation effect and mechanical effect of ultrasound, while the ultrasonic synergistic treatment at room temperature of 25℃ cannot effectively destroy the dense structure of goose muscle fibers, but instead leads to an increase in hardness; among them, the goose meat of E5 had the lowest hardness, indicating that the ultrasonic frequency of 40kHz, ultrasonic power of 300W synergistically with 65℃ medium temperature water bath sterilization, and treatment time of 5min can better loosen the goose muscle bundles and avoid excessive hardening. The elasticity of goose meat samples E1 to E6 is also better than that of goose meat samples C1 to C3. The elasticity of goose meat sample E5 is the largest, reaching 0.81cm, indicating that ultrasound makes the gaps between goose meat muscle fibers more reasonable and enhances the recovery ability after deformation. While destroying the perimysium, ultrasound retains moderate fiber connections, which can prevent the goose meat structure from becoming loose. In addition, ultrasound causes the water originally bound in the tissue gaps to be redistributed, and the water is more evenly retained in the muscle structure. The coordinated medium-temperature environment causes moderate denaturation of myosin. This mild denaturation will not cause excessive contraction of the protein, but will instead cause its hydrophobic groups to be exposed, thereby enhancing the protein's ability to bind to water. The redistribution of water and the protein's strong ability to retain water enable the muscle tissue of goose meat products to release more water during chewing, thereby increasing the juiciness of goose meat products and the elasticity of the goose meat taste. The E3 goose meat sample had slightly higher adhesion than the control group. Ultrasound promoted the uniform distribution of water and solutes, enhancing the adhesion between muscle fibers. The E1 goose meat sample had the highest toughness of all groups, reflecting the characteristic that the muscle fibers were easy to chew but did not break after ultrasound treatment. The E3 goose meat sample had better recoverability than the control, confirming that ultrasound optimizes water holding capacity and improves deformation recovery ability. This invention uses high-power-density ultrasound combined with a medium-temperature water bath sterilization technology to regulate the structure and water holding properties of goose meat muscle fibers, significantly reducing the hardness of goose meat, improving elasticity, and optimizing texture in multiple dimensions. The texture improvement is parameter-dependent, providing data support for precise process design and ultimately improving product palatability.

[0054] Table 4 shows the results of the determination of thiobarbituric acid TBA in goose meat samples of the ultrasonic treatment group (E1-E6) and the control group (C1-C3) on the first day, the fourteenth day, and the twentieth day.

[0055] Table 4 Measurement results of thiobarbituric acid TBA

[0056]

[0057] The thiobarbituric acid (TBA) value reflects the degree of fat oxidation; lower values ​​indicate milder fat oxidation and better storage stability. The results in Table 4 show that the TBA values ​​of goose meat samples in the ultrasound-treated groups (E1-E6) and the control groups (C1-C3) generally increased with storage time, consistent with the cumulative effect of fat oxidation over time. During storage, oxygen and enzymes continuously act on fat, leading to the gradual accumulation of oxidation products. Short-term storage: The TBA values ​​of goose meat samples E1 to E6 were lower than those of goose meat samples C1 to C3, indicating that high-power-density ultrasound combined with medium-temperature water bath can reduce microbial-mediated oxidation by sterilizing or modifying muscle cell structure in the early stage of storage, and hinder the oxidation of fat by contact with oxygen, thereby delaying fat oxidation; medium-term storage: The TBA value of C3 goose meat sample was higher than that of E1 to E6 goose meat samples, indicating that high-temperature and high-pressure sterilization treatment destroyed the integrity of goose meat muscle cells, making fat more easily exposed to oxygen and enzymes, and accelerating oxidation; long-term storage: There was a significant difference in oxidation between goose meat samples sterilized by high-power-density ultrasound combined with medium-temperature water bath and C1 to C3 goose meat samples. The TBA value of E1 to E6 goose meat samples was relatively low, indicating that the high-power-density ultrasound parameter setting in the sterilization process of the ultrasonic treatment group was more conducive to inhibiting lipid oxidation, maintaining the taste of goose meat, and maintaining quality.

[0058] Table 5 Total colony count analysis results

[0059]

[0060] Table 5 shows the results of total colony count determination of goose meat samples on the first, fourteenth, and twenty-eighth days of storage. As the storage time increases, the colony count of each strain at the same dilution generally shows an upward trend, and the dilution at which colonies can be detected gradually increases. This indicates that despite the sterilization treatment, microorganisms continue to proliferate during storage and the bacterial concentration gradually increases. This trend reflects that the sterilization process needs to take into account both initial sterilization and shelf-life antibacterial treatment, providing a basis for optimizing storage conditions (packaging, temperature, etc.).

[0061] Low dilution (10 -1 , 10 -2 ), taking the data of the fourteenth day as an example, the total colony count of E2 goose meat sample was 3.95lgCFU / g (corresponding to 10 -1 The dilution is 891CFU, 10 -2 89CFU), and the total colony count of E4 goose meat sample was 4.26lg CFU / g (10 -1 1820CFU, 10 -2 was 182 CFU), which was significantly lower than 4.31 lg CFU / g (10 -1 2042 CFU, 10 -2The mechanical effect of ultrasound continuously interferes with microbial metabolism and can effectively curb the proliferation of high-concentration bacteria; medium dilution (10 -3 , 10 -4 ): On the 14th day, the total colony count of E4 goose meat sample was 4.26lg CFU / g (10 -3 18CFU, 10 -4 2CFU), only C3(10 -3 20CFU, 10 -4 2CFU), which is about 90% of the total colony count of C3 goose meat sample. Combined with the data on the 28th day (E4 is 4.57lg corresponding to 10 -3 is 372CFU, C3 is 4.34lg corresponding to 10 -3 219 CFU), which proved that ultrasonic treatment significantly accelerated the bacterial inactivation process; high dilution (10 -5 , 10 -6 ), the total colony count of E2 on the 28th day was 4.30 lgCFU / g (10 -5 2CFU, 10 -6 0.2CFU), E4 4.57lg CFU / g (10 -5 3.7 CFU, 10 -6 0.4CFU), which was lower than 4.34lg CFU / g (10 -5 2.2 CFU, 10 -6 The ultrasound-induced leakage of intracellular substances still delayed its recovery, showing long-term antibacterial potential.

[0062] The ultrasound group still maintained stable antibacterial ability at extremely high dilutions, and the E4 goose meat sample maintained stable antibacterial ability at 10 -5 The colony count of the dilution was lower than that of the C3 goose meat sample, indicating that ultrasonic treatment can effectively inhibit bacterial recovery. Comparing the colony count reduction of E2 and E4 goose meat samples on the 28th day, the total sterilization rate of E4 goose meat sample was 94.6%, which was higher than the total sterilization rate of E2 goose meat sample 89.3%, indicating that moderately increasing the ultrasonic power can enhance the cavitation effect, promote the rupture of bacterial cell walls and the leakage of intracellular substances; the ultrasonic group -2 ~10 -4 The decrease in the number of colonies in the dilution group was significantly greater than that in the control group, indicating that the cavitation microjet generated by ultrasound promoted a more uniform distribution of bactericidal factors and reduced the local colony enrichment phenomenon.

[0063] Ultrasound has a broad-spectrum inhibitory effect on microbial proliferation during the mid-storage period (≤14 days), with particularly high efficiency in controlling high-concentration bacterial counts. As storage time increases, the colony counts of goose meat samples C1-C3 and E1-E6 show strain differentiation. The colony counts of E2 and C3 samples at all dilutions are similar, indicating that E2 samples have more stable long-term tolerance to ultrasound damage. With extended storage, from the first day to the fourteenth day, and then to the twenty-eighth day, the colony counts of the control group C3 and the ultrasound-treated groups E2 and E4 all increase, and the detectable dilution range continues to expand, confirming that microorganisms continue to proliferate after sterilization. The ultrasonic treatment group has a significant advantage in the mid-term storage (≤14 days). The colony counts of E2 and E4 goose meat samples are lower than that of C3 goose meat samples at full dilution. The cavitation effect generated by ultrasound destroys the biofilm, and the mechanical effect interferes with bacterial metabolism, effectively curbing the proliferation of high-concentration bacteria and accelerating the inactivation of residual bacteria. The differences in strains are apparent during long-term storage (>14 days). The colony count of E4 goose meat samples explodes due to metabolic compensation, and the colony count of E2 goose meat samples is close to that of C3 goose meat samples due to the difficulty in repairing biofilm damage, exposing the strain-specific limitations of long-term antibacterial effect. In summary, the sterilization process of the present invention is highly effective in controlling microorganisms in the mid-term storage (≤14 days). Long-term storage requires optimization of ultrasonic parameters or supporting preservation technology for E4 to achieve precise antibacterial effect.

[0064] The present invention treats salted goose with high-power density ultrasound in combination with a medium-temperature water bath, showing significant advantages in sensory evaluation, thiobarbituric acid value (TBA), texture characteristics, and total bacterial count. In terms of sensory evaluation, the sensory score of the salted goose treated with ultrasound was significantly higher than that of the control group. Among them, the sample (E5) treated with 40kHz, 300W ultrasound in combination with a 65°C medium-temperature water bath for 5 minutes performed best. Its cross-section was glossy, fragrant, and had the unique aroma of goose meat and spices. The texture was tight and elastic, and the tissue morphology was complete. The total score reached 73.75 points, which was significantly better than the high-temperature and high-pressure sterilization group (C3) and the simple medium-temperature water bath group (C2), reflecting the ultrasonic treatment's retention of flavor substances and improvement of sensory quality. Thiobarbituric acid (TBA) analysis showed that the TBA value of the ultrasonic treatment group was lower than that of the control group during storage (1 day, 14 days, and 28 days), and the advantage was more significant during long-term storage. For example, the TBA values ​​of E2 and E4 at 28 days were 0.22 μg / g and 0.22 μg / g, respectively, which were lower than 0.26 μg / g of the high-temperature and high-pressure group C3 and 0.25 μg / g of the normal-temperature water bath group C1, indicating that ultrasonic treatment effectively inhibited fat oxidation, reduced the accumulation of odorous substances such as fat oxidation products, and improved the storage stability of the product.

[0065] In terms of texture characteristics, ultrasonic treatment significantly optimized the texture of salted goose, and the hardness was lower than that of the control group. For example, the hardness of E5 was only 2731.76gf, which was much lower than that of the normal temperature water bath group (C1, 3769.69gf), and the elasticity reached 0.81cm, the highest among all groups. This shows that the cavitation effect and mechanical effect of ultrasound loosened the muscle fiber structure, reduced the difficulty of chewing, and retained moderate fiber connections, thereby increasing the tenderness and juiciness of the meat and improving the taste. The results of the total colony count determination showed that ultrasonic treatment can effectively inhibit the proliferation of microorganisms and prolong the shelf life. After 28 days of storage, the total colony count of the ultrasonic treatment groups (such as E4 and E6) was significantly lower than that of the simple medium temperature water bath group (C2), among which E4 had a significantly lower total colony count than that of the medium temperature water bath group (C2). -6 The colony count at this dilution was only 101g CFU / g, significantly lower than the 551g CFU / g of C2, confirming the highly effective sterilization effect of ultrasound combined with a moderate-temperature water bath, reducing the risk of microbial contamination during storage. Furthermore, high-power ultrasound, with its low energy consumption and strong penetrating power, produces a cavitation effect that disrupts molecular interactions, improves the cellular structure of goose muscle tissue, promotes marinade penetration and salt diffusion, enhances mass transfer efficiency, and shortens processing time (for example, in some examples, the processing time was only 5-10 minutes), thereby improving production efficiency. The most effective ultrasound process was 40kHz, 300W ultrasound combined with a 65°C moderate-temperature water bath for 5 minutes. Quality-wise, hardness was reduced by 23% (compared to C1), elasticity was increased by 16% (compared to C2), and water retention and flavor retention were significantly improved. Safety-wise, the total colony count decreased by 50% during medium-term storage, and the TBA value decreased by 35% during long-term storage. Production-wise, it shortened processing time and reduced energy consumption, providing a highly efficient and low-loss sterilization solution for the industrial production of poultry products. It is suitable for the industrial production of salted goose, can significantly improve its edible quality, flavor and shelf stability, and has important economic and technical value.

[0066] 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 sterilization process for poultry products using high-power ultrasound combined with a medium-temperature water bath, characterized in that: The steps include: Step 1, raw material pretreatment: slaughtering the goose, removing the hair, opening the stomach, and soaking in blood-removing water to obtain a clean goose; Step 2, marinating: based on the weight of water, add 1wt% Sichuan peppercorns, 1wt% salt, and 3wt% cooking wine to water at room temperature of 20-25°C. After the salt is fully dissolved, completely immerse the clean goose processed in step 1 in the marinade liquid, ensuring that the entire clean goose, especially the abdominal cavity, is covered with the marinade liquid, and refrigerate at 4°C for 12-48 hours; Step 3, preparing brine: taking the mass of water as 100 parts, add 1 part of ginger, 1.2 parts of shallots, 0.5 parts of onions, 0.3 parts of garlic, 7.5 parts of salt, 1.5 parts of rock sugar, 2 parts of cooking wine, 0.4 parts of peppercorns, 0.2 parts of star anise, 0.15 parts of cinnamon bark, 0.25 parts of angelica dahurica, 0.03 parts of cloves, 0.15 parts of tsaoko, 0.15 parts of bay leaves, 0.25 parts of cumin, 0.1 parts of white cardamom, 0.1 parts of dried tangerine peel, 1 part of light soy sauce, 0.5 parts of dark soy sauce, and 0.5 parts of monosodium glutamate to the water, stir thoroughly to dissolve the soluble materials, then heat to boiling and simmer for 0.5-1.5 hours to obtain brine; Step 4, braising the goose: soak the clean goose marinated in step 2 in the brine of step 3, and braising, and then let it stand; Step 5, finished product packaging: after the braising is completed, the goose is vacuum-packed to make a vacuum-packed poultry product; Step 6, sterilization of vacuum-packed products: immerse the vacuum-packed goose products in a constant temperature water bath and apply ultrasonic treatment. After the sterilization treatment is completed, take out the products, wipe off the moisture on the surface of the packaging, and refrigerate them.

2. The sterilization process for poultry products using high-power density ultrasound combined with a medium-temperature water bath according to claim 1, characterized in that: When the clean goose is stewed in brine in step 4, the mass ratio of the clean goose to the brine is 1:

2.

3. The sterilization process for poultry products using high-power ultrasound combined with a medium-temperature water bath according to claim 2, characterized in that: The braising process described in step 4 is to boil over high heat and then turn to low heat, maintain a slight boiling state, and cook for 2 to 3 hours, turning and skimming foam regularly until cooked through. After the goose meat is cooked, turn off the heat and soak the goose body in the brine for more than 1 to 2 hours.

4. The sterilization process for poultry products using high-power ultrasound combined with a medium-temperature water bath according to claim 1, characterized in that: The constant temperature water bath temperature in step 6 is 65° C., the applied ultrasonic frequency is 40 kHz, the ultrasonic power is 100-400 W, and the ultrasonic time is 5-10 min.

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