Preparation method of double cooked pork slice premade dish

Abstract

The invention discloses a preparation method of a double cooked pork slice prefabricated vegetable, and belongs to the technical field of food processing.The method comprises the following steps that 1, pork is cut into pork blocks, the pork blocks are put into a pretreating agent to be soaked for 10-15 min and then fished out, and the treated pork is obtained; (2) pouring clear water into a pot, boiling, putting the treated pork into the pot, cooking until the pork is 60-80% cooked, fishing out, and cutting into pork slices; (3) adding edible oil into a pot, after the oil temperature reaches 120 DEG C, adding the sliced meat, stir-frying for 2-2.5 minutes, adding seasonings, and continuously stir-frying for 3-3.5 minutes to obtain double cooked pork slices; (4) cooling the double-cooked pork slices to room temperature, heating a protective agent, spraying the protective agent on the prepared double-cooked pork slices, and drying the double-cooked pork slices at 25-30 DEG C for 10-15 minutes to obtain the prepared double-cooked pork slices; (5) cutting the cleaned green peppers into inclined blocks, blanching and cooling to obtain prepared green pepper slices; and (6) separately bagging the prepared double cooked pork slices and the prepared green pepper slices, performing freezing treatment, and storing at-20 to-18 DEG C. The problem that the quality is reduced due to serious drying loss in the freezing process of the double cooked pork slice prefabricated vegetable is solved.

Description

Technical Field

[0001] The invention relates to the technical field of food processing, and in particular to a preparation method of a twice-cooked pork pre-dish. Background Art

[0002] Twice-cooked pork is a classic stir-fried dish in Sichuan and Chongqing. In Chongqing, Rongchang pork is mostly used as the raw material. It is deeply loved by consumers because of its soft and glutinous fat and dry and fragrant lean meat. Pre-prepared dishes generally refer to convenient flavor dishes that are processed into finished or semi-finished products with various ingredients and auxiliary materials, and can be eaten after simple processing. Preparing twice-cooked pork into pre-prepared dishes can not only help spread this traditional food culture to a wider area, allowing more people to enjoy this delicacy conveniently, but also reduce the time of cooking food. Pre-prepared dishes can save manpower, space and cost, improve meal efficiency, and meet the current busy pace of modern life. However, in order to extend the shelf life of meat pre-products, they usually need to be frozen. However, during the freezing process, the re-cooking will cause dry loss, that is, the moisture of the twice-cooked pork will gradually evaporate, resulting in food dehydration and drying, reduced quality, changes in the taste and texture of the twice-cooked pork, and a decline in quality. This is because during the freezing process, the water on the surface of the twice-cooked pork will gradually evaporate, and ice crystals will form inside the twice-cooked pork. The ice crystals will sublimate to form tiny pores inside the twice-cooked pork. As the freezing time increases, the ice crystals will continue to grow, and the dry loss will increase, resulting in the problem of serious loss of juice in the twice-cooked pork after thawing. In addition, the tiny pores inside the twice-cooked pork will also increase the area of ​​contact between the twice-cooked pork and the air, promote the oxidation of the twice-cooked pork, and cause the quality of the twice-cooked pork to decrease. At present, most of the pre-prepared dishes are quickly frozen to reduce the formation of large ice crystals, thereby reducing the impact of dry loss. However, as the frozen storage time increases, the ice crystals will continue to grow and sublimate, and it is impossible to effectively avoid the quality degradation caused by the dry loss of the twice-cooked pork.

[0003] Therefore, the present invention provides a method for preparing a twice-cooked pork pre-dish, which reduces dry loss during the freezing process of the twice-cooked pork pre-dish and improves the quality of the twice-cooked pork pre-dish. Summary of the invention

[0004] In view of this, an object of the present invention is to provide a method for preparing a twice-cooked pork pre-dish, so as to solve the problem that the twice-cooked pork pre-dish suffers from serious dry loss during frozen storage, resulting in quality degradation.

[0005] The present invention solves the above technical problems by the following technical means:

[0006] A method for preparing a twice-cooked pork pre-cooked dish, the method comprising the following steps:

[0007] (1) cutting pork into pieces of 6-8 cm in length × 3-4 cm in width × 4-5 cm in height, placing the pieces into a pretreatment agent for soaking for 10-15 min, and then removing the pieces to obtain treated pork;

[0008] (2) Pour clear water into a pot and bring to a boil, put the processed pork into the pot and cook until the pork is 6-8% cooked, then remove it and cut it into uniform slices of 0.3-0.4 cm thickness using a slicer;

[0009] (3) Add cooking oil to a pot, heat the oil to 120° C., add the meat slices, stir-fry for 2-2.5 min, add seasoning, and continue to stir-fry for 3-3.5 min to obtain twice-cooked pork;

[0010] (4) the twice-cooked pork is cooled to room temperature, the protective agent is heated and then sprayed on the prepared twice-cooked pork, and dried at 25-30° C. for 10-15 minutes to obtain the prepared twice-cooked pork;

[0011] (5) Cut the washed green pepper into oblique blocks of 2-2.5 cm in length and 2-2.5 cm in width, blanch at 80-90° C. for 2-3 min, remove and cool to obtain the prepared green pepper slices;

[0012] (6) The prepared twice-cooked pork and the prepared green pepper slices are packed separately, frozen and stored at -20 to -18°C.

[0013] Furthermore, the preparation method of the pretreatment agent in step (1) is: sodium tripolyphosphate, guar gum and water are uniformly mixed in a mass ratio of (0.5-0.6):(1-1.2):(50-60) to obtain the treatment agent.

[0014] The sodium tripolyphosphate in the pretreatment agent can chemically combine with the water molecules in the protein in the pork, thereby increasing the water binding capacity of the pork, improving the water retention of the meat, and reducing water loss; the pretreatment agent also adds a certain amount of guar gum, which can combine with the free water molecules in the pork through hydrogen bonds to form a three-dimensional spatial structure, reducing the water loss of the pork during the cooking process, thereby allowing the cooked pork to retain water to the greatest extent and improving the juiciness of the twice-cooked pork.

[0015] Furthermore, the seasoning in step (3) includes Pixian bean paste, onion, garlic, white sugar, and soy sauce, and the mass ratio of the meat slices, cooking oil, Pixian bean paste, onion, garlic, white sugar, and soy sauce is (100-110):(15-18):(8-10):(4-6):(5-8):(3-4):(4-5).

[0016] Furthermore, the edible oil is selected from rapeseed oil, soybean oil and peanut oil.

[0017] Furthermore, the specific operation of the heating treatment of the protective agent in step (4) is: heating the protective agent at 80-90° C. for 10-15 minutes, and the amount of the protective agent used is 20-25 g of the protective agent per 100 g of twice-cooked pork.

[0018] Furthermore, the freezing treatment in step (6) is as follows: pre-cooling the twice-cooked pork dish to 0-4°C and then quick-freezing it at -35 to -30°C for 2-3h, and finally freezing it for storage.

[0019] Quick freezing allows the water in the twice-cooked pork to quickly form tiny ice crystals, reducing the damage to the twice-cooked pork caused by the formation of ice crystals, reducing the loss of juice when the twice-cooked pork is thawed, and thus reducing the dry loss of food. At the same time, the twice-cooked pork is precooled to 0-4℃ before quick freezing to reduce the quick freezing time and further reduce the impact of dry loss.

[0020] Further, the preparation method of the protective agent is as follows:

[0021] S1: Add monoglyceride to water, stir evenly, then add phosphatidylserine, heat to 40-50°C, stir at a rate of 400-500 r / min for 5-10 min to obtain a stable solution;

[0022] S2: adding maltitol to water, stirring evenly to obtain a maltitol solution, and then adding sodium succinate and corn starch to the maltitol solution, stirring evenly to obtain a mixed solution;

[0023] S3: Evenly mix the stabilizing solution and the mixed solution to obtain a protective agent.

[0024] Furthermore, in step S1, the mass ratio of monoglyceride to phosphatidylserine and water is (1-1.2):(4-5):(80-100).

[0025] Furthermore, in step S2, the mass ratio of maltitol, sodium succinate, corn starch and water is (1-1.2):(1-1.5):(10-12):(100-120).

[0026] Furthermore, the mass ratio of the stabilizing liquid to the mixed liquid is 1:1.

[0027] After the protective agent is diluted with water and heated, it is sprayed on the surface of the prepared twice-cooked pork, and then frozen and stored at low temperature. The protective agent can form a thin film on the surface of the meat slice, reduce the contact between oxygen and the twice-cooked pork, inhibit the oxidation of the twice-cooked pork, and maintain the taste of the twice-cooked pork. The corn starch in the protective agent interacts with phosphatidylserine to form a starch-lipid complex, which increases the stability of the starch molecules, reduces the damage of ice crystals to the starch molecular structure during the freezing process, and avoids the starch crystals being destroyed during the freezing process and losing their original adhesion and adhesiveness, resulting in dehydration and cracking and gradually falling off from the surface of the meat slice, so that the protective agent acts on the meat slice for a longer time. At the same time, phosphatidylserine interacts with corn starch to form a film, which increases the density of the protective agent after film formation, reduces the evaporation of surface water of the twice-cooked pork during the frozen storage process, and reduces the effect of dry loss on the twice-cooked pork during the freezing process. When the twice-cooked pork is heated, the phosphatidylserine in the protective agent on the surface of the meat slice gradually liquefies, causing the protective agent to fall off from the surface of the meat slice, and will not affect the taste of the twice-cooked pork.

[0028] However, due to the poor dispersibility of phosphatidylserine in water, it cannot be well combined with corn starch, and the uncombined starch molecules have poor protective effect on the meat slices after forming a film, resulting in uneven protective effect of the protective agent on the meat slices. Therefore, the use of monoglyceride to modify phosphatidylserine can enhance the dispersibility of phosphatidylserine in water, so that it can better combine with starch molecules to form a starch-lipid complex and evenly form a film on the meat slices; at the same time, monoglyceride can also enhance the wettability of phosphatidylserine, so that the protective agent can better adhere to the surface of the meat slice to form a film, thereby inhibiting the shedding of the protective agent film during frozen storage. In addition, maltitol is added to the preservative, which combines with water molecules by forming hydrogen bonds, thereby reducing the activity and mobility of water molecules, and then inhibiting the formation and growth of ice crystals, reducing the damage to the quality of twice-cooked pork caused by the sublimation of ice crystals during the freezing process. Sodium succinate interacts with water molecules to form hydrated ions, which hinder the growth process of ice crystals, thereby reducing the formation of ice crystals during the freezing process and inhibiting the further growth of ice crystals, thereby reducing the damage of ice crystals to the internal structure of twice-cooked pork.

[0029] Beneficial effects:

[0030] The present invention provides a method for preparing a twice-cooked pork pre-cooked dish, which can effectively reduce the occurrence of dry loss during the freezing process of the twice-cooked pork pre-cooked dish, reduce the water loss during the freezing process of the twice-cooked pork pre-cooked dish, and ensure the taste and quality of the twice-cooked pork. Therefore, the twice-cooked pork pre-cooked dish prepared by the present invention not only retains the flavor of the food, but also meets the modern people's needs for efficiency and convenience. In addition, the present invention can effectively promote the development of pre-cooked dishes, promote the upgrading and innovation of industries such as agriculture, food processing and catering services, and promote economic growth. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 : Experimental picture of stir-frying twice-cooked pork. DETAILED DESCRIPTION

[0032] The present invention will be described in detail below with reference to specific embodiments:

[0033] Embodiment 1:

[0034] Preparation of protective agent:

[0035] S1: Add 1g monoglyceride to 80g water, stir evenly, then add 4g phosphatidylserine, heat to 40°C, and stir at 400r / min for 5min to obtain a stable solution;

[0036] S2: adding 1 g of maltitol to 100 g of water, stirring evenly to obtain a maltitol solution, and then adding 1 g of sodium succinate and 10 g of corn starch to the maltitol solution, stirring evenly to obtain a mixed solution;

[0037] S3: The stabilizing solution and the mixed solution are mixed evenly in a mass ratio of 1:1 to obtain a protective agent.

[0038] Preparation of pretreatment agent:

[0039] 5 g of sodium tripolyphosphate, 10 g of guar gum and 500 g of water were uniformly mixed to obtain a treating agent.

[0040] Preparation of twice cooked pork:

[0041] (1) Cut pork into pieces of 6 cm in length × 3 cm in width × 4 cm in height, put them into a pretreatment agent and soak them for 10 minutes, then remove them and obtain the treated pork;

[0042] (2) Pour clear water into a pot and bring to a boil, put the processed pork into the pot and cook until the pork is 60% cooked, then remove it and cut it into 0.3 cm thick and uniform slices using a slicer;

[0043] (3) Put 15g of rapeseed oil in a pot, heat the oil to 120°C, put in 100g of pork slices, stir-fry for 2min, add 8g of Pixian bean paste, 4g of green onion, 5g of garlic, 3g of white sugar, and 4g of soy sauce, and continue to stir-fry for 3min to obtain twice-cooked pork;

[0044] (4) The twice-cooked pork was cooled to room temperature, 20 g of the protective agent was heated at 80° C. for 10 min, then sprayed on the prepared twice-cooked pork, and dried at 25° C. for 10 min to obtain the prepared twice-cooked pork;

[0045] (5) Cut the washed green pepper into oblique blocks of 2 cm in length and 2 cm in width, blanch at 80° C. for 2 min, remove and cool to obtain the prepared green pepper slices;

[0046] (6) The prepared twice-cooked pork and the prepared green pepper slices are packed separately to obtain a twice-cooked pork pre-dish, which is first pre-cooled to 0° C., then quick-frozen in a -35° C. freezer for 2 h, and then stored at -20° C.

[0047] Embodiment 2:

[0048] Preparation of protective agent:

[0049] S1: Add 1.1 g monoglyceride to 90 g water, stir evenly, then add 4.5 g phosphatidylserine, heat to 45°C, stir at 450 r / min for 5 min to obtain a stable solution;

[0050] S2: adding 1.1 g of maltitol to 110 g of water, stirring evenly to obtain a maltitol solution, and then adding 1.25 g of sodium succinate and 11 g of corn starch to the maltitol solution, stirring evenly to obtain a mixed solution;

[0051] S3: The stabilizing solution and the mixed solution are mixed evenly in a mass ratio of 1:1 to obtain a protective agent.

[0052] Preparation of pretreatment agent:

[0053] 5.5 g of sodium tripolyphosphate, 11 g of guar gum and 550 g of water were uniformly mixed to obtain a treating agent.

[0054] Preparation of twice cooked pork:

[0055] (1) Cut pork into pieces of 7 cm in length × 3.5 cm in width × 4.5 cm in height, put them into a pretreatment agent and soak them for 12 minutes, then remove them and obtain the treated pork;

[0056] (2) Pour clear water into a pot and bring to a boil, put the processed pork into the pot and cook until the pork is 70% cooked, then remove it and cut it into 0.35 cm thick and uniform slices using a slicer;

[0057] (3) Put 16.5g rapeseed oil in the pot, and when the oil temperature reaches 120°C, put in 110g of meat slices and stir-fry for 2.2min. Then add 9g Pixian bean paste, 5g green onion, 6g garlic, 3.5g white sugar, and 4.5g soy sauce, and continue to stir-fry for 3.2min to obtain twice-cooked pork;

[0058] (4) The twice-cooked pork was cooled to room temperature, 22 g of the protective agent was heated at 85° C. for 12 min, and then sprayed on the prepared twice-cooked pork, and dried at 28° C. for 12 min to obtain the prepared twice-cooked pork;

[0059] (5) Cut the washed green pepper into oblique blocks of 2.2 cm in length and 2.2 cm in width, blanch at 85° C. for 2.5 min, remove and cool to obtain the prepared green pepper slices;

[0060] (6) The prepared twice-cooked pork and the prepared green pepper slices are packed separately to obtain a twice-cooked pork pre-dish, which is first pre-cooled to 2° C., then quick-frozen in a -32° C. freezer for 2.5 h, and then stored at -19° C.

[0061] Embodiment 3:

[0062] Preparation of protective agent:

[0063] S1: Add 1.2 g monoglyceride to 100 g water, stir evenly, then add 4 g phosphatidylserine, heat to 50 °C, stir at 500 r / min for 5 min to obtain a stable solution;

[0064] S2: adding 1.2 g of maltitol to 120 g of water, stirring evenly to obtain a maltitol solution, and then adding 1.5 g of sodium succinate and 12 g of corn starch to the maltitol solution, stirring evenly to obtain a mixed solution;

[0065] S3: The stabilizing solution and the mixed solution are mixed evenly in a mass ratio of 1:1 to obtain a protective agent.

[0066] Preparation of pretreatment agent:

[0067] 6 g of sodium tripolyphosphate, 12 g of guar gum and 600 g of water were uniformly mixed to obtain a treating agent.

[0068] Preparation of twice cooked pork:

[0069] (1) Cut the pork into pieces of 8 cm in length × 4 cm in width × 5 cm in height, put them into a pretreatment agent and soak them for 15 minutes, then remove them and obtain the treated pork;

[0070] (2) Pour clear water into a pot and bring to a boil, put the processed pork into the pot and cook until the pork is 80% cooked, then remove it and cut it into 0.4 cm thick and uniform slices using a slicer;

[0071] (3) Put 18g of rapeseed oil in a pot, heat the oil to 120°C, put in 120g of meat slices, stir-fry for 2.5min, add 10g of Pixian bean paste, 6g of green onion, 8g of garlic, 4g of white sugar, and 5g of soy sauce, and continue to stir-fry for 3.5min to obtain twice-cooked pork;

[0072] (4) The twice-cooked pork was cooled to room temperature, 25 g of the protective agent was heated at 90° C. for 15 min, then sprayed on the prepared twice-cooked pork, and dried at 30° C. for 15 min to obtain the prepared twice-cooked pork;

[0073] (5) Cut the washed green pepper into oblique blocks of 2.5 cm in length and 2.5 cm in width, blanch at 90° C. for 3 min, remove and cool to obtain the prepared green pepper slices;

[0074] (6) The prepared twice-cooked pork and the prepared green pepper slices are packed separately to obtain a twice-cooked pork pre-dish, which is first pre-cooled to 4° C., then quick-frozen in a -30° C. freezer for 3 h, and then stored at -18° C.

[0075] Comparative Example 1:

[0076] This comparative example is in contrast to Example 1, the only difference being that the preparation process of the protective agent is different, specifically, the mass ratio of the stabilizing liquid to the mixed liquid is 1:3, and the specific method is as follows:

[0077] S1: Add 1g monoglyceride to 80g water, stir evenly, then add 4g phosphatidylserine, heat to 40°C, and stir at 400r / min for 5min to obtain a stable solution;

[0078] S2: adding 1 g of maltitol to 100 g of water, stirring evenly to obtain a maltitol solution, and then adding 1 g of sodium succinate and 10 g of corn starch to the maltitol solution, stirring evenly to obtain a mixed solution;

[0079] S3: The stabilizing solution and the mixed solution are mixed evenly in a mass ratio of 1:3 to obtain a protective agent.

[0080] The pretreatment agent and twice-cooked pork preparation method used in this comparative example are the same as those in Example 1.

[0081] Comparative Example 2:

[0082] This comparative example is in contrast to Example 1, the only difference being that the preparation process of the protective agent is different, specifically, the mass ratio of the stabilizing liquid to the mixed liquid is 3:1, and the specific method is as follows:

[0083] S1: Add 1g monoglyceride to 80g water, stir evenly, then add 4g phosphatidylserine, heat to 40°C, and stir at 400r / min for 5min to obtain a stable solution;

[0084] S2: adding 1 g of maltitol to 100 g of water, stirring evenly to obtain a maltitol solution, and then adding 1 g of sodium succinate and 10 g of corn starch to the maltitol solution, stirring evenly to obtain a mixed solution;

[0085] S3: The stabilizing solution and the mixed solution are mixed uniformly in a mass ratio of 3:1 to obtain a protective agent.

[0086] The pretreatment agent and twice-cooked pork preparation method used in this comparative example are the same as those in Example 1.

[0087] Comparative Example 3:

[0088] This comparative example is in contrast to Example 1, the only difference being that the preparation process of the protective agent is different, specifically, the phosphatidylserine is not modified, that is, monoglyceride is not added, and the specific method is as follows:

[0089] S1: Mix 4 g of phosphatidylserine with 80 g of water to obtain a stable solution;

[0090] S2: adding 1 g of maltitol to 100 g of water, stirring evenly to obtain a maltitol solution, and then adding 1 g of sodium succinate and 10 g of corn starch to the maltitol solution, stirring evenly to obtain a mixed solution;

[0091] S3: The stabilizing solution and the mixed solution are mixed evenly in a mass ratio of 1:1 to obtain a protective agent.

[0092] The pretreatment agent and twice-cooked pork preparation method used in this comparative example are the same as those in Example 1.

[0093] Comparative Example 4:

[0094] This comparative example is in contrast to Example 1, the only difference being that the raw materials for preparing the protective agent are different, specifically, no phosphatidylserine and monoglyceride are added, that is, no stabilizing liquid is added, and the specific method is as follows:

[0095] S1: Add 1 g of maltitol to 100 g of water, stir evenly to obtain a maltitol solution, then add 1 g of sodium succinate and 10 g of corn starch to the maltitol solution, stir evenly to obtain a protective agent.

[0096] The pretreatment agent and twice-cooked pork preparation method used in this comparative example are the same as those in Example 1.

[0097] Comparative Example 5:

[0098] This comparative example is in contrast to Example 1, the only difference being that the raw materials for preparing the protective agent are different, specifically, no maltitol is added, and the specific method is as follows:

[0099] S1: Add 1g monoglyceride to 80g water, stir evenly, then add 4g phosphatidylserine, heat to 40°C, and stir at 400r / min for 5min to obtain a stable solution;

[0100] S2: Add 1 g of sodium succinate and 10 g of corn starch into 100 g of water and stir to obtain a mixed solution;

[0101] S3: The stabilizing solution and the mixed solution are mixed evenly in a mass ratio of 1:1 to obtain a protective agent.

[0102] The pretreatment agent and twice-cooked pork preparation method used in this comparative example are the same as those in Example 1.

[0103] Comparative Example 6:

[0104] This comparative example is in contrast to Example 1, the only difference being that the raw materials for preparing the protective agent are different, specifically, sodium succinate is not added, and the specific method is as follows:

[0105] S1: Add 1g monoglyceride to 80g water, stir evenly, then add 4g phosphatidylserine, heat to 40°C, and stir at 400r / min for 5min to obtain a stable solution;

[0106] S2: adding 1 g of maltitol to 100 g of water, stirring evenly to obtain a maltitol solution, and then adding 10 g of corn starch to the maltitol solution, stirring evenly to obtain a mixed solution;

[0107] S3: The stabilizing solution and the mixed solution are mixed evenly in a mass ratio of 1:1 to obtain a protective agent.

[0108] The pretreatment agent and twice-cooked pork preparation method used in this comparative example are the same as those in Example 1.

[0109] Comparative Example 7:

[0110] This comparative example is in contrast to Example 1, the only difference being that the preparation process of the twice-cooked pork is different, specifically, the twice-cooked pork is not pretreated, and the specific method is as follows:

[0111] (1) Pour clear water into a pot and bring to a boil. Cut pork into pieces of 6 cm in length × 3 cm in width × 4 cm in height. Put the pork into the pot and cook until the pork is 60% cooked. Then remove the pork and cut it into uniform slices of 0.3 cm in thickness using a slicer.

[0112] (2) Put 15g of rapeseed oil in a pot, heat the oil to 120°C, put in 100g of pork slices, stir-fry for 2min, add 8g of Pixian bean paste, 4g of green onion, 5g of garlic, 3g of white sugar, and 4g of soy sauce, and continue to stir-fry for 3min to obtain twice-cooked pork;

[0113] (3) The twice-cooked pork was cooled to room temperature, 20 g of the protective agent was heated at 80° C. for 10 min, then sprayed on the prepared twice-cooked pork, and dried at 25° C. for 10 min to obtain the prepared twice-cooked pork;

[0114] (4) Cut the washed green pepper into oblique blocks of 2 cm in length and 2 cm in width, blanch at 80° C. for 2 min, remove and cool to obtain the prepared green pepper slices;

[0115] (5) The prepared twice-cooked pork and the prepared green pepper slices are packed separately to obtain a twice-cooked pork pre-dish, which is first pre-cooled to 0° C., then quick-frozen in a -35° C. freezer for 2 h, and then stored at -20° C.

[0116] The protective agent used in this comparative example is the same as that in Example 1.

[0117] Comparative Example 8:

[0118] This comparative example is in contrast to Example 1, the only difference being that the preparation process of the twice-cooked pork is different, specifically, the twice-cooked pork is not pre-cooled, and the specific method is as follows:

[0119] (1) Cut pork into pieces of 6 cm in length × 3 cm in width × 4 cm in height, put them into a pretreatment agent and soak them for 10 minutes, then remove them and obtain the treated pork;

[0120] (2) Pour clear water into a pot and bring to a boil, put the processed pork into the pot and cook until the pork is 60% cooked, then remove it and cut it into 0.3 cm thick and uniform slices using a slicer;

[0121] (3) Put 15g of rapeseed oil in a pot, heat the oil to 120°C, put in 100g of pork slices, stir-fry for 2min, add 8g of Pixian bean paste, 4g of green onion, 5g of garlic, 3g of white sugar, and 4g of soy sauce, and continue to stir-fry for 3min to obtain twice-cooked pork;

[0122] (4) The twice-cooked pork was cooled to room temperature, 20 g of the protective agent was heated at 80° C. for 10 min, then sprayed on the prepared twice-cooked pork, and dried at 25° C. for 10 min to obtain the prepared twice-cooked pork;

[0123] (5) Cut the washed green pepper into oblique blocks of 2 cm in length and 2 cm in width, blanch at 80° C. for 2 min, remove and cool to obtain the prepared green pepper slices;

[0124] (6) The prepared twice-cooked pork and the prepared green pepper slices are packed separately to obtain a twice-cooked pork pre-dish, which is quickly frozen in a -35°C freezer for 2 hours and then stored at -20°C.

[0125] The pretreatment agent and protective agent used in this comparative example are the same as those in Example 1.

[0126] Comparative Example 9:

[0127] This comparative example is in contrast to Example 1, the only difference being that the preparation process of the twice-cooked pork is different, specifically, the twice-cooked pork is not rapidly cooled, and the specific method is as follows:

[0128] (1) Cut pork into pieces of 6 cm in length × 3 cm in width × 4 cm in height, put them into a pretreatment agent and soak them for 10 minutes, then remove them and obtain the treated pork;

[0129] (2) Pour clear water into a pot and bring to a boil, put the processed pork into the pot and cook until the pork is 60% cooked, then remove it and cut it into 0.3 cm thick and uniform slices using a slicer;

[0130] (3) Put 15g of rapeseed oil in a pot, heat the oil to 120°C, put in 100g of pork slices, stir-fry for 2min, add 8g of Pixian bean paste, 4g of green onion, 5g of garlic, 3g of white sugar, and 4g of soy sauce, and continue to stir-fry for 3min to obtain twice-cooked pork;

[0131] (4) The twice-cooked pork was cooled to room temperature, 20 g of the protective agent was heated at 80° C. for 10 min, then sprayed on the prepared twice-cooked pork, and dried at 25° C. for 10 min to obtain the prepared twice-cooked pork;

[0132] (5) Cut the washed green pepper into oblique blocks of 2 cm in length and 2 cm in width, blanch at 80° C. for 2 min, remove and cool to obtain the prepared green pepper slices;

[0133] (6) The prepared twice-cooked pork and the prepared green pepper slices are packed separately to obtain a twice-cooked pork pre-dish, which is first pre-cooled to 0° C. and then stored at -20° C.

[0134] The pretreatment agent and protective agent used in this comparative example are the same as those in Example 1.

[0135] Comparative Example 10:

[0136] This comparative example is in contrast to Example 1, the only difference being that the preparation process of twice-cooked pork is different, specifically, no protective agent is used, and the specific method is as follows:

[0137] (1) Cut pork into pieces of 6 cm in length × 3 cm in width × 4 cm in height, put them into a pretreatment agent and soak them for 10 minutes, then remove them and obtain the treated pork;

[0138] (2) Pour clear water into a pot and bring to a boil, put the processed pork into the pot and cook until the pork is 60% cooked, then remove it and cut it into 0.3 cm thick and uniform slices using a slicer;

[0139] (3) Put 15g of rapeseed oil in a pot, heat the oil to 120°C, put in 100g of pork slices, stir-fry for 2min, add 8g of Pixian bean paste, 4g of green onion, 5g of garlic, 3g of white sugar, and 4g of soy sauce, and continue to stir-fry for 3min to obtain twice-cooked pork;

[0140] (4) Cut the washed green pepper into oblique blocks of 2 cm in length and 2 cm in width, blanch at 80° C. for 2 min, remove and cool to obtain the prepared green pepper slices;

[0141] (5) The prepared twice-cooked pork and the prepared green pepper slices are packed separately to obtain a twice-cooked pork pre-dish, which is first pre-cooled to 0° C., then quick-frozen in a -35° C. freezer for 2 h, and then stored at -20° C.

[0142] The protective agent used in this comparative example is the same as that in Example 1.

[0143] Experiment 1:

[0144] Meat slices and pretreatment: Cut the lower streaky pork into pieces of 6 cm in length × 3 cm in width × 4 cm in height, put them into a pretreatment agent for soaking for 10 minutes, then take them out to obtain the processed pork, add water and boil them in an induction cooker at 2200W, put the processed pork into a pot, cook it in an induction cooker at 800W until the pork is 60% cooked, then take it out and cut it into 0.3 cm thick and uniform meat slices using a slicer;

[0145] Stir-frying: Set the induction cooker to 1800W, add 15g rapeseed oil, when the temperature of the thermocouple in the pot reaches 120℃, add 100g meat slices, stir-fry for 2min, add 8g Pixian bean paste, 4g green onion, 5g garlic, 3g white sugar, 4g soy sauce, turn to 800W and continue to stir-fry for 3min to get twice-cooked pork;

[0146] Protective treatment and freezing: Heat 20g of protective agent at 80℃ for 10min, then spray it on the cooled twice-cooked pork, and dry it at 25℃ for 10min to obtain the prepared twice-cooked pork. Bag the prepared twice-cooked pork, precool it to 0℃, then quickly freeze it in a -35℃ freezer for 2h, and then store it at -20℃.

[0147] The experiment was divided into 12 groups, among which Example 1 and Comparative Examples 8-9 used the pretreatment agent and protective agent prepared in Example 1; Comparative Examples 1-6 used the pretreatment protective agent prepared in Example 1, and used the protective agents prepared in Comparative Examples 1-6 respectively; Comparative Example 7 used the protective agent prepared in Example 1 without pretreatment; Comparative Example 8 did not perform precooling treatment, and Comparative Example 9 did not perform quick freezing treatment; Comparative Example 10 did not use protective agents during the preparation process. The blank control group was fresh twice-cooked pork prepared with reference to the above method, and no pretreatment and protective agent were used during the preparation process, and the test was immediately after the preparation was completed.

[0148] The twice-cooked pork was frozen at -20°C for 1 month and then taken out and re-cooked by microwave heating, and the sensory evaluation was performed. The results are shown in Table 1. The re-heating operation is specifically: heating in a microwave oven at medium heat for 3-5 minutes.

[0149] The results are shown in Table 1. The hardness, elasticity and chewiness were tested. The full texture (TPA) mode was selected, the P5 probe, the pre-test speed was 2 mm / s, the test speed was 1 mm / s, the post-test speed was 10 mm / s, the compression ratio was 65%, the trigger force was 5 g, the time interval between two compressions was 5 s, three parallel tests were performed, and the results were averaged. The results are shown in Table 2.

[0150] Experiment 2:

[0151] The twice-cooked pork pre-cooked dish prepared in Example 1 was further stored in a frozen state, and the hardness, elasticity and chewiness were tested at 1 month, 3 months and 6 months, respectively. The results are shown in Table 3.

[0152] Table 1

[0153]

[0154] Table 2

[0155]

[0156]

[0157] Table 3

[0158] 1 month 3 months 6 months Hardness(g) 1262 1302 1351 elasticity 0.805 0.790 0.778 Chewability(g) 618.3 626.2 642.1

[0159] By analyzing Table 1, Table 2, and Table 3, we can get:

[0160] 1. Comparative Example 1 Compared with Example 1, the mass ratio of the stabilizing liquid to the mixed liquid is 1:3, and the amount of the stabilizing liquid added is too small, resulting in the starch molecules in the protective agent being easily damaged by ice crystals during the freezing process, and the protective agent loses its original adhesion and viscosity, resulting in the protective agent forming a thin film on the twice-cooked pork being easily detached from the meat slices and losing its protective effect on the meat slices. The twice-cooked pork is dried during the frozen storage process, resulting in a large loss of water in the twice-cooked pork, and as the drying proceeds, the ice crystals in the meat continue to sublimate, and the excessive loss of meat water causes the meat slices to be hard and the elasticity to be reduced; and after the ice crystals sublimate, fine cavities are formed in the meat, which increases the contact area between the twice-cooked pork and the air, promotes the oxidation of the twice-cooked pork, and causes the surface of the twice-cooked pork to change color and reduce quality. Therefore, the sensory evaluation of the twice-cooked pork treated in Comparative Example 1 is poor, the juiciness is poor, the surface water evaporates too much, causing the meat slices to become dry and hard, the hardness of the twice-cooked pork increases, the elasticity decreases, and the chewiness increases. In Comparative Example 2 compared with Example 1, the mass ratio of the stabilizing liquid to the mixed liquid is 3:1, the amount of mixed liquid added is too small, and the starch content in the protective agent is low, resulting in a smaller film thickness and lower density of the protective agent on the surface of the meat slices, which reduces the protective effect of the protective agent on the twice-cooked pork, and causes more water loss during frozen storage, resulting in reduced quality.

[0161] 2. Comparative Example 3 Compared with Example 1, phosphatidylserine is not modified, that is, monoglyceride is not added, the dispersibility of phosphatidylserine in water is poor, the binding effect with starch molecules is reduced, the modification effect on starch is poor, and the starch molecules are easily destroyed by ice crystals during the freezing process, resulting in the shedding of the protective agent. At the same time, the unmodified phosphatidylserine has low wettability, resulting in low adhesion of the protective agent on the meat slices, and it is easy to fall off from the meat slices, thereby reducing the effect of the protective agent on the twice-cooked pork, and the dry consumption of the twice-cooked pork is more serious, resulting in poor sensory evaluation of the twice-cooked pork after one month of storage, and more juice loss. Comparative Example 4 Compared with Example 1, phosphatidylserine is not added, and ice crystals destroy the starch molecular structure during the freezing process, resulting in the destruction of the starch crystals and the loss of the original adhesion and adhesiveness from the meat slices, which in turn causes the meat slices to dry during the frozen storage process. Therefore, the sensory evaluation of the twice-cooked pork is poor, the hardness is high and the elasticity is poor, and the juice content continues to decrease with the increase of freezing time.

[0162] 3. Comparative Example 5 Compared with Example 1, maltitol was not added. The obtained twice-cooked pork pre-prepared dish had poor juiciness and poor sensory evaluation after being frozen and stored for 1 month. This is because maltitol can combine with water molecules by forming hydrogen bonds to reduce the activity and mobility of water molecules, thereby inhibiting the formation and growth of ice crystals, reducing the water loss caused by ice crystal sublimation, and reducing the occurrence of dry loss. Comparative Example 6 Compared with Example 1, sodium succinate was not added. During the freezing process of the meat slices, more ice crystals were formed, resulting in greater destructiveness of the ice crystals formed in Comparative Example 6 to the meat slices, thereby causing water loss, increased hardness of the meat slices, reduced elasticity, and reduced quality.

[0163] 4. Compared with Example 1, in Comparative Example 7, the pork is not pretreated, and the pork loses more water during the cooking process, resulting in the wateriness of the twice-cooked gravy prepared in Comparative Example 7 being average, and the wateriness is further reduced during the frozen storage process.

[0164] 5. Compared with Example 1, in Comparative Example 8, the twice-cooked pork was not pre-cooled, and the twice-cooked pork required a longer freezing time in the subsequent quick freezing process, lost more water in the quick freezing process, and formed more ice crystals after quick freezing, which resulted in the sublimation of ice crystals during the frozen storage of the twice-cooked pork, exacerbating the effect of dry loss. In Comparative Example 9, no quick freezing was performed, and overly large ice crystals were formed inside the twice-cooked pork during the frozen storage process, resulting in more serious water loss, resulting in lower quality of the twice-cooked pork in Comparative Example 9.

[0165] 6. Compared with Example 1, in Comparative Example 10, no protective agent was used, and the twice-cooked pork lost more water during the cooking process, and more serious drying occurred during the frozen storage process, resulting in further loss of water in the meat slices. Therefore, the twice-cooked pork in Comparative Example 10 became hard, with reduced elasticity and poor quality.

[0166] 7. Compared with the blank control, the hardness, elasticity and chewiness of Example 1 after storage for 1 month are relatively small, indicating that the twice-cooked pork prepared in Example 1 can better retain the original taste of the twice-cooked pork after frozen storage, and the difference is relatively small compared with the freshly made twice-cooked pork. In addition, during the continued storage of the twice-cooked pork prepared in Example 1, the change range of its hardness, elasticity and chewiness is relatively low, indicating that the twice-cooked pork prepared in Example 1 can maintain the taste of the twice-cooked pork for a long time and maintain its quality.

[0167] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions of the present invention, which should be included in the scope of the claims of the present invention. The techniques, shapes, and structural parts not described in detail in the present invention are all known technologies.

Claims

1. A method for preparing a twice-cooked pork pre-dish, characterized in that: The method comprises the following steps: (1) cutting pork into pieces, placing the pieces into a pretreatment agent for soaking for 10-15 minutes, and then removing the pieces to obtain processed pork; (2) Pour clear water into a pot and bring to a boil, put the processed pork into the pot and cook until the pork is 60% to 80% cooked, then remove and cut into slices; (3) Add cooking oil to a pot, heat the oil to 120° C., add the meat slices, stir-fry for 2-2.5 min, add seasoning, and continue to stir-fry for 3-3.5 min to obtain twice-cooked pork; (4) the twice-cooked pork is cooled to room temperature, the protective agent is heated and then sprayed on the prepared twice-cooked pork, and dried at 25-30° C. for 10-15 minutes to obtain the prepared twice-cooked pork; (5) cutting the washed green pepper into oblique pieces, blanching and cooling to obtain prepared green pepper slices; (6) The prepared twice-cooked pork and the prepared green pepper slices are packed separately to obtain a twice-cooked pork pre-dish, which is then frozen and stored at -20 to -18°C.

2. The method for preparing a twice-cooked pork pre-cooked dish according to claim 1, characterized in that: The preparation method of the pretreatment agent in step (1) is: sodium tripolyphosphate, guar gum and water are uniformly mixed in a mass ratio of (0.5-0.6):(1-1.2):(50-60) to obtain the treatment agent.

3. The method for preparing a twice-cooked pork pre-cooked dish according to claim 2, characterized in that: In the step (3), the seasoning includes Pixian bean paste, onion, garlic, white sugar and soy sauce, and the mass ratio of the meat slices, cooking oil, Pixian bean paste, onion, garlic, white sugar and soy sauce is (100-110):(15-18):(0.8-1):(1-1.2):(1.2-1.4):(0.3-0.4):(1-1.5).

4. The method for preparing a twice-cooked pork pre-dish according to claim 3, characterized in that: The edible oil is selected from rapeseed oil, soybean oil and peanut oil.

5. The method for preparing a twice-cooked pork pre-dish according to claim 4, characterized in that: The specific operation of the heating treatment of the protective agent in step (4) is: heating the protective agent at 80-90° C. for 10-25 min, and the amount of the protective agent used is 20-25 g of the protective agent per 100 g of twice-cooked pork.

6. The method for preparing a twice-cooked pork pre-dish according to claim 4, characterized in that: The freezing treatment in step (6) is as follows: pre-cooling the twice-cooked pork dish to 0-4°C, then quick-freezing it at -35 to -30°C for 2-3h, and finally freezing it for storage.

7. The method for preparing a twice-cooked pork pre-dish according to claim 6, characterized in that: The preparation method of the protective agent is as follows: S1: Add monoglyceride to water, stir evenly, then add phosphatidylserine, heat to 40-50°C, stir at a rate of 400-500 r / min for 5-10 min to obtain a stable solution; S2: adding maltitol to water, stirring evenly to obtain a maltitol solution, and then adding sodium succinate and corn starch to the maltitol solution, stirring evenly to obtain a mixed solution; S3: Evenly mix the stabilizing solution and the mixed solution to obtain a protective agent.

8. The method for preparing a twice-cooked pork pre-dish according to claim 7, characterized in that: In step S1, the mass ratio of monoglyceride to phosphatidylserine and water is (1-1.2):(4-5):(80-100).

9. The method for preparing a twice-cooked pork pre-dish according to claim 6, characterized in that: In the step S2, the mass ratio of maltitol, sodium succinate, corn starch and water is (1-1.2):(1-1.5):(10-12):(100-120).

10. The method for preparing a twice-cooked pork pre-dish according to claim 9, characterized in that: The mass ratio of the stabilizing liquid to the mixed liquid is 1:1.

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