A method for increasing the umami taste of oyster juice by using enzymatic technology

Abstract

The application discloses a method for increasing the fresh taste of oyster juice by using enzymolysis technology, and adopts oysters and edible mushrooms which are ground by high-pressure jet flow to be crushing to be enzymolysis substrates, releases taste flavoring substances by fully enzymolysis of multiple enzymes, removes the fishy smell of oyster enzymolysis liquid by using a deodorization and fresh taste increasing reaction, and improves the fresh taste to obtain oyster juice; the prepared oyster juice has rich fresh and fragrant taste, no fishy smell and no bitterness, and the flavor of the oyster juice is fresh and fragrant.

Description

Technical Field

[0001] This invention belongs to the field of food processing, and specifically relates to a method for enhancing the umami flavor of oyster sauce using enzymatic hydrolysis technology. Background Technology

[0002] Oyster sauce is a condiment made from oysters. It has a delicious flavor, a rich oyster aroma, a suitable consistency, and high nutritional value. Oyster sauce is a commonly used traditional umami seasoning in Guangdong and one of the largest categories of condiments.

[0003] Oyster juice is one of the main raw materials for making oyster sauce, and it is also the main substance that enhances the flavor. Moreover, since oysters, the raw material for making oyster juice, have their own fishy smell, how to enhance the flavor and remove the fishy smell from the oyster juice is a major factor that oyster sauce manufacturers consider.

[0004] There are two traditional methods for preparing oyster sauce. One is to boil whole oysters directly in a jacketed kettle and keep them at a simmer for 2 to 6 hours. Then, the oysters are removed, and the broth is simmered, concentrated, and filtered. The other is to grind the raw oysters using a colloid mill or shearing machine, filter the broth, and then simmer and concentrate the filtrate.

[0005] There are three problems with oyster sauce produced using the two methods described above:

[0006] 1. Because oysters have a natural fishy smell, and no deodorizing measures were taken in the above process, the oyster juice has a strong fishy smell. If the amount of oyster juice added is increased, the overall taste of the oyster sauce will be too fishy, ​​which will affect the flavor of the product.

[0007] Furthermore, existing technologies only report the use of filtration to remove fishy odors, mostly using vibrating screens or Y-type filters in pipelines; and the size of the filter pores directly affects the intensity of the fishy odor, but in order to ensure the yield, production companies will not use filter bags with small pores (generally in the range of 40-60 mesh), so the fishy substances in oyster juice cannot be effectively removed at all.

[0008] Second, due to the low degree of concentration during cooking, the amount of umami substances released from oysters is limited. Furthermore, during the heating and cooking process, the flavor substances in the oyster juice will evaporate into the air, resulting in a significant loss of flavor. Therefore, the umami flavor of the oyster juice is insufficient. Moreover, the protein in oysters is severely lost during the cooking process, resulting in low utilization.

[0009] Third, in the second process mentioned above, the diameter of the raw oyster meat after being processed by the colloid mill and shearing machine is relatively large. When filtered through a 200-mesh pore, more material is retained, resulting in greater loss. However, if it is not filtered through a 200-mesh pore, more sediment will settle during the subsequent storage of oyster juice, affecting the quality of oyster sauce.

[0010] In addition to oyster juice, other substances that enhance the flavor of oyster sauce include flavor enhancers, such as monosodium glutamate, disodium inosinate, and yeast extract.

[0011] However, increasing the amount of the aforementioned flavor enhancers in oyster sauce to improve its umami flavor will actually suppress the original oyster flavor of the oyster sauce itself.

[0012] Therefore, how to remove the fishy smell from oyster juice and enhance its flavor has become a challenging problem in the oyster juice (or oyster sauce) industry, and is also a key point for promoting the industry's development. Summary of the Invention

[0013] The purpose of this invention is to provide a method for enhancing the umami flavor of oyster sauce using enzymatic hydrolysis technology, removing the original fishy smell of oyster sauce, giving oyster sauce a unique umami and aroma, improving the overall taste and flavor, and increasing the utilization rate of raw materials.

[0014] To achieve the above objectives, the present invention adopts the following technical solution:

[0015] A method for enhancing the umami flavor of oyster sauce using enzymatic hydrolysis technology includes the following steps:

[0016] (1) Oyster pretreatment: Rinse fresh oysters with water to remove surface impurities, chop them, and then put the oysters into a high-pressure jet mill for shearing and crushing.

[0017] Then, the oysters are mixed with water to obtain a mixture, which is then heated to cause slight denaturation of the proteins in the oysters.

[0018] (2) Oyster enzymatic hydrolysis:

[0019] Add alkaline protease, papain, Bacillus subtilis neutral protease and deaminase to the mixed raw materials obtained in step (1) for compound enzymatic hydrolysis;

[0020] The oyster hydrolysate obtained after enzymatic hydrolysis is filtered to obtain oyster hydrolysate filtrate;

[0021] (3) Pretreatment of edible fungi: Chop the edible fungi and put them into a high-pressure jet mill for shearing and crushing;

[0022] Then, the edible mushrooms are mixed with water and steamed to obtain a mushroom mixture.

[0023] (4) Enzymatic hydrolysis of edible fungi: Cellulase, deaminase and nuclease are added to the fungi mixture for compound enzymatic hydrolysis;

[0024] The enzymatic hydrolysate of edible fungi obtained after enzymatic hydrolysis was filtered to obtain the enzymatic hydrolysate of edible fungi.

[0025] (5) Deodorizing and enhancing freshness: Transfer the oyster enzymatic hydrolysis filtrate to the reaction vessel, add the edible mushroom enzymatic hydrolysis filtrate and fructose syrup, heat to 90-120℃, keep warm for 30-90 minutes, and then cool to obtain oyster juice.

[0026] The edible mushrooms described in this invention can be one or more of enoki mushrooms, straw mushrooms, shiitake mushrooms, porcini mushrooms, and cordyceps flowers; when using multiple edible mushrooms, they can be combined in any proportion, such as two edible mushrooms combined in a weight ratio of 1 to 2:1 to 2.

[0027] The method of this invention can enhance the umami flavor and remove the fishy smell from oyster sauce; the specific principle is as follows:

[0028] ①This invention adds edible mushroom enzymatic hydrolysis filtrate as a raw material for oyster juice to the oyster enzymatic hydrolysis filtrate. Experimental research has found that the two raw materials have a synergistic effect, which can significantly improve the umami flavor of oyster juice and suppress the fishy smell of oyster enzymatic hydrolysis filtrate, making the flavor of oyster juice more fresh, fragrant and mellow.

[0029] ② Through comparative experiments, the inventors discovered that using a high-pressure jet mill to ultrafinely pulverize oysters and edible mushrooms results in better enzymatic hydrolysis. Specifically, pulverizing with a high-pressure jet mill promotes the full enzymatic hydrolysis of edible mushrooms and oysters, completely releasing flavor compounds, thereby enhancing the umami flavor of oyster sauce and improving its texture, making it more delicate.

[0030] ③ The inventors have discovered that using multiple enzymes in synergistic enzymatic hydrolysis of oysters and edible fungi can increase the specific catalytic sites of proteases, thereby improving the degree of protein hydrolysis and peptide yield, increasing the content of free glycine and alanine, and simultaneously enhancing the flavor of oyster sauce.

[0031] Compared with the prior art, the present invention has confirmed through a large number of experiments that using alkaline protease, papain, Bacillus subtilis neutral protease and deaminase to perform compound enzymatic hydrolysis of oysters can make the characteristic flavor of oysters in oyster juice rich, significantly enhance the umami flavor and reduce the bitterness.

[0032] Using cellulase, deaminase and nuclease to perform compound enzymatic hydrolysis on edible fungi can effectively enhance the characteristic flavor of edible fungi and reduce bitterness.

[0033] ④ This invention employs a deodorizing and flavor-enhancing reaction to remove the fishy smell from the oyster enzymatic hydrolysis filtrate and enhance the umami flavor of the oyster juice.

[0034] The oyster juice obtained by the method of this invention contains a rich total amount of free glycine and alanine. These two amino acids have a special sweet taste and can alleviate or mask the bitterness in the oyster juice. In other words, this invention gives the oyster juice a unique umami flavor and makes it free of fishy and bitter tastes, with a rich umami flavor.

[0035] Furthermore, this invention employs a high-pressure jet mill to perform ultra-fine pulverization of all components of edible fungi and oysters. The pulverized oyster slurry achieves a 98% pass rate through a 200-mesh sieve, while the pulverized edible fungi achieve a 95% pass rate through a 200-mesh sieve. This significantly improves the product's taste and reduces raw material loss, achieving full utilization of all components. Moreover, the temperature rise during high-pressure jet mill pulverization does not exceed 10°C, preventing uncontrollable material denaturation.

[0036] Preferably, in this invention, the pressure and flow rate of the high-pressure jet mill are controlled to control the particle size of the material and reduce losses; therefore, in steps (1) and (3), the pressure of the high-pressure jet mill is 140 MPa and the flow rate is 200-350 m / s.

[0037] Preferably, in step (1), the mixed raw materials are heated to 70-90°C and kept at that temperature for 10-20 minutes to slightly denature the proteins in the oysters, making them easier to be enzymatically hydrolyzed and release flavor compounds, and then cooled to 40-60°C; the weight ratio of oysters to water in the mixed raw materials is 1:2-6.

[0038] Furthermore, in step (2), in order to ensure the effectiveness of enzymatic hydrolysis, suitable enzymatic hydrolysis conditions corresponding to the enzyme preparation are used for enzymatic hydrolysis. Therefore, the oysters are subjected to segmented enzymatic hydrolysis:

[0039] First stage of enzymatic hydrolysis: Alkaline protease and papain are added to the mixed raw materials for enzymatic hydrolysis, and then the enzyme activity is inactivated by heating;

[0040] Second stage of enzymatic hydrolysis: Add Bacillus subtilis neutral protease and deaminase to the mixed raw materials after the first stage of enzymatic hydrolysis, carry out enzymatic hydrolysis, and then heat to inactivate the enzymes to obtain oyster enzymatic hydrolysate.

[0041] Preferably, in step (2), the specific conditions for the first enzymatic hydrolysis are as follows: the weight of alkaline protease and papain added is 0.5-1.6% of the oyster weight, the initial pH value is 7.0-8.0, the enzymatic hydrolysis temperature is 50-60℃, the enzymatic hydrolysis time is 4-8h, the first stage of enzyme inactivation is carried out at 90-95℃ for 5-10min, and the temperature is lowered to 40-60℃ after enzyme inactivation.

[0042] Preferably, in step (2), the specific conditions for the second enzymatic hydrolysis are as follows: the added weight of Bacillus subtilis neutral protease and deaminase is 0.2-1.0% of the oyster weight, the enzymatic hydrolysis conditions are initial pH 7.0-8.0, enzymatic hydrolysis temperature 40-50℃, enzymatic hydrolysis time 3-6h, and the second enzymatic activity inactivation is carried out at 95-100℃ for 15-30min.

[0043] Further, in step (2), the filtration is performed by hot filtration using a cartridge filter at 95–100°C; the pore size of the cartridge filter is 5–10 μm; during this process, the oil and impurities in the oyster enzymatic hydrolysate are intercepted by the cartridge filter, resulting in oyster enzymatic hydrolysate. Experiments have shown that the oyster enzymatic hydrolysate filtered using a filter with a pore size of 5–10 μm is clear and transparent, without subsequent precipitation or impurities, and has a good appearance, thus ensuring the oyster juice has an excellent appearance.

[0044] Preferably, in step (3), the weight ratio of edible mushrooms to water is 1:5 to 20, and the mixture is steamed at 80 to 100°C for 30 to 60 minutes, and then cooled to 45 to 70°C to obtain a mushroom mixture.

[0045] Furthermore, in step (4), in order to ensure the effectiveness of enzymatic hydrolysis, the edible mushrooms are subjected to segmented enzymatic hydrolysis:

[0046] First stage of enzymatic hydrolysis: Cellulase is added to the mushroom mixture for enzymatic hydrolysis, and then the enzyme activity is inactivated by heating;

[0047] Second stage of enzymatic hydrolysis: Deaminase and nuclease are added to the mushroom mixture after the first stage of enzymatic hydrolysis for enzymatic hydrolysis, and then the enzyme activity is inactivated by heating to obtain edible mushroom enzymatic hydrolysate.

[0048] Preferably, in step (4), the specific conditions for the first stage of enzymatic hydrolysis are as follows: the weight of cellulase added is 0.1-0.5% of the weight of edible mushrooms, the pH value is 6.0-8.0, the enzymatic hydrolysis temperature is 40-60℃, the enzymatic hydrolysis time is 3-6h, the first stage of enzyme inactivation is carried out at 90-95℃ for 5-10min, and the temperature is lowered to 40-60℃ after enzyme inactivation.

[0049] The specific conditions for the second stage of enzymatic hydrolysis are as follows: the weight of deaminase and nuclease added are 0.2-0.6% of the weight of edible mushrooms, the pH value is 7.0-8.0, the hydrolysis temperature is 40-60℃, the hydrolysis time is 3-6h, and the second stage of enzyme inactivation is carried out at 95-100℃ for 15-30min.

[0050] Preferably, in step (4), the enzymatic hydrolysate of edible fungi obtained after enzymatic hydrolysis is filtered using a core filter to obtain edible fungi enzymatic hydrolysate filtrate; the pore size of the core filter is 5-10 μm. Experiments have shown that the edible fungi enzymatic hydrolysate filtrate filtered using a filter with a pore size of 5-10 μm is clear and transparent, and no sediment or impurities will appear subsequently, resulting in a better overall condition.

[0051] Preferably, in step (5), 40-70 parts by weight of oyster enzymatic hydrolysis filtrate are transferred to a reaction vessel, 10-30 parts by weight of edible mushroom enzymatic hydrolysis filtrate and 10-30 parts by weight of fructose syrup are added, the pH value is adjusted to 7.0-8.0, the temperature is raised to 90-120°C, and the temperature is kept for 30-90 minutes. Then, the temperature is rapidly cooled to 30-40°C under conditions of 0-10°C to obtain oyster juice.

[0052] Furthermore, in step (5), the cooled material is filtered together with neutral activated carbon and filter cloth to obtain oyster juice. This operation can further remove the fishy smell and improve the taste and texture of the oyster juice.

[0053] Compared with the prior art, the beneficial effects of the present invention are:

[0054] 1. This invention uses oysters and edible fungi as enzymatic hydrolysis substrates. Through the synergistic enzymatic hydrolysis of multiple enzymes, flavor substances are released. Then, a deodorization and umami enhancement reaction is used to remove the fishy smell of the oyster hydrolysate and enhance its umami flavor, resulting in oyster juice. The oyster juice has a rich umami flavor, no fishy smell, no bitterness, and a savory and harmonious flavor.

[0055] 2. The inventors have discovered that using a high-pressure jet mill to perform ultra-fine grinding of all components of edible fungi (such as shiitake mushrooms and cordyceps flowers) and oysters solves the problem that traditional processes cannot effectively grind edible fungi, greatly improves the taste of the products, reduces the loss rate to 0.4-1.8%, achieves full utilization of components, reduces waste discharge, and allows the nutrients in the raw materials to be fully utilized, thereby improving production efficiency.

[0056] 3. This invention utilizes neutral activated carbon and filter cloth for filtration, which can effectively further remove the fishy smell of oyster juice. Combined with the deodorizing and flavor-enhancing reaction to remove the fishy smell and the edible mushrooms to suppress the fishy smell, it solves the problem of the strong fishy smell of oyster juice and makes its flavor fresh and harmonious.

[0057] 4. The total amount of free glycine and alanine in oyster juice obtained by the method of this invention can be increased from 1000 mg / kg in traditional oyster juice to 1800 mg / kg or more, giving the oyster juice a unique umami flavor, significantly reducing bitterness, and enhancing the flavor of the oyster juice.

[0058] The oyster juice obtained by the method of this invention can be applied to oyster sauce, seafood soy sauce, seafood dressing, etc., to obtain high-quality products. Detailed Implementation

[0059] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention.

[0060] Unless otherwise specified, the experimental methods used in the embodiments of this invention are conventional methods; the materials used, unless otherwise specified, are commercially available materials.

[0061] Experimental example: Enzymatic digestion test

[0062] (1) Single-factor experiments were conducted on commonly used enzyme preparations on the market to verify the enzymatic hydrolysis effect, such as 15 enzyme preparations including lipase, glucoamylase, alkaline protease, cellulase and amylase (the optimal enzymatic hydrolysis conditions corresponding to the above enzyme preparations were adopted in the enzymatic hydrolysis experiment).

[0063] Specifically, oysters and edible mushrooms were co-crushed and used as substrates. Equal amounts of enzyme preparations were added in a fixed ratio for enzymatic hydrolysis. The umami flavor of the hydrolyzed products was then evaluated, and the results are shown in Table 1. Six enzyme preparations were initially screened, including alkaline protease, papain, Bacillus subtilis neutral protease, deaminase, cellulase, and nuclease, for further enzymatic hydrolysis experiments.

[0064] Table 1

[0065] Enzyme preparation name Umami rating Enzyme preparation name Umami rating Lipase none Deaminase strength Glucoamylase none Cellulase moderate alkaline protease Mild nuclease moderate Papain moderate β-glucanase none Bacillus subtilis neutral protease moderate Xylosesase none amylase none DNA polymerase none Bromelain none malt starch hydrolase none Fig protease none / /

[0066] (2) The six enzyme preparations and their combinations selected above were used to conduct enzymatic hydrolysis tests on pretreated oysters and edible fungi respectively (the optimal enzymatic hydrolysis conditions corresponding to the enzyme preparations were adopted for the enzymatic hydrolysis test). The flavor evaluation and analysis of the oyster enzymatic hydrolysis filtrate and the edible fungi enzymatic hydrolysis filtrate obtained after the enzymatic hydrolysis were performed. The results are shown in Tables 2 and 3.

[0067] For oysters, it was found that alkaline protease, papain, Bacillus subtilis neutral protein, and deaminase could be used to enzymatically hydrolyze oysters to obtain oyster enzymatic hydrolysate with characteristic flavor and umami. However, cellulase and nuclease had no enzymatic hydrolysis effect (i.e., there was no significant difference in flavor before and after enzymatic hydrolysis). Therefore, a combined enzymatic hydrolysis experiment was conducted on oysters using alkaline protease, papain, Bacillus subtilis neutral protein, and deaminase. It was found that using the combination of these four enzyme preparations resulted in the best flavor in the oyster enzymatic hydrolysate, with the highest levels of free glycine and alanine.

[0068] For edible fungi, it was found that enzymatic hydrolysis using cellulase, deaminase, and nuclease could produce enzymatic hydrolysates with characteristic flavor and umami, while the other two enzyme preparations had no enzymatic hydrolysis effect (i.e., there was no significant difference in flavor before and after enzymatic hydrolysis). Therefore, a combined enzymatic hydrolysis experiment was conducted on edible fungi using cellulase, deaminase, and nuclease. It was found that enzymatic hydrolysis using this combination of three enzyme preparations produced the best flavor in the edible fungi hydrolysate, with the highest levels of free glycine and alanine.

[0069] Results Analysis: Since alkaline protease, papain, Bacillus subtilis neutral protease, cellulase, deaminase, and nuclease are all monomeric enzymes, monomeric enzymes have limited enzymatic hydrolysis effects, low yields, strong bitterness, and poor taste. Currently, most enzymatic preparations of peptides use single-enzyme hydrolysis methods. However, the relatively few cleavage sites of single enzymes limit the hydrolysis of proteins. This invention uses multiple enzymes for synergistic hydrolysis, which can increase the specific catalytic sites of proteases, thereby improving the degree of protein hydrolysis and peptide yield, while simultaneously enhancing the flavor of the enzymatic hydrolysate and reducing bitterness.

[0070] Table 2. Flavor Evaluation Results of Oyster Enzymatic Hydrolysate Filtrate

[0071]

[0072]

[0073] Note: Score 0-1 indicates a very mild rating; score 1.01-2 indicates a slight rating; score 2.01-3 indicates a mild rating; score 3.01-4 indicates a moderate rating; score 4.01-5 indicates a severe rating; score 5.01-6 indicates a strong rating; score > 6.01 indicates a very strong rating.

[0074] Table 3. Flavor Evaluation Results of Enzymatic Hydrolysate from Edible Fungi

[0075]

[0076] Note: Score 0-1 indicates a very mild rating; score 1.01-2 indicates a slight rating; score 2.01-3 indicates a mild rating; score 3.01-4 indicates a moderate rating; score 4.01-5 indicates a severe rating; score 5.01-6 indicates a strong rating; score > 6.01 indicates a very strong rating.

[0077] Example 1:

[0078] A method for enhancing the umami flavor of oyster sauce using enzymatic hydrolysis technology includes the following steps:

[0079] 1. Oyster pretreatment

[0080] 1) Rinse 210kg of oysters with water to remove impurities from the surface of the oysters, and preliminarily chop them with a chopper. The oyster fragments are then fed into a high-pressure jet mill for further pulverization. The pressure during pulverization is 140Mpa and the flow rate is 300m / s. After pulverization, the material passes through a 200-mesh sieve, with 3kg of material remaining on the sieve, resulting in a sieve pass rate of 98.6%.

[0081] 2) Add water at a weight ratio of 1:3 for oyster paste to water to obtain a mixed raw material. Pump the mixed raw material into an enzymatic hydrolysis tank, heat it to 90°C, and keep it at that temperature for 10 minutes to slightly denature the proteins in the oyster paste. Then, cool it down to 40°C using a plate and frame cooling system.

[0082] 2. Segmented enzymatic hydrolysis of oysters

[0083] ① First stage of enzymatic hydrolysis: Alkaline protease and papain were added to the mixed raw materials for enzymatic hydrolysis. The amount of enzyme preparation added was 0.8% of the weight of oysters (210kg). The enzymatic hydrolysis conditions were pH=7.0, enzymatic hydrolysis temperature of 50℃, and enzymatic hydrolysis time of 8h. After the enzymatic hydrolysis was completed, the enzyme was inactivated at 95℃ for 5min, and then the temperature was lowered to 40℃.

[0084] ② Second stage of enzymatic hydrolysis: Bacillus subtilis neutral protease and deaminase were added to the mixed raw materials for enzymatic hydrolysis. The amount of enzyme preparation added was 1.0% of the oyster weight (210kg). The enzymatic hydrolysis conditions were pH=7.0, enzymatic hydrolysis temperature of 40℃, and enzymatic hydrolysis time of 6h.

[0085] Degreasing and enzyme inactivation treatment: After enzymatic hydrolysis, the enzyme was inactivated at 95℃ for 30 min, and then passed through a 5μm core filter at 95℃ to obtain oyster enzymatic hydrolysate;

[0086] 3. Pretreatment of edible fungi

[0087] 1) After 20kg of shiitake mushrooms and enoki mushrooms (weight ratio 1:1) are initially chopped using a chopper, the shiitake mushrooms and enoki mushrooms are then fed into a high-pressure jet mill for pulverization. The pressure during pulverization is 140Mpa and the flow rate is 350m / s. After pulverization, the material passes through a 200-mesh sieve, with 0.8kg of material remaining on the sieve, resulting in a sieve pass rate of 96%.

[0088] 2) Steam the shiitake mushrooms and enoki mushrooms at a weight ratio of 1:20 to water at 100℃ for 30 minutes, then cool down to 70℃.

[0089] 4. Segmented enzymatic hydrolysis of edible fungi

[0090] ① First stage of enzymatic hydrolysis: Cellulase is added to the mixed raw materials for enzymatic hydrolysis. The amount of enzyme added is 0.1% of the weight of edible mushrooms (20kg). The enzymatic hydrolysis conditions are pH=6.0, enzymatic hydrolysis temperature is 55℃, enzymatic hydrolysis time is 5h, enzyme is inactivated at 95℃ for 5min, and then the temperature is lowered to 40℃.

[0091] ② Second stage of enzymatic hydrolysis: Deaminase and nuclease are added to the mixed raw materials for enzymatic hydrolysis. The amount of enzyme preparation added is 0.3% of the weight of edible mushrooms (20kg). The enzymatic hydrolysis conditions are pH=7.0, enzymatic hydrolysis temperature is 50℃, and enzymatic hydrolysis time is 4h.

[0092] After enzymatic hydrolysis, the enzyme was inactivated at 100℃ for 15 minutes. Impurities in the enzymatic hydrolysate of shiitake and enoki mushrooms were intercepted by a core filter (pore size of 5μm) to obtain the enzymatic hydrolysate of shiitake and enoki mushrooms.

[0093] 5. Removes fishy smell and enhances freshness

[0094] 70 parts by weight of oyster enzymatic hydrolysis filtrate were transferred to a reaction vessel, and 20 parts by weight of shiitake mushroom and enoki mushroom enzymatic hydrolysis filtrate and 10 parts by weight of fructose syrup were added. The pH was adjusted to 7.0, the temperature was raised to 115℃ and kept at that temperature for 50 minutes. The mixture was then rapidly cooled to 30℃ at 0℃. The cooled material was then filtered through neutral activated carbon adsorption and a 5μm filter cloth to remove the fishy smell and obtain oyster juice. At this point, the total glycine and alanine content of the oyster juice reached 1800mg / kg, with a strong umami flavor and no fishy or bitter taste.

[0095] Example 2:

[0096] A method for enhancing the umami flavor of oyster sauce using enzymatic hydrolysis technology includes the following steps:

[0097] 1. Oyster pretreatment

[0098] 1) Rinse 100kg of oysters with water to remove impurities from the surface of the oysters, and preliminarily chop them with a chopper. The oyster fragments are then fed into a high-pressure jet mill for further pulverization. The pressure during pulverization is 140Mpa and the flow rate is 350m / s. After pulverization, the material passes through a 200-mesh sieve, with 1.8kg of material remaining on the sieve, resulting in a sieve pass rate of 98.2%.

[0099] 2) Add water at a weight ratio of 1:2 for oyster paste to water to obtain a mixed raw material. Pump the mixed raw material into an enzymatic hydrolysis tank, heat it to 85°C, and keep it at that temperature for 15 minutes to slightly denature the proteins in the oyster paste. Then, cool it down to 55°C using a plate and frame cooling system.

[0100] 2. Segmented enzymatic hydrolysis of oysters

[0101] ① First stage of enzymatic hydrolysis: Alkaline protease and papain were added to the mixed raw materials for enzymatic hydrolysis. The amount of enzyme preparation added was 1.6% of the weight of oysters (100kg). The enzymatic hydrolysis conditions were pH=7.2, enzymatic hydrolysis temperature of 55℃, and enzymatic hydrolysis time of 6h. After the enzymatic hydrolysis was completed, the enzyme was inactivated at 92℃ for 8min, and then the temperature was lowered to 55℃.

[0102] ② Second stage of enzymatic hydrolysis: Bacillus subtilis neutral protease and deaminase were added to the mixed raw materials for enzymatic hydrolysis. The amount of enzyme preparation added was 0.5% of the weight of oysters (100kg). The enzymatic hydrolysis conditions were pH=7.5, enzymatic hydrolysis temperature of 45℃, and enzymatic hydrolysis time of 5h.

[0103] Degreasing and enzyme inactivation treatment: After enzymatic hydrolysis, the enzyme was inactivated at 95℃ for 30 min, and then passed through a 5μm core filter at 95℃ to obtain oyster enzymatic hydrolysate;

[0104] 3. Pretreatment of edible fungi

[0105] 1) After 15kg of shiitake mushrooms and straw mushrooms (weight ratio 2:1) are initially chopped using a chopper, the shiitake mushrooms and straw mushrooms are then fed into a high-pressure jet mill for pulverization. The pressure during pulverization is 140Mpa and the flow rate is 200m / s. After pulverization, the material passes through a 200-mesh sieve, with 0.23kg of material remaining on the sieve, resulting in a sieve pass rate of 98.5%.

[0106] 2) Steam the shiitake mushrooms and straw mushrooms at a weight ratio of 1:10 to water at 90℃ for 45 minutes, then cool down to 60℃.

[0107] 4. Segmented enzymatic hydrolysis of edible fungi

[0108] ① First stage of enzymatic hydrolysis: Cellulase is added to the mixed raw materials for enzymatic hydrolysis. The amount of enzyme added is 0.2% of the weight of edible mushrooms (15kg). The enzymatic hydrolysis conditions are pH=7.0, enzymatic hydrolysis temperature is 60℃, enzymatic hydrolysis time is 3h, and the enzyme is inactivated at 95℃ for 10min. After inactivation, the temperature is lowered to 50℃.

[0109] ② Second stage of enzymatic hydrolysis: Deaminase and nuclease are added to the mixed raw materials for enzymatic hydrolysis. The amount of enzyme preparation added is 0.2% of the weight of edible mushrooms (15kg). The enzymatic hydrolysis conditions are pH=7.5, enzymatic hydrolysis temperature is 40℃, and enzymatic hydrolysis time is 6h.

[0110] After enzymatic hydrolysis, the enzyme was inactivated at 95℃ for 30 minutes. Impurities in the enzymatic hydrolysate of shiitake and straw mushrooms were intercepted by a core filter (pore size of 10μm) to obtain the enzymatic hydrolysate of shiitake and straw mushrooms.

[0111] 5. Removes fishy smell and enhances freshness

[0112] 40 parts by weight of oyster enzymatic hydrolysis filtrate were transferred to a reaction vessel, and 30 parts by weight of shiitake and straw mushroom enzymatic hydrolysis filtrate and 30 parts by weight of fructose syrup were added. The pH was adjusted to 7.2, the temperature was raised to 90℃, and the temperature was maintained for 90 minutes. After being rapidly cooled to 40℃ at 5℃, the cooled substance was filtered through neutral activated carbon adsorption and a 5μm filter cloth to remove the fishy smell and obtain oyster juice. At this time, the total glycine and alanine in the oyster juice reached 2100mg / kg, with a strong umami flavor and no fishy or bitter taste.

[0113] Example 3:

[0114] A method for enhancing the umami flavor of oyster sauce using enzymatic hydrolysis technology includes the following steps:

[0115] 1. Oyster pretreatment

[0116] 1) Rinse 200kg of oysters with water to remove impurities from the surface of the oysters, and preliminarily chop them with a chopper. The oyster fragments are then fed into a high-pressure jet mill for further pulverization. The pressure during pulverization is 140Mpa and the flow rate is 200m / s. After pulverization, the material passes through a 200-mesh sieve, with 0.9kg of material remaining on the sieve, resulting in a sieve pass rate of 99.6%.

[0117] 2) Add water at a weight ratio of 1:4 for oyster paste to water to obtain a mixed raw material. Pump the mixed raw material into an enzymatic hydrolysis tank, heat it to 75°C, and keep it at that temperature for 20 minutes to slightly denature the proteins in the oyster paste. Then, cool it down to 55°C using a plate and frame cooling system.

[0118] 2. Segmented enzymatic hydrolysis of oysters

[0119] ① First stage of enzymatic hydrolysis: Alkaline protease and papain are added to the mixed raw materials for enzymatic hydrolysis. The amount of enzyme preparation added is 1.0% of the weight of oysters (200kg). The enzymatic hydrolysis conditions are pH=7.6, enzymatic hydrolysis temperature is 55℃, and enzymatic hydrolysis time is 5h. After the enzymatic hydrolysis is completed, the enzyme is inactivated at 95℃ for 5min, and then the temperature is lowered to 50℃.

[0120] ② Second stage of enzymatic hydrolysis: Bacillus subtilis neutral protease and deaminase were added to the mixed raw materials for enzymatic hydrolysis. The amount of enzyme preparation added was 0.5% of the weight of oysters (200kg). The enzymatic hydrolysis conditions were pH=8.0, enzymatic hydrolysis temperature of 45℃, and enzymatic hydrolysis time of 4h.

[0121] Degreasing and enzyme inactivation treatment: After enzymatic hydrolysis, the enzyme was inactivated at 95℃ for 30 min, and then passed through a 10μm core filter at 95℃ to obtain oyster enzymatic hydrolysate;

[0122] 3. Pretreatment of edible fungi

[0123] 1) After 20kg of porcini mushrooms are initially chopped using a chopper, the porcini mushrooms are then fed into a high-pressure jet mill for pulverization. The pressure during pulverization is 140Mpa and the flow rate is 320m / s. After pulverization, the material is passed through a 200-mesh sieve to ensure that there are no impurities or large particles of porcini mushrooms before proceeding to the next process. The amount of material on the sieve is 0.7kg, and the sieve passing rate is 96.5%.

[0124] 2) Steam at 85℃ for 45 minutes with a bolete to water weight ratio of 1:5, then cool to 60℃.

[0125] 4. Segmented enzymatic hydrolysis of edible fungi

[0126] ① First stage of enzymatic hydrolysis: Cellulase is added to the mixed raw materials for enzymatic hydrolysis. The amount of enzyme added is 0.5% of the weight of edible mushrooms (20kg). The enzymatic hydrolysis conditions are pH=7.5, enzymatic hydrolysis temperature is 40℃, enzymatic hydrolysis time is 4h, and the enzyme is inactivated at 95℃ for 5min. After inactivation, the temperature is lowered to 60℃.

[0127] ② Second stage of enzymatic hydrolysis: Deaminase and nuclease are added to the mixed raw materials for enzymatic hydrolysis. The amount of enzyme preparation added is 0.4% of the weight of edible mushrooms (20kg). The enzymatic hydrolysis conditions are pH=7.2, enzymatic hydrolysis temperature is 55℃, and enzymatic hydrolysis time is 4h.

[0128] After enzymatic hydrolysis, the enzyme was inactivated at 100℃ for 20 min. Impurities in the Boletus enzymatic hydrolysate were intercepted by a core filter (5 μm pore size) to obtain Boletus enzymatic hydrolysate.

[0129] 5. Removes fishy smell and enhances freshness

[0130] 60 parts by weight of oyster enzymatic hydrolysis filtrate were transferred to a reaction vessel, and 20 parts by weight of porcini enzymatic hydrolysis filtrate and 20 parts by weight of fructose syrup were added. The pH was adjusted to 8.0, the temperature was raised to 100℃, and the temperature was maintained for 45 minutes. After being rapidly cooled to 35℃ at 5℃, the cooled substance was filtered through neutral activated carbon adsorption and a 5μm filter cloth to remove the fishy smell and obtain oyster juice. At this time, the total glycine and alanine in the oyster juice reached 1900mg / kg, with a strong umami flavor and no fishy or bitter taste.

[0131] Example 4:

[0132] A method for enhancing the umami flavor of oyster sauce using enzymatic hydrolysis technology includes the following steps:

[0133] 1. Oyster pretreatment

[0134] 1) Rinse 400kg of oysters with water to remove impurities from the surface of the oysters, and then preliminarily chop them with a chopper. The oyster fragments are then fed into a high-pressure jet mill for further pulverization. The pressure during pulverization is 140Mpa and the flow rate is 300m / s. After pulverization, the material passes through a 200-mesh sieve, with 4.9kg of material remaining on the sieve, resulting in a sieve pass rate of 98.8%.

[0135] 2) Add water at a weight ratio of 1:6 for oyster paste to water to obtain a mixed raw material. Pump the mixed raw material into an enzymatic hydrolysis tank, heat it to 70°C, and keep it at that temperature for 20 minutes to slightly denature the proteins in the oyster paste. Then, cool it down to 60°C using a plate and frame cooling system.

[0136] 2. Segmented enzymatic hydrolysis of oysters

[0137] ① First stage of enzymatic hydrolysis: Alkaline protease and papain were added to the mixed raw materials for enzymatic hydrolysis. The amount of enzyme preparation added was 0.5% of the weight of oysters (400kg). The enzymatic hydrolysis conditions were pH=8.0, enzymatic hydrolysis temperature of 60℃, and enzymatic hydrolysis time of 4h. After the enzymatic hydrolysis was completed, the enzyme was inactivated at 90℃ for 10min, and then the temperature was lowered to 60℃.

[0138] ② Second stage of enzymatic hydrolysis: Bacillus subtilis neutral protease and deaminase were added to the mixed raw materials for enzymatic hydrolysis. The amount of enzyme preparation added was 0.2% of the weight of oysters (400kg). The enzymatic hydrolysis conditions were pH=7.5, enzymatic hydrolysis temperature of 50℃, and enzymatic hydrolysis time of 3h.

[0139] Degreasing and enzyme inactivation treatment: After enzymatic hydrolysis, the enzyme was inactivated at 100℃ for 15 min, and then passed through a 10μm core filter at 100℃ to obtain oyster enzymatic hydrolysate;

[0140] 3. Pretreatment of edible fungi

[0141] 1) After 50kg of cordyceps flowers and straw mushrooms (weight ratio 1:2) are initially chopped using a chopper, the cordyceps flowers and straw mushrooms are then fed into a high-pressure jet mill for pulverization. The pressure during pulverization is 140Mpa and the flow rate is 280m / s. After pulverization, the material passes through a 200-mesh sieve, with 1.9kg of material remaining on the sieve, resulting in a sieve pass rate of 96.2%.

[0142] 2) Steam the cordyceps flowers and straw mushrooms at a weight ratio of 1:10 to water at 80℃ for 60 minutes, then cool down to 45℃.

[0143] 4. Segmented enzymatic hydrolysis of edible fungi

[0144] ① First stage of enzymatic hydrolysis: Cellulase is added to the mixed raw materials for enzymatic hydrolysis. The amount of enzyme added is 0.5% of the weight of edible mushrooms (50kg). The enzymatic hydrolysis conditions are pH=8.0, enzymatic hydrolysis temperature is 60℃, enzymatic hydrolysis time is 6h, and the enzyme is inactivated at 90℃ for 10min. After inactivation, the temperature is lowered to 60℃.

[0145] ② Second stage of enzymatic hydrolysis: Deaminase and nuclease are added to the mixed raw materials for enzymatic hydrolysis. The amount of enzyme preparation added is 0.6% of the weight of edible mushrooms (50kg). The enzymatic hydrolysis conditions are pH=8.0, enzymatic hydrolysis temperature is 60℃, and enzymatic hydrolysis time is 3h.

[0146] After enzymatic hydrolysis, the enzyme was inactivated at 95℃ for 20 minutes. Impurities in the enzymatic hydrolysate of Cordyceps militaris and Strawberry were intercepted by a core filter (pore size of 10μm) to obtain the enzymatic hydrolysate of Cordyceps militaris and Strawberry.

[0147] 5. Removes fishy smell and enhances freshness

[0148] 70 parts by weight of oyster enzymatic hydrolysis filtrate were transferred to a reaction vessel, and 15 parts by weight of cordyceps flower and straw mushroom enzymatic hydrolysis filtrate and 15 parts by weight of fructose syrup were added. The pH was adjusted to 8.0, the temperature was raised to 120℃ and kept at that temperature for 30 minutes. After being rapidly cooled to 40℃ at 10℃, the cooled substance was filtered through neutral activated carbon adsorption and a 5μm filter cloth to remove the fishy smell and obtain oyster juice. At this time, the total glycine and alanine in the oyster juice reached 2000mg / kg, with a strong umami flavor and no fishy or bitter taste.

[0149] Comparative Example 1 (no mushrooms added, other conditions the same as Example 4):

[0150] 1. Oyster pretreatment

[0151] 1) Rinse 400kg of oysters with water to remove impurities from the surface of the oysters, and preliminarily chop them with a chopper. The oyster fragments are then fed into a high-pressure jet mill for further pulverization. The pressure during pulverization is 140Mpa and the flow rate is 300m / s. After pulverization, the material passes through a 200-mesh sieve, with 4.8kg of material remaining on the sieve, resulting in a sieve pass rate of 98.7%.

[0152] 2) Add water at a weight ratio of 1:6 for oyster paste to water to obtain a mixed raw material. Pump the mixed raw material into an enzymatic hydrolysis tank, heat it to 70°C, and keep it at that temperature for 20 minutes to slightly denature the proteins in the oyster paste. Then, cool it down to 60°C using a plate and frame cooling system.

[0153] 2. Segmented enzymatic hydrolysis of oysters

[0154] ① First stage of enzymatic hydrolysis: Alkaline protease and papain were added to the mixed raw materials for enzymatic hydrolysis. The amount of enzyme preparation added was 0.5% of the weight of oysters (400kg). The enzymatic hydrolysis conditions were pH=8.0, enzymatic hydrolysis temperature of 60℃, and enzymatic hydrolysis time of 4h. After the enzymatic hydrolysis was completed, the enzyme was inactivated at 90℃ for 10min, and then the temperature was lowered to 60℃.

[0155] ② Second stage of enzymatic hydrolysis: Bacillus subtilis neutral protease and deaminase were added to the mixed raw materials for enzymatic hydrolysis. The amount of enzyme preparation added was 0.2% of the weight of oysters (400kg). The enzymatic hydrolysis conditions were pH=7.5, enzymatic hydrolysis temperature of 50℃, and enzymatic hydrolysis time of 3h.

[0156] Degreasing and enzyme inactivation treatment: After enzymatic hydrolysis, the enzyme was inactivated at 100℃ for 15 min, and then passed through a 10μm core filter at 100℃ to obtain oyster enzymatic hydrolysate;

[0157] 3. Removes fishy smell and enhances freshness

[0158] 70 parts by weight of oyster enzymatic hydrolysis filtrate were added to 15 parts by weight of water and 15 parts by weight of fructose syrup and transferred to a reaction vessel. The pH was adjusted to 8.0, the temperature was raised to 120°C and kept at that temperature for 30 minutes. The mixture was then rapidly cooled to 40°C at 10°C. The cooled material was then filtered through neutral activated carbon adsorption and a 5μm filter cloth to obtain oyster juice. At this point, the total glycine and alanine content of the oyster juice reached 1150 mg / kg. It had a strong oyster smell, a mild umami flavor, and a slight bitterness.

[0159] Comparative Example 2 (using a colloid mill, other conditions are the same as in Example 4):

[0160] 1. Oyster pretreatment

[0161] 1) Rinse 400kg of oysters with water to remove impurities from the surface of the oysters, and pre-chop them with a chopper. The oyster fragments are then fed into a colloid mill for processing at a speed of about 1500-3000 rpm and a processing aperture of about 80-200 micrometers. The crushed material is then passed through a 200-mesh sieve, with 120kg of material passing through the sieve, resulting in a sieve pass rate of 70%.

[0162] 2) Add water at a weight ratio of 1:6 for oyster paste to water to obtain a mixed raw material. Pump the mixed raw material into an enzymatic hydrolysis tank, heat it to 70°C, and keep it at that temperature for 20 minutes to slightly denature the proteins in the oyster paste. Then, cool it down to 60°C using a plate and frame cooling system.

[0163] 2. Segmented enzymatic hydrolysis of oysters

[0164] ① First stage of enzymatic hydrolysis: Alkaline protease and papain were added to the mixed raw materials for enzymatic hydrolysis. The amount of enzyme preparation added was 0.5% of the weight of oysters (400kg). The enzymatic hydrolysis conditions were pH=8.0, enzymatic hydrolysis temperature of 60℃, and enzymatic hydrolysis time of 4h. After the enzymatic hydrolysis was completed, the enzyme was inactivated at 90℃ for 10min, and then the temperature was lowered to 60℃.

[0165] ② Second stage of enzymatic hydrolysis: Bacillus subtilis neutral protease and deaminase were added to the mixed raw materials for enzymatic hydrolysis. The amount of enzyme preparation added was 0.2% of the weight of oysters (400kg). The enzymatic hydrolysis conditions were pH=7.5, enzymatic hydrolysis temperature of 50℃, and enzymatic hydrolysis time of 3h.

[0166] Degreasing and enzyme inactivation treatment: After enzymatic hydrolysis, the enzyme was inactivated at 100℃ for 15 min, and then passed through a 10μm core filter at 100℃ to obtain oyster enzymatic hydrolysate;

[0167] 3. Pretreatment of edible fungi

[0168] 1) After 50 kg of cordyceps flowers and straw mushrooms (weight ratio 1:2) are initially chopped using a chopper, the cordyceps flowers and straw mushrooms are then fed into a colloid mill for further pulverization. The rotation speed is approximately 1500-3000 rpm, and the pore size is approximately 80-200 micrometers. The pulverized material is then passed through a 200-mesh sieve, with 30.65 kg of material remaining on the sieve, resulting in a sieve pass rate of 38.7%, which indicates a significant loss.

[0169] 2) Steam the cordyceps flowers and straw mushrooms at a weight ratio of 1:10 to water at 80℃ for 60 minutes, then cool down to 45℃.

[0170] 4. Segmented enzymatic hydrolysis of edible fungi

[0171] ① First stage of enzymatic hydrolysis: Cellulase is added to the mixed raw materials for enzymatic hydrolysis. The amount of enzyme added is 0.5% of the weight of edible mushrooms (50kg). The enzymatic hydrolysis conditions are pH=8.0, enzymatic hydrolysis temperature is 60℃, enzymatic hydrolysis time is 6h, and the enzyme is inactivated at 90℃ for 10min. After inactivation, the temperature is lowered to 60℃.

[0172] ② Second stage of enzymatic hydrolysis: Deaminase and nuclease are added to the mixed raw materials for enzymatic hydrolysis. The amount of enzyme preparation added is 0.6% of the weight of edible mushrooms (50kg). The enzymatic hydrolysis conditions are pH=8.0, enzymatic hydrolysis temperature is 60℃, and enzymatic hydrolysis time is 3h.

[0173] After enzymatic hydrolysis, the enzyme was inactivated at 95℃ for 20 minutes. Impurities in the enzymatic hydrolysate of shiitake and straw mushrooms were intercepted by a core filter (pore size of 10μm) to obtain the enzymatic hydrolysate of cordyceps flower and straw mushroom.

[0174] 5. Removes fishy smell and enhances freshness

[0175] 70 parts by weight of oyster enzymatic hydrolysis filtrate were transferred to a reaction vessel, and 15 parts by weight of shiitake and straw mushroom enzymatic hydrolysis filtrate and 15 parts by weight of fructose syrup were added. The pH was adjusted to 8.0, the temperature was raised to 120℃, and kept at that temperature for 30 minutes. After being rapidly cooled to 40℃ at 10℃, the cooled substance was filtered through neutral activated carbon adsorption and a 5μm filter cloth to remove the fishy smell and obtain oyster juice. At this time, the total glycine and alanine in the oyster juice reached 1450mg / kg, with a mild umami flavor and no fishy or bitter taste.

[0176] Comparative Example 3 (no activated carbon adsorption, no filter cloth filtration, other conditions the same as Example 4):

[0177] 1. Oyster pretreatment

[0178] 1) Rinse 400kg of oysters with water to remove impurities from the surface of the oysters, and then preliminarily chop them with a chopper. The oyster fragments are then fed into a high-pressure jet mill for further pulverization. The pressure during pulverization is 140Mpa and the flow rate is 300m / s. After pulverization, the material passes through a 200-mesh sieve, with 5.0kg of material remaining on the sieve, resulting in a sieve pass rate of 98.8%.

[0179] 2) Add water at a weight ratio of 1:6 for oyster paste to water to obtain a mixed raw material. Pump the mixed raw material into an enzymatic hydrolysis tank, heat it to 70°C, and keep it at that temperature for 20 minutes to slightly denature the proteins in the oyster paste. Then, cool it down to 60°C using a plate and frame cooling system.

[0180] 2. Segmented enzymatic hydrolysis of oysters

[0181] ① First stage of enzymatic hydrolysis: Alkaline protease and papain were added to the mixed raw materials for enzymatic hydrolysis. The amount of enzyme preparation added was 0.5% of the weight of oysters (400kg). The enzymatic hydrolysis conditions were pH=8.0, enzymatic hydrolysis temperature of 60℃, and enzymatic hydrolysis time of 4h. After the enzymatic hydrolysis was completed, the enzyme was inactivated at 90℃ for 10min, and then the temperature was lowered to 60℃.

[0182] ② Second stage of enzymatic hydrolysis: Bacillus subtilis neutral protease and deaminase were added to the mixed raw materials for enzymatic hydrolysis. The amount of enzyme preparation added was 0.2% of the weight of oysters (400kg). The enzymatic hydrolysis conditions were pH=7.5, enzymatic hydrolysis temperature of 50℃, and enzymatic hydrolysis time of 3h.

[0183] Degreasing and enzyme inactivation treatment: After enzymatic hydrolysis, the enzyme was inactivated at 100℃ for 15 min, and then passed through a 10μm core filter at 100℃ to obtain oyster enzymatic hydrolysate;

[0184] 3. Pretreatment of edible fungi

[0185] 1) After 50kg of cordyceps flowers and straw mushrooms (weight ratio 1:2) are initially chopped using a chopper, the cordyceps flowers and straw mushrooms are then fed into a high-pressure jet mill for pulverization. The pressure during pulverization is 140Mpa and the flow rate is 280m / s. After pulverization, the material passes through a 200-mesh sieve, with 2.0kg of material remaining on the sieve, resulting in a sieve pass rate of 96.0%.

[0186] 2) Steam the cordyceps flowers and straw mushrooms at a weight ratio of 1:10 to water at 80℃ for 60 minutes, then cool down to 45℃.

[0187] 4. Segmented enzymatic hydrolysis of edible fungi

[0188] ① First stage of enzymatic hydrolysis: Cellulase is added to the mixed raw materials for enzymatic hydrolysis. The amount of enzyme added is 0.5% of the weight of edible mushrooms (50kg). The enzymatic hydrolysis conditions are pH=8.0, enzymatic hydrolysis temperature is 60℃, enzymatic hydrolysis time is 6h, and the enzyme is inactivated at 90℃ for 10min. After inactivation, the temperature is lowered to 60℃.

[0189] ② Second stage of enzymatic hydrolysis: Deaminase and nuclease are added to the mixed raw materials for enzymatic hydrolysis. The amount of enzyme preparation added is 0.6% of the weight of edible mushrooms (50kg). The enzymatic hydrolysis conditions are pH=8.0, enzymatic hydrolysis temperature is 60℃, and enzymatic hydrolysis time is 3h.

[0190] After enzymatic hydrolysis, the enzyme was inactivated at 95℃ for 20 minutes. Impurities in the enzymatic hydrolysate of Cordyceps militaris and Strawberry were intercepted by a core filter (pore size of 10μm) to obtain the enzymatic hydrolysate of Cordyceps militaris and Strawberry.

[0191] 5. Removes fishy smell and enhances freshness

[0192] 70 parts by weight of oyster enzymatic hydrolysis filtrate were transferred to a reaction vessel, and 15 parts by weight of cordyceps flower and straw mushroom enzymatic hydrolysis filtrate and 15 parts by weight of fructose syrup were added. The pH was adjusted to 8.0, the temperature was raised to 120℃, and the temperature was kept for 30 minutes. After being rapidly cooled to 40℃ at 10℃, oyster juice was obtained. At this time, the total glycine and alanine content of the oyster juice was 1900 mg / kg. It had a strong umami flavor, a strong oyster fishy smell, and no bitterness.

[0193] Comparative Example 4 (no mushrooms added, no activated carbon adsorption added, other conditions the same as Example 4):

[0194] 1. Oyster pretreatment

[0195] 1) Rinse 400kg of oysters with water to remove impurities from the surface of the oysters, and then preliminarily chop them with a chopper. The oyster fragments are then fed into a high-pressure jet mill for further pulverization. The pressure during pulverization is 140Mpa and the flow rate is 300m / s. After pulverization, the material passes through a 200-mesh sieve, with 5.0kg of material remaining on the sieve, resulting in a sieve pass rate of 98.8%.

[0196] 2) Add water at a weight ratio of 1:6 for oyster paste to water to obtain a mixed raw material. Pump the mixed raw material into an enzymatic hydrolysis tank, heat it to 70°C, and keep it at that temperature for 20 minutes to slightly denature the proteins in the oyster paste. Then, cool it down to 60°C using a plate and frame cooling system.

[0197] 2. Segmented enzymatic hydrolysis of oysters

[0198] ① First stage of enzymatic hydrolysis: Alkaline protease and papain were added to the mixed raw materials for enzymatic hydrolysis. The amount of enzyme preparation added was 0.5% of the weight of oysters (400kg). The enzymatic hydrolysis conditions were pH=8.0, enzymatic hydrolysis temperature of 60℃, and enzymatic hydrolysis time of 4h. After the enzymatic hydrolysis was completed, the enzyme was inactivated at 90℃ for 10min, and then the temperature was lowered to 60℃.

[0199] ② Second stage of enzymatic hydrolysis: Bacillus subtilis neutral protease and deaminase were added to the mixed raw materials for enzymatic hydrolysis. The amount of enzyme preparation added was 0.2% of the weight of oysters (400kg). The enzymatic hydrolysis conditions were pH=7.5, enzymatic hydrolysis temperature of 50℃, and enzymatic hydrolysis time of 3h.

[0200] Degreasing and enzyme inactivation treatment: After enzymatic hydrolysis, the enzyme was inactivated at 100℃ for 15 min, and then passed through a 10μm core filter at 100℃ to obtain oyster enzymatic hydrolysate;

[0201] 3. Removes fishy smell and enhances freshness

[0202] 70 parts by weight of oyster enzymatic hydrolysis filtrate, 15 parts by weight of water and 15 parts by weight of fructose syrup were transferred to a reaction vessel, the pH was adjusted to 8.0, the temperature was raised to 120℃ and kept at that temperature for 30 minutes, and then rapidly cooled to 40℃ at 10℃ to obtain oyster juice. At this time, the total glycine and alanine content of the oyster juice reached 1050 mg / kg, with a strong oyster smell, a mild umami flavor and a slight bitterness.

[0203] The raw material losses and flavor indicators of the oyster sauce prepared in the above examples and comparative examples are recorded in Table 4; and the flavor evaluation and analysis of the oyster sauce prepared in the examples and comparative examples are shown in Table 5.

[0204] Table 4

[0205]

[0206]

[0207] Table 5. Evaluation and Analysis of Oyster Sauce Flavor

[0208]

[0209] Note: Score 0-1 indicates a very mild rating, close to none; score 1.01-2 indicates a slight rating; score 2.01-3 indicates a mild rating; score 3.01-4 indicates a moderate rating; score 4.01-5 indicates a severe rating; score 5.01-6 indicates a strong rating; score > 6.01 indicates a very strong rating.

[0210] The results in Tables 4 and 5 show that, compared to existing oyster sauces, the oyster sauce prepared by this invention has a more prominent umami flavor, a delicate texture, and virtually no fishy or bitter taste, indicating a better overall flavor. Specifically, ① this invention adds edible mushroom enzymatic hydrolysis filtrate to the oyster enzymatic hydrolysis filtrate as a raw material for oyster sauce, significantly improving the umami flavor of the oyster sauce and suppressing the fishy taste of the oyster enzymatic hydrolysis filtrate; ② this invention uses a high-pressure jet mill to pre-treat the raw materials, which promotes the full enzymatic hydrolysis of edible mushrooms and oysters, completely releasing the flavor substances, enhancing the umami flavor of the oyster sauce, improving the taste of the oyster sauce, and reducing raw material loss; ③ this invention uses neutral activated carbon and filter cloth for filtration, which can effectively further remove the fishy taste of the oyster sauce. Combined with the deodorization and umami enhancement reaction to remove the fishy taste and the edible mushrooms to suppress the fishy taste, this solves the problem of the strong fishy taste of the oyster sauce, making its flavor better.

[0211] Obviously, the above embodiments of the present invention are merely examples to clearly illustrate the technical solution of the present invention, and are not intended to limit the specific implementation of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the claims of the present invention should be included within the protection scope of the claims of the present invention.

Claims

1. A method for enhancing the umami flavor and removing the fishy smell of oyster sauce using enzymatic hydrolysis technology, characterized in that, Includes the following steps: (1) Oyster pretreatment: Rinse fresh oysters with water to remove surface impurities, chop them, and then put the oysters into a high-pressure jet mill for shearing and crushing. Then, the oysters are mixed with water to obtain a mixture, which is then heated to cause slight denaturation of the proteins in the oysters. (2) Oyster enzymatic hydrolysis: Add alkaline protease, papain, Bacillus subtilis neutral protease and deaminase to the mixed raw materials obtained in step (1) for compound enzymatic hydrolysis; The oyster hydrolysate obtained after enzymatic hydrolysis is filtered to obtain oyster hydrolysate filtrate; (3) Pretreatment of edible fungi: Chop the edible fungi and put them into a high-pressure jet mill for shearing and crushing; Then, the edible mushrooms are mixed with water and steamed to obtain a mushroom mixture. (4) Enzymatic hydrolysis of edible fungi: Add cellulase, deaminase and nuclease to the fungi mixture for compound enzymatic hydrolysis; The enzymatic hydrolysate of edible fungi obtained after enzymatic hydrolysis was filtered to obtain the enzymatic hydrolysate of edible fungi. (5) Deodorization and flavor enhancement: Transfer the oyster enzymatic hydrolysis filtrate to the reaction vessel, add the edible mushroom enzymatic hydrolysis filtrate and fructose syrup, heat to 90~120℃, keep warm for 30~90min, and then cool; the cooled material is filtered through neutral activated carbon and filter cloth to obtain oyster juice.

2. The method for enhancing the umami flavor and removing the fishy smell of oyster sauce using enzymatic hydrolysis technology according to claim 1, characterized in that, The edible mushrooms mentioned are one or more of the following: enoki mushrooms, straw mushrooms, shiitake mushrooms, porcini mushrooms, and cordyceps flowers.

3. The method for enhancing the umami flavor and removing the fishy smell of oyster sauce using enzymatic hydrolysis technology according to claim 2, characterized in that, in In steps (1) and (3), the pressure of the high-pressure jet mill is 140 MPa and the flow rate is 200~350 m / s.

4. The method for enhancing the umami flavor and removing the fishy smell of oyster sauce using enzymatic hydrolysis technology according to claim 3, characterized in that, in In step (1), the weight ratio of oysters to water in the mixed raw materials is 1:2~6; the mixed raw materials are heated to 70~90℃ and kept warm for 10~20min to slightly denature the proteins in the oysters, and then cooled down.

5. The method for enhancing the umami flavor and removing the fishy smell of oyster sauce using enzymatic hydrolysis technology according to claim 4, characterized in that, In step (2), the oysters are subjected to segmented enzymatic hydrolysis: First stage of enzymatic hydrolysis: Alkaline protease and papain are added to the mixed raw materials for enzymatic hydrolysis, and then the enzyme activity is inactivated by heating; Second stage of enzymatic hydrolysis: Add Bacillus subtilis neutral protease and deaminase to the mixed raw materials after the first stage of enzymatic hydrolysis, carry out enzymatic hydrolysis, and then heat to inactivate the enzymes to obtain oyster enzymatic hydrolysate; The specific conditions for the first stage of enzymatic hydrolysis are as follows: the weight of alkaline protease and papain added is 0.5-1.6% of the oyster weight, the initial pH value is 7.0-8.0, the enzymatic hydrolysis temperature is 50-60℃, the enzymatic hydrolysis time is 4-8h, and the first stage of enzyme inactivation is carried out at 90-95℃ for 5-10min. The specific conditions for the second stage of enzymatic hydrolysis are as follows: the weight of Bacillus subtilis neutral protease and deaminase added is 0.2-1.0% of the oyster weight, the hydrolysis conditions are initial pH 7.0-8.0, hydrolysis temperature 40-50℃, hydrolysis time 3-6h, and the second stage of enzyme inactivation is carried out at 95-100℃ for 15-30min.

6. The method for enhancing the umami flavor and removing the fishy smell of oyster sauce using enzymatic hydrolysis technology according to claim 5, characterized in that, In step (2), the filtration is performed by thermal filtration using a cartridge filter at 95~100℃; the pore size of the cartridge filter is 5~10μm.

7. The method for enhancing the umami flavor and removing the fishy smell of oyster sauce using enzymatic hydrolysis technology according to claim 6, characterized in that, In step (3), the weight ratio of edible mushrooms to water is 1:5~20. The mixture is steamed at 80~100℃ for 30~60 minutes and then cooled to obtain a mushroom mixture.

8. The method for enhancing the umami flavor and removing the fishy smell of oyster sauce using enzymatic hydrolysis technology according to claim 7, characterized in that, in In step (4), the edible mushrooms are subjected to segmented enzymatic hydrolysis: First stage of enzymatic hydrolysis: Cellulase is added to the mushroom mixture for enzymatic hydrolysis, and then the enzyme activity is inactivated by heating; Second stage of enzymatic hydrolysis: Deaminase and nuclease are added to the mushroom mixture after the first stage of enzymatic hydrolysis for enzymatic hydrolysis, and then the enzyme activity is inactivated by heating to obtain edible mushroom enzymatic hydrolysate; The specific conditions for the first stage of enzymatic hydrolysis are as follows: the weight of cellulase added is 0.1~0.5% of the weight of edible mushrooms, the pH value is 6.0~8.0, the enzymatic hydrolysis temperature is 40~60℃, the enzymatic hydrolysis time is 3~6h, and the first stage of enzyme inactivation is carried out at 90~95℃ for 5~10min. The specific conditions for the second stage of enzymatic hydrolysis are as follows: the weight of deaminase and nuclease added is 0.2-0.6% of the weight of edible mushrooms, the pH value is 7.0-8.0, the hydrolysis temperature is 40-60℃, the hydrolysis time is 3-6h, and the second stage of enzyme inactivation is carried out at 95-100℃ for 15-30min.

9. The method for enhancing the umami flavor and removing the fishy smell of oyster sauce using enzymatic hydrolysis technology according to claim 8, characterized in that, In step (5), 40-70 parts by weight of oyster enzymatic hydrolysis filtrate are transferred to a reaction vessel, 10-30 parts by weight of edible mushroom enzymatic hydrolysis filtrate and 10-30 parts by weight of fructose syrup are added, the pH value is adjusted to 7.0-8.0, the temperature is raised to 90-120℃, and the temperature is kept for 30-90 minutes. Then, the temperature is rapidly cooled to 30-40℃ under the condition of 0-10℃. The cooled material is filtered through neutral activated carbon and filter cloth to obtain oyster juice.

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