Refining process of chicken oil

Abstract

The invention relates to a chicken oil refining process, and relates to the technical field of animal fat, and the chicken oil refining process comprises pretreatment, low temperature degumming, deacidification and decoloration, low temperature deodorization, and ceramic membrane filtration. According to the refining process disclosed by the invention, efficient refining of the chicken oil is realized at low temperature through the steps of bio-enzyme directional degumming, electrified membrane separation deacidification and decolorization, nitrogen micro-bubble low-temperature deodorization and the like, so that nutrient substances of the chicken oil are not oxidized.

Description

Technical Field

[0001] The invention relates to the technical field of animal fats and oils, in particular to a chicken fat refining process. Background Art

[0002] Oils and fats have functions such as supplying energy, promoting the absorption and utilization of fat-soluble nutrients, and providing essential fatty acids. In addition, some special oils and fats also have pharmacological effects such as gene regulation, promoting wound healing, anti-tumor, antiviral, and antibacterial. Some oils and fats can also be used as industrial oils. Therefore, oils and fats are widely used in food, medicine, and industrial fields.

[0003] Animal fats and oils are usually present in the form of fat particles or fat droplets in oil-bearing cells, or are present in cells by combining with other macromolecular substances, such as forming lipoproteins with proteins and forming lipopolysaccharides with carbohydrates. Common methods for extracting animal fats and oils include: boiling method, cooking method, solvent method, enzymolysis method, supercritical fluid extraction method and water-soluble method. In the process of extracting animal fats and oils, if properly handled, the obtained oil product does not need to be further processed and can be used. However, in production practice, due to a series of reasons such as blood stains left during slaughter, the acid value of the obtained product is too high or impurities such as collagen are present. Therefore, these animal fats and oils also need to be further refined.

[0004] The Chinese invention patent application with publication number CN109234006A discloses an animal fat refining process, which comprises: transferring crude oil to an oil refining container, stirring at a speed of 55r / min to 65r / min, and preheating to 60°C to 65°C; adding hot brine to the oil refining container; reducing the speed and stirring at a speed of 25r / min to 35r / min; when the flocculation of the colloidal particles shows an obvious separation state, stopping stirring, standing for 2.5h to 4h, and separating and degumming; adding hot soft water to the oil refining container, stirring at the same time, standing and settling, separating to remove residual soap stock, and entering an oil storage tank; transferring the oil in the oil storage tank to a dryer for drying. The drying temperature of the dryer is 100° C. to 110° C.; 1% to 4% by weight of the oil is added with food-grade activated clay, the mixture is fully stirred and mixed, and the oil is decolorized for 20 minutes at an oil temperature of 110° C. to 120° C. and a pressure of 6 kPa to 7 kPa; the decolorized oil is pumped into a vibration filter, and filtered through the vibration filter and a bag filter in sequence; the filtered oil is pumped into a deodorizing tower using a gasifier oil pump, and when the oil reaches a specified liquid level in the deodorizing tower, the pumping is stopped, the deodorizing tower is self-circulated for 30 minutes, and when the oil temperature in the deodorizing tower rises to 230° C. to 250° C., a sample is taken for inspection, and when the oil passes the inspection, the oil outlet temperature is set and the refined animal oil is output.

[0005] The invented refining process improves the quality of refined animal fats, increases production efficiency, saves energy, and reduces costs. Compared to animal fats such as beef tallow and lard, chicken fat contains a large amount of non-hydratable phospholipids (β-phospholipids) (accounting for 40%-50% of the total phospholipid content). Hot brine only removes hydrated phospholipids (α-phospholipids). The remaining β-phospholipids oxidize during subsequent high-temperature deodorization (230-250°C), causing the phospholipids to oxidize and recolor during deodorization. Chicken fat also contains a large amount of protein and sugar colloids, which cannot be completely removed by conventional filtration. Incomplete degumming leads to poor oil stability and prone to rancidity. The free fatty acid content in chicken fat is typically 2%-5%. Soft water washing alone, as in the aforementioned process, cannot remove the free fatty acids. While high-temperature deodorization can volatilize some free fatty acids, the remaining free fatty acids catalyze oxidation, resulting in an increased peroxide value. Chicken fat contains natural antioxidants (such as vitamin E and oryzanol), but bleaching clay selectively adsorbs these components, increasing the loss of vitamin E and reducing oxidative stability. Furthermore, during bleaching at 110-120°C, unsaturated fatty acids (such as oleic acid and linoleic acid) in chicken fat oxidize to form hydroperoxides, which are subsequently decomposed into aldehydes and ketones during the subsequent deodorization stage. This is especially true for applications in high-value-added industries, which place high demands on the quality of chicken fat. Therefore, to obtain high-quality chicken fat, a suitable refining process is necessary. Summary of the Invention

[0006] To solve the above technical problems, the present invention provides a chicken fat refining process. The refining process of the present invention achieves efficient chicken fat refining at low temperature through steps such as enzyme-directed degumming, charged membrane separation, deacidification and decolorization, and nitrogen microbubble low-temperature deodorization, thereby preventing the nutrients in the chicken fat from being oxidized.

[0007] In a first aspect, the present invention provides a chicken fat refining process, the refining process comprising the following steps: Pretreatment: chicken feather oil is passed through an 80-100 mesh vibrating screen, the oil temperature is raised to 45-50°C, and stirred at 30-50 r / min for 8-12 minutes; Low-temperature degumming: based on the weight of the crude oil, dissolve 0.02-0.05% w / w of phospholipase A1 and 0.005-0.015% w / w of rosemary extract in a citric acid buffer solution with a concentration of 0.08-0.12M and a pH of 4.0-5.0 to obtain a mixed solvent, preheat the mixed solvent to 45-50° C., then add the mixed solvent to the pretreated chicken feather oil, stir at a low speed of 30-50 r / min for 25-35 minutes, heat to 80-90° C. and maintain for 3-8 minutes to inactivate the enzyme, and obtain enzymatic hydrolyzed oil; Deacidification and decolorization: Under the conditions of pressure 1-2 MPa, temperature 45-50°C, and pH 4.5-5.0, the enzymatic hydrolyzed oil is tangentially circulated through the surface of a sulfonated polyethersulfone nanofiltration membrane at a flow rate of 1.5-2.5 m / s, with a single pass time of ≤10 min, and the permeated oil is collected; Low-temperature deodorization: The permeate oil temperature is raised to 175-180°C, and nitrogen microbubbles are introduced into the oil at a pressure of 9-11 kPa for 10-20 minutes to obtain deodorized oil; Ceramic membrane filtration: Under the conditions of 0.5-1.0 MPa and temperature of 55-65° C., the deodorized oil is filtered through a 0.2 μm Al 2 O 3 ceramic membrane at a tangential flow rate of 1-3 m / s to obtain the chicken oil.

[0008] In this technical solution, vibration screening uses the size exclusion effect to intercept solid impurities (bone residue, connective tissue) and remove large particles. At 50°C, the oil's viscosity decreases, enhancing Brownian motion and disrupting initial colloid aggregation, creating a uniform reaction interface for enzymatic hydrolysis and improving degumming efficiency.

[0009] Phospholipase A1 can specifically cut the Sn-1 ester bond of phospholipid molecules, converting non-hydratable phospholipids (β-phospholipids) into lysophospholipids, greatly enhancing water solubility. Rosemary extract can inhibit oxidation, and carnosic acid can chelate metal ions (Fe 2+ / Cu + ), blocking the lipid peroxidation free radical chain reaction.

[0010] The sulfonic acid groups (-SO3H) on the surface of the sulfonated polyethersulfone nanofiltration membrane are ionized to generate negative charges, and the free fatty acids dissociate into RCOO at pH 5.0. - The membrane pore size is 0.5nm, which can physically retain carotenoids and chlorophyll derivatives.

[0011] Nitrogen gas creates bubbles with a diameter of 50-200 μm, creating a gas-liquid interface area of 2000 m² / m³. Volatile odorants (aldehydes and ketones) diffuse from the oil phase into the bubbles according to Henry's law. Trans fatty acid formation slows at 180°C.

[0012] The oil flows tangentially through the membrane surface at 1-3m / s for cross-flow screening. The shear force peels off the filter cake layer, and the 0.2μm pore size intercepts colloidal particles and thermal polymers for deep impurity removal.

[0013] Optionally, the preparation steps of the sulfonated polyethersulfone nanofiltration membrane are as follows: immerse the polyethersulfone particles in concentrated sulfuric acid with a liquid-to-solid ratio of 18-22:1, and magnetically stir at 100-300 r / min and 35-45°C for 80-100 minutes, pour the reaction solution into ice water to terminate, filter to obtain the sulfonated polyethersulfone, wash with water until neutral, and dry at 55-65°C, dissolve the sulfonated polyethersulfone in N,N-dimethylacetamide with a concentration of 18% w / w, stir at 55-65°C until a transparent viscous liquid is obtained to obtain a casting solution, cast the casting solution on a glass plate, immediately immerse in deionized water at room temperature to solidify for 25-35 seconds, transfer the membrane to a 35-45°C water bath and soak for 0.8-1.2 hours, and then dry in an oven at 55-65°C for 1-3 hours.

[0014] In this technical solution, the SO₃ groups in concentrated sulfuric acid attack the polyethersulfone benzene rings, causing electrophilic substitution. N,N-dimethylacetamide disrupts the hydrogen bonds between the sulfonated polyethersulfone molecules, forming a homogeneous solution. Water and N,N-dimethylacetamide are miscible, triggering nonsolvent-induced phase separation. The sulfonated polyethersulfone precipitates into a membrane, forming a dense separation layer on the surface and a macroporous support layer at the bottom. Residual N,N-dimethylacetamide is extracted in a water bath to prevent membrane pore collapse, and the drying process stabilizes the porous structure.

[0015] Optionally, the low-temperature degumming step further comprises dissolving, based on the mass of the crude oil, 0.2-0.5% w / w of phospholipase A1, 0.005-0.015% w / w of rosemary extract, and 0.01-0.02% w / w of phytic acid-zinc coordination polymer in a citric acid buffer solution with a concentration of 0.08-0.12 M and a pH of 4.0-5.0 to obtain a mixed solvent.

[0016] In the above technical solution, although carnosic acid in rosemary extract can chelate metal ions, its ability to scavenge free radicals is insufficient. Phytic acid in phytic acid-zinc coordination polymer can chelate Fe 3+ / Cu 2+ , blocking metal catalytic oxidation, among which Zn 2+ It can activate the o-diphenolic hydroxyl group of rosmarinic acid, improve the scavenging rate of ·OH, and synergize with rosemary extract in antioxidant effect.

[0017] Optionally, the phytic acid-zinc coordination polymer is prepared as follows: sodium phytate is dissolved in 55-65°C hot water to prepare a 0.1M solution A, and zinc acetate is dissolved in room temperature water to prepare a 0.15M solution B. Solution B is slowly added dropwise to solution A in a volume ratio of 1:1 between solution A and solution B. A white flocculent precipitate is immediately formed under magnetic stirring at 400-600 rpm. After standing at 55-65°C for 8-12 minutes, the precipitate is centrifuged at 3500-4500 rpm for 5-8 minutes, and then washed 2-3 times with 55-65°C water and dried at 55-65°C for 1-3 hours to obtain the phytic acid-zinc coordination polymer.

[0018] In the above technical solution, hot water dissolution can improve the solubility of sodium phytate (cold water is easy to gel), and zinc acetate is used to avoid the introduction of sulfate impurities. 2+ With the phosphate group (-PO4 3- ) undergo coordination crosslinking to form a three-dimensional network polymer. Aging can increase particle size for easier separation, and hot water washing can remove unreacted ions.

[0019] Optionally, the low-temperature degumming step further comprises dissolving 0.2-0.5% w / w phospholipase A1, 0.005-0.015% w / w rosemary extract, and 0.004-0.006% w / w fullerol-polyphenol composite powder in a citric acid buffer solution with a concentration of 0.08-0.12 M and a pH of 4.0-5.0 to obtain a mixed solvent.

[0020] In the above technical solution, the fullerol cage structure loads epigallocatechin gallate through π-π interaction, and fullerol can quench the singlet oxygen in chicken fat ( 1 O2), cut off lipid peroxyl radicals, and epigallocatechin gallate can undergo phenol-phenol coupling with rosmarinic acid to regenerate antioxidant activity.

[0021] Optionally, the preparation steps of the fullerenol-polyphenol composite powder are as follows: dissolving fullerenol in a phosphate buffer preheated to 55-65°C at a concentration of 10 mg / mL to obtain solution A, dissolving epigallocatechin gallate in a phosphate buffer preheated to 55-65°C at a concentration of 2.2 mg / mL to obtain solution B, mixing the solution A and the solution B in a volume ratio of 1:1, ultrasonicating at 30-50 kHz for 1-2 hours at room temperature to obtain a reaction solution, dialyzing the reaction solution using flowing deionized water for 2-3 hours, and freeze-drying to obtain a brown fluffy powder.

[0022] In the above technical solution, phosphate buffer maintains a neutral environment, preventing oxidation of epigallocatechin gallate. Ultrasonic cavitation is used to disrupt fullerol aggregates, while simultaneously driving the self-assembly of the phenolic rings in epigallocatechin gallate and the fullerol spheres through π-π stacking to form a complex. Unbound epigallocatechin gallate is removed by dialysis, while the complex is retained.

[0023] In a second aspect, the present invention provides a chicken fat refining process, which is prepared using the above-mentioned chicken fat refining process.

[0024] In a third aspect, the present invention provides a chicken oil refining process for preparing chicken oil and its application in the food processing industry, the pharmaceutical and health care product industry, the cosmetics industry, and the pet food industry.

[0025] In summary, the present invention includes at least one of the following beneficial technical effects: 1. During the pretreatment step, vibration screening uses the size exclusion effect to intercept solid impurities (bone residue, connective tissue) and remove large particles. At 50°C, the oil viscosity decreases, Brownian motion is enhanced, and the initial colloid aggregation is destroyed, creating a uniform reaction interface for enzymatic hydrolysis and improving degumming efficiency.

[0026] 2. During the low-temperature degumming step, phospholipase A1 can specifically cut the Sn-1 ester bond of the phospholipid molecule, converting the non-hydratable phospholipid (β-phospholipid) into lysophospholipid, which greatly enhances the water solubility. Rosemary extract can inhibit oxidation, and carnosic acid can chelate metal ions (Fe 2+ / Cu + ), blocking the lipid peroxidation free radical chain reaction.

[0027] 3. During the deacidification and decolorization step, the sulfonic acid groups (-SO3H) on the membrane surface ionize to generate negative charges, and free fatty acids dissociate into RCOO at pH 5.0. - The membrane pore size is 0.5nm, which can physically retain carotenoids and chlorophyll derivatives.

[0028] 4. During low-temperature deodorization, nitrogen gas creates bubbles with a diameter of 50-200μm, forming a gas-liquid interface area of 2000m² / m³. Volatile odorous compounds (aldehydes and ketones) diffuse from the oil phase into the bubbles according to Henry's law. The rate of trans fatty acid formation decreases at 180°C.

[0029] 5. In ceramic membrane filtration, grease flows tangentially through the membrane surface at a speed of 1-3 m / s for cross-flow screening, the shear force peels off the filter cake layer, and the 0.2 μm pore size intercepts colloidal particles and thermal polymers for deep impurity removal. DETAILED DESCRIPTION

[0030] The present invention is further described in detail below with reference to the examples.

[0031] The materials used in the following examples can all be purchased from the market.

[0032] Example 1: A chicken fat refining process The refining process comprises the following steps: S1. Pretreatment: chicken feather oil was passed through an 80-mesh vibrating screen, the oil temperature was raised to 45°C, and stirred at 30 r / min for 12 min.

[0033] S2. Low-temperature degumming: Based on the mass of the crude oil, 0.02% w / w phospholipase A1 and 0.015% w / w rosemary extract were dissolved in a 0.08 M citric acid buffer solution with a pH of 4.0-5.0 to obtain a mixed solvent, the mixed solvent was preheated to 45° C., and then the mixed solvent was added to the pretreated chicken feather oil. The mixture was stirred at a low speed of 30 r / min for 35 min, and the temperature was raised to 80° C. and maintained for 8 min to inactivate the enzyme to obtain enzymatic hydrolyzed oil.

[0034] S3. Deacidification and decolorization: Under the conditions of pressure 1 MPa, temperature 45°C, and pH 4.5-5.0, the enzymatic hydrolyzed oil is tangentially circulated through the surface of a sulfonated polyethersulfone nanofiltration membrane at a flow rate of 1.5 m / s. The single pass time is 10 min, and the permeated oil is collected.

[0035] S4. Low-temperature deodorization: the temperature of the permeated oil was raised to 175° C., nitrogen microbubbles were introduced into the oil at a pressure of 9 kPa, and the reaction was carried out for 20 minutes to obtain deodorized oil.

[0036] S5. Ceramic membrane filtration: Under the conditions of 0.5 MPa and 55° C., the deodorized oil was filtered through a 0.2 μm Al 2 O 3 ceramic membrane at a tangential flow rate of 1 m / s to obtain the chicken oil #1.

[0037] Among them, the preparation steps of sulfonated polyethersulfone nanofiltration membrane are as follows: immerse polyethersulfone particles in concentrated sulfuric acid with a liquid-to-solid ratio of 20:1, magnetically stir at 200 r / min and 40°C for 90 minutes, pour the reaction solution into ice water to terminate, filter to obtain sulfonated polyethersulfone, wash with water until neutral, and dry at 50°C. Dissolve the sulfonated polyethersulfone in N,N-dimethylacetamide with a concentration of 18% w / w, stir at 50°C until a transparent viscous liquid is obtained to obtain a casting liquid, cast the casting liquid on a glass plate, immediately immerse in deionized water at room temperature to solidify for 30 seconds, transfer the membrane to a 40°C water bath and soak for 1 hour, and then dry in a 60°C oven for 2 hours.

[0038] Example 2: A chicken fat refining process The refining process comprises the following steps: S1. Pretreatment: chicken feather oil was passed through a 100-mesh vibrating screen, the oil temperature was raised to 50°C, and stirred at 50 r / min for 8 min; S2, low-temperature degumming: based on the mass of crude oil, 0.05% w / w phospholipase A1 and 0.015% w / w rosemary extract were dissolved in a 0.1M citric acid buffer solution with a pH of 4.0-5.0 to obtain a mixed solvent, the mixed solvent was preheated to 48° C., and then the mixed solvent was added to the pretreated chicken feather oil, stirred at a low speed of 50 r / min for 25 min, and heated to 90° C. for 3 min to inactivate the enzyme to obtain enzymatic hydrolyzed oil; S3, deacidification and decolorization: under the conditions of pressure 2 MPa, temperature 45-55 ° C, pH 4.5-5.0, the enzymatic hydrolyzed oil was tangentially circulated through the surface of the sulfonated polyethersulfone nanofiltration membrane at a flow rate of 2.5 m / s, with a single pass time of 9 minutes, and the permeated oil was collected; S4, low-temperature deodorization: the temperature of the permeated oil is raised to 180°C, nitrogen microbubbles are introduced into the oil at a pressure of 11 kPa, and the reaction is carried out for 10 minutes to obtain deodorized oil; S5. Ceramic membrane filtration: Under the conditions of 1.0 MPa and 65° C., the deodorized oil was filtered through a 0.2 μm Al 2 O 3 ceramic membrane at a tangential flow rate of 3 m / s to obtain the chicken oil #2.

[0039] The preparation steps of the sulfonated polyethersulfone nanofiltration membrane are the same as those in Example 1.

[0040] Example 3: A chicken fat refining process The refining process comprises the following steps: S1. Pretreatment: chicken feather oil was passed through an 80-mesh vibrating screen, the oil temperature was raised to 50°C, and stirred at 40 r / min for 10 min; S2, low-temperature degumming: based on the mass of crude oil, 0.03% w / w phospholipase A1 and 0.01% w / w rosemary extract were dissolved in a 0.1M citric acid buffer solution with a pH of 4.0-5.0 to obtain a mixed solvent, the mixed solvent was preheated to 50° C., and then the mixed solvent was added to the pretreated chicken feather oil, stirred at a low speed of 40 r / min for 30 min, and heated to 85° C. and maintained for 5 min to inactivate the enzyme to obtain enzymatic hydrolyzed oil; S3, deacidification and decolorization: under the conditions of pressure 1.5 MPa, temperature 50°C, pH 4.5-5.0, the enzymatic hydrolyzed oil was tangentially circulated through the surface of the sulfonated polyethersulfone nanofiltration membrane at a flow rate of 2 m / s, with a single pass time of 6 min, and the permeated oil was collected; S4, low-temperature deodorization: the temperature of the permeated oil is raised to 180°C, nitrogen microbubbles are introduced into the oil at a pressure of 10 kPa, and the reaction is carried out for 150 minutes to obtain deodorized oil; S5. Ceramic membrane filtration: Under the conditions of 0.8 MPa and 60° C., the deodorized oil was filtered through a 0.2 μm Al 2 O 3 ceramic membrane at a tangential flow rate of 2 m / s to obtain the chicken oil #3.

[0041] The preparation steps of the sulfonated polyethersulfone nanofiltration membrane are the same as those in Example 1.

[0042] Example 4: A chicken fat refining process The refining process comprises the following steps: S1. Pretreatment: chicken feather oil was passed through an 80-mesh vibrating screen, the oil temperature was raised to 50°C, and stirred at 40 r / min for 10 min; S2, low-temperature degumming: based on the mass of crude oil, 0.03% w / w of phospholipase A1, 0.01% w / w of rosemary extract, and 0.015% w / w of phytic acid-zinc coordination polymer were dissolved in a 0.1M citric acid buffer solution with a pH of 4.0-5.0 to obtain a mixed solvent, the mixed solvent was preheated to 50 ° C, and then the mixed solvent was added to the pretreated chicken feather oil, stirred at a low speed of 40 r / min for 30 min, and heated to 85 ° C and maintained for 5 min to inactivate the enzyme to obtain enzymatic hydrolyzed oil; S3, deacidification and decolorization: under the conditions of pressure 1.5 MPa, temperature 50°C, pH 4.5-5.0, the enzymatic hydrolyzed oil was tangentially circulated through the surface of the sulfonated polyethersulfone nanofiltration membrane at a flow rate of 2 m / s, with a single pass time of 6 min, and the permeated oil was collected; S4, low-temperature deodorization: the temperature of the permeated oil is raised to 180°C, nitrogen microbubbles are introduced into the oil at a pressure of 10 kPa, and the reaction is carried out for 150 minutes to obtain deodorized oil; S5. Ceramic membrane filtration: Under the conditions of 0.8 MPa and 60° C., the deodorized oil was filtered through a 0.2 μm Al 2 O 3 ceramic membrane at a tangential flow rate of 2 m / s to obtain the chicken oil #4.

[0043] The preparation steps of the sulfonated polyethersulfone nanofiltration membrane are the same as those in Example 1.

[0044] The phytic acid-zinc coordination polymer is prepared as follows: sodium phytate is dissolved in 60°C hot water to prepare a 0.1M solution A, and zinc acetate is dissolved in room temperature water to prepare a 0.15M solution B. Solution B is slowly added dropwise to solution A at a volume ratio of 1:1. A white flocculent precipitate is immediately formed under magnetic stirring at 500 rpm. After standing at 50°C for 10 minutes, the precipitate is centrifuged at 4000 rpm for 5 minutes, washed three times with 50°C water, and dried at 60°C for 2 hours to obtain the phytic acid-zinc coordination polymer.

[0045] Example 5: A chicken fat refining process The refining process comprises the following steps: S1. Pretreatment: chicken feather oil was passed through an 80-mesh vibrating screen, the oil temperature was raised to 50°C, and stirred at 40 r / min for 10 min; S2, low-temperature degumming: based on the mass of crude oil, dissolve 0.03% w / w phospholipase A1, 0.01% w / w rosemary extract, and 0.005% w / w fullerenol-polyphenol composite powder in 0.1M citric acid buffer at pH 4.0-5.0 to obtain a mixed solvent, preheat the mixed solvent to 50° C., then add the mixed solvent to the pretreated chicken feather oil, stir at a low speed of 40 rpm for 30 min, heat to 85° C. and maintain for 5 min to inactivate the enzyme, and obtain enzymatic hydrolyzed oil; S3, deacidification and decolorization: under the conditions of pressure 1.5 MPa, temperature 50°C, pH 4.5-5.0, the enzymatic hydrolyzed oil was tangentially circulated through the surface of the sulfonated polyethersulfone nanofiltration membrane at a flow rate of 2 m / s, with a single pass time of 6 min, and the permeated oil was collected; S4, low-temperature deodorization: the temperature of the permeated oil is raised to 180°C, nitrogen microbubbles are introduced into the oil at a pressure of 10 kPa, and the reaction is carried out for 150 minutes to obtain deodorized oil; S5. Ceramic membrane filtration: Under the conditions of 0.8 MPa and 60° C., the deodorized oil was filtered through a 0.2 μm Al 2 O 3 ceramic membrane at a tangential flow rate of 2 m / s to obtain the chicken oil #5.

[0046] The preparation steps of the sulfonated polyethersulfone nanofiltration membrane are the same as those in Example 1.

[0047] The preparation steps of the fullerenol-polyphenol composite powder are as follows: dissolving fullerenol in a phosphate buffer solution preheated to 60° C. at a concentration of 10 mg / mL to obtain solution A; dissolving epigallocatechin gallate in a phosphate buffer solution preheated to 60° C. at a concentration of 2.2 mg / mL to obtain solution B; mixing the solution A and the solution B in a volume ratio of 1:1; ultrasonicating at 40 kHz for 1.5 hours at room temperature to obtain a reaction solution; dialyzing the reaction solution with flowing deionized water for 2 hours; and freeze-drying to obtain a brown fluffy powder.

[0048] Example 6: A chicken fat refining process The refining process comprises the following steps: S1. Pretreatment: chicken feather oil was passed through an 80-mesh vibrating screen, the oil temperature was raised to 50°C, and stirred at 40 r / min for 10 min; S2, low-temperature degumming: based on the mass of crude oil, 0.03% w / w phospholipase A1, 0.01% w / w rosemary extract, 0.015% w / w phytic acid-zinc coordination polymer, and 0.005% w / w fullerol-polyphenol composite powder were dissolved in a 0.1M citric acid buffer solution with a pH of 4.0-5.0 to obtain a mixed solvent, the mixed solvent was preheated to 50° C., and then the mixed solvent was added to the pretreated chicken feather oil, stirred at a low speed of 40 r / min for 30 min, and the temperature was raised to 85° C. and maintained for 5 min to inactivate the enzyme to obtain enzymatic hydrolyzed oil; S3, deacidification and decolorization: under the conditions of pressure 1.5 MPa, temperature 50°C, pH 4.5-5.0, the enzymatic hydrolyzed oil was tangentially circulated through the surface of the sulfonated polyethersulfone nanofiltration membrane at a flow rate of 2 m / s, with a single pass time of 6 min, and the permeated oil was collected; S4, low-temperature deodorization: the temperature of the permeated oil is raised to 180°C, nitrogen microbubbles are introduced into the oil at a pressure of 10 kPa, and the reaction is carried out for 150 minutes to obtain deodorized oil; S5. Ceramic membrane filtration: Under the conditions of 0.8 MPa and 60° C., the deodorized oil was filtered through a 0.2 μm Al 2 O 3 ceramic membrane at a tangential flow rate of 2 m / s to obtain the chicken oil #6.

[0049] The preparation steps of the sulfonated polyethersulfone nanofiltration membrane are the same as those in Example 1.

[0050] The phytic acid-zinc coordination polymer is prepared as follows: sodium phytate is dissolved in 60°C hot water to prepare a 0.1M solution A, and zinc acetate is dissolved in room temperature water to prepare a 0.15M solution B. Solution B is slowly added dropwise to solution A at a volume ratio of 1:1. A white flocculent precipitate is immediately formed under magnetic stirring at 500 rpm. After standing at 50°C for 10 minutes, the precipitate is centrifuged at 4000 rpm for 5 minutes, washed three times with 50°C water, and dried at 60°C for 2 hours to obtain the phytic acid-zinc coordination polymer.

[0051] The preparation steps of the fullerenol-polyphenol composite powder are as follows: dissolving fullerenol in a phosphate buffer solution preheated to 60° C. at a concentration of 10 mg / mL to obtain solution A; dissolving epigallocatechin gallate in a phosphate buffer solution preheated to 60° C. at a concentration of 2.2 mg / mL to obtain solution B; mixing the solution A and the solution B in a volume ratio of 1:1; ultrasonicating at 40 kHz for 1.5 hours at room temperature to obtain a reaction solution; dialyzing the reaction solution with flowing deionized water for 2 hours; and freeze-drying to obtain a brown fluffy powder.

[0052] Comparative Example 1: The refining process of a comparative chicken fat provided in this comparative example is the same as that in Example 6, except that the pretreatment step is missing.

[0053] Comparative Example 2: The refining process of a comparative chicken fat provided in this comparative example is the same as that in Example 6, except that phospholipase A1 is missing in the low-temperature degumming step.

[0054] Comparative Example 3: The refining process of a comparative chicken fat provided in this comparative example is the same as that in Example 6, except that the rosemary extract is missing in the low-temperature degumming step.

[0055] Comparative Example 4: The refining process of a comparative chicken fat provided in this comparative example is the same as that in Example 6, except that phospholipase A2 is used instead of phospholipase A1 in the low-temperature degumming step.

[0056] Comparative Example 5: The refining process of a comparative chicken fat provided in this comparative example is the same as that in Example 6, except that vitamin E (tocopherol) is used instead of rosemary extract in the low-temperature degumming step.

[0057] Comparative Example 6: The refining process of a comparative chicken fat provided in this comparative example is the same as that in Example 6, except that an ordinary nanofiltration membrane is used instead of a sulfonated polyethersulfone nanofiltration membrane in the deacidification and decolorization steps.

[0058] Comparative Example 7: The refining process of a comparative chicken oil provided in this comparative example is the same as that in Example 6, except that: a low-temperature deodorization step: the temperature of the permeated oil is raised to 180°C, nitrogen is introduced into the oil at a pressure of 10 kPa, and the reaction is carried out for 150 minutes to obtain deodorized oil.

[0059] Chicken fats #1-#6, prepared using the chicken fat refining processes of Examples 1-6, and comparative chicken fats D1-D7, prepared using the comparative chicken fat refining processes of Comparative Examples 1-7, were tested for performance, including oxidative stability, acid value control, trans fatty acid content, and phospholipid residual rate. The test results are shown in Table 1. Oxidative stability was measured using the Schall oven method (110°C) to determine the oxidation induction period.

[0060] Table 1 Example Performance Oxidation induction period (h) Acid value control content (mgKOH / g) Trans fatty acid content (%) Phospholipid residual rate (ppm) Example 1 36 0.32 0.11 10.2 Example 2 37 0.30 0.10 10.1 Example 3 39 0.29 0.09 9.8 Example 4 42 0.25 0.07 9.2 Example 5 44 0.23 0.06 8.9 Example 6 47 0.20 0.04 8.3 Comparative Example 1 34 0.35 0.15 10.5 Comparative Example 2 33 0.37 0.18 12.9 Comparative Example 3 22 0.41 0.22 11.3 Comparative Example 4 35 0.37 0.15 11.8 Comparative Example 5 25 0.39 0.17 10.7 Comparative Example 6 33 0.38 0.21 10.5 Comparative Example 7 34 0.34 0.13 10.0 From the test data of Examples 1-3 in Table 1, especially the data of Example 3, it can be seen that by reasonably setting the parameters in the chicken oil refining process steps, the chicken oil obtained has relatively excellent performance in various properties.

[0061] Compared with Example 3 and Example 6 and Example 5, a phytic acid-zinc coordination polymer is added in the low-temperature degumming step. The chicken oil #4 prepared by the chicken oil refining process of Example 4 has improved properties compared with the chicken oil #3 prepared by the chicken oil refining process of Example 3. The chicken oil #6 prepared by the chicken oil refining process of Example 6 has improved properties compared with the chicken oil #5 prepared by the chicken oil refining process of Example 5. This is because the phytic acid in the phytic acid-zinc coordination polymer can chelate Fe 3+ / Cu 2+ , blocking metal catalytic oxidation, among which Zn 2+ It can activate the o-diphenolic hydroxyl group of rosmarinic acid, improve the scavenging rate of ·OH, and synergize with rosemary extract in antioxidant effect.

[0062] Compared with Example 3, Example 5 adds fullerol-polyphenol composite powder in the low-temperature degumming step. The chicken fat #5 prepared by the chicken fat refining process of Example 5 has improved properties compared with the chicken fat #3 prepared by the chicken fat refining process of Example 3. This is because the fullerol cage structure supports epigallocatechin gallate through π-π interaction, and fullerol can quench singlet oxygen in the chicken fat ( 1 O2), cut off lipid peroxyl radicals, and epigallocatechin gallate can undergo phenol-phenol coupling with rosmarinic acid to regenerate antioxidant activity.

[0063] Compared to Example 6, Comparative Example 1 lacks a pretreatment step, resulting in decreased performance across all of the comparative chicken fat obtained in Comparative Example 1. This is due to the vibration screening in the pretreatment step, which intercepts solid impurities (bone residue, connective tissue) and removes large particles based on the size exclusion effect. At 50°C, the oil's viscosity decreases, enhancing Brownian motion and disrupting initial colloidal aggregation, creating a uniform reaction interface for enzymatic hydrolysis and improving degumming efficiency.

[0064] Compared with Example 6, Comparative Example 2 lacks phospholipase A1 in the low-temperature degumming step, resulting in a decrease in all properties of the comparative chicken fat obtained in Comparative Example 2. This is because phospholipase A1 can specifically cleave the Sn-1 ester bond of the phospholipid molecule, converting non-hydratable phospholipids (β-phospholipids) into hemolysophospholipids, greatly enhancing the water solubility.

[0065] Comparative Example 3 Compared with Example 6, the low-temperature degumming step lacks rosemary extract, resulting in a decrease in the performance of the comparative chicken fat obtained in Comparative Example 3. The reason is that rosemary extract can inhibit oxidation, and carnosic acid can chelate metal ions (Fe 2+ / Cu + ), blocking the lipid peroxidation free radical chain reaction.

[0066] Compared with Example 6, in Comparative Example 4, phospholipase A2 was used instead of phospholipase A1 in the low-temperature degumming step, resulting in a decrease in all properties of the comparative chicken fat obtained in Comparative Example 4. The reason is that although phospholipase A2 and phospholipase A1 belong to the same phospholipase family, phospholipase A2 hydrolyzes the Sn-2 ester bond of phospholipids, and the degumming efficiency is significantly reduced.

[0067] Compared with Example 6, in Comparative Example 5, vitamin E (tocopherol) was used instead of rosemary extract in the low-temperature degumming step. As a result, all properties of the comparative chicken fat obtained in Comparative Example 5 were reduced. This is because although vitamin E can provide hydrogen atoms to interrupt the free radical chain reaction and scavenge lipid peroxyl radicals (ROO·), its oxidation potential is lower than that of rosmarinic acid, its reactivity is weak, and it cannot effectively chelate metal ions. In addition, it is easily decomposed at high temperatures above 80°C.

[0068] Comparative Example 6 Compared with Example 6, the use of ordinary nanofiltration membrane instead of sulfonated polyethersulfone nanofiltration membrane in the deacidification and decolorization step resulted in a decrease in the performance of the comparative chicken fat obtained in Comparative Example 6. The reason is that the sulfonic acid group (-SO3H) on the surface of the sulfonated polyethersulfone nanofiltration membrane ionizes to generate a negative charge, and the free fatty acids dissociate into RCOO at pH 5.0. - The membrane pore size is 0.5nm, which can physically retain carotenoids and chlorophyll derivatives.

[0069] Compared with Example 6, in Comparative Example 7, nitrogen gas instead of nitrogen microbubbles was introduced during the low-temperature deodorization step, resulting in a decrease in all properties of the comparative chicken fat obtained in Comparative Example 7. This is because nitrogen gas generates bubbles with a diameter of 50-200 μm, forming a gas-liquid interface area of 2000 m² / m³, and volatile odorous substances (aldehydes and ketones) diffuse from the oil phase into the bubbles according to Henry's law.

[0070] The above are all preferred embodiments of the present invention, and are not intended to limit the scope of protection of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. A chicken fat refining process, characterized in that: The refining process comprises the following steps: Pretreatment: chicken feather oil is passed through an 80-100 mesh vibrating screen, the oil temperature is raised to 45-50°C, and stirred at 30-50 r / min for 8-12 minutes; Low-temperature degumming: based on the weight of the crude oil, dissolve 0.02-0.05% w / w of phospholipase A1 and 0.005-0.015% w / w of rosemary extract in a citric acid buffer solution with a concentration of 0.08-0.12M and a pH of 4.0-5.0 to obtain a mixed solvent, preheat the mixed solvent to 45-50° C., then add the mixed solvent to the pretreated chicken feather oil, stir at a low speed of 30-50 r / min for 25-35 minutes, heat to 80-90° C. and maintain for 3-8 minutes to inactivate the enzyme, and obtain enzymatic hydrolyzed oil; Deacidification and decolorization: Under the conditions of pressure 1-2 MPa, temperature 45-50°C, and pH 4.5-5.0, the enzymatic hydrolyzed oil is tangentially circulated through the surface of a sulfonated polyethersulfone nanofiltration membrane at a flow rate of 1.5-2.5 m / s, with a single pass time of ≤10 min, and the permeated oil is collected; Low-temperature deodorization: The permeate oil temperature is raised to 175-180°C, and nitrogen microbubbles are introduced into the oil at a pressure of 9-11 kPa for 10-20 minutes to obtain deodorized oil; Ceramic membrane filtration: Under the conditions of 0.5-1.0 MPa and temperature of 55-65° C., the deodorized oil is filtered through a 0.2 μm Al 2 O 3 ceramic membrane at a tangential flow rate of 1-3 m / s to obtain the chicken oil.

2. A chicken fat refining process according to claim 1, characterized in that, The preparation steps of the sulfonated polyethersulfone nanofiltration membrane are as follows: immersing polyethersulfone particles in concentrated sulfuric acid with a liquid-to-solid ratio of 18-22:1, magnetically stirring at 100-300 r / min and 35-45°C for 80-100 minutes, pouring the reaction solution into ice water to terminate, filtering to obtain sulfonated polyethersulfone, washing with water until neutral, and drying at 55-65°C, dissolving the sulfonated polyethersulfone in N,N-dimethylacetamide with a concentration of 18% w / w, stirring at 55-65°C until a transparent viscous liquid is obtained to obtain a casting solution, casting the casting solution on a glass plate, immediately immersing it in deionized water at room temperature for solidification for 25-35 seconds, transferring the membrane to a 35-45°C water bath for 0.8-1.2 hours, and then drying it in an oven at 55-65°C for 1-3 hours.

3. A chicken fat refining process according to claim 1 or 2, characterized in that: The low-temperature degumming step further comprises dissolving, based on the mass of the crude oil, 0.2-0.5% w / w of phospholipase A1, 0.005-0.015% w / w of rosemary extract, and 0.01-0.02% w / w of phytic acid-zinc coordination polymer in a citric acid buffer solution with a concentration of 0.08-0.12 M and a pH of 4.0-5.0 to obtain a mixed solvent.

4. A chicken fat refining process according to claim 1, characterized in that, The phytic acid-zinc coordination polymer is prepared as follows: sodium phytate is dissolved in 55-65°C hot water to prepare a 0.1M solution A, and zinc acetate is dissolved in room temperature water to prepare a 0.15M solution B. Solution B is slowly added dropwise to solution A at a volume ratio of 1:

1. A white flocculent precipitate is immediately formed under magnetic stirring at 400-600 rpm. After standing at 55-65°C for 8-12 minutes, the precipitate is centrifuged at 3500-4500 rpm for 5-8 minutes, and then washed with 55-65°C water 2-3 times and dried at 55-65°C for 1-3 hours to obtain the phytic acid-zinc coordination polymer.

5. The chicken fat refining process according to claim 4, characterized in that: The low-temperature degumming step further comprises dissolving 0.2-0.5% w / w phospholipase A1, 0.005-0.015% w / w rosemary extract, and 0.004-0.006% w / w fullerol-polyphenol composite powder in a citric acid buffer solution with a concentration of 0.08-0.12 M and a pH of 4.0-5.0 to obtain a mixed solvent.

6. The chicken fat refining process according to claim 4 or 5, characterized in that: The preparation steps of the fullerenol-polyphenol composite powder are as follows: dissolving fullerenol in a phosphate buffer solution preheated to 55-65° C. at a concentration of 10 mg / mL to obtain solution A; dissolving epigallocatechin gallate in a phosphate buffer solution preheated to 55-65° C. at a concentration of 2.2 mg / mL to obtain solution B; mixing the solution A and the solution B in a volume ratio of 1:1; ultrasonicating at 30-50 kHz for 1-2 hours at room temperature to obtain a reaction solution; dialyzing the reaction solution with flowing deionized water for 2-3 hours; and freeze-drying to obtain a brown fluffy powder.

7. A chicken fat, characterized in that The chicken fat is prepared using the refining process of any one of claims 1 to 6.

8. Use of the chicken fat as claimed in claim 7 in the food processing industry, the medicine and health care product industry, the cosmetics industry, and the pet food industry.