A method for extracting active substances containing eggshell membrane

Abstract

The present invention relates to the technical field of egg processing and utilization, and in particular to a method for extracting active substances containing eggshell membranes, comprising: step S1, mixing eggshells with water and performing temperature pretreatment to achieve preliminary eggshell membrane separation; step S2, heating and stirring to achieve secondary separation of the eggshell membranes, and adjusting the stirring speed and / or stirring time according to the residual degree of the eggshell membranes and eggshells; step S3, adjusting the pH value after heating the eggshell membranes and water, adding keratinase and stirring to obtain an enzymolysis solution. The preset amount of enzyme / enzymolysis time / enzymolysis temperature is adjusted according to the product generation rate characterization value, and the adjustment cycle of the pH value of the enzymolysis solution is determined according to the product generation rate characterization value or the pH value of the enzymolysis solution; step S4, high-temperature enzyme inactivation, filtration, and nanofiltration of the enzymolysis solution to obtain a nanofiltration concentrate; step S5, high-temperature sterilization of the nanofiltration concentrate and drying to obtain the eggshell membrane active substances. The present invention improves the extraction rate of eggshell membranes, and improves the extraction purity and yield of eggshell membrane active substances.

Description

Technical Field

[0001] The invention relates to the technical field of egg processing and utilization, and in particular to a method for extracting active substances containing eggshell membranes. Background Art

[0002] The eggshell membrane is a thin film attached to the eggshell, which is rich in proteins, lipids, sugars, amino acids and other substances. The proteins are mainly keratin and collagen. Existing research shows that keratin can be widely used in medicine, agriculture, light industry and daily cosmetics as sponge tissue for cell culture, wound healing agent, fertilizer release carrier, composite fiber material, fabric dyeing and finishing agent and skin care cream.

[0003] Chinese patent publication number: CN111808215B, discloses a method for preparing bioactive substances from eggshell membranes by a composite enzyme hydrolysis method, which mainly includes the following steps: eggshell membrane preparation, prehydrolysis, multi-enzyme hydrolysis and preparation of bioactive substances, wherein the composite enzyme includes trypsin and neutral protease in a mass ratio of 1:4 to 5:1; the preparation method avoids the use of toxic reagents such as ionic liquids and organic solvents, and the use of the composite enzyme allows the eggshell membrane to be hydrolyzed more thoroughly, so that the prepared substance contains rich active substances such as protein, hyaluronic acid, chondroitin sulfate, etc.

[0004] It can be seen that the above technical solution has the following problems: the conditions such as the enzymatic hydrolysis temperature, pH value, and enzymatic hydrolysis time are not strictly controlled, thereby affecting the extraction efficiency and purity of the eggshell membrane active substances. Summary of the invention

[0005] To this end, the present invention provides a method for extracting active substances from eggshell membranes, so as to overcome the problems of low extraction efficiency and low extraction purity of active substances from eggshell membranes extracted by enzymatic hydrolysis in the prior art.

[0006] To achieve the above object, the present invention provides a method for extracting active substances from eggshell membranes, comprising:

[0007] Step S1, mixing egg shells and water in a volume ratio of 1 part:1 part to 1.5 parts to form an egg shell extraction raw material, and performing a temperature-variable pretreatment on the egg shell extraction raw material, wherein the temperature-variable pretreatment includes heating and then cooling;

[0008] Step S2, heating the pretreated eggshell extraction raw material to 55°C to 75°C, stirring for 20min to 40min, and then separating the eggshell membranes by precipitation and filtration.

[0009] wherein the stirring speed and / or stirring time are adjusted according to the process state of the eggshell raw material during the stirring process, wherein the process state includes the degree of eggshell residue and the degree of eggshell membrane residue;

[0010] Step S3, mixing the eggshell membranes with water in a volume ratio of 1 part:1 part to 1.5 parts to form an eggshell membrane aqueous solution, heating the eggshell membrane aqueous solution to 40° C. to 60° C., adjusting the pH value to 9 to 11, adding a preset amount of keratinase to form a mixed preparation, and fully stirring to obtain an enzymolysis solution, wherein the enzymolysis time is 3 hours to 6 hours and the enzymolysis temperature is 45° C. to 55° C.,

[0011] Wherein, the product generation rate characterization value of the enzymatic solution is calculated based on the pH value of the enzymatic solution detected at several detection time points, and the preset dosage / the enzymatic hydrolysis time / the enzymatic hydrolysis temperature is adjusted according to the product generation rate characterization value;

[0012] Determining an adjustment period of the pH of the enzymatic solution based on the product generation rate characterization value or the pH value of the enzymatic solution;

[0013] Step S4, inactivating the enzyme in the enzymatic hydrolysis solution by high temperature, cooling the enzymatic hydrolysis solution after high temperature inactivation, adding diatomaceous earth to filter to obtain a filtrate, nanofiltering the filtrate and recovering the nanofiltration concentrate;

[0014] Step S5, performing high temperature sterilization and drying treatment on the nanofiltration concentrated liquid to obtain the eggshell membrane active substance.

[0015] Furthermore, in step S1, the temperature variable pretreatment includes a heating stage and a cooling stage after heating, the heating time of the heating stage is 10min to 20min, the heating temperature is 50℃ to 70℃, the cooling time of the cooling stage is 10min to 20min, and the cooling temperature is 20℃ to 25℃.

[0016] Furthermore, in the step S2, the eggshell extraction raw material is placed in a flexible container and stirred by a flexible stirring rod, wherein the flexibility means that the surface of the container in contact with the eggshell extraction raw material or the surface of the stirring rod is made of an elastic deformable material.

[0017] Furthermore, in the step S2, the eggshell membrane is obtained by filtering the stirred eggshell extraction raw material based on a preset filtration aperture.

[0018] Furthermore, in step S2, the degree of residual eggshell membranes is determined by comparing the maximum size of eggshell membranes floating during stirring with a first preset threshold, and the degree of residual eggshells is determined by comparing the average size of eggshell fragments during stirring with a second preset threshold.

[0019] Further, in the step S2, if the maximum eggshell membrane size is smaller than the first preset threshold, the stirring speed is increased; if the maximum eggshell membrane size is greater than or equal to the first preset threshold, the current stirring speed is maintained.

[0020] Furthermore, in step S2, if the average size of the eggshell fragments is smaller than the second preset threshold, the stirring time is increased.

[0021] Furthermore, in step S3, the pH change rate is calculated based on the pH values ​​of the enzymatic hydrolysis solution detected at several detection time points, and the product generation rate characterization value of the enzymatic hydrolysis solution is calculated according to the pH change rate.

[0022] Furthermore, in step S3, the pH value of the enzymatic hydrolysis solution within 20 minutes to 30 minutes after the start of the enzymatic hydrolysis process is obtained, and the product generation rate characterization value corresponding to the maximum pH value change rate is calculated. If the calculated product generation rate characterization value is less than the preset characterization value, the preset dosage or the enzymatic hydrolysis temperature is increased according to the difference between the product generation rate characterization value and the preset characterization value; the pH value of the enzymatic hydrolysis solution within 3 hours to 3.5 hours after the start of the enzymatic hydrolysis process is obtained, and the product generation rate characterization value corresponding to the maximum pH value change rate is calculated. If the calculated product generation rate characterization value is greater than the preset characterization value, the enzymatic hydrolysis time is increased according to the difference between the product generation rate characterization value and the preset characterization value.

[0023] Furthermore, in step S3, the pH value of the enzymatic hydrolysis solution within 20 minutes to 30 minutes after the start of the enzymatic hydrolysis process is obtained, and the product generation rate characterization value corresponding to the maximum pH value change rate is calculated. If the calculated product generation rate characterization value is greater than the preset characterization value, the adjustment period of shortening the pH of the enzymatic hydrolysis solution is determined according to the difference between the product generation rate characterization value and the preset characterization value; the pH value of the enzymatic hydrolysis solution within 3 hours to 3.5 hours after the start of the enzymatic hydrolysis process is obtained, and the product generation rate characterization value corresponding to the maximum pH value change rate is calculated. If the calculated product generation rate characterization value is less than the preset characterization value, the adjustment period of extending the pH of the enzymatic hydrolysis solution is determined according to the difference between the product generation rate characterization value and the preset characterization value.

[0024] Compared with the prior art, the beneficial effect of the present invention is that the eggshell is effectively softened and the eggshell membrane is initially separated by temperature pretreatment (heating followed by cooling), and the pretreated eggshell extraction raw material is subsequently heated and stirred for shell membrane separation, and the extraction rate of the eggshell membrane is improved by accurately controlling the stirring speed and stirring time. At the same time, during the enzymolysis process, the product generation rate characterization value of the enzymolysis solution is calculated according to the pH value of the enzymolysis solution detected at several detection time points, and the preset dosage / the enzymolysis time / the enzymolysis temperature are adjusted according to the product generation rate characterization value; at the same time, the adjustment cycle of the pH value of the enzymolysis solution is determined based on the product generation rate characterization value or the pH value of the enzymolysis solution. This ensures the efficient enzymolysis reaction, maximizes the generation of target active substances, and improves the extraction purity and yield of eggshell membrane active substances.

[0025] Furthermore, when separating the eggshell membrane, the present invention puts the eggshell extraction raw material into a flexible container and stirs it with a flexible stirring rod, so that the eggshell membrane is not easy to break and is easy to pick up, and the stirred eggshell extraction raw material is filtered based on a preset filter aperture to obtain all the eggshell membranes. This further improves the extraction rate of the eggshell membrane, maximizes the generation of the target active substance, and improves the extraction purity and yield of the eggshell membrane active substance.

[0026] Furthermore, the present invention determines the degree of eggshell membrane residue by comparing the maximum eggshell membrane size floating during stirring with a first preset threshold, and determines the degree of eggshell residue by comparing the average size of eggshell fragments during stirring with a second preset threshold. If the maximum eggshell membrane size is less than the first preset threshold, the stirring speed is increased, and if the maximum eggshell membrane size is greater than or equal to the first preset threshold, the current stirring speed is maintained. If the average size of eggshell fragments is less than the second preset threshold, the stirring time is increased. This further improves the extraction rate of eggshell membranes, maximizes the generation of target active substances, and improves the extraction purity and yield of eggshell membrane active substances.

[0027] Furthermore, the present invention calculates the pH change rate based on the pH value of the enzymatic hydrolysis solution detected at several detection time points, calculates the product generation rate characterization value of the enzymatic hydrolysis solution according to the pH change rate, represents the reaction progress and product generation of the enzymatic hydrolysis reaction through the product generation rate characterization value, and dynamically adjusts key parameters such as the enzymatic hydrolysis temperature, the preset enzyme dosage, and the enzymatic hydrolysis time based on this, thereby further ensuring the efficient progress of the enzymatic hydrolysis reaction, maximizing the generation of target active substances, and improving the extraction purity and yield of eggshell membrane active substances.

[0028] Furthermore, the present invention calculates the product generation rate characterization value in the early stage of the enzymolysis reaction, compares it with the preset characterization value, and dynamically adjusts the preset enzyme dosage / enzymolysis temperature according to the real-time monitoring result. In the late stage of the enzymolysis reaction, the product generation rate characterization value is calculated, and compared with the preset characterization value, and the enzyme enzymolysis time is dynamically adjusted according to the real-time monitoring result. This further ensures the efficient enzymolysis reaction, maximizes the generation of the target active substance, and improves the extraction purity and yield of the eggshell membrane active substance.

[0029] Furthermore, the present invention calculates the product generation rate characterization value in the early stage and the late stage of the enzymatic hydrolysis reaction respectively, and compares it with the preset characterization value, and determines the adjustment period of the pH value of the enzymatic hydrolysis solution according to the real-time monitoring result, thereby further ensuring the efficient progress of the enzymatic hydrolysis reaction, maximizing the generation of target active substances, and improving the extraction purity and yield of eggshell membrane active substances. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The present invention is a flow chart of the method for extracting active substances from eggshell membranes;

[0031] Figure 2 This is a diagram for determining the stirring speed of eggshell membrane separation in the method for extracting active substances from eggshell membranes of the present invention;

[0032] Figure 3 This is a diagram for determining the stirring time for separation of eggshell membranes in the method for extracting active substances from eggshell membranes of the present invention;

[0033] Figure 4 A determination diagram of the preset dosage / enzymatic hydrolysis temperature and pH adjustment period of the method for extracting active substances from eggshell membranes of the present invention;

[0034] Figure 5 This is a diagram showing the determination of the enzymatic hydrolysis time and pH adjustment cycle in the method for extracting active substances from eggshell membranes of the present invention. DETAILED DESCRIPTION

[0035] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0036] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0037] It should be noted that, in the description of the present invention, terms such as "up", "down", "left", "right", "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings. This is merely for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0038] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] See also Figure 1 As shown, it is a flow chart of the method for extracting active substances containing eggshell membranes of the present invention. Specifically, the present invention provides a method for extracting active substances containing eggshell membranes, comprising:

[0040] Step S1, mixing egg shells and water in a volume ratio of 1 part:1 part to 1.5 parts to form an egg shell extraction raw material, and performing a temperature-variable pretreatment on the egg shell extraction raw material, wherein the temperature-variable pretreatment includes heating and then cooling;

[0041] Step S2, heating the pretreated eggshell extraction raw material to 55° C. to 75° C., stirring for 20 min to 40 min, and then separating the eggshell membranes by precipitation and filtration.

[0042] wherein the stirring speed and / or stirring time are adjusted according to the process state of the eggshell raw material during the stirring process, wherein the process state includes the degree of eggshell residue and the degree of eggshell membrane residue;

[0043] Step S3, mixing the eggshell membranes with water in a volume ratio of 1 part:1 part to 1.5 parts to form an eggshell membrane aqueous solution, heating the eggshell membrane aqueous solution to 40° C. to 60° C., adjusting the pH value to 9 to 11, adding a preset amount of keratinase to form a mixed preparation, and fully stirring to obtain an enzymolysis solution, wherein the enzymolysis time is 3 hours to 6 hours and the enzymolysis temperature is 45° C. to 55° C.,

[0044] Wherein, the product generation rate characterization value of the enzymatic solution is calculated based on the pH value of the enzymatic solution detected at several detection time points, and the preset dosage / the enzymatic hydrolysis time / the enzymatic hydrolysis temperature is adjusted according to the product generation rate characterization value;

[0045] Determining an adjustment period of the pH of the enzymatic solution based on the product generation rate characterization value or the pH value of the enzymatic solution;

[0046] Step S4, inactivating the enzyme in the enzymatic solution at high temperature, cooling it, adding diatomaceous earth to filter to obtain a filtrate, nanofiltering the filtrate and recovering the nanofiltration concentrate;

[0047] Step S5, performing high temperature sterilization and drying treatment on the nanofiltration concentrated liquid to obtain the eggshell membrane active substance.

[0048] It can be understood that in step S1 and step S2, the eggshell is a fresh eggshell, and the eggshell needs to be washed before the variable temperature pretreatment, and the water is drained after washing and then the shell membrane is separated. The variable temperature pretreatment can soften the eggshell and allow the eggshell membrane to be initially separated from the eggshell, and then heating and stirring are performed to further separate the eggshell membrane. The eggshell membrane and the eggshell are separated during the stirring process of the eggshell membrane aqueous solution. Therefore, the stirring speed and / or stirring time are adjusted according to the degree of eggshell residue and the degree of eggshell membrane residue during the stirring process, so as to improve the eggshell membrane extraction rate. The degree of eggshell membrane residue is the size of the eggshell membrane floating in the stirring container, and the degree of eggshell residue is the size of the eggshell precipitated in the stirring container.

[0049] In implementation, egg shells and water are mixed in a volume ratio of 1 part: 1 part to 1.5 parts, the pretreated egg shell extraction raw material is heated to 55°C to 75°C, stirred for 20min to 40min, and the initial stirring speed is 100r / min to 120r / min. Preferably, egg shells and water are mixed in a volume ratio of 1 part: 1.2 parts, the pretreated egg shell extraction raw material is heated to 60°C, stirred for 10 to 15min, and the initial stirring speed is 110r / min. The stirring speed and / or stirring time are subsequently adjusted according to the process state of the egg shell raw material during the stirring process. The initial heating temperature, initial stirring speed and initial stirring time of the pretreated egg shell extraction raw material can be adjusted according to actual conditions, which will not be repeated here.

[0050] It is understandable that in step S3, the reaction process and product generation of the enzymolysis reaction are represented by the change in the pH value of the enzymolysis solution, the product generation rate characterization value of the enzymolysis solution is calculated based on the pH value of the enzymolysis solution detected at several detection time points, and the preset dosage / the enzymolysis time / the enzymolysis temperature are adjusted according to the product generation rate characterization value to ensure the enzymolysis reaction conditions. At the same time, based on the product generation rate characterization value or the pH value of the enzymolysis solution, the pH value change in the enzymolysis reaction is indicated, so as to determine the adjustment period of the pH value of the enzymolysis solution to ensure that the enzymolysis reaction is always maintained in the best state.

[0051] In the implementation, eggshell membrane and water are mixed in a volume ratio of 1 part: 1 part to 1.5 parts to form an eggshell membrane aqueous solution, the eggshell membrane aqueous solution is heated to 40°C to 60°C, 30% (w / v) sodium hydroxide is added to adjust the pH value of the eggshell membrane aqueous solution to 9 to 11, and a preset amount of keratinase of 0.3% to 0.6% of the weight of the eggshell is added to form a mixed preparation, and the enzymolysis solution is fully stirred. The enzymolysis time is 3h to 6h, and the enzymolysis temperature is 40°C to 60°C. Preferably, the eggshell membrane and water are mixed in a volume ratio of 1 part: 1.2 parts to form an eggshell membrane aqueous solution. The eggshell membrane aqueous solution is heated to 50°C, the pH value is adjusted to 10, a preset amount of keratinase of 0.45% of the weight of the eggshell is added to form a mixed preparation, and the enzymolysis solution is fully stirred. The preset enzymolysis time is 4.5h, and the preset enzymolysis temperature is 50°C. The heating temperature, pH value, preset amount of keratinase, preset enzymolysis time, preset enzymolysis temperature of the eggshell membrane aqueous solution and the preferred value range and the solvent for adjusting the pH value of the eggshell membrane aqueous solution can be adjusted according to actual conditions, which will not be repeated here.

[0052] It is understood that in step S4 and step S5, after the enzymatic hydrolysis reaction, in order to prevent the degradation or change of the product due to residual enzyme activity, the enzymatic hydrolysis solution needs to be treated with high temperature enzyme inactivation, and impurities in the enzymatic hydrolysis solution are effectively removed by diatomaceous earth to obtain a relatively clear filtrate. The filtrate is then once again subjected to nanofiltration and the nanofiltration concentrate is recovered. This step is to selectively separate the molecules, thereby improving the purity of the eggshell membrane active substance extraction. The nanofiltration concentrate is then sterilized at high temperature to kill microorganisms such as bacteria and viruses in the nanofiltration concentrate, and then dried to remove moisture from the nanofiltration concentrate to obtain a solid form of eggshell membrane active substance.

[0053] The present invention effectively softens the eggshell and preliminarily separates the eggshell membrane through temperature pretreatment (heating followed by cooling), and then heats and stirs the pretreated eggshell extraction raw material to separate the eggshell membrane, and improves the extraction rate of the eggshell membrane by accurately controlling the stirring speed and stirring time. At the same time, during the enzymolysis process, the product generation rate characterization value of the enzymolysis solution is calculated according to the pH value of the enzymolysis solution detected at several detection time points, and the preset dosage / the enzymolysis time / the enzymolysis temperature are adjusted according to the product generation rate characterization value; at the same time, the adjustment period of the pH value of the enzymolysis solution is determined based on the product generation rate characterization value or the pH value of the enzymolysis solution. This ensures the efficient enzymolysis reaction, maximizes the generation of target active substances, and improves the extraction purity and yield of eggshell membrane active substances.

[0054] Specifically, in step S1, the temperature variable pretreatment includes a heating stage and a cooling stage after heating. The heating time of the heating stage is 10min to 20min, the heating temperature is 50℃ to 70℃, and the cooling time of the cooling stage is 10min to 20min, and the cooling temperature is 20℃ to 25℃.

[0055] In the implementation, the heating time is 10min to 20min, the heating temperature is 50°C to 70°C, the cooling time is 10min to 20min, and the cooling temperature is 20°C to 25°C. Preferably, the heating time is 15min, the heating temperature is 65°C, the cooling time is 15min, and the cooling temperature is 22°C. The ranges and preferred values ​​of the heating time, heating temperature, cooling time, and cooling temperature of the temperature-variable pretreatment can be adjusted according to actual conditions, and will not be repeated here. It can be understood that the temperature-variable treatment makes it easier to separate the eggshell and the eggshell membrane by utilizing the different degrees of influence of temperature changes between different substances in the eggshell membrane and the eggshell on their physical properties.

[0056] Specifically, in step S2, the eggshell extraction raw material is placed in a flexible container and stirred by a flexible stirring rod, wherein the flexibility is that the surface of the container in contact with the eggshell extraction raw material or the surface of the stirring rod is an elastic deformable material. The stirred eggshell extraction raw material is filtered based on a preset filter aperture to obtain the eggshell membrane. In implementation, the elastic deformable material can be set to an elastic material such as rubber, silicone, etc., and the flexible container and the flexible stirring rod can be obtained by setting the above-mentioned material on the inner surface of the existing stirring container and the surface of the stirring rod.

[0057] It can be understood that stirring the eggshell with the flexible stirring rod reduces physical damage to the eggshell membrane, ensuring the integrity of the eggshell membrane during the separation process, and the flexible stirring rod can easily pick up large pieces of eggshell membrane. Then, the stirred eggshell extraction raw material is filtered based on a preset filter aperture to obtain all the eggshell membrane.

[0058] In implementation, a filter screen / filter paper can be used to separate the stirred eggshell extraction raw materials. The preset filter aperture value range is 2mm to 5mm. Preferably, the preset filter aperture is 3mm. The preset filter aperture value range and preferred value, as well as the eggshell membrane filtering method can be adjusted according to actual conditions, which will not be repeated here.

[0059] During the separation of eggshell membranes, the eggshell extraction raw material is placed in a flexible container and stirred by a flexible stirring rod, so that the eggshell membranes are not easily broken and are easy to pick up, and the stirred eggshell extraction raw material is filtered based on a preset filtration aperture to obtain all the eggshell membranes, thereby further improving the extraction rate of the eggshell membranes, maximally promoting the generation of target active substances, and improving the extraction purity and yield of the eggshell membrane active substances.

[0060] See also Figure 2 and Figure 3 As shown, Figure 2 This is a diagram for determining the stirring speed of eggshell membrane separation in the method for extracting active substances from eggshell membranes of the present invention; Figure 3 The present invention is a judgment diagram of the eggshell membrane separation stirring time of the extraction method containing eggshell membrane active substances. Specifically, in the step S2, the eggshell membrane residue degree is determined by comparing the maximum eggshell membrane size floating during the stirring process with the first preset threshold, and the eggshell residue degree is determined by comparing the average size of the eggshell fragments during the stirring process with the second preset threshold. If the maximum eggshell membrane size is less than the first preset threshold, the stirring speed is increased, and if the maximum eggshell membrane size is greater than or equal to the first preset threshold, the current stirring speed is maintained. If the average size of the eggshell fragments is less than the second preset threshold, the stirring time is increased.

[0061] It can be understood that the residual eggshell membrane degree refers to the separation of the eggshell membrane after the eggshell membrane and the eggshell are separated due to stirring. The larger the size of the floating eggshell membrane during the stirring process, the better the separation effect is, and the less the eggshell membrane remains on the eggshell fragments. Therefore, the stirring speed is increased or the stirring speed is maintained to separate the eggshell membrane. The residual eggshell degree refers to the eggshell fragments that sink to the bottom after the eggshell membrane and the eggshell are separated due to stirring. The smaller the average size of the eggshell fragments that sink to the bottom during the stirring process, the more the eggshell membrane has been separated, and there may be a small part still attached to the eggshell fragments. At this time, because the average size of the eggshell fragments is too small, increasing the stirring speed has little effect, so the stirring time is increased to separate the eggshell membrane remaining in the eggshell fragments.

[0062] It can be understood that the maximum eggshell membrane size floating during the stirring process is the area of ​​the maximum eggshell membrane floating during the stirring process, and the average size of the eggshell fragments during the stirring process is the average area of ​​the eggshell fragments during the stirring process. If the maximum floating eggshell membrane size caused by stirring during the first 40% to 60% of the stirring time during the stirring process is less than the first preset threshold, it means that the stirring speed is not high enough, so the stirring speed is increased to facilitate the separation of large pieces of eggshell membrane. If the maximum eggshell membrane size during the first 40% to 60% of the stirring time during the stirring process is greater than or equal to the first preset threshold, it means that the stirring speed is appropriate and the eggshell membrane can be separated, then the stirring speed is maintained. After the stirring is completed, if the average size of the eggshell fragments is less than the second preset threshold, it means that the stirring time needs to be extended to allow the eggshell membrane on the small pieces of eggshell to be separated, so the stirring time is increased.

[0063] The calculation formula for the average size of eggshell fragments (average area of ​​eggshell fragments) is as follows:

[0064] (1)

[0065] in, =1,2,3,.. , is the number of eggshell fragments in the flexible container as samples for detection, The first It is understood that the eggshell fragments used as samples for testing follow the sample sampling rules and are generally randomly and evenly sampled so as to be able to characterize the size state of the overall eggshell fragments.

[0066] Specifically, if the maximum eggshell membrane size is smaller than the first preset threshold, the stirring speed is increased, and the increase in the stirring speed is positively correlated with the first difference;

[0067] The first difference is the difference between the maximum eggshell membrane size and the first preset threshold.

[0068] Specifically, if the average size of the eggshell fragments is smaller than the second preset threshold, the stirring time is increased, and the increase in the stirring time is positively correlated with the second difference;

[0069] Among them, the second difference is the difference between the average size of the eggshell fragments and the second preset threshold.

[0070] In the implementation, the first preset threshold value ranges from 0.8 ~1.2 Preferably, the first preset threshold is 1 The second preset threshold value range is 0.1 ~0.25 Preferably, the second preset threshold is 0.15 , the value range of the stirring speed increase is 5r / min~10r / min, preferably, the stirring speed increase is 8r / min, and the larger the first difference is, the larger the stirring speed increase is within the value range. The stirring time increase is 5min~15min, preferably, the stirring time increase is 10min, and the larger the second difference is, the larger the stirring time increase is within the value range. The first preset threshold, the second preset threshold, the stirring speed increase, the stirring time increase range and the preferred value can be adjusted according to actual conditions, and will not be repeated here.

[0071] The present invention determines the residual degree of the eggshell membrane by comparing the maximum eggshell membrane size floating during the stirring process with a first preset threshold value, and determines the residual degree of the eggshell by comparing the average size of the eggshell fragments during the stirring process with a second preset threshold value. If the maximum eggshell membrane size is less than the first preset threshold value, the stirring speed is increased, and if the maximum eggshell membrane size is greater than or equal to the first preset threshold value, the current stirring speed is maintained. If the average size of the eggshell fragments is less than the second preset threshold value, the stirring time is increased. This further improves the extraction rate of the eggshell membrane, maximizes the generation of the target active substance, and improves the extraction purity and yield of the eggshell membrane active substance.

[0072] Specifically, in step S3, the pH change rate is calculated based on the pH values ​​of the enzymatic solution detected at several detection time points, and the product generation rate characterization value of the enzymatic solution is calculated according to the pH change rate.

[0073] It is understood that during the enzymatic hydrolysis process, as the target active substance is generated, the pH value of the enzymatic solution tends to change, and this rate of change can indirectly reflect the rate of product generation. Therefore, by measuring the pH value of the enzymatic solution at several detection time points and calculating the pH change rate, the product generation rate characterization value of the enzymatic solution is calculated based on the pH change rate.

[0074] No. The calculation formula for the pH change rate of the enzymatic solution at each detection time point is as follows:

[0075] (2)

[0076] in, For the + pH value of the enzymatic solution at 1 detection time point, For the The pH value of the enzymatic solution at each detection time point, For the +1 detection time point, For the A detection time point.

[0077] No. The calculation formula for the product generation rate characterization value of the enzymatic solution at each detection time point is as follows:

[0078] (3)

[0079] in, is the pH change rate of the enzymatic solution during normal enzymatic hydrolysis, The value of can be determined based on the average value of the pH change rate of the enzymatic solution corresponding to each time point during several enzymatic hydrolysis tests with higher enzymatic product extraction efficiency.

[0080] In implementation, the preferred enzymatic hydrolysis time is 4.5h, then the detection time interval is 3min to 10min, preferably, the detection time interval is 5min, and the number of detection time points is determined according to the detection time interval and the enzymatic hydrolysis time. The value range and preferred value of the detection time interval and the number of detection time points can be adjusted according to actual conditions, and will not be repeated here.

[0081] The invention calculates the pH value change rate based on the pH value of the enzymatic solution detected at several detection time points, calculates the product generation rate characterization value of the enzymatic solution according to the pH value change rate, represents the reaction process and product generation of the enzymatic reaction through the product generation rate characterization value, and dynamically adjusts the key parameters such as the enzymatic temperature, the preset amount of the enzyme, the enzymatic time and so on based on the value, so as to further ensure the efficient progress of the enzymatic reaction, promote the generation of the target active substance to the maximum extent, and improve the extraction purity and yield of the eggshell membrane active substance.

[0082] See also Figure 4 and Figure 5 As shown, Figure 4 A determination diagram of the preset dosage / enzymatic hydrolysis temperature and pH adjustment period of the method for extracting active substances from eggshell membranes of the present invention; Figure 5 This is a diagram showing the determination of the enzymatic hydrolysis time and pH adjustment cycle in the method for extracting active substances from eggshell membranes of the present invention.

[0083] Specifically, in step S3, the pH value of the enzymatic solution within 20 minutes to 30 minutes after the start of the enzymatic hydrolysis process is obtained and the product generation rate characterization value corresponding to the maximum pH value change rate is calculated. If the calculated product generation rate characterization value is less than or equal to the preset characterization value, then the preset dosage or the enzymatic hydrolysis temperature is increased according to the difference between the product generation rate characterization value and the preset characterization value; if the calculated product generation rate characterization value is greater than the preset characterization value, there is no need to adjust the preset dosage or the enzymatic hydrolysis temperature;

[0084] Obtain the pH value of the enzymolysis solution within 3h to 3.5h after the start of the enzymolysis process and calculate the product generation rate characterization value corresponding to the maximum pH value change rate. If the calculated product generation rate characterization value is greater than the preset characterization value, then the increase in the enzymolysis time is determined based on the difference between the product generation rate characterization value and the preset characterization value. At this time, the increase in the enzymolysis time, the increase in the preset dosage, and the increase in the enzymolysis temperature are all related to the difference. If the calculated product generation rate characterization value is less than or equal to the preset characterization value, there is no need to adjust the enzymolysis time.

[0085] It is understandable that based on the product generation rate characterization value, the technician can monitor the state of the enzymolysis reaction in real time and compare it with the preset characterization value. If the product generation rate characterization value corresponding to the maximum pH value change rate calculated within 20min to 30min after the start of the enzymolysis process is less than or equal to the preset characterization value, it means that the enzymolysis reaction may be inhibited. At this time, the preset amount of the enzyme can be dynamically adjusted to accelerate the reaction process or adjust the enzymolysis temperature to activate the activity of the enzyme. On the contrary, within 3h to 3.5h after the start of the enzymolysis process, the product generation rate characterization value corresponding to the calculated maximum pH value change rate is greater than the preset characterization value, indicating that the enzymolysis process reacts well, and the enzymolysis time is extended.

[0086] In implementation, the preset characterization value has a value range of 0.8 to 1.2, preferably, the preset characterization value is 1, the preset dosage increase is 8% to 15% of the preset dosage, preferably, when the difference is 0.1, the preset dosage increase is 10% of the original preset dosage, and the enzymolysis temperature increase is 3°C to 6°C, preferably, when the difference is 0.1, the enzymolysis temperature increase is 4°C. The enzymolysis time increase is 10min to 20min, preferably, when the difference is 0.1, the enzymolysis time increase is 15min. It is understandable that the greater the difference, the greater the increase in enzymolysis time, the increase in the preset dosage, and the increase in the enzymolysis temperature are within the range, but they do not exceed the corresponding set range. The range and preferred value of the preset characterization value, the preset dosage increase, the enzymolysis temperature increase, and the enzymolysis time increase can be adjusted according to actual conditions, and will not be repeated here. The preset dosage is 0.4% to 0.5% keratinase of the eggshell weight.

[0087] The present invention calculates the product generation rate characterization value in the early stage of the enzymolysis reaction, compares it with the preset characterization value, and dynamically adjusts the preset enzyme dosage / enzymolysis temperature according to the real-time monitoring result. In the late stage of the enzymolysis reaction, the product generation rate characterization value is calculated, and compared with the preset characterization value, and the enzyme enzymolysis time is dynamically adjusted according to the real-time monitoring result. Thereby, the efficient enzymolysis reaction is further ensured, the generation of the target active substance is promoted to the maximum extent, and the extraction purity and yield of the eggshell membrane active substance are improved.

[0088] Specifically, in step S3, the pH value of the enzymatic solution within 20 minutes to 30 minutes after the start of the enzymatic hydrolysis process is obtained and the product generation rate characterization value corresponding to the maximum pH value change rate is calculated. If the calculated product generation rate characterization value is greater than the preset characterization value, the adjustment period of shortening the pH of the enzymatic solution is determined according to the difference between the product generation rate characterization value and the preset characterization value; if the calculated product generation rate characterization value is less than or equal to the preset characterization value, there is no need to adjust the adjustment period of the pH of the enzymatic solution;

[0089] Obtain the pH value of the enzymatic hydrolysis solution within 3h to 3.5h after the start of the enzymatic hydrolysis process and calculate the product generation rate characterization value corresponding to the maximum pH value change rate. If the calculated product generation rate characterization value is less than the preset characterization value, determine to extend the adjustment period of the pH value of the enzymatic hydrolysis solution based on the difference between the product generation rate characterization value and the preset characterization value; if the calculated product generation rate characterization value is greater than or equal to the preset characterization value, there is no need to adjust the adjustment period of the pH of the enzymatic hydrolysis solution.

[0090] It is understandable that based on this characterization value, the technician can monitor the state of the enzymolysis reaction in real time and compare it with the preset characterization value. If the product generation rate characterization value calculated within 20min to 30min after the start of the enzymolysis process is greater than the preset characterization value, it means that the enzymolysis reaction is very fast, and the adjustment period of the pH of the enzymolysis solution is shortened. On the contrary, within 3h to 3.5h after the start of the enzymolysis process, the calculated product generation rate characterization value is less than the preset characterization value, indicating that the pH change in the enzymolysis process reaction is small, and the adjustment period of the pH value of the enzymolysis solution is extended.

[0091] In implementation, the adjustment period of the pH of the enzymatic solution is 0.8h to 1.2h, preferably, the adjustment period of the pH of the enzymatic solution is 1h. The adjustment period of the pH of the enzymatic solution after shortening is 0.5h to 0.8h, preferably, the adjustment period of the pH of the enzymatic solution after shortening is 0.5h. The adjustment period of the pH of the enzymatic solution after extending is 1h to 1.3h, preferably, the adjustment period of the pH of the enzymatic solution after extending is 1.2h. The adjustment period of the pH of the enzymatic solution, the adjustment period of the pH of the enzymatic solution after shortening, and the range of values ​​and preferred values ​​of the adjustment period of the pH of the enzymatic solution after extending can be adjusted according to actual conditions, and will not be repeated here.

[0092] In another specific embodiment, the adjustment period of the pH of the enzymatic hydrolysis solution can also be determined directly based on the pH value of the enzymatic hydrolysis solution, including obtaining the pH value of the enzymatic hydrolysis solution within 20 minutes to 30 minutes after the start of the enzymatic hydrolysis process and calculating the maximum pH value change rate. If the maximum pH value change rate is greater than a preset change threshold, the adjustment period of the pH value of the enzymatic hydrolysis solution is shortened; obtaining the pH value of the enzymatic hydrolysis solution within 3 hours to 3.5 hours after the start of the enzymatic hydrolysis process and calculating the maximum pH value change rate. If the maximum pH value change rate is less than the preset change threshold, the adjustment period of the pH value of the enzymatic hydrolysis solution is extended. It can be understood that the preset change threshold is based on the pH value at each time point. The maximum value in is determined.

[0093] The present invention calculates the product generation rate characterization value in the early stage of the enzymolysis reaction and the late stage of the enzymolysis reaction respectively, compares it with the preset characterization value, and determines the adjustment period of the pH value of the enzymolysis solution according to the real-time monitoring result, thereby further ensuring the efficient progress of the enzymolysis reaction, maximally promoting the generation of target active substances, and improving the extraction purity and yield of eggshell membrane active substances.

[0094] Embodiment 1:

[0095] Specific extraction process:

[0096] Step S1, mixing eggshells and water in a flexible container at a volume ratio of 1 part:1.2 parts (the water just covers the eggshell material) to form an eggshell extraction raw material, and performing variable temperature pretreatment on the eggshell extraction raw material, the variable temperature pretreatment includes: heating time of 15 minutes, heating temperature of 65°C, cooling time of 15 minutes, and cooling temperature of 22°C.

[0097] Step S2, heating the pretreated eggshell extraction raw material to 60°C, stirring for 12 minutes with a flexible stirring rod, with an initial stirring speed of 110 r / min, and within the first 8 minutes of the stirring process, the maximum floating eggshell membrane size is 0.78 Less than the first preset threshold 1 , the stirring speed was increased to 118r / min. After the overall stirring time reached 12min, the average size of the eggshell fragments was 0.098 Less than the second preset threshold 0.15 , the stirring time was increased by 10 min, so the total stirring time was 22 min. After post-precipitation, the eggshell membrane was separated by filtration through a filter with a preset pore size of 3 mm, and the eggshell membrane extraction rate was 95.56%.

[0098] Step S3, the eggshell membrane and water are mixed in a volume ratio of 1 part: 1.2 parts to form an eggshell membrane aqueous solution, the eggshell membrane aqueous solution is heated to a preset enzymolysis temperature of 50°C, the pH value is adjusted to 10, and a preset amount of keratinase of 0.45% of the weight of the eggshell is added to form a mixed preparation, and the enzymolysis solution is fully stirred. The preset enzymolysis time is 4.5h, the preset enzymolysis temperature is 50°C, the preset enzymolysis solution pH adjustment period is 1h, and the detection time interval is selected as 5min, and the enzymolysis solution is pH tested. The pH value of the enzymolysis solution within 20min to 30min after the start of the enzymolysis process and the product generation rate characterization value corresponding to the maximum pH value change rate are calculated to be 0.90 less than the preset characterization value 1, the enzymolysis temperature is increased by 4°C, and the adjusted enzymolysis temperature is 54°C. Then, the product generation rate characterization value corresponding to the calculated maximum pH value change rate within 3h to 3.5h after the start of the enzymolysis process is obtained, which is 0.9 less than the preset characterization value 1, and the pH adjustment period is changed to 1.2h.

[0099] Step S4, inactivate the enzyme in the enzymatic solution at high temperature, raise the temperature to 80-90°C, add 30% (w / v) hydrochloric acid, adjust the pH value to 6-7, and inactivate the enzyme for 25-30 minutes. After the enzyme is inactivated, cool the enzymatic solution to 45-50°C, add diatomaceous earth with a mass of 4%-6% of the total mass of the enzymatic solution, filter to obtain a filtrate, and perform nanofiltration on the filtrate, pass through a nanofiltration membrane of 100-300Da, stop nanofiltration when the conductivity at the wastewater outlet is 3-4ms / cm, and recover the nanofiltration concentrate.

[0100] Step S5, transfer the nanofiltration concentrate to a clean transfer tank, start stirring, start steam heating, control the temperature of the nanofiltration concentrate at 90-95°C, stir for 20-30 minutes, turn off stirring, and sterilize for 4-6 hours at a sterilization temperature of 90-95°C for 4-6 hours. Transfer the sterilized material to a transfer tank, start a spray dryer with an air inlet temperature of 180-185°C and an air outlet temperature of 80-90°C for spray drying to obtain the eggshell membrane active substance.

[0101] Table 1: Different parameters involved in Examples 1 to 23

[0102]

[0103] Note: The relevant parameters in Example 1 are adjusted parameters.

[0104] Please refer to Table 2, which shows the eggshell membrane extraction rate and eggshell membrane active substance extraction rate results of Examples 1 to 23.

[0105] Table 2: Results of eggshell membrane extraction rate and eggshell membrane active substance yield in Examples 1 to 17

[0106]

[0107] The above-mentioned Examples 1 to 7 and Comparative Examples 1 and 2 show that the difference in the thermal expansion and contraction properties of the eggshell and the eggshell membrane is effectively utilized by the variable temperature pretreatment (cooling after heating), and the adhesion between the eggshell membrane and the eggshell is weakened by temperature change, thereby promoting the initial separation of the eggshell and the eggshell membrane, significantly improving the separation efficiency of the eggshell membrane and the eggshell, and providing a basis for the subsequent secondary separation of the eggshell membrane and the eggshell. It can be understood that Examples 1 to 7 only give preferred examples of variable temperature pretreatment and comparative examples outside the range. Within the adjustment range of the relevant parameters of the variable temperature pretreatment set by the present invention, the degree of separation of the eggshell membrane and the eggshell is better.

[0108] Example 1 and Example 8 to Example 12 show that in the process of shell membrane separation by heating and stirring, the stirring speed and / or stirring time of the flexible stirring rod in the shell membrane separation process are adjusted according to the residual degree of the eggshell membrane and the residual degree of the eggshell, and combined with appropriate heating, the effective separation of the eggshell membrane and the eggshell can be achieved, and the eggshell membrane extraction rate is above 95%. This adjustment strategy improves the separation efficiency of the eggshell membrane and the eggshell, reduces the damage to the eggshell membrane and the eggshell, and further promotes the increase in the yield of the active substance of the eggshell membrane. It can be understood that Examples 8 to 12 only give example data after some stirring parameters are adjusted. Within the stirring parameter adjustment range set by the present invention, the degree of separation of the eggshell membrane and the eggshell is better.

[0109] Example 1 and Example 13 to Example 23 show that during the enzymolysis process, the pH change rate is calculated based on the pH value of the enzymolysis solution detected at several detection time points, the product generation rate characterization value of the enzymolysis solution is calculated according to the pH change rate, the preset dosage / the enzymolysis time / the enzymolysis temperature is adjusted according to the product generation rate characterization value, and the adjustment cycle of the pH value of the enzymolysis solution is determined, which can further ensure the efficient enzymolysis reaction and effectively improve the yield (extraction rate) of the eggshell membrane active substance. The yield of the eggshell membrane active substance is above 92%. It can be understood that only some example data after the enzymolysis parameters are adjusted are given in Example 13 to Example 23, and the eggshell membrane active substance extraction effect is better within the enzymolysis parameter adjustment range set by the present invention.

[0110] The comparison results of the above embodiments show that the eggshell can be effectively softened and the eggshell membrane can be preliminarily separated by temperature pretreatment (heating followed by cooling), and then the shell membrane is separated by heating and stirring, and the stirring speed and stirring time are accurately controlled during the shell membrane separation process to improve the extraction rate of the eggshell membrane. At the same time, during the enzymolysis process, the product generation rate characterization value of the enzymolysis solution is indirectly calculated according to the pH value of the enzymolysis solution detected at several detection time points, and the preset dosage / the enzymolysis time / the enzymolysis temperature are adjusted according to the product generation rate characterization value, and the adjustment cycle of the pH value of the enzymolysis solution is determined. This ensures the efficient enzymolysis reaction, maximizes the generation of target active substances, and improves the extraction purity and yield of eggshell membrane active substances.

[0111] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A method for extracting active substances from eggshell membranes, characterized in that: include: Step S1, mixing egg shells and water in a volume ratio of 1 part:1 part to 1.5 parts to form an egg shell extraction raw material, and performing a temperature-variable pretreatment on the egg shell extraction raw material, wherein the temperature-variable pretreatment includes heating and then cooling; Step S2, heating the pretreated eggshell extraction raw material to 55°C to 75°C, stirring for 20min to 40min, and then separating the eggshell membranes by precipitation and filtration. wherein the stirring speed and / or stirring time are adjusted according to the process state of the eggshell raw material during the stirring process, wherein the process state includes the degree of eggshell residue and the degree of eggshell membrane residue; the degree of eggshell membrane residue is determined by comparing the maximum eggshell membrane size floating during the stirring process with a first preset threshold value, and the degree of eggshell residue is determined by comparing the average size of eggshell fragments during the stirring process with a second preset threshold value; If the maximum eggshell membrane size generated by stirring is smaller than the first preset threshold value during the first 40% to 60% of the stirring time during the stirring process, increasing the stirring speed; If the maximum eggshell membrane size is greater than or equal to the first preset threshold value during the first 40% to 60% of the stirring time during the stirring process, the current stirring speed is maintained; After the stirring is completed, if the average size of the eggshell fragments is smaller than the second preset threshold, increasing the stirring time; Step S3, mixing the eggshell membranes with water in a volume ratio of 1 part:1 part to 1.5 parts to form an eggshell membrane aqueous solution, heating the eggshell membrane aqueous solution to 40° C. to 60° C., adjusting the pH value to 9 to 11, adding a preset amount of keratinase to form a mixed preparation, and fully stirring to obtain an enzymolysis solution, wherein the enzymolysis time is 3 hours to 6 hours and the enzymolysis temperature is 45° C. to 55° C., Wherein, the product generation rate characterization value of the enzymatic solution is calculated based on the pH value of the enzymatic solution detected at several detection time points, and the preset dosage / the enzymatic hydrolysis time / the enzymatic hydrolysis temperature is adjusted according to the product generation rate characterization value; Determining an adjustment period of the pH of the enzymatic solution based on the product generation rate characterization value or the pH value of the enzymatic solution; Calculating the pH change rate based on the pH values ​​of the enzymatic solution detected at several detection time points, and calculating the product generation rate characterization value of the enzymatic solution according to the pH change rate; Step S4, inactivating the enzyme in the enzymatic hydrolysis solution by high temperature, cooling the enzymatic hydrolysis solution after high temperature inactivation, adding diatomaceous earth to filter to obtain a filtrate, nanofiltering the filtrate and recovering the nanofiltration concentrate; Step S5, performing high temperature sterilization and drying treatment on the nanofiltration concentrated liquid to obtain the eggshell membrane active substance.

2. The method for extracting active substances from eggshell membranes according to claim 1, characterized in that: In step S1, the temperature-variable pretreatment includes a heating stage and a cooling stage after heating. The heating time of the heating stage is 10 min to 20 min, the heating temperature is 50°C to 70°C, and the cooling time of the cooling stage is 10 min to 20 min, the cooling temperature is 20°C to 25°C.

3. The method for extracting active substances from eggshell membranes according to claim 1, characterized in that: In step S2, the eggshell extraction raw material is placed in a flexible container and stirred by a flexible stirring rod, wherein the flexibility means that the surface of the container in contact with the eggshell extraction raw material or the surface of the stirring rod is made of an elastic deformable material.

4. The method for extracting active substances from eggshell membranes according to claim 3, characterized in that: In the step S2, the eggshell membranes are obtained by filtering the stirred eggshell extraction raw material based on a preset filtration aperture.

5. The method for extracting active substances from eggshell membranes according to claim 1, characterized in that: In step S3, the pH value of the enzymatic solution within 20 minutes to 30 minutes after the start of the enzymatic hydrolysis process is obtained and the product generation rate characterization value corresponding to the maximum pH value change rate is calculated. If the calculated product generation rate characterization value is less than the preset characterization value, it is determined to increase the preset dosage or increase the enzymatic hydrolysis temperature according to the difference between the product generation rate characterization value and the preset characterization value; Obtain the pH value of the enzymatic solution within 3h to 3.5h after the start of the enzymatic hydrolysis process and calculate the product generation rate characterization value corresponding to the maximum pH value change rate. If the calculated product generation rate characterization value is greater than the preset characterization value, increase the enzymatic hydrolysis time based on the difference between the product generation rate characterization value and the preset characterization value.

6. The method for extracting active substances from eggshell membranes according to claim 5, characterized in that: In the step S3, the pH value of the enzymatic solution within 20 minutes to 30 minutes after the start of the enzymatic hydrolysis process is obtained and the product generation rate characterization value corresponding to the maximum pH value change rate is calculated. If the calculated product generation rate characterization value is greater than the preset characterization value, the adjustment period of shortening the pH of the enzymatic solution is determined according to the difference between the product generation rate characterization value and the preset characterization value; Obtain the pH value of the enzymatic hydrolysis solution within 3h to 3.5h after the start of the enzymatic hydrolysis process and calculate the product generation rate characterization value corresponding to the maximum pH value change rate. If the calculated product generation rate characterization value is less than the preset characterization value, determine to extend the adjustment period of the pH value of the enzymatic hydrolysis solution based on the difference between the product generation rate characterization value and the preset characterization value.

Images