Oyster sauce base material and preparation method thereof, and oyster sauce containing the oyster sauce base material

Abstract

The present invention discloses an oyster sauce base and a preparation method thereof, and oyster sauce containing the oyster sauce base, belonging to the technical field of seasonings. In the preparation method of the oyster sauce base provided by the present invention, ultrasonic combined heat treatment and enzymatic hydrolysis are performed after the ultrasonic combined heat treatment, and protamine and chili paste are added during the enzymatic hydrolysis process. This method can not only effectively reduce the microbial level of the material before and during enzymatic hydrolysis, thereby reducing the volatile basic nitrogen content produced by microorganisms and reducing the degree of fishy smell in the oyster sauce base, but also significantly increase the amino acid nitrogen content in the oyster sauce base, thereby improving the taste of the subsequently prepared oyster sauce. At the same time, the preparation method provided by the present invention is simple to operate and is conducive to actual production.

Description

Technical Field

[0001] The invention belongs to the technical field of condiments, and in particular relates to an oyster sauce base material and a preparation method thereof, and oyster sauce containing the oyster sauce base material. Background Art

[0002] Oysters, commonly known as raw oysters, are a highly nutritious and delicious shellfish, rich in amino acids, glycogen, vitamins, and other nutrients. Currently, oyster sauce is primarily made from steamed and concentrated oyster juice or enzymatically hydrolyzed oyster juice, supplemented with salt, sugar, MSG, and starch. Enzymatically hydrolyzed oyster juice is made by enzymatically hydrolyzing oyster meat. Due to the lengthy enzymatic hydrolysis process and the impact on enzyme activity, the enzymatic hydrolysis of oyster meat often results in high volatile basic nitrogen content and a strong fishy odor.

[0003] To obtain enzymatically hydrolyzed oyster juice with a high amino acid nitrogen content, the enzymatic hydrolysis time of oyster meat is typically prolonged. During the hydrolysis process, the oyster meat is broken down into small molecules such as amino acids and peptides. However, microorganisms also multiply during the hydrolysis process, producing unhealthy biogenic amines. This increases the volatile basic nitrogen content and enhances the fishy odor in the hydrolyzed liquid. Various technical solutions have been proposed in the prior art to address this issue. For example, patent CN114403386A proposes enzymatic hydrolysis of the oyster meat directly after washing it. However, as the enzymatic hydrolysis time increases, microorganisms produce more biogenic amines, increasing the volatile basic nitrogen content and resulting in a stronger fishy odor, affecting the flavor and quality of the oyster juice. Patent CN114365838A reduces the volatile basic nitrogen content by treating the oyster meat fermentation liquid with edible alkali. This method involves the introduction of chemical reagents, which can affect the oyster juice's labeling, leave chemical residues that are harmful to human health, and compromise the flavor of the oyster juice. Patent CN109198573A uses high temperature and long duration to treat oyster meat. This method can appropriately reduce the level of microorganisms during the enzymatic hydrolysis process, but this method only controls the microorganisms in the oyster meat raw material and does not effectively control the microbial growth during the enzymatic hydrolysis process. At the same time, high temperature treatment can also cause excessive denaturation of oyster meat protein, which can encapsulate the enzymatic hydrolysis sites, thereby reducing the efficiency of enzymatic hydrolysis and destroying heat-sensitive nutrients in the oyster meat. Patent CN109486887A uses ultrasound and enzymatic hydrolysis to treat oyster meat simultaneously. The ultrasound treatment in this patent is mainly used to increase enzyme activity and thus improve enzymatic hydrolysis efficiency. This method has low ultrasound power and short treatment time, and fails to reduce the volatile basic nitrogen produced by microbial growth during the enzymatic hydrolysis process. In addition, although this method can increase ultrasound power and time, high-power ultrasound can inactivate both microorganisms and enzymes, reducing enzymatic hydrolysis efficiency, which violates the purpose of the patent.

[0004] In summary, existing technologies fail to effectively control biogenic amines and other substances before and during enzymatic hydrolysis. Consequently, the resulting enzymatic hydrolysates often contain high levels of volatile basic nitrogen and a strong fishy odor. Addressing these issues has become a research priority. Summary of the Invention

[0005] The object of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide an oyster sauce base having a low total colony count of an enzymatic hydrolysis substrate, and having a low volatile basic nitrogen content, a high ammonia nitrogen level and an excellent comprehensive sensory score in the prepared oyster sauce, as well as a preparation method thereof, and an oyster sauce containing the oyster sauce base.

[0006] To achieve the above objectives, in a first aspect of the present invention, the present invention provides a method for preparing an oyster sauce base, the preparation method comprising the following steps:

[0007] (1) subjecting the oyster meat slurry to an ultrasonic combined with heat treatment to obtain oyster meat liquid;

[0008] (2) adding a composite enzyme preparation, protamine, and chili paste to the oyster meat liquid for a first enzymatic hydrolysis, and allowing the liquid to stand for stratification after the first enzymatic hydrolysis to obtain a supernatant and a precipitate;

[0009] (3) subjecting the precipitate to a secondary ultrasonic combined with heat treatment, and then adding a composite enzyme preparation for secondary enzymatic hydrolysis to obtain a secondary enzymatic hydrolyzate;

[0010] (4) The supernatant and the secondary enzymatic hydrolysate are mixed and heated, and then concentrated and centrifuged to obtain the oyster juice base.

[0011] In the preparation method of the oyster sauce base provided by the present invention, ultrasonic combined with heat treatment and enzymatic hydrolysis are performed after the ultrasonic combined with heat treatment, and protamine and chili paste are added during the enzymatic hydrolysis process. This can not only effectively reduce the microbial level of the material before and during enzymatic hydrolysis, thereby reducing the volatile basic nitrogen content produced by microorganisms and reducing the degree of fishy smell in the oyster sauce base, but also significantly increase the amino acid nitrogen content in the oyster sauce base, thereby improving the taste of the oyster sauce prepared subsequently. Specifically, the method of the present invention can reduce the temperature of the heat treatment and avoid the impact of high-temperature treatment on the material; at the same time, the process of ultrasonic combined with heat treatment followed by enzymatic hydrolysis can effectively avoid the destruction of enzyme activity by ultrasonic combined with heat treatment; in addition, the addition of protamine and chili paste can not only inhibit the reproduction of microorganisms, but also help promote the increase of the amino acid nitrogen content in the oyster sauce base.

[0012] As a preferred embodiment of the preparation method of the present invention, in the first ultrasonic combined heat treatment and the second ultrasonic combined heat treatment, the ultrasonic power is independently 700-900w, and the heat treatment temperature is independently 60-65°C.

[0013] As a preferred embodiment of the preparation method of the present invention, the treatment time of the first ultrasonic combined heat treatment and the second ultrasonic combined heat treatment is independently 30-50 minutes.

[0014] The present invention has found that in ultrasonic combined with heat treatment, the cavitation effect of ultrasound combined with heat treatment can destroy the cell membrane of microorganisms, thereby achieving the purpose of killing microorganisms, thereby affecting the total colony count; in addition, the power of ultrasound and the temperature of heat treatment will also affect the content of volatile basic nitrogen and amino acid nitrogen. When the ultrasonic power is further selected to be 700-900w and the heat treatment temperature is further selected to be 60-65℃, the comprehensive effect of the obtained product is even better.

[0015] As a preferred embodiment of the preparation method of the present invention, in the primary enzymatic hydrolysis, based on the oyster meat liquid, the mass percentage of protamine is 0.05-0.1%, the mass percentage of chili paste is 4-6%, and the mass percentage of the complex enzyme preparation is 3-4%;

[0016] The temperature of the primary enzymatic hydrolysis is 50-60° C., and the time is 3-5 hours.

[0017] As a preferred embodiment of the preparation method of the present invention, the mass percentage of the complex enzyme preparation is 3-4.8% based on the precipitate;

[0018] The temperature of the secondary enzymatic hydrolysis is 50-60° C., and the time is 1.5-2.5 h.

[0019] The present invention has found that during the enzymatic hydrolysis process, the addition amount of protamine, chili paste and compound enzyme preparation will not only affect the amino acid nitrogen content of the product, but also affect the microbial level and volatile basic nitrogen content of the product, thereby affecting the taste of the product; when the addition amount of the substances in the enzymatic hydrolysis process is further selected to be within the above range, a product with excellent comprehensive effect can be obtained.

[0020] As a preferred embodiment of the preparation method of the present invention, the composite enzyme preparation comprises flavor protease, papain and amylase, and the mass ratio of flavor protease, papain and amylase is (0.75-1.5): (0.75-1.5): (1.5-1.8).

[0021] In one embodiment, in the complex enzyme, the mass ratio of flavor protease, papain, and amylase is 1:1:1.5.

[0022] As a preferred embodiment of the preparation method of the present invention, in the step (4), centrifugation is performed until the centrifugal sediment value is 3-5%.

[0023] The calculation method of the centrifugal sediment value is: centrifugal sediment value = sediment mass after centrifugation / total mass before centrifugation * 100%.

[0024] The present invention has found that controlling the centrifugal sediment value between 3-5% can improve the overall taste of the product.

[0025] As a preferred embodiment of the preparation method of the present invention, the preparation method of the oyster meat slurry is: mixing oyster meat with water and beating to obtain oyster meat slurry;

[0026] And / or, the preparation method of the chili paste is: mixing chili with water and beating the mixture to obtain the chili paste.

[0027] Preferably, the pepper is red pepper, and the mass ratio of the red pepper to water is 1:(0.4-0.6).

[0028] Preferably, the mass ratio of the oyster meat to water is 1:(1.2-1.8).

[0029] As a preferred embodiment of the preparation method of the present invention, in the step (4), the temperature of the mixed heating is 105-115° C. and the time is 1-2 h.

[0030] The mixed heating here can inactivate enzymes while reacting and enhancing flavor, thereby improving the overall taste score of the product.

[0031] As a preferred embodiment of the preparation method of the present invention, in the step (4), the Brix after concentration is 17-21%.

[0032] In a second aspect of the present invention, the present invention provides an oyster sauce base, which is prepared by the above-mentioned preparation method of the oyster sauce base.

[0033] In a third aspect of the present invention, the present invention provides an oyster sauce comprising the oyster sauce base of the present invention.

[0034] As a preferred embodiment of the oyster sauce described in the present invention, the oyster sauce includes the following components in parts by mass: 18-22 parts of the oyster sauce base described in the present invention, 6-10 parts of modified starch, 13-17 parts of white sugar, 8-12 parts of edible salt, 2-4 parts of caramel color, 4-6 parts of MSG, and 36-40 parts of water.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] In the preparation method of the oyster sauce base provided by the present invention, ultrasonic combined heat treatment and enzymolysis are carried out after ultrasonic combined heat treatment, and protamine and chili paste are added during the enzymolysis process, which can not only effectively reduce the microbial level of the material before and during enzymolysis, reduce the volatile basic nitrogen content produced by microorganisms, and reduce the degree of fishy smell in the oyster sauce base, but also significantly increase the amino acid nitrogen content in the oyster sauce base, thereby improving the taste of the oyster sauce prepared subsequently. Specifically, the total colony count in the prepared oyster sauce is below 590 cfu / mL, the amino acid nitrogen content is above 0.58 g / 100 mL, the volatile basic nitrogen is below 59.43 mg / 100 g, and the comprehensive sensory score is above 7.5 points. At the same time, the preparation method provided by the present invention is simple to operate, which is conducive to actual production. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 The figure is a flow chart of the oyster sauce preparation process of the present invention. DETAILED DESCRIPTION

[0038] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0039] Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0040] The oyster meat slurry used in the examples and comparative examples was prepared from the same batch of oyster meat. Specifically, the oyster meat was shelled and washed, and then pulped with distilled water at a mass ratio of 1:1.5 (the pulping operation was performed by intermittently processing with a high-speed pulper for 10 minutes until the texture was uniform and fine), to obtain the oyster meat slurry;

[0041] The chili pulp used in the embodiment and the comparative example is the chili pulp processed from the same batch, specifically: fresh red peppers are added with distilled water at a mass ratio of 1:0.5 and beaten (the beating operation is to use a high-speed beater for intermittent processing for 15 minutes until the tissue is uniform and fine without large particles) to obtain a chili pulp;

[0042] Complex enzyme preparation: a mixture of flavor protease, papain and amylase, wherein the mass ratio of flavor protease, papain and amylase is 1:1:1.5;

[0043] If other raw materials are not mentioned, the parallel experiments used the same batch of raw materials.

[0044] Example 1

[0045] The embodiment of the present invention provides an oyster sauce base material, and the oyster sauce base material preparation process flow chart is as follows: Figure 1 As shown, the preparation method comprises the following steps:

[0046] (1) placing the oyster meat slurry under the conditions of ultrasonic power of 800W and temperature of 60°C for an ultrasonic combined heat treatment for 40 minutes to obtain oyster meat liquid;

[0047] (2) adding 3.5% by weight of a composite enzyme preparation, 0.05% by weight of protamine, and 5% by weight of chili paste to the oyster meat liquid in sequence, performing enzymatic hydrolysis at 55° C. for 4 h to obtain a primary enzymatic hydrolyzate, allowing the solution to stand for stratification, and obtaining a supernatant and a precipitate;

[0048] (3) The precipitate was placed under the conditions of an ultrasonic power of 800W and a temperature of 60°C for a secondary ultrasonic combined heat treatment for 40 minutes; after the treatment, a 3.5% by weight composite enzyme preparation was added and a secondary enzymatic hydrolysis was carried out at 55°C for 2 hours to obtain a secondary enzymatic hydrolyzate;

[0049] (4) The supernatant and the secondary enzymatic hydrolysate were mixed and heated to 110°C for 1.5 h, and then concentrated to 19 Brix. The mixture was centrifuged and filtered until the centrifugal sediment value was reduced to 3%. The collected supernatant was the oyster juice base.

[0050] Example 2

[0051] The embodiment of the present invention provides an oyster sauce base material. The only difference between the preparation method of the oyster sauce base material and that of Example 1 is that the ultrasonic power in step (1) is 700w and the temperature is 65°C.

[0052] Example 3

[0053] The embodiment of the present invention provides an oyster sauce base. The only difference between the preparation method of the oyster sauce base and that of Example 1 is that the mass percentage of protamine in step (2) is 0.1% and the mass percentage of chili paste is 4%.

[0054] Example 4

[0055] The embodiment of the present invention provides an oyster sauce base. The only difference between the preparation method of the oyster sauce base and that of Example 1 is that in step (4), centrifugation is performed until the centrifugal sediment value is reduced to 5%.

[0056] Example 5

[0057] The embodiment of the present invention provides an oyster sauce base material. The only difference between the preparation method of the oyster sauce base material and that of Example 1 is that the ultrasonic power in step (1) is 500w and the temperature is 50°C.

[0058] Example 6

[0059] The embodiment of the present invention provides an oyster sauce base. The only difference between the preparation method of the oyster sauce base and that of Example 1 is that the mass percentage of protamine in step (2) is 0.02% and the mass percentage of chili paste is 2%.

[0060] Example 7

[0061] The embodiment of the present invention provides an oyster sauce base. The only difference between the preparation method of the oyster sauce base and that of Example 1 is that in step (4), centrifugation is performed until the centrifugal sediment value is reduced to 8%.

[0062] Comparative Example 1

[0063] The comparative example of the present invention provides an oyster sauce base, and the preparation method of the oyster sauce base comprises the following steps:

[0064] (1) adding 3.5% by weight of a composite enzyme preparation to the oyster meat slurry, performing enzymatic hydrolysis at 55° C. for 4 h to obtain a primary enzymatic hydrolyzate, allowing the slurry to stand and separate into layers to obtain a supernatant and a precipitate;

[0065] (3) adding 3.5% by mass of a composite enzyme preparation to the precipitate and performing secondary enzymolysis at 55°C for 2 h to obtain a secondary enzymolysis solution;

[0066] (4) The supernatant and the secondary enzymatic hydrolysate were mixed and heated to 110°C for 1.5 h, and then concentrated to 19 Brix. The mixture was centrifuged and filtered until the centrifugal sediment value was reduced to 3%. The collected supernatant was the oyster juice base.

[0067] Comparative Example 2

[0068] The comparative example of the present invention provides an oyster sauce base, and the preparation method of the oyster sauce base comprises the following steps:

[0069] (1) heating the oyster meat slurry at 100° C. for 30 minutes to obtain oyster meat liquid;

[0070] (2) adding 3.5% by weight of a composite enzyme preparation to the oyster meat liquid, performing enzymatic hydrolysis at 55° C. for 4 h to obtain a primary enzymatic hydrolyzate, allowing the solution to stand for stratification, and obtaining a supernatant and a precipitate;

[0071] (3) adding 3.5% by weight of a composite enzyme preparation to the precipitate, performing secondary enzymolysis at 55°C for 2 h, and allowing the mixture to stand and separate to obtain a secondary enzymolysis solution.

[0072] (4) The supernatant and the secondary enzymatic hydrolysate were mixed and heated to 110°C for 1.5 h, and then concentrated to 19 Brix. The mixture was centrifuged and filtered until the centrifugal sediment value was reduced to 3%. The collected supernatant was the oyster juice base.

[0073] Comparative Example 3

[0074] The comparative example of the present invention provides an oyster sauce base, and the preparation method of the oyster sauce base comprises the following steps:

[0075] (1) 3.5% by weight of a composite enzyme preparation, 0.05% by weight of protamine, and 5% by weight of chili paste were sequentially added to the oyster meat slurry, and enzymatic hydrolysis was performed at 55°C for 4 hours. During the enzymatic hydrolysis, an ultrasonic combined heat treatment was performed at an ultrasonic power of 800W and a temperature of 60°C for 40 minutes. After the enzymatic hydrolysis was completed, the mixture was allowed to stand for stratification to obtain a supernatant and a precipitate.

[0076] (3) adding 3.5% by weight of a composite enzyme preparation to the precipitate, performing secondary enzymatic hydrolysis at 55°C for 2 h, and simultaneously performing secondary ultrasonic combined heat treatment at an ultrasonic power of 800 W and a temperature of 60°C for 40 min. After the enzymatic hydrolysis is completed, a secondary enzymatic hydrolyzate is obtained;

[0077] (4) The supernatant and the secondary enzymatic hydrolysate were mixed and heated to 110°C for 1.5 h, and then concentrated to 19 Brix. The mixture was centrifuged and filtered until the centrifugal sediment value was reduced to 3%. The collected supernatant was the oyster juice base.

[0078] Comparative Example 4

[0079] The comparative example of the present invention provides an oyster juice base material. The only difference between the preparation method of the oyster juice base material and that of Example 1 is step (2). Step (2) of this comparative example is: adding 3.5% by mass of a complex enzyme and 5.05% by mass of edible salt to the oyster meat liquid in sequence, performing a single enzymatic hydrolysis at 55° C. for 4 hours to obtain a primary enzymatic hydrolyzate, standing to separate layers, and obtaining a supernatant and a precipitate.

[0080] Comparative Example 5

[0081] The comparative example of the present invention provides an oyster sauce base. The only difference between the preparation method of the oyster sauce base and Example 1 is step (4). Step (4) of this comparative example is: mixing the primary enzymatic hydrolyzate and the secondary enzymatic hydrolyzate to 110°C and maintaining for 1.5 hours, and then concentrating to 19 Brix to obtain the oyster sauce base.

[0082] Comparative Example 6

[0083] The comparative example of the present invention provides an oyster sauce base material. The only difference between the preparation method of the oyster sauce base material and that of Example 1 is step (2). Step (2) of this comparative example is: adding 3.5% by mass of a complex enzyme and 5.05% by mass of chili paste to the oyster meat liquid in sequence, performing a single enzymatic hydrolysis at 55° C. for 4 hours to obtain a primary enzymatic hydrolyzate, standing to separate layers, and obtaining a supernatant and a precipitate.

[0084] Comparative Example 7

[0085] The comparative example of the present invention provides an oyster sauce base material. The only difference between the preparation method of the oyster sauce base material and that of Example 1 is step (2). Step (2) of this comparative example is: adding 3.5% by mass of a complex enzyme and 5.05% by mass of protamine to the oyster meat liquid in sequence, performing a single enzymatic hydrolysis at 55° C. for 4 hours to obtain a primary enzymatic hydrolyzate, standing to separate layers, and obtaining a supernatant and a precipitate.

[0086] Comparative Example 8

[0087] The comparative example of the present invention provides an oyster sauce base material. The only difference between the preparation method of the oyster sauce base material and that of Example 1 is step (1) and step (2). In this comparative example, the oyster meat slurry is not subjected to ultrasonic combined heat treatment. Instead, 3.5% by mass of a composite enzyme preparation, 0.05% by mass of protamine, and 5% by mass of chili paste are directly added to the oyster meat slurry in sequence. The oyster meat slurry is enzymatically hydrolyzed at 55° C. for 4 hours to obtain a primary enzymatic hydrolyzate, which is then allowed to stand for stratification to obtain a supernatant and a precipitate.

[0088] Comparative Example 9

[0089] The comparative example of the present invention provides an oyster sauce base material. The only difference between the preparation method of the oyster sauce base material and Example 1 is step (3). Step (3) of this comparative example is: adding 3.5% by mass of a composite enzyme preparation to the precipitate, performing secondary enzymolysis at 55°C for 2h, and obtaining a secondary enzymolysis solution.

[0090] Effect Examples

[0091] The present invention prepares oyster sauce from the oyster juice base prepared in Examples 1-7 and Comparative Examples 1-9. The process flow chart of the preparation of oyster sauce is as follows: Figure 1 Specifically, 30 parts of oyster sauce base, 8 parts of modified starch, 15 parts of white sand, 10 parts of edible salt, 3 parts of caramel color, 5 parts of monosodium glutamate, and 29 parts of water were mixed and boiled at 100°C for 20 minutes to obtain oyster sauce. The performance of the prepared oyster sauce was tested, including the following aspects:

[0092] 1. Total Colony Count: Determine the total colony count of the enzymatic substrate before the addition of the composite enzyme preparation for the first enzymatic hydrolysis in the oyster sauce base prepared in Examples 1-7 and Comparative Examples 1-9. Dilute the substrate to be enzymatically hydrolyzed by an appropriate multiple and then determine the total colony count. The detection method for the total colony count is based on GB 4789.2-2022 National Food Safety Standard - Determination of Total Colony Count for Food Microbiological Examination;

[0093] 2. Amino Acid Nitrogen and Volatile Basic Nitrogen Content: The amino acid nitrogen and volatile basic nitrogen contents in oyster sauces prepared using the oyster sauce bases prepared in Examples 1-7 and Comparative Examples 1-9 were measured. Specific detection methods were as described in GB5009.235-2016 National Food Safety Standard - Determination of Amino Acid Nitrogen in Foods and GB5009.228-2016 National Food Safety Standard - Determination of Volatile Basic Nitrogen in Foods, respectively.

[0094] 3. Sensory evaluation: 20 professional sensory evaluators were asked to perform comprehensive sensory evaluation on the prepared oyster sauce, and then the average value was taken; the sensory evaluation was used to score the pleasantness of the aroma of the oyster sauce; the sensory evaluation principle was as follows: the aroma score was 10 points: 7-10 points, with a strong sweet and scorched wheat aroma, a good oyster aroma, no fishy smell or a weak fishy smell, and a harmonious aroma; 5-7 points, with a weak sweet and scorched aroma, weak oyster aroma and wheat aroma, a moderate fishy smell, and a slightly unharmonious aroma; 0-5 points, with a strong fishy smell The taste is strong, the aroma is not harmonious, and the oyster aroma and burnt sweet aroma are very weak; the higher the score, the better the sensory experience; the taste score is 10 points: 7-10 points, the fresh and sweet taste and oyster meat taste are good, there is no fishy smell or very weak fishy smell, the taste is harmonious, and there is no burnt bitterness; 5-7 points, the oyster taste is strong, the seafood and earthy smell are slightly strong, the fresh and sweet taste is slightly weak, and the taste is slightly harmonious; 0-5 points, the taste has a strong earthy smell, the fresh and sweet taste is weak, there is a burnt taste, and the taste is not harmonious; the comprehensive sensory score is aroma score * 0.6 + taste score * 0.4;

[0095] The test results are shown in Table 1;

[0096] Table 1

[0097]

[0098]

[0099] As can be seen from Table 1, when the preparation method of the present invention (Examples 1-7) is used, the comprehensive sensory scores of the prepared oyster sauces are all higher than those of Comparative Example 1 (preparation method of enzymatically hydrolyzed oyster sauce base in the prior art), that is, the sensory scores are all 7.5 points or above, the total colony count of the substrate before the first enzymatic hydrolysis is significantly reduced, and at the same time, the amino acid nitrogen content in the oyster sauce base is above 0.58 g / 100 mL and the volatile basic nitrogen content is below 59.43 mg / 100 g. As can be seen from the data, the oyster sauce base obtained by the present invention has a higher amino acid nitrogen content and a lower volatile basic nitrogen content, and the sensory score of the prepared oyster sauce is higher;

[0100] At the same time, the ultrasonic power, heat treatment temperature, the amount of protamine and chili paste, and the centrifugal sediment value all affect the quality of the present invention. From Examples 1-7, Examples 1-4 with better effects were further selected, that is, when the ultrasonic power was ≥700w, the heat treatment temperature was 60-65°C, the amount of protamine and chili paste added (protamine 0.05-0.1%, chili paste 4-6%), and the centrifugal sediment value was 3-5%, the comprehensive effect of the obtained sample was better (Example 1-4), the amino acid nitrogen content was above 0.63g / 100mL, the volatile basic nitrogen was below 46mg / 100g, and the comprehensive sensory score was 8.7 points or above;

[0101] It can be seen from Example 1 and Comparative Example 1 that when ultrasonic combined with heat treatment is not used, the microbial level of the oyster meat liquid is relatively high, which is 3.1*10 6 cfu / mL, compared with Example 1, the amino acid nitrogen content in the prepared enzymatically hydrolyzed oyster sauce base decreased by 0.18 g / 100 mL, and the volatile basic nitrogen content increased by 52.87 mg / 100 g, which reduced the sensory score of the oyster sauce to 3.5 points;

[0102] As can be seen from Example 1 and Comparative Example 2, when pre-treated by heating at 100°C for 30 minutes, the amino acid nitrogen in the prepared oyster sauce base decreased by 39.40%, the volatile basic nitrogen content increased by 32.4 mg / 100g, and the sensory score of the oyster sauce decreased to 4.5 points compared with Example 1. The reason for the decrease in ammonia nitrogen may be that the high temperature treatment causes excessive denaturation of the protein, resulting in the entrapment of enzyme binding sites and reduced enzymatic hydrolysis efficiency. At the same time, in Comparative Example 2, no measures were taken to control microorganisms during the enzymatic hydrolysis process, resulting in the proliferation of microorganisms and the production of more volatile basic nitrogen.

[0103] As can be seen from Example 1 and Comparative Example 3, when enzymatic hydrolysis was performed simultaneously with ultrasonic combined heat treatment and no protamine and chili paste were added during the enzymatic hydrolysis process, the microbial level of the oyster liquid was controlled. However, compared with Example 1, the amino acid nitrogen in the resulting oyster sauce base decreased by 56.06%, the volatile basic nitrogen content increased by 34.72 mg / 100 g, and the total sensory score of the oyster sauce decreased to 4.0 points. The reason for the decrease in ammonia nitrogen may be that the ultrasonic combined heat treatment, while inactivating microorganisms, destroyed the structure of the enzyme, inactivating the enzyme and resulting in a decrease in enzymatic hydrolysis efficiency. At the same time, in Comparative Example 3, no measures were taken to control microorganisms during the enzymatic hydrolysis process, resulting in the proliferation of microorganisms and the production of a large amount of volatile basic nitrogen.

[0104] As can be seen from Example 1 and Comparative Example 4, when edible salt was used instead of protamine and chili paste, the amino acid nitrogen in the enzymatically hydrolyzed oyster sauce base obtained decreased by 22.73%, the volatile basic nitrogen content increased by 25.58 mg / 100 g, and the total sensory score of the oyster sauce decreased to 5.5 points compared with Example 1. The reason for the decrease in ammonia nitrogen may be that the high content of edible salt creates a high osmotic pressure environment, inhibiting enzyme activity and causing a decrease in ammonia nitrogen content. At the same time, the antibacterial effect of edible salt is limited, allowing some microorganisms to reproduce.

[0105] As can be seen from Example 1 and Comparative Example 5, after heat treatment, when no centrifugation treatment is performed, the sensory quality of the oyster sauce prepared is slightly worse, causing the total sensory score to drop to 6.5 points; the reason for the decreased sensory quality may be that the large amount of sediment produced by the concentration without centrifugation reduces the sensory quality of the oyster sauce;

[0106] As can be seen from Example 1 and Comparative Examples 6-7, when only either protamine or chili paste is added to the enzymatic hydrolysis, the effect obtained is far inferior to that of Example 1, indicating that protamine and chili paste can cooperate to a certain extent to achieve an increase in the amino acid nitrogen content of the product and a decrease in the volatile basic nitrogen content;

[0107] It can be seen from Example 1 and Comparative Examples 8-9 that when either the primary ultrasonic combined heat treatment or the secondary ultrasonic combined heat treatment is lacking, the obtained effect is far inferior to that of Example 1.

[0108] Finally, it should be noted that the above embodiments are intended to illustrate the technical solutions of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for preparing oyster sauce base, characterized in that: The preparation method comprises the following steps: (1) subjecting the oyster meat slurry to an ultrasonic combined with heat treatment to obtain oyster meat liquid; (2) adding a composite enzyme preparation, protamine, and chili paste to the oyster meat liquid for a first enzymatic hydrolysis, and allowing the liquid to stand for stratification after the first enzymatic hydrolysis to obtain a supernatant and a precipitate; (3) subjecting the precipitate to a secondary ultrasonic combined with heat treatment, and then adding a composite enzyme preparation for secondary enzymatic hydrolysis to obtain a secondary enzymatic hydrolyzate; (4) mixing the supernatant and the secondary enzymatic hydrolyzate, heating the mixture, and then concentrating and centrifuging the mixture to obtain an oyster juice base; In the first ultrasonic combined heat treatment and the second ultrasonic combined heat treatment, the ultrasonic power is independently 700-900w, the heat treatment temperature is independently 60-65°C, and the treatment time is independently 30-50min; In the primary enzymatic hydrolysis, based on the oyster meat liquid, the mass percentage of protamine is 0.05-0.1%, and the mass percentage of chili paste is 4-6%.

2. The preparation method according to claim 1, characterized in that In the primary enzymatic hydrolysis, the mass percentage of the complex enzyme preparation is 3-4% based on the oyster meat liquid; The temperature of the primary enzymatic hydrolysis is 50-60° C., and the time is 3-5 hours.

3. The preparation method according to claim 1, characterized in that In the secondary enzymatic hydrolysis, the mass percentage of the complex enzyme preparation is 3-4.8% based on the precipitate; The temperature of the secondary enzymatic hydrolysis is 50-60° C., and the time is 1.5-2.5 h.

4. The preparation method according to any one of claims 1 to 3, characterized in that The composite enzyme preparation comprises flavor protease, papain and amylase, and the mass ratio of flavor protease, papain and amylase is (0.75-1.5): (0.75-1.5): (1.5-1.8).

5. The preparation method according to any one of claims 1 to 3, characterized in that In the step (4), centrifugation is performed until the centrifugal sediment value is 3-5%.

6. The preparation method according to any one of claims 1 to 3, characterized in that The preparation method of the oyster meat slurry is as follows: oyster meat is mixed with water and beaten to obtain oyster meat slurry; And / or, the preparation method of the chili paste is: mixing chili with water and beating the mixture to obtain the chili paste.

7. An oyster sauce base, characterized in that: The oyster sauce base is prepared by the preparation method according to any one of claims 1 to 6.

8. An oyster sauce, characterized in that: The oyster sauce comprises the oyster sauce base as claimed in claim 7.

9. The oyster sauce according to claim 8, characterized in that The oyster sauce comprises the following components in parts by weight: 18-22 parts of the oyster sauce base as claimed in claim 8, 6-10 parts of modified starch, 13-17 parts of white sugar, 8-12 parts of edible salt, 2-4 parts of caramel color, 4-6 parts of monosodium glutamate, and 36-40 parts of water.

Images