Rapid cooling method for pig viscera

Abstract

The invention relates to the technical field of food processing, in particular to a method for rapidly cooling pig viscera. The rapid cooling method of the pig red viscera comprises the following steps: 1) putting the slaughtered pig red viscera into a cooling liquid for water cooling treatment; (2) performing draining treatment on the pig red viscera subjected to water cooling treatment; (3) carrying out air cooling treatment on the drained pig viscera; in the step 1), the temperature of the cooling liquid is not higher than 4 DEG C; after the water cooling treatment, the central temperature of the pig red viscera is reduced to 15 DEG C or below. According to the method, the cooling time can be remarkably shortened, the cooling uniformity is greatly improved, the water loss is greatly reduced, the economic value and the yield of the pig red viscera are improved, the original color, the original texture and the original sensory quality of the pig red viscera can be maintained, and the economic value is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of food processing, and particularly relates to a rapid cooling method for pig red viscera. BACKGROUND

[0002] In the processing of slaughtered pigs, the rapid cooling of pig red viscera (liver, heart, lung, kidney and other internal organs) is crucial for maintaining its freshness, nutritional components and extending the shelf life. The cold air circulates around the pig red viscera to take away heat to achieve cooling. The air cooling of pig red viscera is a key step to achieve cooling in the processing of slaughtered pigs, and the specific process is as follows: first, the pig red viscera which is preliminarily cleaned (removing surface residual blood, fascia and other impurities) after slaughter is placed on the special tray or hanging rack in the cooling room according to the principle of "dispersing and avoiding stacking" - the tray / hanging rack needs to reserve enough gap to ensure that there is enough air flow space around the pig red viscera; then, the air cooling system is started, and the refrigerating unit cools the air in the cooling room to 0-4℃, and at the same time, the high-power fan forms directional airflow through the air duct to make the low-temperature air continuously circulate around the pig red viscera; in this process, the low-temperature air contacts the surface of the pig red viscera and takes away the heat carried by the pig red viscera (the initial temperature of the pig red viscera after slaughter is usually 38-40℃) through heat exchange, and the heat enters the refrigerating unit again to be cooled, forming a cycle of "cooling-heat absorption-recooling"; throughout the process, the temperature sensor needs to monitor the center temperature of the pig red viscera in real time, and when the temperature drops from 38-40℃ to below 7℃ (out of the "dangerous temperature zone" of microorganism reproduction), the air cooling process can be ended, and usually lasts for 4-6h (the specific duration is affected by the number of pig red viscera and the power of the air cooling system).

[0003] At present, the pig red viscera after slaughter in large-scale slaughterhouse is mainly cooled by air cooling. However, this method has many limitations: 1. Long cooling time: the existing air cooling technology uses air as the heat exchange medium, because the air has a very low thermal conductivity coefficient (only 0.026 W / (m·K)), it takes 4-6 hours for the pig red viscera to drop from the initial temperature of 38-40℃ to the safe temperature below 7℃, the temperature of the pig red viscera stays in the rapid microbial reproduction interval for a long time, which increases the risk of product deterioration and slows down the overall pace of the post-slaughter processing line; 2. Non-uniform cooling: during the air cooling process, the flow rate and contact area of the cold air on the surface of the pig red viscera are difficult to be completely uniform and consistent, resulting in differences in cooling speed at different parts of the pig red viscera. For example, the cooling speed of the outside and inside of the pig heart is not consistent, the outside cools faster, while the inside cools relatively slowly, which easily causes local overheating and affects the overall quality. 3. Serious water loss: during the air cooling process, the water on the surface of the pig red viscera continuously evaporates under the blowing of the cold air, resulting in weight loss and nutrient loss of the pig red viscera. Research data shows that the water loss rate of the pig red viscera cooled by air cooling can reach 2%-3%. Water loss not only causes the actual yield to decrease, but also makes the surface of the pig red viscera rough, wrinkled and lose luster, which damages the sensory quality of the product. With the increasing demand for product quality in the meat processing industry and the increasing demand for fresh and nutritious meat products from consumers, it is urgent to develop a cooling method that is efficient, fast and can effectively maintain the quality of the pig red viscera. SUMMARY

[0004] To solve the above technical problems, the present application provides a rapid cooling method for pig red viscera. The present application can significantly shorten the cooling time, achieve rapid cooling, greatly improve the freshness and safety of the pig red viscera, and greatly improve the cooling uniformity, with a temperature difference of less than 1℃ between different parts of the cooled pig red viscera, effectively avoiding local overheating or overcooling, and ensuring the overall quality of the pig red viscera. At the same time, the water loss is significantly reduced, which not only improves the economic value and yield of the pig red viscera, but also maintains the original color, texture and sensory quality of the pig red viscera, so that the pig red viscera can maintain a fresh and juicy taste after cooking. The method of the present application also simplifies the operation process and reduces labor costs.

[0005] Specifically, the present application provides a rapid cooling method for pig red viscera, which comprises: 1) placing the pig red viscera after slaughter into a cooling liquid for water cooling treatment.

[0006] 2) draining the water from the pig red viscera after water cooling treatment.

[0007] 3) air cooling treatment of the pig red viscera after water draining treatment.

[0008] In step 1), the temperature of the cooling liquid is not higher than 4 DEG C; and after the water cooling treatment, the central temperature of the pig red offal is reduced to below 15 DEG C.

[0009] The method provided by the application can shorten the cooling time of pig red offal, reduce the period for reducing the temperature of pig red offal from 38-40 DEG C to a safe temperature below 7 DEG C, avoid the long-time stay of pig red offal in a 'dangerous temperature zone', improve the cooling efficiency and product safety, ensure the uniformity of the cooling of pig red offal, eliminate the local cooling blind area, make the surface and central temperature of pig red offal synchronously reduced to a safe interval, guarantee the consistency of the cooling quality of each batch of pig red offal, effectively reduce the water loss of pig red offal, reduce the dry consumption rate, maintain the original color, texture and sensory quality of pig red offal, and improve the product yield.

[0010] In step 1), the central temperature of the pig red offal is preferably reduced to 10-15 DEG C, preferably 10-13 DEG C, after the water cooling treatment. The temperature of the cooling liquid is preferably 0-4 DEG C, and the water cooling time is preferably 20-40 min. This is beneficial to the subsequent cooling treatment and further improves the cooling effect and the quality of pig red offal.

[0011] In step 1), the pig red offal is preferably selected from one or more of pig heart, pig liver and pig lung. The method is excellent for pig heart, pig liver and pig lung.

[0012] In step 1), the cooling liquid is preferably purified low-temperature sterile water. The cooling liquid is preferably obtained by mixing ice and water in a mass ratio of 1-2:1-2, and is preferably prepared by uniformly mixing equal amounts of ice and water. This can quickly reduce the temperature of the cooling liquid to 0-4 DEG C, is helpful to maintain the temperature of the cooling liquid, and is suitable for actual production requirements.

[0013] Further preferably, in step 1), ice is added when the temperature of the cooling liquid rises, so that the water temperature is maintained at 0-4 DEG C. This ensures that the cooling liquid is always maintained within the optimal cooling temperature range, and guarantees the cooling efficiency and cooling effect.

[0014] In step 1), the pig red offal is preferably immersed in the cooling liquid after being loaded into a pre-cooling basket, and each basket is loaded with 30-40 pig red offals. This ensures the sufficient contact between the cooling liquid and the pig red offal, realizes uniform cooling, guarantees the production efficiency, and avoids the excessive stacking of pig red offal affecting the cooling effect.

[0015] As preferred, in step 2), the pig red viscera after the water cooling treatment is hung on a draining rack for rinsing and draining treatment, and the rinsing and draining treatment time is preferably 5-10 min, so that the surface of the pig red viscera keeps a water-wet luster, but the water droplets do not flow in a stream. The surface residual moisture can be effectively removed, while the surface of the pig red viscera is prevented from being excessively dried, and the sensory quality of the pig red viscera is maintained.

[0016] As preferred, in step 3), the air cooling treatment temperature is 0-4℃, and the air cooling treatment time is 15-30 min. This is helpful for improving the cooling effect of the pig red viscera in cooperation with the water cooling treatment, and maintaining the quality of the pig red viscera.

[0017] Further preferably, in step 3), after the air cooling treatment, the center temperature of the pig red viscera is reduced to below 7℃.

[0018] Further preferably, step 4) is further included, that is, the cooled pig red viscera is packaged and transferred to a refrigerator at 0-4℃.

[0019] As a preferred embodiment of the present application, the present application provides a pig red viscera rapid cooling method, which comprises the following steps as shown in the accompanying drawings: Figure 1 As shown in the accompanying drawings, the present application provides a pig red viscera rapid cooling method, which comprises the following steps: 1) An equal amount of ice and water is added to a water cooling tank and mixed uniformly. The cooling liquid preferably uses low-temperature sterile water treated by purification, and the water temperature is controlled at 0-4℃. The pig red viscera after slaughter is preliminarily divided to obtain a pig heart, a pig liver and a pig lung, and is quickly transferred to a water cooling device. In the transfer process, it is ensured that the pig red viscera is not secondarily contaminated, and the time exposed to the air is minimized. The cooling liquid in the water cooling device is detected and pretreated to ensure that the temperature and cleanliness of the cooling liquid meet the cooling requirements. A large number of pig red viscera is loaded into a pre-cooling basket and immersed in the cooling liquid in sequence, 30-50 per basket. In the water cooling process, the temperature of the cooling liquid is monitored in real time. When the cooling liquid temperature rises by more than 4℃, ice is added to reduce the temperature, so that the water temperature is maintained at 0-4℃.

[0020] 2) After water cooling for 20-40 min, the pig red viscera can be taken out and hung on a draining rack for short rinsing and draining, and then transferred to an air cooling library after the surface residual moisture is removed. The draining time is controlled at 5-10 min to avoid excessive drying of the surface of the pig red viscera.

[0021] 3) The pig red viscera is transferred to an air cooling library and placed for 15-30 min, and the air cooling library temperature is 0-4℃.

[0022] 4) The cooled pig red viscera is packaged, weighed, and then quickly transferred to a refrigerator for storage, delivery and transportation, and the refrigerator temperature is 0-4℃.

[0023] The present application has at least the following beneficial effects: 1) Cooling time is significantly shortened: Compared with traditional air cooling, the water cooling method of the present application can shorten the cooling time of pig red offal from 4-6h to within 1h. For example, in the cooling test of a batch of pig livers, it takes 4-6h to cool to below 7℃ by air cooling, while it only takes 1h by the water cooling method of the present application. Rapid cooling can effectively inhibit the growth and reproduction of microorganisms, greatly improving the freshness and safety of pig red offal. At the same time, it is beneficial to rapid delivery and facilitates personnel arrangement.

[0024] 2) Cooling uniformity is greatly improved: Since the pig red offal is completely immersed in the circulating cooling liquid, the cooling liquid can uniformly contact each part of the pig red offal, achieving uniform cooling. Through temperature detection of the cooled pig red offal, it is found that the temperature difference of different parts of the pig red offal is less than 1℃, effectively avoiding the situation of local overheating or overcooling, and ensuring the overall quality of the pig red offal.

[0025] 3) Water loss is significantly reduced: In the water cooling process, the surface of the pig red offal is always covered with cooling liquid, reducing the evaporation of water. Experimental data show that by using the water cooling method of the present application, the water loss rate of the pig red offal can be controlled within 1%, and compared with the air cooling method, the water loss rate is reduced by 2%. Reducing water loss not only improves the economic value of the pig red offal, but also makes the pig red offal maintain a fresh and tender taste after cooking. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the present application or prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0027] Figure 1 The process flow chart of the pig red offal rapid cooling method provided by the embodiment of the present application.

[0028] Figure 2 One of the result charts of the pig red offal rapid cooling method provided by the embodiment 1 of the present application.

[0029] Figure 3 The second result chart of the pig red offal rapid cooling method provided by the embodiment 1 of the present application.

[0030] Figure 4 One of the result charts of the pig red offal rapid cooling method provided by the embodiment 2 of the present application.

[0031] Figure 5 The second result chart of the pig red offal rapid cooling method provided by the embodiment 2 of the present application.

[0032] Figure 6This is one of the results of the rapid cooling method for pig offal provided in Embodiment 3 of the present invention.

[0033] Figure 7 The second result is shown in the diagram of the rapid cooling method for pig offal provided in Embodiment 3 of the present invention. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0035] The endpoints and any values ​​of the ranges disclosed in this invention are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this invention.

[0036] Unless otherwise specified, the techniques or conditions described in the embodiments of this invention shall be performed in accordance with the techniques or conditions described in the literature in this field, or in accordance with the product instructions. Devices, instruments, reagents, etc., without specified manufacturers, are all conventional products that can be purchased through legitimate channels. All experimental reagents and raw materials involved are commercially available products, and all reagents are analytical grade products.

[0037] Example 1 This embodiment provides a method for rapid cooling of pig liver, as detailed below: 1. Preparation: Add equal amounts of ice and water to the water cooling tank, mix well, and ensure the coolant temperature is 0-4℃. Select 40 freshly slaughtered pig livers, weigh them, place them in a pre-cooling metal basket, and quickly transfer them to the water cooling tank.

[0038] 2. Water Cooling Process: The pig liver is completely submerged in the cooling liquid. The cooling liquid temperature is checked every 10 minutes. When the cooling liquid temperature rises to 4℃, 10kg of ice is manually added to lower the cooling liquid temperature to 0-4℃. After 40 minutes of cooling, the core temperature of the pig liver drops from 39℃ to 12℃. The pig liver is then removed and hung on a draining rack for a brief rinse and draining to remove any residual blood from the surface. After 5 minutes, it is transferred to a cold storage room.

[0039] 3. Transfer the pig liver to a cold storage room and let it stand for 15 minutes. The temperature of the cold storage room is 0-4℃.

[0040] 4. The center temperature of the cooled pig liver is reduced to 7℃, meeting the delivery standard. After the weighing and packaging steps, it is quickly transferred to a refrigeration warehouse for storage or directly shipped.

[0041] This example also provides air cooling, which is different from Example 1 only in that it is not water cooled, and the air cooling time is changed to 4h. The following experimental groups are also provided, which are different from Example 1 only in that the water cooling time is changed to 30min and the air cooling time is changed to 20min.

[0042] The color, moisture, and overall score of the pig liver surface are scored by professional meat science researchers: for color, 1 represents a dull yellow and dull surface of the internal organs, and 9 represents a uniform red surface of the internal organs with luster. For moisture, 1 represents a wet, water-beaded, and sticky surface of the internal organs, and 9 represents a slightly dry surface that is not sticky. For the bloated condition, 1 represents a large area of white, and 9 represents a slightly dry surface with no water-beaded traces after dripping. For overall sensory evaluation, 1 represents an unsatisfactory overall sensory evaluation with no willingness to purchase, and 9 represents a very satisfactory overall sensory evaluation with a strong willingness to purchase.

[0043] The test results of this example are shown in Table Figures 2-3 , and the results show that the moisture loss rate of the pig liver before and after cooling is 0.3%, and the temperature difference of different parts is less than 1℃; in the sensory evaluation, there is no significant difference between the rapidly cooled pig liver and the ordinary air-cooled pig liver in the color, moisture, and overall score.

[0044] Example 2 This example provides a method for rapidly cooling pig hearts, which is as follows: 1. Preparation: Add an equal amount of ice and water to the water cooling tank and mix well to ensure that the cooling liquid temperature is 0-4℃. Select 40 freshly slaughtered pig hearts, weigh them, and quickly transfer them to the water cooling tank after being loaded into the pre-cooled metal basket.

[0045] 2. Water cooling process: The pig hearts are completely immersed in the cooling liquid. The cooling liquid temperature is detected every 10min. When the cooling liquid temperature rises to 4℃, 10kg of ice is manually added to reduce the cooling liquid temperature to 0-4℃. After 30min of cooling, the center temperature of the pig hearts is reduced from 39℃ to 15℃, and the pig hearts are taken out and hung on a draining rack for a short rinse and draining to remove the surface residual blood. After 10min, they are transferred to an air cooling warehouse.

[0046] 3. The pig hearts are transferred to the air cooling warehouse and left for 20min, and the warehouse temperature is 0-4℃.

[0047] 4. The center temperature of the cooled pig hearts is reduced to 7℃, meeting the delivery standard. After the weighing and packaging steps, it is quickly transferred to a refrigeration warehouse for storage or directly shipped.

[0048] The embodiment also provides air cooling group, and the difference from the embodiment 2 is only that water cooling is not provided, and the air cooling time is changed to 4 h. The following experimental groups are also provided. The experimental group 1 is only different from the embodiment 2 in that the water cooling time is changed to 20 min, and the air cooling time is changed to 30 min. The experimental group 2 is only different from the embodiment 2 in that the water cooling time is changed to 10 min, and the air cooling time is changed to 40 min.

[0049] The color, moisture and overall score of the surface of the pig heart are scored by professional meat science researchers. In terms of color, 1 represents that the surface of the internal organs is dark yellow and dull, and 9 represents that the surface of the internal organs is uniform red and shiny. In terms of moisture, 1 represents that the surface of the internal organs is wet, with water droplets and sticky, and 9 represents that the surface is slightly dry and not sticky. In terms of the condition of the surface, 1 represents that there are large areas of white, and 9 represents that the surface is slightly dry and no water droplets flow after leaving traces. In terms of overall sensory evaluation, 1 represents that the overall sensory evaluation is not satisfactory, and there is no willingness to buy, and 9 represents that the overall sensory evaluation is very satisfactory, and there is a strong willingness to buy.

[0050] The test results of the embodiment are shown in Figures 4-5 , and it is found that the moisture loss rate of the pig heart before and after cooling is 0.2%, and the temperature difference of different parts is less than 1℃. In the sensory evaluation, the pig heart cooled quickly and the pig heart air-cooled normally have no significant difference in moisture, but the scores of color, condition of the surface and overall score are significantly lower than those of the air-cooled group.

[0051] Embodiment 3 The embodiment provides a method for rapidly cooling pig lungs, which specifically comprises the following steps. 1. Preparation: Add an equal amount of ice and water into the water cooling tank and mix well to ensure that the temperature of the cooling liquid is 0-4℃. Select 30 fresh pig lungs from slaughtered pigs, weigh them, and quickly transfer them into the pre-cooled metal basket and then into the water cooling tank.

[0052] 2. Water cooling process: The pig lungs are completely immersed in the cooling liquid. The temperature of the cooling liquid is detected every 10 min. When the temperature of the cooling liquid rises to 4℃, 10 kg of ice is manually added to reduce the temperature of the cooling liquid to 0-4℃. After 30 min of cooling, the center temperature of the pig lungs is reduced from 39℃ to 17℃, and the pig lungs are taken out and hung on a draining rack for a short time for flushing, draining and removing the surface residual blood, and then transferred to the air cooling warehouse after 5 min.

[0053] 3. The pig lungs are transferred to the air cooling warehouse and kept for 20 min, and the temperature of the air cooling warehouse is 0-4℃.

[0054] 4. The center temperature of the cooled pig lungs is reduced to 8℃, which meets the delivery standard. After the weighing and packaging steps, the pig lungs are quickly transferred to the refrigeration warehouse for storage or directly shipped.

[0055] The embodiment also provides air cooling group, and the difference from the embodiment 3 is only that the water cooling is not provided, and the air cooling time is changed to 4 hours. The following experimental groups are also provided, and the difference from the embodiment 3 is only that the water cooling time is changed to 20 minutes, and the air cooling time is changed to 30 minutes.

[0056] The color, moisture and overall score of the surface of the pig lung are scored by professional meat science researchers: in terms of color, 1 represents that the surface of the viscera is dark yellow and dull, and 9 represents that the surface of the viscera is uniform in color. In terms of moisture, 1 represents that the surface of the viscera is wet, has water droplets and is sticky, and 9 represents that the surface is slightly dry and not sticky. In terms of the stink condition, 1 represents that there is a large area of gray, and 9 represents that the surface is slightly dry and no water droplets flow and leave traces. In terms of overall sensory evaluation, 1 represents that the overall sensory evaluation is not satisfactory, and there is no purchase intention, and 9 represents that the overall sensory evaluation is very satisfactory, and there is strong purchase intention.

[0057] The test results of the embodiment are shown in Table 1. Figures 6-7 It is found that the moisture loss rate of the pig lung before and after cooling is 0.2%, the temperature difference of different parts is less than 1℃, in the sensory evaluation, the color, moisture and overall score of the pig lung cooled rapidly and the pig lung cooled by air are not significantly different between groups, and only the stink condition is worse than the control air cooling group.

[0058] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit it; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method of rapid cooling of pork red meat, characterized in that, The method comprises: 1) placing the pig red viscera after slaughtering into a cooling liquid for water cooling treatment; 2) draining the pig red viscera after the water cooling treatment; 3) air cooling treatment of the pig red viscera after the draining treatment; In step 1), the temperature of the cooling liquid is not higher than 4℃; and the central temperature of the pig red viscera after the water cooling treatment is reduced to below 15℃.

2. The method of rapid cooling of pig red offal according to claim 1, characterized in that, In step 1), the central temperature of the pig red viscera after the water cooling treatment is reduced to 10-15℃.

3. The method of rapid cooling of pig red offal according to claim 1 or 2, characterized in that, The temperature of the cooling liquid is 0-4℃, and the water cooling time is 20-40 min.

4. The method of rapid cooling of pig red offal according to any one of claims 1-3, characterized in that, In step 1), the pig red viscera is selected from one or more of pig heart, pig liver and pig lung.

5. The method of rapid cooling of pig red offal according to any one of claims 1-4, characterized in that, In step 1), the cooling liquid is obtained by mixing ice and water at a mass ratio of 1-2:1-2.

6. The method of rapid cooling of pork red offal according to claim 5, characterized in that, In step 1), when the temperature of the cooling liquid increases, ice or ice water mixture is preferably added to keep the temperature of the cooling liquid at 0-4℃.

7. The method of rapid cooling of pig red offal according to any one of claims 1-6, characterized in that, In step 2), the pig red viscera after the water cooling treatment is hung on a draining rack for flushing and draining treatment, and the time for the flushing and draining treatment is preferably 5-10 min.

8. The method of rapid cooling of pig red offal according to any one of claims 1-7, characterized in that, In step 3), the temperature for the air cooling treatment is 0-4℃, and the time for the air cooling treatment is 15-30 min.

9. The method of rapid cooling of pig red offal according to claim 8, characterized in that, In step 3), the central temperature of the pig red viscera after the air cooling treatment is reduced to below 7℃.

10. The method of rapid cooling of pig red offal according to any one of claims 1-9, characterized in that, Step 4) is further included, i.e. packaging the cooled pig red viscera and transferring into a refrigerator at 0-4℃.

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