Preparation method of digestible dried shrimps

Abstract

The invention belongs to the technical field of aquatic product processing, and relates to an easily digestible dried shrimp preparation method, which comprises: carrying out a shelling treatment on fresh shrimps to obtain shrimp meat; putting the shrimp meat into a container, and adding the bromelain solution; then, the container is placed in ultrasonic treatment equipment for ultrasonic treatment; and carrying out primary hot air drying on the shrimp meat obtained in the previous step, then taking out the shrimp meat, standing for 10-60 minutes at 1-6 DEG C, then continuing secondary hot air drying, and cooling to obtain the dried shrimp finished product. According to the whole innovative process, the tenderness and the taste of the dried shrimps are improved, the digestibility and the free amino content of the dried shrimps are remarkably improved compared with those of conventional dried shrimps, further, the prepared dried shrimps are rich in flavor and delicious in taste, the requirements of the market for high-quality and digestible instant aquatic products are met, and the dried shrimps have wide market prospects and application potential.

Description

Technical Field

[0001] The invention belongs to the technical field of aquatic product processing and relates to a method for preparing easily digestible dried shrimp. Background Art

[0002] As a kind of aquatic product with delicious meat and high nutritional value, Penaeus vannamei is rich in high-quality protein and a variety of amino acids that are beneficial to the human body, and has a low fat content, so it is deeply favored by consumers. As an important processed product of Penaeus vannamei, dried shrimp occupies a certain share in the market. It not only prolongs the shelf life of shrimp, but also facilitates transportation and storage, providing consumers with a more convenient way to eat. However, in the preparation process of dried shrimp, a series of technical difficulties have always plagued the entire industry. How to retain the original tender and smooth taste of shrimp meat to the greatest extent during the drying and dehydration process, so that consumers can still feel the tender texture of fresh shrimp when tasting dried shrimp, while retaining the delicious flavor of the shrimp itself, has become a difficult problem that needs to be overcome urgently. In addition, with the aggravation of population aging and the increasing attention to people with special dietary needs, meeting the needs of people with poor chewing ability has also become an important factor that must be considered in the preparation process of dried shrimp.

[0003] In the existing dried shrimp preparation process, single drying methods such as sun drying, hot air drying, and vacuum freeze drying are often used. For example, Chinese patent CN105077383A discloses the use of hot air drying or sun drying to reduce the water weight content in the Antarctic krill to 18-20%; another example is Chinese patent CN109549134A discloses a method for preparing dried shrimp by vacuum freeze drying, which increases the content of polyunsaturated fatty acids in the dried shrimp by staged heating under vacuum conditions. Although these methods can effectively remove moisture, due to insufficient control of temperature and humidity during the drying process, it is easy to cause excessive contraction and hardening of muscle fibers in the shrimp meat, which seriously affects the taste and eating experience, and is especially not suitable for groups with weak chewing ability. In addition, traditional drying technology may also cause the degradation of flavor components and nutrients, further affecting the quality and market competitiveness of the product. Summary of the invention

[0004] In order to solve the above problems existing in the prior art, the object of the present invention is to provide a method for preparing easily digestible dried shrimps to overcome the shortcomings of the prior art.

[0005] One object of the present invention is achieved by the following technical solutions:

[0006] A method for preparing easily digestible dried shrimps comprises the following steps:

[0007] S1, shelling fresh shrimps to obtain shrimps;

[0008] S2, placing the shrimp in a container, adding bromelain solution; then placing the container in an ultrasonic treatment device for ultrasonic treatment;

[0009] S3, hot-air drying the shrimp obtained in step S2 for the first time, then taking it out and standing it at 1-6° C. for 10-60 minutes, and then continuing to hot-air dry it for the second time, and obtaining the dried shrimp product after cooling.

[0010] The present invention firstly performs a precise pre-tenderization treatment on the white shrimp through the synergistic effect of bromelain and ultrasound. Specifically, bromelain, as a natural proteolytic enzyme, can hydrolyze the muscle protein in shrimp meat under mild conditions, significantly reduce the hardness of shrimp meat, improve its structure, and make it more tender and smooth; the ultrasonic pretreatment technology uses physical effects such as cavitation effect, shear force and turbulence to deeply change the molecular structure of protein without destroying the intrinsic nutrients of shrimp meat, significantly improve its physical and chemical properties, and thus improve the tenderness and taste of shrimp meat. The natural tenderizing effect of bromelain is combined with the physical promotion effect of ultrasound, and the cavitation effect and mechanical shearing effect of ultrasound are used to accelerate the penetration and uniform distribution of bromelain, thereby enhancing the enzymatic effect and significantly improving the texture of shrimp meat. This process can effectively destroy the muscle fiber structure of shrimp meat, reduce its mechanical strength, make it softer and easier to process subsequently. Subsequently, in the drying stage, an innovative moisture balance control technology is adopted, that is, after preliminary drying, the shrimp meat is placed in a low temperature environment for 10 to 60 minutes, and then the subsequent drying is continued. The moisture balance treatment in this stage can not only adjust the internal moisture distribution of the dried shrimp and maintain the ideal moisture content of the shrimp meat, but also effectively prevent water loss caused by over-drying and excessive contraction of muscle fibers, thereby maintaining the taste; in addition, the moisture balance stage effectively reduces thermal damage and retains the tenderness and flavor of the shrimp to the maximum extent; most importantly, the moisture balance stage reduces the thermal damage inside the sample, reduces the cross-linking and aggregation of proteins, thereby improving the enzyme hydrolysis efficiency, releasing more free amino groups, and improving the nutritional value and digestibility of the shrimp.

[0011] The shrimp in step S1 is preferably of the Penaeidae family, and examples thereof include whiteleg shrimp, giant tiger shrimp, Chinese shrimp, and Japanese shrimp.

[0012] In step S1, preferably, the shrimps are rinsed 1 to 5 times with a 1 to 5 wt% chloride salt solution. Rinsing with the chloride salt solution can achieve the purpose of sterilization, inhibit or kill harmful microorganisms, and thus extend the shelf life of the shrimps.

[0013] Preferably, in step S2, the mass ratio of shrimp to bromelain solution is 1:(0.8-2).

[0014] Preferably, in step S2, in the bromelain solution, the concentration of bromelain is 1-5w / w%, and the enzyme activity of bromelain is 20-25U / mL.

[0015] Preferably, in step S2, the power of ultrasonic treatment is 50-300 W, the treatment temperature is 50-60° C., and the treatment time is 1-10 min. More preferably, the power of ultrasonic treatment is 100-200 W, the treatment temperature is 50-60° C., and the treatment time is 2-8 min.

[0016] Preferably, in step S3, the conditions of the first hot air drying and the second hot air drying are independently: the drying temperature is 95-100°C, and the drying time is 30-100 minutes. The hot air drying temperature is 95-100°C. If the temperature is too low, the dried shrimp product will have a strange taste. The conditions of the first hot air drying and the second hot air drying can be the same or different, and can be adjusted according to actual needs.

[0017] Preferably, in step S3, after the first hot air drying, the mixture is taken out and allowed to stand at 2 to 5°C for 20 to 50 minutes. More preferably, the mixture is taken out and allowed to stand at 4°C for 30 minutes.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. The present invention breaks through the technical bottleneck of the traditional drying process through the synergistic effect of bromelain and ultrasonic pretreatment technology, as well as the innovative moisture balance control drying process, and effectively solves the problems of rough taste, lack of flavor, nutrient loss, low digestibility, etc. in the traditional preparation method.

[0020] 2. The overall innovative process of the present invention not only improves the tenderness and taste of dried shrimps, making them suitable for more consumer groups, especially those with poor chewing ability; but also significantly improves their digestibility and free amino content compared to conventional dried shrimps, and can better provide nutrients that can be absorbed by the human body, meeting the needs of modern consumers for easily digestible high-protein foods; further, the prepared dried shrimps are rich in flavor and delicious in taste, and have obvious advantages over traditional drying methods, meeting the market demand for high-quality, easily digestible, ready-to-eat aquatic products, and have broad market prospects and application potential.

[0021] 3. The preparation process of the present invention is simple and controllable, has low requirements on equipment and technology during the production process, and has good prospects for industrial application. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is the drying curve diagram of comparative example 1-2 and embodiment 1-2;

[0023] Figure 2It is a comparison chart of protein digestibility of Comparative Examples 1-3 and Examples 1-2;

[0024] Figure 3 It is a comparison chart of the free amino group content of Comparative Examples 1-3 and Examples 1-2;

[0025] Figure 4 It is the flavor component analysis diagram of Comparative Example 1-2 and Example 1-2. DETAILED DESCRIPTION

[0026] The technical scheme of the present invention is further described below by specific examples and accompanying drawings. It should be understood that the specific examples described herein are only used to help understand the present invention and are not intended for specific limitations of the present invention. The accompanying drawings used herein are only for better illustrating the disclosure of the present invention and do not have a limiting effect on the scope of protection. If not otherwise specified, the raw materials used in the embodiments of the present invention are all commonly used raw materials in the art, and the methods used in the embodiments are all conventional methods in the art.

[0027] Example 1

[0028] The dried shrimp preparation method of the present embodiment is as follows:

[0029] S1. Preparation of shrimp: fresh white shrimps were artificially shelled to obtain shrimps, which were then rinsed once with a 3 wt % chloride saline solution and placed on ice for later use.

[0030] S2. Pre-tenderization treatment: the treated shrimps are placed in a container, and an aqueous solution containing 2 wt% bromelain is added at a solid-liquid ratio of 1:1, wherein the enzyme activity of bromelain is 20 U / mL; the container is then placed in an ultrasonic treatment device, the ultrasonic treatment power is set to 100 W, and the treatment time is 5 min at a temperature of 50° C. to obtain pre-tenderized shrimps.

[0031] S3, drying treatment: the pre-tenderized shrimps were evenly spread on the metal wire mesh, dried in a hot air dryer at 100°C for 60 minutes, then taken out, placed in a 4°C refrigerator for 30 minutes, and then placed in the hot air dryer again and dried at 100°C for 60 minutes. After cooling, the dried shrimps were obtained, named UT30.

[0032] Example 2

[0033] The difference between Example 2 and Example 1 is that in step S3 of Example 2, the dried shrimp is placed in a 4° C. refrigerator for 60 minutes, and the rest is the same as Example 1. After cooling, a dried shrimp product is obtained, which is named UT60.

[0034] Example 3

[0035] The dried shrimp preparation method of the present embodiment is as follows:

[0036] S1. Preparation of shrimp: fresh white shrimps were artificially shelled to obtain shrimps, which were then rinsed twice with a 3 wt % chloride saline solution and placed on ice for later use.

[0037] S2. Pre-tenderization treatment: the treated shrimps are placed in a container, and an aqueous solution containing 2.5 wt% bromelain is added at a solid-liquid ratio of 1:1.5, wherein the enzyme activity of bromelain is 25 U / mL; the container is then placed in an ultrasonic treatment device, the ultrasonic treatment power is set to 150 W, and the treatment time is 7 min at a temperature of 60° C. to obtain pre-tenderized shrimps.

[0038] S3, drying treatment: the pre-tenderized shrimps are evenly spread on the metal wire mesh, and dried in a hot air dryer at 100° C. for 50 minutes, then taken out, placed in a 3° C. refrigerator for 40 minutes, and then placed in the hot air dryer again and continued to be dried at 100° C. for 80 minutes, and the dried shrimp products are obtained after cooling.

[0039] Comparative Example 1

[0040] The dried shrimp preparation method of Comparative Example 1 is as follows:

[0041] S1. Preparation of shrimp: fresh white shrimps were artificially shelled to obtain shrimps, which were then rinsed once with a 3 wt % chloride saline solution and placed on ice for later use.

[0042] S2. Drying treatment: The shrimps were evenly spread on a metal wire mesh and dried in a hot air dryer at 100° C. for 120 min. After cooling, the dried shrimps were obtained and named as the control group (control).

[0043] Comparative Example 2

[0044] The dried shrimp preparation method of Comparative Example 2 is as follows:

[0045] S1. Preparation of shrimp: fresh white shrimps were artificially shelled to obtain shrimps, which were then rinsed once with a 3 wt % chloride saline solution and placed on ice for later use.

[0046] S2. Pre-tenderization treatment: the treated shrimps are placed in a container, and an aqueous solution containing 2 wt% bromelain is added at a solid-liquid ratio of 1:1, wherein the enzyme activity of bromelain is 20 U / mL; the container is then placed in an ultrasonic treatment device, the ultrasonic treatment power is set to 100 W, and the treatment time is 5 min at a temperature of 50° C. to obtain pre-tenderized shrimps.

[0047] S3, drying treatment: the pre-tenderized shrimps were evenly spread on a metal wire mesh, and dried in a hot air dryer at 100° C. for 120 min. After cooling, the dried shrimps were obtained, which was named UB1.

[0048] Comparative Example 3

[0049] The dried shrimp preparation method of Comparative Example 3 is as follows:

[0050] S1. Preparation of shrimp: fresh white shrimps were artificially shelled to obtain shrimps, which were then rinsed once with a 3 wt % chloride saline solution and placed on ice for later use.

[0051] S2. Drying treatment: The shrimps were evenly spread on a metal wire mesh, dried in a hot air dryer at 100° C. for 60 min, then taken out and placed in a 4° C. refrigerator for 30 min, then placed in a hot air dryer again and dried at 100° C. for 60 min, and after cooling, the dried shrimps were obtained, named NT30.

[0052] The protein digestibility and free amino group of the dried shrimp were tested by the following methods, and the free amino acid and flavor nucleotide component content and flavor analysis were performed. The flavor and taste of the dried shrimp were evaluated by sensory evaluation.

[0053] (1) Determination of protein digestibility: Take 4 g of the evenly stirred dried shrimp sample, add 16 mL of pre-cooled phosphate buffer solution (PBS: 10 mM Na2HPO4-NaH2PO4, pH 7.0), and homogenize at 10,000 r / min for 30 seconds in an ice bath, repeat 3 times. Adjust the pH of the solution to 2.0±0.1 with 1 M HCl, and then add 4 mL of pepsin solution (specific activity 15 U / mg, concentration: 0.48 g / 15 mL 0.1 mol / L HCl). Digest the mixture on a 37°C constant temperature oscillator (speed 160 r / min), and adjust the pH to 7.5 with 1 M NaOH to terminate the gastric simulation reaction. Then, adjust the pH of the solution to 7.5±0.1, and add 4 mL of trypsin solution (specific activity 250 U / mL, concentration: 0.288 g / 12 mL 0.01 M PBS), and continue to shake the mixture for digestion under the same conditions. Digestion was terminated with 5% phenylmethylsulfonyl fluoride (PMSF). Samples were taken at 0 and 60 minutes of gastric digestion and 60 minutes of small intestinal digestion, mixed with ethanol in a ratio of 1:3, and stored at 4°C for 12 hours. The total protein content of shrimp samples before and after digestion was determined by the biuret method at 10,000 g for 20 minutes, and the protein digestibility was calculated according to the formula.

[0054] Protein digestibility (%) = (W0-W1) / W0×100

[0055] Wherein, W0 is the protein content before digestion, and W1 is the protein content in the precipitate after digestion.

[0056] (2) Determination of free amino groups: OPA reagent was used for the determination of free amino groups. The preparation method is as follows: 200 mg SDS and 7.62 g borax were added to 150 mL deionized water, then mixed with OPA (160 mg dissolved in 4 mL ethanol), 176 mg DTT was added, and the volume was adjusted to 200 mL with deionized water.

[0057] Sample preparation: Centrifuge the digestion mixture at 10,000g for 20 minutes at 4°C, take the supernatant and dilute 50 times, take 400μL and add it to 3mL OPA reagent, shake well and let it stand for 2 minutes, and measure the absorbance at 340nm using a spectrophotometer. Draw a standard curve with L-leucine in the range of 0.1-0.5mg / mL.

[0058] (3) Analysis of free amino acids and flavor nucleotide components

[0059] Free amino acids: 1 g of sample was mixed with 10 mL of 5% trichloroacetic acid (TCA) and homogenized. After shaking at room temperature for 5 min, the mixture was centrifuged at 10,000 r / min for 15 min. The supernatant was collected, the pH was adjusted to 9.0 ± 0.1 using 10 M KOH, and the volume was adjusted to 50 mL with derivatization buffer. Next, 2 mL was taken out of the mixture, 1 mL of the derivatization reagent (2,4-dinitrofluorobenzene) was added, and the derivatization process was carried out in a dark environment with the temperature maintained at about 60 ° C. Finally, the solution was supplemented to 10 mL by adding the equilibrium buffer for use. Before analysis, the solution was filtered using a 0.45 μm filter membrane.

[0060] High performance liquid chromatography (HPLC) analysis conditions: Elite-AAK column (4.6 mm × 250 mm, 5 μm, Dalian Elite Analytical Instrument Co., Ltd.) was used for separation. The column temperature was maintained at 27 ° C. A diode array detector (DAD) was used, and the detection wavelength was 360 nm / 4 nm. The flow rate was set to 1.2 mL / min and the injection volume was 10 μL. The mobile phase included mobile phase A: 50% acetonitrile; mobile phase B: 0.41% (w / v) of mobile phase B solid components were added, the pH was adjusted to 6.4-6.8 with acetic acid, and finally 10 mL of N, N-dimethylformamide was added.

[0061] Flavor nucleotides: Take 1.5g of dried shrimp and mix it with 10 times the volume of 5% perchloric acid (PCA). Grind on ice, then take 5mL of supernatant, adjust the pH to 2.8-3.2 with KOH solution (use acidic pH test paper for control), and centrifuge at 5000r / min for 3min at 4°C to obtain supernatant. Add phosphate buffer (0.5M, pH=7.5) to the supernatant and adjust the pH to 7.0. Finally, filter the substance to be tested through a 0.22μm filter membrane. Determine by HPLC.

[0062] HPLC conditions: the chromatographic column was Shodex GS-320HQ (7.5 mm id×300 mm), the mobile phase was 0.2 M phosphate buffer (pH 3.7), the temperature was 30°C, the detection wavelength was 254 nm / 4 nm, and the flow rate was 0.6 mL / min.

[0063] (4) Flavor determination: Dried shrimps were mixed with 0.18 mg / mL saline at a ratio of 1:1 and homogenized. 4.00 g was placed in a 20 mL headspace bottle and 10 μL of 10% -6 ppm internal standard 2,4,6-trimethylpyridine was used for detection by HS-SPME-GC-MS.

[0064] Extraction conditions: using 65 μm PDMS / DVB / CAR fiber, temperature 50°C, time 50 minutes.

[0065] Chromatographic conditions: splitless mode, initial temperature 40°C, hold for 2 minutes, increase to 160°C at 4°C / min, then increase to 250°C at 10°C / min and hold for 5 minutes. Carrier gas is high-purity helium, flow rate 1.0 mL / min, injection port temperature 250°C.

[0066] Mass spectrometry conditions: EI electron source, electron energy 70 eV, ion source temperature 200 °C, detector voltage 1.2 kV.

[0067] The GC-MS analysis results were searched against the NIST11 and WLIEY spectral libraries, and the volatile components were identified based on the results with a similarity greater than 80.

[0068] (5) Sensory evaluation: 10 professional sensory assessors (5 males and 5 females, aged 20-30 years old) were selected to score the flavor and taste of the dried shrimp. The higher the score, the better the flavor and taste of the prepared shrimp.

[0069] Figure 1 It is the drying curve diagram of comparative example 1-2 and embodiment 1-2, from Figure 1It can be seen that compared with continuous drying (Figures A and B), the samples that introduced the moisture balance stage (Figures C and D) increased the total drying time, but their effective drying time to achieve the required final moisture content was significantly shortened. In this way, it can not only effectively prevent the shrimp meat from being exposed to high temperature for too long, reduce flavor deterioration and nutrient loss, but also complete the main dehydration process within a relatively short "critical time period".

[0070] Specifically, UT30 (Figure C) performs best in the process of moisture balance stage (30min): although the placement step is added, the overall drying rate is more stable, the effective drying time is significantly reduced, and the final moisture content of the product can be quickly reduced to the target level. Through this process, the freshness and nutrients of the shrimp meat can be retained to the greatest extent, and the deterioration of taste caused by over-drying is avoided. In summary, the UT30 solution not only ensures drying efficiency, but also takes into account the retention of flavor and nutrition, showing the best overall effect.

[0071] Figure 2 The protein digestibility comparison chart of Comparative Examples 1-3 and Examples 1-2 is shown in FIG. Figure 2 From the data, it can be seen that the protein digestibility of the samples (UT30, UT60) treated in the water balance stage at 60 minutes of intestinal digestion was higher than that of the control group, UB1 and NT30, and the samples treated in the water balance stage showed a faster digestion speed. Figure 3 The free amino content of different treatment groups is shown in the figure. The free amino content is an important indicator to measure the degree of hydrolysis of food protein. The higher the free amino content, the more complete the protein degradation. The free amino content of the UT30 group ranks higher among all groups, especially in the determination after the intestinal digestion process, the release of free amino groups in the UT30 group is significantly higher than that in other groups. This further confirms that the introduction of the water balance stage can better promote protein hydrolysis, release more free amino groups, and improve the nutritional value and digestibility of shrimp.

[0072] Compared with the control group, the improvement of protein digestibility and free amino content in NT30 was very small. It can be seen that when the dried shrimp was not subjected to ultrasonic-assisted enzymatic hydrolysis, even the introduction of the moisture balance stage (NT0) did not greatly help the improvement of protein digestion and hydrolysis. The above results show that the present invention requires the dried shrimp to be subjected to ultrasonic-assisted enzymatic hydrolysis first, and then the drying treatment of the moisture balance stage is introduced. The coordinated effect of the two is beneficial to protein digestion and hydrolysis.

[0073] The results of combining digestibility and free amino content showed that the UT30 group performed outstandingly. Compared with the control group, the protein hydrolysis of the UT30 group was more complete, and the digestibility and free amino content were both high, which means that it can better provide nutrients that can be absorbed by the human body during the digestion process. In addition, the moisture balance stage effectively reduced heat damage and maximized the tenderness and flavor of the shrimp, making it perform better in digestibility and nutrient retention. Therefore, the processing technology of the UT30 group proved to be the best choice, capable of providing high-quality and easily digestible dried shrimp products.

[0074] Table 1 Free amino acid and flavor nucleotide contents of Comparative Examples 1-2 and Examples 1-2

[0075]

[0076] As can be seen from Table 1, compared with the control group and UB1, UT30 and UT60 have higher umami amino acids and IMP, which can improve the umami taste of dried shrimp and give better flavor and taste.

[0077] Figure 4 The flavor component analysis diagrams of Comparative Examples 1-2 and Examples 1-2 show that the flavor analysis results show that although the UT60 group has a higher lipid content, the richness of this lipid does not necessarily bring an ideal flavor and taste, but may lead to decolorization and flavor deterioration of the shrimp. In contrast, the UT30 group significantly increased the types and quantities of ester compounds through the treatment of the moisture balance stage, especially the appearance of nonanal, which gave the dried shrimp a fresh grassy aroma. This compound has a lower sensory threshold and can therefore effectively improve the overall flavor. In addition, the UT30 group showed a better balance in flavor improvement. Although the content of 1-octen-3-ol increased, the mushroom aroma it brought did not adversely affect the overall flavor and did not interfere with the coordination of the flavor.

[0078] Table 2 Sensory evaluation table of comparative examples 1-2 and embodiments 1-2

[0079] Control group UB1 UT30 UT60 score 12 14 16 15

[0080] As can be seen from Table 2, UT30 and UT60 have better flavor and taste than the control group and UB1, among which UT30 has the best taste.

[0081] In general, the UT30 and UT60 groups not only performed well in the balance of lipids and ester compounds, which was beneficial to improving flavor and had high scores in sensory evaluation, but also showed significant advantages in improving digestibility. In particular, the UT30 group proved to be the best choice for processing technology.

[0082] The various aspects, embodiments, and features of the present invention should be considered to be illustrative in all aspects and not limiting of the present invention, the scope of which is defined solely by the claims. Other embodiments, modifications, and uses will be apparent to those skilled in the art without departing from the spirit and scope of the claimed invention.

[0083] In the preparation method of the present invention, the order of each step is not limited to the order listed. For those skilled in the art, without creative work, the order of each step is also within the protection scope of the present invention. In addition, two or more steps or actions can be performed simultaneously.

[0084] Finally, it should be noted that the specific embodiments described herein are merely examples of the present invention, and are not intended to limit the implementation methods of the present invention. A person skilled in the art of the present invention may make various modifications or supplements to the specific embodiments described, or replace them in a similar manner. It is not necessary and impossible to provide all examples of all implementation methods here. However, these obvious changes or modifications derived from the essential spirit of the present invention still fall within the scope of protection of the present invention, and interpreting them as any additional limitation is contrary to the spirit of the present invention.

Claims

1. A method for preparing easily digestible dried shrimp, characterized in that: The following steps are involved: S1, shelling fresh shrimps to obtain shrimps; S2, placing the shrimp in a container, adding bromelain solution; then placing the container in an ultrasonic treatment device for ultrasonic treatment; S3, hot-air drying the shrimp obtained in step S2 for the first time, then taking it out and standing it at 1-6° C. for 10-60 minutes, and then continuing to hot-air dry it for the second time, and obtaining the dried shrimp product after cooling.

2. The method for preparing easily digestible dried shrimp according to claim 1, characterized in that: The shrimp in step S1 is of the Penaeidae family, including one or more of the whiteleg shrimp, giant tiger shrimp, Chinese shrimp, and Japanese shrimp.

3. The method for preparing easily digestible dried shrimp according to claim 1, characterized in that: The shrimps are rinsed 1 to 5 times with a 1 to 5 wt % chloride salt solution.

4. The method for preparing easily digestible dried shrimp according to claim 1, characterized in that: In step S2, the mass ratio of shrimp to bromelain solution is 1:(0.8-2).

5. The method for preparing easily digestible dried shrimp according to claim 1, characterized in that: In step S2, in the bromelain solution, the concentration of bromelain is 1-5w / w%, and the enzyme activity of bromelain is 20-25U / mL.

6. The method for preparing easily digestible dried shrimp according to claim 1, characterized in that: In step S2, the power of the ultrasonic treatment is 50-300 W, the treatment temperature is 50-60° C., and the treatment time is 1-10 min.

7. The method for preparing easily digestible dried shrimp according to claim 1 or 6, characterized in that: The power of ultrasonic treatment is 100-200W, the treatment temperature is 50-60°C, and the treatment time is 2-8min.

8. The method for preparing easily digestible dried shrimp according to claim 1, characterized in that: Preferably, in step S3, the conditions of the first hot air drying and the second hot air drying are independently: the drying temperature is 95-100° C., and the drying time is 30-100 min.

9. The method for preparing easily digestible dried shrimp according to claim 1, characterized in that: In step S3, after the first hot air drying, the product is taken out and allowed to stand at 2 to 5°C for 20 to 50 minutes.

10. The method for preparing easily digestible dried shrimp according to claim 1 or 9, characterized in that: In step S3, after the first hot air drying, the mixture is taken out and allowed to stand at 4°C for 30 minutes.

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