An oligopeptide complex composition and its preparation method and application

Abstract

The present application relates to the field of polypeptide compositions, and in particular to an oligopeptide complex composition and a preparation method thereof. The oligopeptide complex composition, in terms of mass percentage, comprises the following raw materials: 5-20% oligopeptide complex, 10-25% functional additive, 1-15% particle additive, and deionized water to supplement the balance. The oligopeptide complex composition prepared in the present application can obtain excellent self-stability and anti-hygroscopicity while ensuring its effects such as soil remediation and plant growth promotion. It can replace existing polypeptides / oligopeptides for addition in the preparation of fertilizers, and has excellent applicability in the fertilizer / fertilizer field.

Description

Technical Field

[0001] The present application relates to the field of polypeptide compositions, and in particular to an oligopeptide complex composition and a preparation method thereof. Background Art

[0002] In recent years, the production and application of various chemical fertilizers have continued to increase, which has played an important role in promoting the development of agricultural production. However, with the continuous increase in the application of chemical fertilizers, its application shortcomings have gradually been exposed, mainly including the following two aspects: first, the fertilizer efficiency of some fertilizers is low, resulting in serious soil compaction, deteriorating the physical and chemical properties of the soil, blocking the soil pores, destroying the soil aggregate structure, causing imbalance of soil nutrients, compaction, pollution and decreased fertility; secondly, fertilizers have little effect on improving and repairing the soil, resulting in continuous deterioration of soil quality during the long-term plant planting cycle, making the planting of plants or crops more and more resistant to stress. Therefore, in view of the above-mentioned drawbacks, in plant planting or field farming of crops, a soil conditioner that can not only activate and improve the soil, but also reduce the use of chemical fertilizers, reduce pollution to the environment, and increase the yield of crops is very much needed. Soil conditioners are used in conjunction with conventional compound fertilizers to overcome the shortcomings of compound fertilizers.

[0003] As a natural organic fertilizer, polypeptide / oligopeptide contains rich nitrogen, phosphorus, potassium and trace elements, which can effectively improve soil fertility, improve soil structure, increase soil water and fertilizer retention capacity, and can also improve plant / crop growth and material metabolism capacity, and further improve plant / crop immunity and resistance. Therefore, polypeptide / oligopeptide is a high-quality soil / plant conditioner, which can play a good effect when mixed with compound fertilizer. But at the same time, polypeptide / oligopeptide also has serious quality problems in the production, storage, transportation and other aspects of fertilizer because of its own instability and hygroscopicity. Therefore, in order to solve the above problems, the present application provides an oligopeptide complex composition and a preparation method thereof, and the prepared oligopeptide complex composition can obtain excellent self-stability and anti-hygroscopicity under the premise of ensuring its soil remediation and plant growth promotion effects, and can replace the existing polypeptide / oligopeptide for addition in the preparation of fertilizer, and has excellent fertilizer / fertilizer field applicability. Summary of the invention

[0004] In order to solve the above problems, the first aspect of the present application provides an oligopeptide complex composition, which includes, by mass percentage, 5-20% oligopeptide complex, 10-25% functional additive, 1-15% particle additive, and deionized water to supplement the balance.

[0005] As a preferred solution, the raw materials for preparing the oligopeptide complex include freshwater fish collagen oligopeptide and an inorganic metal compound.

[0006] As a preferred scheme, the preparation method of freshwater fish collagen oligopeptide comprises the following steps: S1: cutting freshwater fish waste into pieces, soaking them in acidic and alkaline solutions and washing them with water to obtain clean freshwater fish waste; S2: mixing the clean freshwater fish waste with sterile water, heating them to 50-60°C and extracting them at a constant temperature for 8-16 hours, collecting the supernatant by centrifugation after completion, freezing them, and then filtering them by microfiltration to obtain a collagen solution; S3: adding protease to the collagen solution for enzymolysis, the enzymolysis temperature is 50-55°C, the enzymolysis time is 3-5 hours, and after the enzymolysis is completed, heating them with boiling water to inactivate the enzyme for 10-15 minutes, then cooling them to room temperature, centrifuging them, collecting the supernatant, freezing them, and then filtering them by microfiltration to obtain a collagen oligopeptide solution; S4: filtering and collecting the collagen oligopeptide solution, freeze-drying them, and preparing powder.

[0007] As a preferred solution, the mass ratio of the freshwater fish waste to sterile water is (1-1.5):(20-40).

[0008] As a preferred solution, the collagen concentration of the collagen solution is 10-15 wt %.

[0009] As a preferred solution, the amount of the protease added is 1 to 5 wt % of the collagen solution.

[0010] As a preferred solution, the proteases are papain and trypsin.

[0011] As a preferred solution, the mass ratio of papain to trypsin is 1:(1-3).

[0012] As a preferred scheme, the preparation method of the oligopeptide complex comprises the following steps: S1: mixing the inorganic metal compound and the freshwater fish collagen oligopeptide into a reaction container, adding a reaction solvent, and adjusting the pH to 6-8; S2: heating to 40-50°C, then keeping the temperature for reaction for 1-3 hours, and always controlling the pH to 6-8 during the reaction. After the reaction is completed, filtering the product to remove impurities, and the obtained filtrate is the oligopeptide complex.

[0013] As a preferred solution, the inorganic metal compound is at least one of inorganic compounds of copper, iron, zinc, calcium and magnesium.

[0014] As a preferred solution, as a preferred solution, the inorganic copper compound is at least one of copper chloride, copper sulfate, copper carbonate, copper oxide and copper hydroxide.

[0015] As a preferred solution, the inorganic iron compound is at least one of ferrous chloride, ferrous sulfate and ferric nitrate.

[0016] As a preferred solution, the inorganic zinc compound is at least one of zinc chloride, zinc nitrate and zinc carbonate.

[0017] As a preferred solution, the inorganic calcium compound is calcium chloride.

[0018] As a preferred solution, the inorganic compound of magnesium is at least one of magnesium chloride, magnesium sulfate, magnesium nitrate and magnesium hydroxide.

[0019] As a preferred solution, the inorganic metal compound used in the present application includes its hydrate form.

[0020] As a preferred solution, the reaction solvent is sterile water.

[0021] As a preferred solution, the amount of the reaction solvent added is 3 to 8 times the total volume of the mixture of the inorganic metal compound and the freshwater fish collagen oligopeptide.

[0022] As a preferred solution, the mass ratio of the inorganic metal compound to the freshwater fish collagen oligopeptide is (1-2):(3-5).

[0023] As a preferred solution, the mass ratio of the inorganic metal compound to the freshwater fish collagen oligopeptide is (1-1.5):(3.5-4).

[0024] The oligopeptide complex prepared by the above method in the present application can successfully utilize discarded freshwater fish fertilizers, obtain fish protein therefrom and enzymatically hydrolyze it into 2 to 10 amino acid oligopeptide chains, and successfully complex the amino acid oligopeptide chains with metal compounds. The complex connection structure after complexation works together with the network structure in the composition system, so that the oligopeptide complex can obtain excellent stability different from oligopeptide substances in previous fertilizers while ensuring its good plant growth promotion, stress resistance and soil improvement performance, overcome the technical problems of oligopeptide / polypeptide substances in previous fertilizers being difficult to store and transport and having poor stability, and can reduce the influence of high-temperature active molecules on oligopeptides / polypeptides through a regular connection network system structure in the system, and can also effectively ensure the structural characteristics of the oligopeptide itself, thereby ensuring its fertilizer efficacy.

[0025] As a preferred solution, the functional additives are epoxy copolymer and C12-14 fatty alcohol polyoxyethylene ether.

[0026] As a preferred solution, the mass ratio of the epoxy copolymer to the C12-14 fatty alcohol polyoxyethylene ether is (1-3):(4-7).

[0027] As a preferred solution, the mass ratio of the epoxy copolymer to the C12-14 fatty alcohol polyoxyethylene ether is (1.5-2):(5-6).

[0028] As a preferred solution, the epoxy copolymer is a block copolymer of ethylene oxide and propylene oxide.

[0029] As a preferred solution, the weight average molecular weight of the epoxy copolymer is 2500-8000.

[0030] As a preferred solution, the epoxy copolymer is a composition of an epoxy copolymer with a weight average molecular weight of 2500-3000 and an epoxy copolymer with a weight average molecular weight of 6000-8000.

[0031] As a preferred solution, the mass ratio of the epoxy copolymer with a weight average molecular weight of 2500 to 3000 and the epoxy copolymer with a weight average molecular weight of 6000 to 8000 is (2 to 3.5): (0.4 to 1).

[0032] As a preferred solution, the mass ratio of the epoxy copolymer with a weight average molecular weight of 2500-3000 to the epoxy copolymer with a weight average molecular weight of 6000-8000 is (2.5-3): (0.5-0.8).

[0033] In the present application, the block copolymer of ethylene oxide and propylene oxide under the above-mentioned specific molecular weight can effectively improve the stability of the complex composition itself, especially the thermal stability, thereby ensuring the stability of the complex composition itself during long-term use, storage and transportation, and avoiding decomposition, precipitation and deterioration. This is mainly because when the block copolymer of ethylene oxide and propylene oxide is used in combination, it can work together with the added C12-14 fatty alcohol polyoxyethylene ether to form a good mutual entanglement structure in the continuous phase of the system, thereby greatly reducing the movement space of the complex molecules inside the system when the system is heated at high temperature, thereby reducing the collision frequency between molecules, and then maintaining its own complex structure in this state; and on the other hand, the use of the above-mentioned scheme can also form an interface film in the system, thereby greatly reducing its contact form and frequency with the outside world, thereby maintaining a good interface film expansion volume when heated at high temperature, and maintaining a good protective effect.

[0034] As a preferred solution, the C12-14 fatty alcohol polyoxyethylene ether is isomeric 13 fatty alcohol polyoxyethylene ether and lauryl alcohol polyoxyethylene ether.

[0035] As a preferred solution, the hydroxyl value of the C12-14 fatty alcohol polyoxyethylene ether is 175-200 mgKOH / g.

[0036] As a preferred solution, the mass ratio of the isomeric 13-fatty alcohol polyoxyethylene ether to the lauryl alcohol polyoxyethylene ether is (3-5):(1-2).

[0037] As a preferred solution, the mass ratio of the isomeric 13-fatty alcohol polyoxyethylene ether to the lauryl alcohol polyoxyethylene ether is (3.5-4):1.2.

[0038] In the present application, by adopting the compounding scheme of the above-mentioned specific epoxy copolymer and C12-14 fatty alcohol polyoxyethylene ether, the deterioration, decomposition, stratification and other phenomena of the complex composition can be greatly reduced. This is mainly because the C12-14 fatty alcohol polyoxyethylene ether in the above-mentioned scheme is more likely to form a superimposed multilayer structure on the surface of the oligopeptide complex, and the presence of these multilayer structures can ensure the interfacial viscosity and interfacial motion resistance of the complex composition system itself, which directly leads to greater resistance to changes between phases in any system than under normal circumstances, thereby increasing the upper limit of the system's phase change tolerance, and then having excellent tolerance effects in various fertilizer systems and use and storage environments, thereby avoiding a large number of oligopeptide complexes. Deterioration, decomposition, stratification and other phenomena.

[0039] As a preferred solution, the particle additives are oyster shell powder and bentonite.

[0040] As a preferred solution, the mass ratio of the oyster shell powder to bentonite is (2-4): (0.5-1).

[0041] As a preferred solution, the bentonite is calcium-based bentonite.

[0042] The second aspect of the present application provides a method for preparing the above-mentioned oligopeptide complex composition, which comprises the following steps: S1: preferentially mixing the obtained oligopeptide complex with the functional additive, and setting aside after the mixing is completed; S2: adding the particle additive and deionized water to the mixture obtained in S1, adjusting the temperature to 20-25°C to activate and keep warm for 5-10 minutes, then cooling to 5-15°C and mixing and stirring at a speed of 100-200r / min for 1-3 hours, and sterilizing after the stirring is completed to obtain the product.

[0043] The third aspect of the present application provides an application of the above-mentioned oligopeptide complex composition, including the application of the oligopeptide complex composition in agricultural fertilizer formulation.

[0044] As a preferred solution, the content of the oligopeptide complex composition in the agricultural fertilizer formula is 0.1-10 wt%.

[0045] The beneficial effects of this application are:

[0046] 1. An oligopeptide complex composition provided in the present application can obtain excellent self-stability and anti-hygroscopicity while ensuring its effects such as soil remediation and plant growth promotion. It can replace existing polypeptides / oligopeptides for addition in the preparation of fertilizers and has excellent applicability in the fertilizer / chemical fertilizer field.

[0047] 2. An oligopeptide complex composition provided in the present application can successfully utilize discarded freshwater fish fertilizers to obtain fish protein and enzymatically hydrolyze it into 2 to 10 amino acid oligopeptide chains, and successfully complex the amino acid oligopeptide chains with metal compounds. The complex connection structure after complexation works together with the network structure in the composition system, so that the oligopeptide complex can obtain excellent stability different from oligopeptide substances in previous fertilizers while ensuring its good plant growth promotion, stress resistance and soil improvement performance, thereby overcoming the technical problems of oligopeptide / polypeptide substances in previous fertilizers being difficult to store and transport and having poor stability.

[0048] 3. An oligopeptide complex composition provided in the present application can effectively improve the stability of the complex composition itself, especially the thermal stability, by adopting a block copolymer of ethylene oxide and propylene oxide at a specific molecular weight, thereby ensuring the self-stability of the complex composition during long-term use, storage and transportation, and avoiding decomposition, precipitation and deterioration; when the block copolymer of ethylene oxide and propylene oxide is combined, it can work together with the added C12-14 fatty alcohol polyoxyethylene ether to form a good mutual entanglement structure in the continuous phase of the system, thereby greatly reducing the movement space of the complex molecules inside the system when the system is heated at high temperature, thereby reducing the frequency of collisions between molecules, and maintaining its own complex structure in this state.

[0049] 4. An oligopeptide complex composition provided in the present application adopts a compounding scheme of a specific epoxy copolymer and C12-14 fatty alcohol polyoxyethylene ether, which can greatly reduce the deterioration, decomposition, stratification and the like of the complex composition; C12-14 fatty alcohol polyoxyethylene ether is more likely to form a superimposed multilayer structure on the surface of the oligopeptide complex, and the existence of these multilayer structures can ensure the interfacial viscosity and interfacial movement resistance of the complex composition system itself, which directly leads to greater resistance to changes between phases in any system than under normal circumstances, thereby increasing the upper limit of the system's phase change tolerance, and thus having excellent tolerance effects in various fertilizer systems and usage and storage environments. DETAILED DESCRIPTION

[0050] The following will further explain and demonstrate the technical solutions in the above invention content of this application in the form of specific implementation schemes. The following embodiments are only practical examples used to illustrate and explain the contents of the technical solutions in the specification, and should not limit the scope of the claims to be protected by this application. All technical products based on the technical solutions described in the invention content of this application should be included in the scope to be protected by this application.

[0051] In the following examples, unless otherwise specified, the raw materials are all commercially available products, or can be prepared by methods well known to those skilled in the art.

[0052] Example 1

[0053] Embodiment 1 The first aspect provides an oligopeptide complex composition, wherein the raw materials include, by mass percentage: 15% oligopeptide complex, 20% functional additive, 8% particle additive, and deionized water to supplement the balance.

[0054] The raw materials for preparing the oligopeptide complex include freshwater fish collagen oligopeptide and an inorganic metal compound; the preparation method of the freshwater fish collagen oligopeptide includes the following steps: S1: cutting freshwater fish waste (carp skin) into pieces of skin of 0.5×0.5 cm, soaking the pieces of skin in 0.5wt% HCl (the volume ratio of the pieces to the skin is 1:8), then washing with water, and then soaking in 0.5wt% NaOH and (the volume ratio of the pieces to the skin is 1:8), and then washing with water to obtain clean freshwater fish waste; S2: mixing the clean freshwater fish waste with sterile water (the mass ratio of the freshwater fish waste to the sterile water is 1:25), heating to 55°C for constant temperature extraction for 1 4h, after completion, the supernatant was collected by centrifugation and frozen at 5℃ for 30min, and then filtered through 0.2μm microfiltration to obtain a collagen solution (collagen concentration is 12wt%); S3: the collagen solution was added with protease for enzymatic hydrolysis (the amount of protease added is 3wt% of the collagen solution), the enzymatic hydrolysis temperature is 55℃, the enzymatic hydrolysis pH is 7.8, the enzymatic hydrolysis time is 3.5h, and after the enzymatic hydrolysis is completed, the enzyme is heated in boiling water for 10min, and then cooled to room temperature 25℃, the supernatant was collected by centrifugation and frozen at 5℃ for 30min, and then filtered through 0.2μm microfiltration to obtain a collagen oligopeptide solution; S4: the collagen oligopeptide solution was collected by ultrafiltration membrane interception filtration, freeze-dried, and ground into powder.

[0055] The proteases are papain papain and trypsin, and the mass ratio of the two is 1:2.

[0056] The preparation method of the oligopeptide complex comprises the following steps: S1: mixing anhydrous magnesium chloride and freshwater fish collagen oligopeptide (the mass ratio of anhydrous magnesium chloride to freshwater fish collagen oligopeptide is 1.2:3.8) and adding them into a reaction container, adding sterile water (the amount of sterile water added is 5 times the total amount of the anhydrous magnesium chloride and freshwater fish collagen oligopeptide), and adjusting the pH to 7.5 with a sodium hydroxide aqueous solution; S2: heating to 45°C, then keeping the temperature for reaction for 2h, always controlling the pH to 7.5 during the reaction, cooling to 5°C after the reaction is completed, filtering the product through 0.2μm to remove impurities, and the obtained filtrate is the oligopeptide complex.

[0057] The functional additives are epoxy copolymer and C12-14 fatty alcohol polyoxyethylene ether, and the mass ratio of the two is 2:5.

[0058] The epoxy copolymer is a block copolymer of ethylene oxide and propylene oxide. The specific epoxy copolymer is a composition of BASF L64 (weight average molecular weight 2800) and BASF L87 (weight average molecular weight 7800), and the mass ratio of the two is 2.5:0.6.

[0059] C12-14 fatty alcohol polyoxyethylene ether is isomeric 13 fatty alcohol polyoxyethylene ether and lauryl alcohol polyoxyethylene ether, and the mass ratio of the two is 3.6:1.2.

[0060] Isomerized 13 fatty alcohol polyoxyethylene ether was purchased from Hai'an Guoyun Chemical Co., Ltd. as E-1302, with a hydroxyl value of 200 mgKOH / g; lauryl alcohol polyoxyethylene ether was purchased from Hai'an Guoyun Chemical Co., Ltd. as MOA-3, with a hydroxyl value of 180 mgKOH / g.

[0061] The particle additives are oyster shell powder and calcium-based bentonite, and the mass ratio of the two is 3:1; the average particle size of the oyster shell powder is 3800 mesh; the calcium-based bentonite is purchased from the calcium-based bentonite products sold by Xuyi Taihe High-tech Technology Co., Ltd., and after secondary grinding, the average particle size is 3500 mesh.

[0062] The second aspect of this embodiment also provides a method for preparing the above-mentioned oligopeptide complex composition, which comprises the following steps: S1: preferentially mixing the obtained oligopeptide complex with the functional additive, and setting aside after the mixing; S2: adding the particle additive and deionized water to the mixture obtained in S1, adjusting the temperature to 25°C to activate and keep warm for 10 minutes, then cooling to 10°C and mixing and stirring at a speed of 120r / min for 2.5 hours, and sterilizing after the stirring is completed.

[0063] Example 2

[0064] Example 2 The first aspect provides an oligopeptide complex composition, in which the raw materials include, by mass percentage: 12% oligopeptide complex, 18% functional additive, 5% particle additive, and deionized water to make up the balance.

[0065] The raw materials for preparing the oligopeptide complex include freshwater fish collagen oligopeptide and an inorganic metal compound; the preparation method of the freshwater fish collagen oligopeptide includes the following steps: S1: cutting freshwater fish waste (carp skin) into pieces of skin of 0.5×0.5 cm, soaking the pieces of skin in 0.5wt% HCl (the volume ratio of the pieces to the skin is 1:8), then washing with water, and then soaking in 0.5wt% NaOH and (the volume ratio of the pieces to the skin is 1:8), and then washing with water to obtain clean freshwater fish waste; S2: mixing the clean freshwater fish waste with sterile water (the mass ratio of the freshwater fish waste to the sterile water is 1:25), heating to 55°C for constant temperature extraction for 1 4h, after completion, the supernatant was collected by centrifugation and frozen at 5℃ for 30min, and then filtered through 0.2μm microfiltration to obtain a collagen solution (collagen concentration is 12wt%); S3: the collagen solution was added with protease for enzymatic hydrolysis (the amount of protease added is 3wt% of the collagen solution), the enzymatic hydrolysis temperature is 55℃, the enzymatic hydrolysis pH is 7.8, the enzymatic hydrolysis time is 3.5h, and after the enzymatic hydrolysis is completed, the enzyme is heated in boiling water for 10min, and then cooled to room temperature 25℃, the supernatant was collected by centrifugation and frozen at 5℃ for 30min, and then filtered through 0.2μm microfiltration to obtain a collagen oligopeptide solution; S4: the collagen oligopeptide solution was collected by ultrafiltration membrane interception filtration, freeze-dried, and ground into powder.

[0066] The proteases are papain papain and trypsin, and the mass ratio of the two is 1:2.

[0067] The preparation method of the oligopeptide complex comprises the following steps: S1: mixing anhydrous magnesium chloride and freshwater fish collagen oligopeptide (the mass ratio of anhydrous magnesium chloride to freshwater fish collagen oligopeptide is 1.2:3.8) and adding them into a reaction container, adding sterile water (the amount of sterile water added is 5 times the total amount of the anhydrous magnesium chloride and freshwater fish collagen oligopeptide), and adjusting the pH to 7.5 with a sodium hydroxide aqueous solution; S2: heating to 45°C, then keeping the temperature for reaction for 2h, always controlling the pH to 7.5 during the reaction, cooling to 5°C after the reaction is completed, filtering the product through 0.2μm to remove impurities, and the obtained filtrate is the oligopeptide complex.

[0068] The functional additives are epoxy copolymer and C12-14 fatty alcohol polyoxyethylene ether, and the mass ratio of the two is 2:5.

[0069] The epoxy copolymer is a block copolymer of ethylene oxide and propylene oxide. The specific epoxy copolymer is a composition of BASF L64 (weight average molecular weight 2800) and BASF L87 (weight average molecular weight 7800), and the mass ratio of the two is 2.1:0.9.

[0070] C12-14 fatty alcohol polyoxyethylene ether is isomeric 13 fatty alcohol polyoxyethylene ether and lauryl alcohol polyoxyethylene ether, and the mass ratio of the two is 3:2.

[0071] Isomerized 13 fatty alcohol polyoxyethylene ether was purchased from Hai'an Guoyun Chemical Co., Ltd. as E-1302, with a hydroxyl value of 200 mgKOH / g; lauryl alcohol polyoxyethylene ether was purchased from Hai'an Guoyun Chemical Co., Ltd. as MOA-3, with a hydroxyl value of 180 mgKOH / g.

[0072] The particle additives are oyster shell powder and calcium-based bentonite, and the mass ratio of the two is 3:1; the average particle size of the oyster shell powder is 3800 mesh; the calcium-based bentonite is purchased from the calcium-based bentonite products sold by Xuyi Taihe High-tech Technology Co., Ltd., and after secondary grinding, the average particle size is 3500 mesh.

[0073] The second aspect of this embodiment also provides a method for preparing the above-mentioned oligopeptide complex composition, which comprises the following steps: S1: preferentially mixing the obtained oligopeptide complex with the functional additive, and setting aside after the mixing; S2: adding the particle additive and deionized water to the mixture obtained in S1, adjusting the temperature to 25°C to activate and keep warm for 10 minutes, then cooling to 10°C and mixing and stirring at a speed of 120r / min for 2.5 hours, and sterilizing after the stirring is completed.

[0074] Example 3

[0075] Example 3 The first aspect provides an oligopeptide complex composition, in which the raw materials include, by mass percentage: 18% oligopeptide complex, 22% functional additive, 6% particle additive, and deionized water to make up the balance.

[0076] The raw materials for preparing the oligopeptide complex include freshwater fish collagen oligopeptide and an inorganic metal compound; the preparation method of the freshwater fish collagen oligopeptide includes the following steps: S1: cutting freshwater fish waste (carp skin) into pieces of skin of 0.5×0.5 cm, soaking the pieces of skin in 0.5wt% HCl (the volume ratio of the pieces to the skin is 1:8), then washing with water, and then soaking in 0.5wt% NaOH and (the volume ratio of the pieces to the skin is 1:8), and then washing with water to obtain clean freshwater fish waste; S2: mixing the clean freshwater fish waste with sterile water (the mass ratio of the freshwater fish waste to the sterile water is 1:25), heating to 55°C for constant temperature extraction for 1 4h, after completion, the supernatant was collected by centrifugation and frozen at 5℃ for 30min, and then filtered through 0.2μm microfiltration to obtain a collagen solution (collagen concentration is 12wt%); S3: the collagen solution was added with protease for enzymatic hydrolysis (the amount of protease added is 3wt% of the collagen solution), the enzymatic hydrolysis temperature is 55℃, the enzymatic hydrolysis pH is 7.8, the enzymatic hydrolysis time is 3.5h, and after the enzymatic hydrolysis is completed, the enzyme is heated in boiling water for 10min, and then cooled to room temperature 25℃, the supernatant was collected by centrifugation and frozen at 5℃ for 30min, and then filtered through 0.2μm microfiltration to obtain a collagen oligopeptide solution; S4: the collagen oligopeptide solution was collected by ultrafiltration membrane interception filtration, freeze-dried, and ground into powder.

[0077] The proteases are papain papain and trypsin, and the mass ratio of the two is 1:2.

[0078] The preparation method of the oligopeptide complex comprises the following steps: S1: mixing anhydrous magnesium chloride and freshwater fish collagen oligopeptide (the mass ratio of anhydrous magnesium chloride to freshwater fish collagen oligopeptide is 1.2:3.8) and adding them into a reaction container, adding sterile water (the amount of sterile water added is 5 times the total amount of the anhydrous magnesium chloride and freshwater fish collagen oligopeptide), and adjusting the pH to 7.5 with a sodium hydroxide aqueous solution; S2: heating to 45°C, then keeping the temperature for reaction for 2h, always controlling the pH to 7.5 during the reaction, cooling to 5°C after the reaction is completed, filtering the product through 0.2μm to remove impurities, and the obtained filtrate is the oligopeptide complex.

[0079] The functional additives are epoxy copolymer and C12-14 fatty alcohol polyoxyethylene ether, and the mass ratio of the two is 2.5:4.5.

[0080] The epoxy copolymer is a block copolymer of ethylene oxide and propylene oxide. The specific epoxy copolymer is a composition of BASF L64 (weight average molecular weight 2800) and BASF L87 (weight average molecular weight 7800), and the mass ratio of the two is 2.5:0.6.

[0081] C12-14 fatty alcohol polyoxyethylene ether is isomeric 13 fatty alcohol polyoxyethylene ether and lauryl alcohol polyoxyethylene ether, and the mass ratio of the two is 4.2:1.

[0082] Isomerized 13 fatty alcohol polyoxyethylene ether was purchased from Hai'an Guoyun Chemical Co., Ltd. as E-1302, with a hydroxyl value of 200 mgKOH / g; lauryl alcohol polyoxyethylene ether was purchased from Hai'an Guoyun Chemical Co., Ltd. as MOA-3, with a hydroxyl value of 180 mgKOH / g.

[0083] The particle additives are oyster shell powder and calcium-based bentonite, and the mass ratio of the two is 3:1; the average particle size of the oyster shell powder is 3800 mesh; the calcium-based bentonite is purchased from the calcium-based bentonite products sold by Xuyi Taihe High-tech Technology Co., Ltd., and after secondary grinding, the average particle size is 3500 mesh.

[0084] The second aspect of this embodiment also provides a method for preparing the above-mentioned oligopeptide complex composition, which comprises the following steps: S1: preferentially mixing the obtained oligopeptide complex with the functional additive, and setting aside after the mixing; S2: adding the particle additive and deionized water to the mixture obtained in S1, adjusting the temperature to 25°C to activate and keep warm for 10 minutes, then cooling to 10°C and mixing and stirring at a speed of 120r / min for 2.5 hours, and sterilizing after the stirring is completed.

[0085] Comparative Example 1

[0086] The specific implementation of this comparative example is basically the same as that of Example 1, except that in the preparation method of the oligopeptide complex, the mass ratio of anhydrous magnesium chloride to freshwater fish collagen oligopeptide is 0.5:4.

[0087] Comparative Example 2

[0088] The specific implementation of this comparative example is basically the same as that of Example 1, except that the epoxy copolymer is a block copolymer of ethylene oxide and propylene oxide, and the specific epoxy copolymer is a composition of BASF L64 (weight average molecular weight 2800) and BASF L87 (weight average molecular weight 7800), and the mass ratio of the two is 5:0.2.

[0089] Comparative Example 3

[0090] The specific implementation of this comparative example is basically the same as that of Example 1, except that the epoxy copolymer is a block copolymer of ethylene oxide and propylene oxide, and the specific epoxy copolymer is BASF L64 (weight average molecular weight 2800).

[0091] Comparative Example 4

[0092] The specific implementation of this comparative example is basically the same as that of Example 1, except that the C12-14 fatty alcohol polyoxyethylene ether is isomeric 13 fatty alcohol polyoxyethylene ether and lauryl alcohol polyoxyethylene ether, and the mass ratio of the two is 10:1.

[0093] Comparative Example 5

[0094] The specific implementation of this comparative example is basically the same as that of Example 1, except that the C12-14 fatty alcohol polyoxyethylene ether is isomeric 13 fatty alcohol polyoxyethylene ether and lauryl alcohol polyoxyethylene ether, and the mass ratio of the two is 1:1.

[0095] Comparative Example 6

[0096] The specific implementation of this comparative example is basically the same as that of Example 1, except that: C12-14 fatty alcohol polyoxyethylene ether is lauryl alcohol polyoxyethylene ether, and lauryl alcohol polyoxyethylene ether is purchased from Hai'an Guoyun Chemical Co., Ltd. as MOA-5, and the hydroxyl value is 135 mgKOH / g.

[0097] Performance Evaluation

[0098] Thermal stability: The oligopeptide complex compositions prepared in the examples and comparative examples were subjected to a thermal stability test. The oligopeptide complex compositions were stored in a constant temperature box at a humidity of 75±2% and a temperature of 45±2°C for 14 days, and the mass decomposition rate (mass decrease percentage %) of the entire composition after 14 days of storage was calculated. The average value of 10 measured values ​​was recorded in Table 1; and the same storage method was used for testing to observe whether the composition had obvious deterioration, yellowing, precipitation, decomposition and stratification after 14 days. If so, it was unqualified, otherwise it was qualified. In this test, 100 samples were tested in parallel for each example and comparative example group, and the qualified rate of the samples among the 100 samples was recorded, and the results were recorded in Table 1.

[0099] Viscosity change: The oligopeptide complex compositions prepared in the examples and comparative examples were subjected to a viscosity tester. After being stored in a constant temperature box at a humidity of 75±2% and a temperature of 45±2°C for 14 days, the viscosity of the oligopeptide complex composition was tested a second time, and the percentage change in viscosity of the composition was calculated and recorded. The results were recorded as the average value of 10 tests in Table 1.

[0100] Table 1

[0101]

[0102] From the examples and comparative examples of the present application and the data results in Table 1, it can be seen that the examples 1 to 3 adopting the necessary technical solutions given in the present application have achieved excellent results in terms of thermal stability and self-stability of the complex composition, which enables it to effectively replace the oligopeptide or polypeptide raw materials in the existing fertilizer products when used, thereby achieving excellent plant promotion effects and soil improvement effects while avoiding the technical problems that the oligopeptide / polypeptide raw materials in the prior art products are not easy to store and transport, are greatly affected by the environment, and ultimately lead to fertilizer deterioration or quality degradation. Comparative Examples 1 to 6, because they did not fully adopt the necessary technical solutions described by the applicant, were significantly worse than Examples 1 to 3 in the corresponding test results, which better proves the irreplaceable nature of the specific technical solutions of the present application in achieving technical effects and solving technical problems.

Claims

1. An oligopeptide complex composition, characterized in that: In terms of mass percentage, the raw materials include: 5-20% oligopeptide complex, 10-25% functional additive, 1-15% particle additive, and deionized water to supplement the balance; The raw materials for preparing the oligopeptide complex include freshwater fish collagen oligopeptide and inorganic metal compound; The preparation method of freshwater fish collagen oligopeptide comprises the following steps: S1: cutting freshwater fish waste into pieces, soaking in acidic and alkaline solutions and washing with water to obtain clean freshwater fish waste; S2: mixing the clean freshwater fish waste with sterile water, heating to 50-60°C and extracting at a constant temperature for 8-16 hours, and after completion, centrifuging and collecting the supernatant, freezing and filtering by microfiltration to obtain a collagen solution; S3: adding protease to the collagen solution for enzymolysis, the enzymolysis temperature is 50-55°C, the enzymolysis time is 3-5 hours, and after the enzymolysis is completed, heating with boiling water to inactivate the enzyme for 10-15 minutes, then cooling to room temperature, centrifuging and collecting the supernatant, freezing and filtering by microfiltration to obtain a collagen oligopeptide solution; S4: filtering and collecting the collagen oligopeptide solution, freeze-drying and powdering to obtain the collagen oligopeptide solution; The mass ratio of the freshwater fish waste to sterile water is (1-1.5): (20-40); The collagen concentration of the collagen solution is 10-15wt%; the amount of the protease added is 1-5wt% of the collagen solution; The preparation method of the oligopeptide complex comprises the following steps: S1: mixing an inorganic metal compound and a freshwater fish collagen oligopeptide into a reaction container, adding a reaction solvent, and adjusting the pH to 6-8; S2: heating to 40-50° C., then keeping the temperature for reaction for 1-3 hours, and controlling the pH to be 6-8 during the reaction process. After the reaction is completed, filtering the product to remove impurities, and the obtained filtrate is the oligopeptide complex; The inorganic metal compound is at least one of inorganic compounds of copper, iron, zinc, calcium and magnesium; The mass ratio of the inorganic metal compound to the freshwater fish collagen oligopeptide is (1-2):(3-5); The functional additives are epoxy copolymer and C12-14 fatty alcohol polyoxyethylene ether; The mass ratio of the epoxy copolymer to the C12-14 fatty alcohol polyoxyethylene ether is (1-3):(4-7); The weight average molecular weight of the epoxy copolymer is 2500-8000; The C12~14 fatty alcohol polyoxyethylene ether is isomeric 13 fatty alcohol polyoxyethylene ether and lauryl alcohol polyoxyethylene ether; The hydroxyl value of the C12-14 fatty alcohol polyoxyethylene ether is 175-200 mgKOH / g; The mass ratio of the isomeric 13-fatty alcohol polyoxyethylene ether to the lauryl alcohol polyoxyethylene ether is (3-5):(1-2).

2. A method for preparing the oligopeptide complex composition according to claim 1, characterized in that: Preparation method The following steps are involved: S1: The obtained oligopeptide complex is preferentially mixed with the functional additive, and the mixture is set aside after the mixing is completed; S2: Add particle additives and deionized water to the mixture obtained in S1, adjust the temperature to 20-25°C for activation and heat preservation for 5-10 minutes, then cool to 5-15°C and mix and stir at a speed of 100-200 r / min for 1-3 hours. After stirring, sterilize and obtain the product.

3. An application of the oligopeptide complex composition according to claim 1, characterized in that: The invention comprises application of the oligopeptide complex composition in agricultural fertilizer formula; the content of the oligopeptide complex composition in the agricultural fertilizer formula is 0.1-10wt%.

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