Method for improving color quality of instant salted shrimp

Abstract

The application discloses a method for improving color quality of instant shrimps, and belongs to the technical field of aquatic food processing. The preparation method can realize stable storage of soft-packaged instant shrimps at normal temperature, and can maintain the color of shrimp meat, inhibit oil oxidation, inhibit browning, improve the texture quality of instant shrimps, and prolong the shelf life. The redness value and yellowness value of the obtained instant shrimps obviously decrease, the brightness and whiteness are obviously improved compared with traditional cooking methods, the thiobarbituric acid reactant is reduced, the browning index is decreased, and astaxanthin has a good protection effect, and astaxanthin in shrimp meat is a natural antioxidant, which plays an important role in inhibiting oil oxidation and protecting color. Thus, the instant shrimps prepared by the application are obviously superior to instant shrimp products on the market in color protection and oxidation inhibition, and the operation steps are practical.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of aquatic food processing, and particularly relates to a method for improving the color quality of instant salt pond shrimp. BACKGROUND

[0002] Shrimp is a kind of aquatic animal with high economic value, and is an intensive high-yield breeding excellent variety. Shrimp meat is delicious and has attractive color, and is loved by consumers. In addition, shrimp meat is rich in nutrients such as protein, amino acids, vitamins and minerals, and is also rich in polyunsaturated fatty acids, which has good effects on preventing and treating high blood lipids, atherosclerosis and cardiovascular and cerebrovascular diseases. Salt pond shrimp is mainly distributed in the junction of freshwater and seawater in Bohai Bay, and has rich microorganisms as natural bait, lives in natural sunlight salt field, and has 2-3 times seawater salinity of vast beach resources and wetland environment. Compared with normal sea shrimp, salt pond shrimp has higher astaxanthin content, richer trace elements, more compact meat and more delicious taste, and has strong market potential.

[0003] However, salt pond shrimp has strong seasonality, and is only harvested in September every year. The conventional means such as food processing and storage of salt pond shrimp on the market cannot meet the needs of people in the time dimension. Fresh salt pond shrimp has high protein and water content, and is rich in polyphenol oxidase, and is prone to browning. At the same time, under the action of microorganisms, fresh shrimp products are prone to spoilage and discoloration, and have a short shelf life. Therefore, developing a method for improving the color quality of instant salt pond shrimp will meet the market demand and expand the utilization rate of shrimp.

[0004] Instant shrimp undergoes cooking, sterilization and other links in processing, reduces the water activity, inactivates microorganisms and endogenous enzymes, and improves the storage stability. However, shrimp is rich in a large amount of components such as protein, oil, astaxanthin and other components, which are prone to oxidation, leading to browning of shrimp body color. At present, most of the instant shrimp products on the market delay and mask the browning of shrimp body caused by oxidation by adding antioxidants and / or a large amount of seasonings. However, this method not only masks the unique fresh and fragrant flavor of shrimp, affecting the sensory quality of the product, but also causes consumers to doubt the safety of the product. Moreover, the commonly used natural polyphenol antioxidant itself is also prone to browning, affecting the sensory quality of the product. Therefore, it is urgent to use some natural antioxidants suitable for instant shrimp and physical methods to inhibit color browning and improve the color quality of instant shrimp, and to develop new soft-packaged instant shrimp products with better storage stability to meet the needs of consumers. SUMMARY

[0005] In order to achieve the above-mentioned purpose, the application provides a method for improving the color quality of instant salted shrimp, which comprises the following technical units: L-cysteine solution room temperature soaking before shrimp boiling, low temperature soaking in γ-polyglutamic acid solution after boiling and cooling, vacuum packaging, and water bath-ultra-high pressure heat-assisted sterilization.

[0006] A method for improving the color quality of instant shrimp, comprising the following steps:

[0007] S1, shrimp is soaked in L-cysteine solution;

[0008] S2, the shrimp soaked in step S1 is boiled in salt water;

[0009] S3, the shrimp boiled in step S2 is soaked in γ-polyglutamic acid solution;

[0010] S4, the shrimp soaked in step S3 is dried;

[0011] S5, the shrimp dried in step S4 is packaged;

[0012] S6, the shrimp packaged in step S5 is boiled in boiling water, and then subjected to ultra-high pressure heat-assisted sterilization, so as to obtain instant shrimp.

[0013] Further, the shrimp in step S1 is taken from salted shrimp, Chinese white shrimp and / or white shrimp.

[0014] Further, the mass concentration of the L-cysteine solution in step S1 is 0.2% to 0.4%.

[0015] Further, the weight ratio of the shrimp to the L-cysteine solution in step S1 is 1:2 to 4.

[0016] Further, the soaking temperature in step S1 is 20 to 25℃, and the soaking time is 15 to 20 min.

[0017] Further, the mass concentration of the salt water in step S2 is 1% to 3%.

[0018] Further, the weight ratio of the shrimp to the salt water in step S2 is 1:2 to 4.

[0019] Further, the boiling temperature in step S2 is 90 to 100℃, and the boiling time is 4 to 8 min.

[0020] Further, the mass concentration of the γ-polyglutamic acid solution in step S3 is 2% to 4%.

[0021] Further, the weight ratio of the shrimp to the γ-polyglutamic acid solution in step S1 is 1:2 to 4.

[0022] Further, the soaking temperature in step S3 is 20-25 DEG C, and the time is 1.5-2.5 h.

[0023] Further, the drying in step S4 is drying at 40-50 DEG C for 1-2 h.

[0024] Further, the ultrahigh pressure heat-assisted treatment in step S6 is treatment at 70-80 DEG C and 250-300 MPa for 5-10 min.

[0025] The instant shrimp prepared according to the method is provided.

[0026] The present application has the following advantages:

[0027] 1. The shrimp meat is soaked with the preservative, so that the growth of bacteria in the shrimp meat product is effectively inhibited, and the preservation and antioxidant effects are stronger.

[0028] 2. The present application first proposes that L-cysteine has the effect of color protection in instant shrimp. The L-cysteine used in the present application has the effects of color protection, preservation, and freshness, and is safe and reliable. Compared with the commonly used polyphenol natural antioxidant, L-cysteine itself does not produce colored substances due to oxidation, and does not adversely affect the appearance and color of the product. The antioxidant used in the prior art is mainly polyphenol, which produces colored quinone substances after oxidation, causing the product to change color. The L-cysteine in the present application does not produce browning due to oxidation while having antioxidant effect, and also has good color protection effect.

[0029] 3. The shrimp meat is soaked with the color protection agent, which effectively reduces the oxidation and deepening speed of the color of the shrimp meat, maintains the original shape and texture of the shrimp meat, and improves the stability of the product.

[0030] 4. The present application first proposes the application of gamma-polyglutamic acid in instant shrimp, which has the effects of color protection, preservation, water retention, and texture enhancement in instant shrimp. The gamma-polyglutamic acid used in the present application is safe and edible, has good biodegradability and biocompatibility, and is commonly used in the food field for water retention, preservation, and improvement of food texture and shape. It can effectively inhibit the decrease of salt-soluble protein content, gel strength, and partial enzyme activity, and maintain good muscle color and microstructure.

[0031] 5. The present application first proposes that the ultrahigh pressure heat-assisted sterilization combined with natural antioxidant has the effect of color protection in instant shrimp. The ultrahigh pressure heat-assisted sterilization has certain effect on the color, flavor, and texture of shrimp meat compared with traditional sterilization methods, has tenderizing effect on shrimp meat, and improves the water holding capacity of shrimp meat.

[0032] 6、The method for improving the color quality of instant shrimps of the present application maximally retains the original color of shrimps, and the structure of shrimps is stable, and the surface hardening phenomenon is avoided.

[0033] 7、The present application is obtained on the basis of repeated experiments, and each process step combination and condition setting will significantly affect the quality of the obtained product. DETAILED DESCRIPTION

[0034] The present application will be further described below through specific implementation examples.

[0035] The L-cysteine (CAS No.: 52-90-4) and gamma-polyglutamic acid (CAS No.: 25513-46-6) used in the following examples are food grade.

[0036] Example 1

[0037] S1, after the frozen salted shrimp meat is thawed, it is soaked in an L-cysteine solution with a mass concentration of 0.3%, and the room temperature soaking time is 15 min; the weight ratio of the shrimp meat to the L-cysteine solution is 1:3;

[0038] S2, the shrimp meat soaked in step S1 is cooked in a 2% mass concentration of salt water at 100℃ for 5 min, and then cooled in ice water for 25 min; the weight ratio of the shrimp meat to the salt water is 1:3;

[0039] S3, the shrimp meat cooled in step S2 is soaked in a 3% mass concentration of gamma-polyglutamic acid at 4℃ for 3 h; the weight ratio of the shrimp meat to the gamma-polyglutamic acid is 1:3;

[0040] S4, the shrimp meat soaked in step S3 is dried at 40℃ for 2 h;

[0041] S5, the shrimp meat dried in step S4 is packaged, -80KPa, heated for 3 s, and tightly sealed, the packaging material is polypropylene, and the packaging is vacuum packaging;

[0042] S6, the shrimp meat packaged in step S5 is cooked in boiling water at 100℃ for 40 min, and then subjected to high-pressure heat-assisted sterilization at 500MPa and 100℃ for 10 min.

[0043] Example 2

[0044] S1, after the frozen salted shrimp meat is thawed, it is soaked in an L-cysteine solution with a mass concentration of 0.2%, and the room temperature soaking time is 15 min; the weight ratio of the shrimp meat to the L-cysteine solution is 1:3;

[0045] S2, the shelled prawn after soaking in step S1 is cooked in 2% mass concentration of salt water at 100℃ for 5 min, and then is cooled in ice water for 25 min, the weight ratio of the shelled prawn and the salt water being 1:3;

[0046] S3, the shelled prawn after cooling in step S2 is soaked in 3% mass concentration of γ-polyglutamic acid at 4℃ for 3 h, the weight ratio of the shelled prawn and the γ-polyglutamic acid being 1:3;

[0047] S4, the shelled prawn after soaking in step S3 is dried at 40℃ for 2 h;

[0048] S5, the shelled prawn after drying in step S4 is packaged, -80KPa, heated for 3 s, tightly sealed, the packaging material is polypropylene, and the packaging is vacuum packaging;

[0049] S6, the shelled prawn after packaging in step S5 is cooked in 100℃ boiling water for 40 min, and then is subjected to high-pressure heat-assisted sterilization at 500MPa and 100℃ for 10 min.

[0050] Example 3

[0051] S1, the shelled prawn after being thawed from frozen salted prawn is soaked in 0.3% mass concentration of L-cysteine solution at room temperature for 15 min, the weight ratio of the shelled prawn and the L-cysteine solution being 1:3;

[0052] S2, the shelled prawn after soaking in step S1 is cooked in 2% mass concentration of salt water at 100℃ for 5 min, and then is cooled in ice water for 25 min, the weight ratio of the shelled prawn and the salt water being 1:3;

[0053] S3, the shelled prawn after cooling in step S2 is soaked in 2% mass concentration of γ-polyglutamic acid at 4℃ for 3 h, the weight ratio of the shelled prawn and the γ-polyglutamic acid being 1:3;

[0054] S4, the shelled prawn after soaking in step S3 is dried at 40℃ for 2 h;

[0055] S5, the shelled prawn after drying in step S4 is packaged, -80KPa, heated for 3 s, tightly sealed, the packaging material is polypropylene, and the packaging is vacuum packaging;

[0056] S6, the shelled prawn after packaging in step S5 is cooked in 100℃ boiling water for 40 min, and then is subjected to high-pressure heat-assisted sterilization at 500MPa and 100℃ for 10 min.

[0057] Comparative Example 1

[0058] S1, the frozen salted shrimp shelled shrimp after thawing is soaked in L-cysteine solution with a mass concentration of 0.3%, and is soaked at room temperature for 15 min; the weight ratio of the shelled shrimp to the L-cysteine solution is 1:3;

[0059] S2, the shelled shrimp soaked in step S1 is cooked in salt water with a mass concentration of 2% at 100 DEG C for 5 min, and then is cooled in ice water for 25 min; the weight ratio of the shelled shrimp to the salt water is 1:3;

[0060] S3, the shelled shrimp cooked in step S2 is soaked in gamma-polyglutamic acid with a mass concentration of 3% at 4 DEG C for 3 h; the weight ratio of the shelled shrimp to the gamma-polyglutamic acid is 1:3;

[0061] S4, the shelled shrimp soaked in step S3 is dried at 40 DEG C for 2 h;

[0062] S5, the shelled shrimp dried in step S4 is packaged, is tightly sealed after being heated for 3 s under-80 KPa, and the packaging material is polypropylene; the packaging is vacuum packaging.

[0063] Comparative Example 2

[0064] S1, the frozen salted shrimp shelled shrimp after thawing is cooked in salt water with a mass concentration of 2% at 100 DEG C for 5 min, and then is cooled in ice water for 25 min; the weight ratio of the shelled shrimp to the salt water is 1:3;

[0065] S2, the shelled shrimp soaked in step S1 is soaked in gamma-polyglutamic acid with a mass concentration of 3% at 4 DEG C for 3 h; the weight ratio of the shelled shrimp to the gamma-polyglutamic acid is 1:3;

[0066] S3, the shelled shrimp cooked in step S2 is dried at 40 DEG C for 2 h;

[0067] S4, the shelled shrimp dried in step S3 is packaged, is tightly sealed after being heated for 3 s under-80 KPa, and the packaging material is polypropylene; the packaging is vacuum packaging;

[0068] S5, the shelled shrimp packaged in step S4 is cooked in boiling water at 100 DEG C for 40 min, and then is subjected to high-pressure heat-assisted sterilization at 100 DEG C for 10 min under 500 MPa.

[0069] Comparative Example 3

[0070] S1, the frozen salted shrimp shelled shrimp after thawing is soaked in L-cysteine solution with a mass concentration of 0.3%, and is soaked at room temperature for 15 min; the weight ratio of the shelled shrimp to the L-cysteine solution is 1:3;

[0071] S2, the shrimp meat after soaking in step S1 is cooked in 100 DEG C, mass concentration is 2% salt water 5min, then placed in ice water cooling 25min, the weight ratio of the shrimp meat and salt water is 1:3;

[0072] S3, the shrimp meat after cooking in step S2 is dried at 40 DEG C for 2h;

[0073] S4, the shrimp meat after drying in step S3 is packaged, -80Kpa, heating 3s tightly sealed, the packaging material is polypropylene, the package is vacuum packaging;

[0074] S5, the shrimp meat after packaging in step S4 is cooked in 100 DEG C boiling water for 40min, and then is subjected to high pressure heat assisted sterilization at 500MPa, 100 DEG C for 10min.

[0075] The quality of instant shrimp prepared by example 1-3 and comparative example 1-3 is compared, and the results are shown in table 1:

[0076] 1, according to GB 5009.227-2016 (national food safety standard-determination of peroxide value in food), the preparation method of the application has obvious antioxidant effect on instant shrimp, and the oil peroxide value is lower than that of instant shrimp prepared by traditional water boiling method, which increases the stability of instant shrimp product.

[0077] 2, according to GB 10136-2015 (national food safety standard-animal aquatic products), compared with the instant shrimp prepared by traditional water boiling method, the shelf life of the instant shrimp prepared by the application can reach 25 days at room temperature (24 DEG C).

[0078] 2, the color quality improvement method of the application has good protection effect on astaxanthin of instant shrimp products.

[0079] 3, compared with the comparative example, the thiobarbituric acid reactant is reduced, which indicates that the method has inhibitory effect on lipid peroxidation of instant shrimp products.

[0080] 4, compared with the comparative example, the browning index decreases, which indicates that the method well retains the original color and quality of the shrimp meat.

[0081] 5, compared with the comparative example, the brightness of instant shrimp is obviously improved, the redness value is obviously decreased, the yellowness value is obviously decreased, and the whiteness is obviously improved, which indicates that the method of the application can improve the comprehensive color quality of instant shrimp.

[0082] Table 1

[0083]

[0084] Note: The brightness, redness value, yellowness value, whiteness, thiobarbituric acid reactant, peroxide value, browning index and astaxanthin value determination are unified as the sample value of 0 days of storage

[0085] In summary, the preparation method of the present application can realize stable storage of soft package instant shrimp at room temperature, and can maintain the color of shrimp, inhibit oil oxidation, inhibit browning, improve the texture quality of instant shrimp, and prolong the shelf life. The redness value and yellowness value of the obtained instant shrimp decrease significantly, the brightness and whiteness are significantly improved compared with the traditional cooking method, the thiobarbituric acid reactant is reduced, the browning index is decreased, and astaxanthin has a good protective effect. The astaxanthin in shrimp meat is a natural antioxidant, which plays an important role in inhibiting oil oxidation and protecting color. Therefore, the instant shrimp prepared by the present application is significantly better than the instant shrimp products on the market in terms of color protection and oxidation inhibition, and the operation steps are practical.

[0086] The above is only the preferred embodiment and comparison method of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can make equivalent replacement or change within the technical range disclosed in the present application according to the technical solution and inventive concept of the present application, which should be covered within the protection scope of the present application.

Claims

1. A method for preparing ready-to-eat shrimp, characterized in that, Including the following steps: S1. Soak shrimp meat in L-cysteine ​​solution; the mass concentration of L-cysteine ​​solution is 0.2%~0.4%; the weight ratio of shrimp meat to L-cysteine ​​solution is 1:2~4; the soaking temperature is 20~25℃, and the soaking time is 15~20 min. S2. Cook the shrimp that have been soaked in step S1 in salt water. S3. Soak the shrimp cooked in step S2 in a γ-polyglutamic acid solution; the mass concentration of the γ-polyglutamic acid solution is 2%~4%; the weight ratio of shrimp to γ-polyglutamic acid solution is 1:2~4; the soaking temperature is 20~25℃, and the soaking time is 1.5~2.5 h. S4. Dry the shrimp that have been soaked in step S3; S5. Package the dried shrimp from step S4. S6. After boiling the packaged shrimp in step S5 in boiling water, sterilize them under ultra-high pressure heat at 500 MPa and 100 ℃ for 10 minutes to obtain ready-to-eat shrimp.

2. The method for preparing ready-to-eat shrimp according to claim 1, characterized in that, The shrimp meat mentioned in step S1 is taken from salt field shrimp, tiger prawns and / or white shrimp.

3. The method for preparing ready-to-eat shrimp according to claim 1, characterized in that, In step S2, the concentration of the brine is 1% to 3%; the weight ratio of shrimp to brine is 1:2 to 4; the cooking temperature is 90 to 100 ℃, and the cooking time is 4 to 8 min.

4. The method for preparing ready-to-eat shrimp according to claim 1, characterized in that, In step S4, the drying process involves drying at 40-50 ℃ for 1-2 hours.

5. Ready-to-eat shrimp prepared according to any one of claims 1 to 4.

Images