Industrial processing method of traditional tea eggs

Abstract

The invention belongs to the technical field of food processing. The invention provides an industrial processing method of traditional tea eggs, which comprises the following steps: baking eggs, heating with steam, and steaming and curing; enabling the eggshells to have cracks through low-frequency vibration so as to obtain shell-cracked eggs; preparing marinating soup from green mandarin oranges, black tea, spices, salt, soy sauce, monosodium glutamate, white granulated sugar and water, putting the marinating soup and the shell-cracked eggs into a pressure container, heating the marinating soup and marinating, and circulating the marinating soup during marinating to obtain marinated eggs; and carrying out vacuum cooling dehydration, shelling, vacuum packaging and high-temperature sterilization on the marinated eggs to obtain the tea eggs. According to the invention, baking treatment is adopted to reduce the gel property of egg white, so that the protein of the prepared tea eggs is tender; baking treatment, low-frequency vibration and vacuum cooling dehydration are adopted to promote the tea eggs to be tasty; performing low-frequency vibration and vacuum cooling dehydration to enhance crack textures of the tea eggs; high-temperature sterilization prolongs the shelf life of the tea eggs.

Description

Technical Field

[0001] The invention belongs to the technical field of food processing, and in particular relates to an industrial processing method for traditional tea eggs. Background Art

[0002] Tea eggs are a traditional braised egg product, which are loved by people for their delicate taste and unique flavor. In the traditional processing of tea eggs, in order to enhance the flavor of tea-cured eggs with shells, they are often stewed for a long time. In addition, in order to extend the shelf life of braised eggs, most of the vacuum-packed braised egg products on the market are high-temperature sterilized products. Due to high-temperature sterilization, the texture is firmer than traditional tea eggs, and the taste is worse than traditional non-high-temperature tea-cured eggs. Patent CN 112889908 B uses a medium-temperature sterilization method (105°C, sterilization for 40 to 60 minutes) to better maintain the original fatty acid composition of the braised eggs, but the room temperature shelf life is only about 10 weeks, which is difficult to meet the shelf life requirements of more than 6 months for commercial circulation leisure braised egg products. Although direct sterilization at 115 to 121°C can allow braised egg products to meet the shelf life requirements, the taste of the braised eggs will become too hard due to the high-intensity thermal denaturation of protein, which is quite different from the taste of traditional braised tea-cured eggs. Therefore, how to ensure that long-shelf-life tea eggs can absorb flavor quickly through innovative processing methods, maintain good tenderness after sterilization, and restore the surface texture of the tea eggs is the key to restoring the taste, flavor, and appearance of traditional tea-marinated eggs. Summary of the invention

[0003]

Technical issues

[0004] Most commercially available vacuum-packed marinated eggs are sterilized at high temperatures, which makes the eggs more solid and have a poor taste, while medium-temperature sterilized eggs are difficult to meet shelf life requirements. An industrial processing method for tea eggs that can quickly absorb flavor, have good tenderness, restore the crack texture on the surface of tea eggs, and have a long shelf life is urgently needed.

[0005]

Technical solution

[0006] The first object of the present invention is to provide an industrial processing method for traditional tea eggs, comprising the steps of:

[0007] (1) Baking and ripening: Baking the eggs, heating them with steam, and steaming them to obtain ripened eggs;

[0008] (2) Low-frequency vibration shell cracking: The cooked eggs are vibrated at a low frequency to cause cracks in the eggshell, thus obtaining cracked eggs;

[0009] (3) Circulating high-temperature stewing: prepare stewed eggs with green tangerines, black tea, spices, salt, soy sauce, monosodium glutamate, white sugar and water, place the stewed eggs and cracked eggs in a pressure vessel, heat the stewed eggs and stew them, circulate the stewed eggs during stewing, and obtain stewed eggs;

[0010] (4) vacuum cooling and dehydration: vacuum cooling and dehydration of the stewed eggs to obtain dehydrated eggs;

[0011] (5) Shelling and packaging: removing the shells of dehydrated eggs and vacuum packaging to obtain packaged eggs;

[0012] (6) High temperature sterilization: sterilize the packaged eggs to obtain tea eggs.

[0013] In one embodiment of the present invention, in step (1), the baking temperature is 40 to 60° C., and the baking time is 2 to 4 hours.

[0014] In one embodiment of the present invention, in step (1), the temperature is raised to 85-100° C., and the steaming time is 15-30 min.

[0015] In one embodiment of the present invention, in step (1), a steam oven is used for baking and steaming.

[0016] In one embodiment of the present invention, in step (2), the amplitude of the low-frequency vibration is 2 to 4 mm, the frequency is 10 to 20 Hz, and the time of the low-frequency vibration is 3 to 6 s.

[0017] In one embodiment of the present invention, in step (2), a linear vibrator is used to vibrate the cracked shell at a low frequency.

[0018] In one embodiment of the present invention, in step (3), the amounts of the raw materials for the braising soup are, in terms of weight percentage with water: 0.05-0.1% green tangerine, 0.5-2% black tea, 0.5-2% spices, 2-4% salt, 2-10% soy sauce, 0.5-2% monosodium glutamate, and 1-8% white sugar.

[0019] The spice is a seasoning made from seeds, fruits, roots and barks of dry plants, and has the functions of promoting appetite and improving food flavor.

[0020] In one embodiment of the present invention, in step (3), the weight ratio of the brine to the cracked eggs is 1 to 1.5:1.

[0021] The pressure container is a container that can increase the boiling point of the braising soup by increasing the gas pressure, so that the braising soup reaches a higher temperature without boiling, thereby accelerating the efficiency of braising food.

[0022] In one embodiment of the present invention, in step (3), the pressure container is a brine tank.

[0023] In one embodiment of the present invention, in step (3), heating the brine is heating the brine to 102-105°C.

[0024] In one embodiment of the present invention, in step (3), the marinating time is 3 to 5 hours.

[0025] In one embodiment of the present invention, in step (3), the brine is circulated for 3 to 8 minutes every 10 to 20 minutes.

[0026] The circulating brine utilizes a circulating centrifugal pump to evenly distribute the solute in the brine.

[0027] In one embodiment of the present invention, in step (4), the vacuum degree of vacuum dehydration is -0.06 to -0.08 MPa, and the time of vacuum dehydration is 15 to 25 min.

[0028] In one embodiment of the present invention, in step (5), an egg shelling machine is used to rotate and remove the eggshells of the dehydrated eggs.

[0029] In one embodiment of the present invention, in step (6), the sterilization temperature is 115-121° C., and the sterilization time is 13-20 min.

[0030] The second object of the present invention is to provide tea eggs prepared by the above method.

[0031] The third object of the present invention is to provide the application of the tea egg in the food field.

[0032] Beneficial effects:

[0033] The industrial processing method of the present invention is different from the traditional processing method of tea eggs. The present invention bakes fresh shell eggs. After baking, the viscosity of egg white is reduced, which leads to reduced gelling of egg white, making the protein of tea eggs prepared by subsequent heat treatment more tender and easier to taste. In addition, the baking process with shells will cause a small amount of water loss in the egg white, and the taste will be faster and more fully absorbed in the subsequent high-temperature braising process.

[0034] The industrial processing method of the invention adopts low-frequency vibration to break the shell, which ensures that the shell membrane is not broken while the eggshell is broken, simulates the artificial shell breaking process, makes the prepared tea eggs have the crack texture of traditional tea eggs, and promotes the flavoring.

[0035] The industrial processing method of the invention adopts a circulating high-temperature braising process, which makes the flavor more fully absorbed, and the braising soup is circulated regularly, so the flavoring effect is better.

[0036] The industrial processing method of the invention adopts vacuum cooling and dehydration, so that the tea eggs are quickly cooled after being marinated, and the product can be prevented from staying too long in a temperature range of 20° C. to 50° C. where bacteria reproduce rapidly, thereby preventing excessive proliferation of microorganisms and maintaining high product quality; the vacuum cooling and dehydration can also increase the salt content of the prepared tea eggs, evaporate the brine on the surface of the shelled eggs, and enhance the formation of crack textures of the tea eggs.

[0037] The industrial processing method of the present invention combines a baking treatment at 40-60° C. with high-temperature sterilization. The baking treatment at 40-60° C. is beneficial to offset the increase in the chewiness of the protein caused by the high-temperature sterilization, thereby extending the shelf life of the tea eggs while maintaining the original chewiness of the tea eggs before sterilization.

[0038] The tea eggs prepared by the invention have a long shelf life, are not too chewy, have a good taste, are fully flavored, and have typical crack textures of tea eggs. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a photo of the appearance of the tea eggs prepared in Example 1. DETAILED DESCRIPTION

[0040] The detection and analysis methods involved in the present invention are as follows:

[0041] (1) The weight loss rate of shell eggs during baking is calculated according to the following formula:

[0042]

[0043] (2) Determination of egg white viscosity in shell eggs: Take shell eggs before and after baking, separate the egg white, filter the egg white with gauze, and measure the viscosity with a DV-1 rotational viscometer. After the reading stabilizes, the viscosity value is measured.

[0044] (3) The texture of tea eggs was determined using a texture analyzer: The chewiness of the sample was determined using the TPA texture analysis method. The egg white sample was cut into small pieces of 1.0 cm × 1.0 cm × 0.5 cm. The height of the probe from the upper surface of the sample was 10 mm. The test conditions were a pre-test speed of 5.0 mm / s, a test speed of 2.0 mm / s, and a post-test speed of 2.0 mm / s. A P36R flat-bottomed cylindrical aluminum probe was used to compress the egg white to 60% of its original height. The contact force was Auto-5.0 g.

[0045] (4) The salt content of tea egg protein was determined by silver nitrate titration as follows: 10 mL of 0.1 mol / L AgNO 3 With 5mL HNO 3 (30%, v / v) was added to 2 g of the sample and sheared at 5000 rpm for 2 min. The mixture was lightly boiled on a hot plate, then cooled at room temperature and 2.5 mL of FeNH 4 (SO 4 ) 2 12H 2 O (5%, w / w). Then the mixture was titrated with 0.1 mol / L KSCN standard solution until the solution turned into a stable light brown color. The NaCl content was determined as follows:

[0046]

[0047] Among them, V 1 It is AgNO 3 Volume of solution (mL), N 1 It is AgNO 3 The concentration of the solution (mol / L), V 2 is the volume of KSCN solution consumed (mL), N 2 is the concentration of KSCN solution (mol / L), and M is the weight of the sample (g).

[0048] Example 1

[0049] A traditional tea egg industrial processing method comprises the following steps:

[0050] (1) Baking and ripening: After washing the eggs, place them on a tray, place them in a steam oven, bake the eggs at 40°C for 4 hours, raise the temperature to 85°C with steam, and steam for 30 minutes to obtain ripe eggs;

[0051] (2) Low-frequency vibration shell cracking: The cooked eggs are vibrated at a low frequency in a linear vibrator to cause cracks in the eggshell, thereby obtaining cracked eggs; the amplitude of the low-frequency vibration is 2 mm, the frequency is 10 Hz, and the low-frequency vibration time is 6 s;

[0052] (3) Circulating high-temperature braising: Use green mandarin oranges, black tea, spices, salt, soy sauce, monosodium glutamate, white sugar and water to prepare braising soup, place the cracked-shell eggs in a special stacked cooking basket, place the basket and the braising soup in a braising soup tank (pressure vessel), cover it, heat the braising soup to 102° C. with a steam jacket, and braising for 5 hours. During the braising process, the circulating soup pump circulates the braising soup tank for 5 minutes every 15 minutes to obtain boiled eggs; the amount of each raw material used in the braising soup is as follows, in terms of weight percentage with water: green mandarin orange 0.05%, black tea 0.5%, five spices 0.5%, salt 4%, soy sauce 2%, monosodium glutamate 2%, white sugar 8%; the weight ratio of braising soup to cracked-shell eggs is 1.2:1;

[0053] (4) vacuum cooling and dehydration: vacuum cooling and dehydration of the stewed eggs to obtain dehydrated eggs; the vacuum degree of vacuum cooling and dehydration is -0.06 MPa, and the vacuum cooling and dehydration time is 25 min;

[0054] (5) Shelling and packaging: using an egg shelling machine to rotate and remove the eggshells of the dehydrated eggs, vacuum packing, and obtaining packaged eggs;

[0055] (6) High temperature sterilization: Sterilize the packaged eggs at 115°C for 20 minutes to obtain tea eggs.

[0056] Example 2

[0057] A traditional tea egg industrial processing method comprises the following steps:

[0058] (1) Baking and ripening: After washing the eggs, place them on a tray, place them in a steam oven, bake the eggs at 50°C for 3 h, raise the temperature to 92°C with steam, and steam for 22 min to obtain ripe eggs;

[0059] (2) Low-frequency vibration shell cracking: The cooked eggs are vibrated at a low frequency in a linear vibrator to cause cracks in the eggshell, thereby obtaining cracked eggs; the amplitude of the low-frequency vibration is 3 mm, the frequency is 15 Hz, and the low-frequency vibration time is 4 s;

[0060] (3) Circulating high-temperature braising: Use green mandarin oranges, black tea, spices, salt, soy sauce, monosodium glutamate, white sugar and water to prepare braising soup, place the cracked-shell eggs in a special stacked cooking basket, place the basket and the braising soup in a braising soup tank (pressure vessel), cover it, heat the braising soup to 105° C. with a steam jacket, and braising for 3 hours. During the braising process, the circulating soup pump circulates the braising soup tank for 5 minutes every 15 minutes to obtain boiled eggs; the amount of each raw material used in the braising soup is as follows, in terms of weight percentage with water: green mandarin oranges 0.07%, black tea 1%, five spices 1%, salt 3%, soy sauce 5%, monosodium glutamate 1%, white sugar 5%; the weight ratio of braising soup to cracked-shell eggs is 1.3:1;

[0061] (4) vacuum cooling and dehydration: vacuum cooling and dehydration of the stewed eggs to obtain dehydrated eggs; the vacuum degree of vacuum cooling and dehydration is -0.07 MPa, and the vacuum cooling and dehydration time is 20 min;

[0062] (5) Shelling and packaging: using an egg shelling machine to rotate and remove the eggshells of the dehydrated eggs, vacuum packing, and obtaining packaged eggs;

[0063] (6) High temperature sterilization: Sterilize the packaged eggs at 118°C for 16 minutes to obtain tea eggs.

[0064] Example 3

[0065] A traditional tea egg industrial processing method comprises the following steps:

[0066] (1) Baking and ripening: After washing the eggs, place them on a tray, place them in a steam oven, bake the eggs at 60°C for 2 h, raise the temperature to 100°C with steam, and steam for 15 min to obtain ripe eggs;

[0067] (2) Low-frequency vibration shell cracking: The cooked eggs are vibrated at a low frequency in a linear vibrator to cause cracks in the eggshell, thereby obtaining cracked eggs; the amplitude of the low-frequency vibration is 4 mm, the frequency is 20 Hz, and the low-frequency vibration time is 3 s;

[0068] (3) Circulating high-temperature braising: Use green mandarin oranges, black tea, spices, salt, soy sauce, monosodium glutamate, white sugar and water to prepare braising soup, place the cracked-shell eggs in a special stacked cooking basket, place the basket and the braising soup in a braising soup tank (pressure vessel), cover it, heat the braising soup to 103° C. with a steam jacket, and braising for 4 hours. During the braising process, the circulating soup pump circulates the braising soup tank for 5 minutes every 15 minutes to obtain boiled eggs; the amount of each raw material used in the braising soup is as follows, in terms of weight percentage with water: green mandarin orange 0.1%, black tea 2%, spices 2%, salt 2%, soy sauce 10%, monosodium glutamate 0.5%, white sugar 1%; the weight ratio of braising soup to cracked-shell eggs is 1.5:1;

[0069] (4) vacuum cooling and dehydration: vacuum cooling and dehydration of the stewed eggs to obtain dehydrated eggs; the vacuum degree of vacuum cooling and dehydration is -0.08 MPa, and the vacuum cooling and dehydration time is 15 minutes;

[0070] (5) Shelling and packaging: using an egg shelling machine to rotate and remove the eggshells of the dehydrated eggs, vacuum packing, and obtaining packaged eggs;

[0071] (6) High temperature sterilization: Sterilize the packaged eggs at 121°C for 13 minutes to obtain tea eggs.

[0072] Comparative Example 1

[0073] The difference from Example 1 is that step (1) is not performed.

[0074] Comparative Example 2

[0075] The difference from Example 1 is that step (2) is not performed.

[0076] Comparative Example 3

[0077] The difference from Example 1 is that in step (3), the marinating temperature of 102°C is replaced by a medium temperature of 95°C.

[0078] Comparative Example 4

[0079] The difference from Example 1 is that step (4) is not performed.

[0080] Comparative Example 5

[0081] The difference from Example 1 is that step (1) is not performed and step (6) is not performed.

[0082] Table 1 shows the test results of the tea eggs prepared in Examples 1 to 3 and Comparative Examples 1 to 5.

[0083] Table 1

[0084]

[0085] As shown in Table 1, after baking, Examples 1 to 3 all have a certain baking weight loss rate, the viscosity of egg white is significantly reduced, and the salt content in the egg white is also relatively high, indicating that the tea egg has a good taste. By comparing Example 1 with Control Example 1, it can be seen that when no baking treatment is performed, the chewiness of the tea egg protein is significantly increased, and the salt content in the protein is relatively low, indicating that baking treatment can significantly reduce the chewiness of the protein and enhance the penetration of salt during brine preparation.

[0086] It can be seen from Example 1 and Comparative Example 2 that the salt content in tea egg protein is significantly reduced when the shells are not broken by vibration before braising, indicating that not breaking the shells by vibration is not conducive to the penetration of salt.

[0087] It can be seen from Example 1 and Comparative Example 3 that the salt content in tea egg protein is significantly lower when medium-temperature braising is used, indicating that high-temperature braising is conducive to the penetration of salt.

[0088] It can be seen from Example 1 and Comparative Example 4 that when vacuum cooling and dehydration are cancelled, the chewiness and salt content are slightly reduced, indicating that vacuum cooling treatment to partially dehydrate tea eggs is conducive to increasing the salt content.

[0089] It can be seen from Example 1 and Control Example 5 that there is no significant difference in the chewiness of the egg white when the baking treatment and high-temperature sterilization are eliminated, indicating that the baking treatment can offset the increase in the chewiness of the egg white caused by high-temperature sterilization and maintain the chewiness of the tea egg before sterilization.

[0090] The embodiments provided above are not intended to limit the scope of the present invention, and the steps described are not intended to limit the execution order thereof. Those skilled in the art may make obvious improvements to the present invention in combination with existing common knowledge, which also fall within the scope of protection defined by the claims of the present invention.

Claims

1. An industrial processing method for traditional tea eggs, characterized in that: Includes steps: (1) Baking and ripening: Baking the eggs, heating them with steam, and steaming them to obtain ripened eggs; (2) Low-frequency vibration shell cracking: The cooked eggs are vibrated at a low frequency to cause cracks in the eggshell, thus obtaining cracked eggs; (3) Circulating high-temperature stewing: prepare stewed eggs with green tangerines, black tea, spices, salt, soy sauce, monosodium glutamate, white sugar and water, place the stewed eggs and cracked eggs in a pressure vessel, heat the stewed eggs and stew them, circulate the stewed eggs during stewing, and obtain stewed eggs; (4) vacuum cooling and dehydration: vacuum cooling and dehydration of the stewed eggs to obtain dehydrated eggs; (5) Shelling and packaging: removing the shells of dehydrated eggs and vacuum packaging to obtain packaged eggs; (6) High temperature sterilization: sterilize the packaged eggs to obtain tea eggs.

2. The industrial processing method according to claim 1, characterized in that: In step (1), the baking temperature is 40-60° C., and the baking time is 2-4 hours; the temperature is raised to 85-100° C., and the steaming time is 15-30 minutes.

3. The industrial processing method according to claim 1, characterized in that: In step (2), the amplitude of the low-frequency vibration is 2 to 4 mm, the frequency is 10 to 20 Hz, and the time of the low-frequency vibration is 3 to 6 s.

4. The industrial processing method according to claim 1, characterized in that: In step (3), the amounts of the raw materials for the braising soup are as follows, based on the weight percentage with water: 0.05-0.1% green tangerine, 0.5-2% black tea, 0.5-2% spices, 2-4% salt, 2-10% soy sauce, 0.5-2% monosodium glutamate, and 1-8% white sugar.

5. The industrial processing method according to claim 1, characterized in that: In step (3), the weight ratio of the brine to the cracked eggs is 1 to 1.5:

1.

6. The industrial processing method according to claim 1, characterized in that: In step (3), the braising soup is heated to 102-105° C.; the braising time is 3-5 hours; and the circulating braising soup is circulated for 3-8 minutes every 10-20 minutes.

7. The industrial processing method according to claim 1, characterized in that: In step (4), the vacuum degree of vacuum dehydration is -0.06 to -0.08 MPa, and the time of vacuum dehydration is 15 to 25 min.

8. The industrial processing method according to claim 1, characterized in that: In step (6), the sterilization temperature is 115-121° C., and the sterilization time is 13-20 min.

9. Tea eggs prepared by the industrial processing method according to any one of claims 1 to 8.

10. Application of the tea eggs according to claim 9 in the food field.

Images