Method for preparing phospholipid flavor base material through enzymatic oxidation

Abstract

The invention provides a method for preparing a phospholipid flavor base material through enzymatic oxidation, and relates to the technical field of food processing. The method for preparing the phospholipid flavor base material through enzymatic oxidation mainly comprises the following steps: redissolving phospholipid prepared from tuna as a raw material through a solvent, cleaning, drying, preparing a lipoxygenase solution with the pH value of 6, mixing the lipoxygenase solution with the dried phospholipid, carrying out heating oxidation treatment at 37 DEG C, boosting, introducing supercritical carbon dioxide for middle-stage enzymatic oxidation, and carrying out freeze-drying to obtain the phospholipid flavor base material. And finally, heating again to continue enzymatic oxidation, cooling in a water bath, and refrigerating. The preparation method overcomes the defects in the prior art, can effectively realize enzyme-added oxidation of phospholipid under the condition of lower temperature, and effectively enriches key flavor substances of phospholipid, so that the phospholipid has better fat flavor and fresh flower and herb flavor, and the final base material mainly presents a'stewed 'flavor.

Description

Technical Field

[0001] The invention relates to the technical field of food processing, and in particular to a method for preparing a phospholipid flavor base material by enzymatic oxidation. Background Art

[0002] Lecithin is a food additive widely used in the food industry, mainly used as an emulsifier, dispersant and antioxidant. Lecithin is a lipid substance naturally present in cell membranes. It has good emulsification, dispersing and antioxidant functions, can improve the texture and taste of food, enhance the stability of food and extend the shelf life. For infants, lecithin is generally safe as a food additive, but long-term and large-scale intake may affect the nutritional balance of infants. In addition, after lecithin is oxidized, it will release a variety of volatile compounds, which play an important role in the aroma of food. The presence of lecithin in meat is essential for the production of a specific meat aroma. Separating the intermuscular and intramuscular triglycerides of lean beef does not significantly change the sensory properties of the food, but removing triglycerides and lecithin will cause obvious sensory differences, indicating that lecithin is essential for the generation of the overall meat aroma.

[0003] In addition to the traditional high-temperature oxidation method, the prior art also attempts to use oxidase to directly oxidize fat. The catalytic activity of the enzyme can selectively promote the oxidation reaction at a specific location, avoiding nonspecific oxidation. This highly specific catalytic effect helps to improve the reaction efficiency and maintain the accuracy and controllability of the reaction. In the reaction, the oxidase provides a specific active site to allow the substrate molecule to combine with oxygen and undergo an oxidation reaction to generate an oxidation product. The oxidase can reduce the activation energy of the oxidation reaction and increase the reaction rate.

[0004] Lipoxygenase (LOX) is a typical oxidase, which is characterized by catalyzing unsaturated fatty acids to form hydroperoxides. Rapeseed oil and linseed oil were treated with LOX and hydroperoxide lyase to obtain products containing high C6-C9 aldehydes. Factors affecting the activity of LOX include reaction temperature, pH value, substrate concentration, buffer concentration and additives. By comparing and analyzing the effects of different organic solvent media on the catalytic effect of LOX, it was observed that in the single-phase isooctane medium, the activity of LOX was significantly improved compared with that in the water medium, with an increase of up to 2.6 times. In addition, in the two single-phase reaction media of octane and n-hexane, the activity of LOX was also improved by 2.2 times and 1.8 times, respectively. However, single-phase reaction media such as toluene, chloroform and dichloromethane showed an inhibitory effect on enzyme activity. Enzymatic oxidation reactions are fast and the reaction conditions are relatively mild, which is closer to the oxidation reaction in vivo. However, enzymes with specific catalytic activity are required, and the purification and stability of the enzyme may increase the complexity and cost of the experiment.

[0005] Compared with thermal oxidation, the products obtained by enzymatic oxidation of fat have different flavors, the former tends to be "barbecued" and the latter tends to be "clear stewed". Beef tallow was oxidized for 40 minutes at a temperature of 160-170°C. Subsequently, the oxidized beef tallow was mixed with raw materials such as fermented soy sauce and cysteine ​​to generate beef flavor with a unique flavor through thermal reaction. Sunflower oil and chicken fat were used as raw materials, and green flavoring and meat flavor precursors were prepared after catalytic oxidation by lipoxygenase. The fatty acids obtained by enzymatic hydrolysis are further heated under relatively mild conditions and oxidized by passing air or oxygen, which is a more efficient enzymatic hydrolysis and oxidation method. Beef tallow was enzymatically hydrolyzed by lipase, oxidized at a temperature of 80-100°C, and further thermally reacted with other substrates to obtain a flavor essence with a strong meaty aroma and prominent characteristic aroma.

[0006] However, the existing thermal oxidation and enzymatic oxidation have high temperature requirements, and the overall aroma is mostly meaty. On this basis, controlling the conditions for phospholipid oxidation and developing a new flavor base is an important research and development direction for the food processing industry. Summary of the invention

[0007] In view of the shortcomings of the prior art, the present invention provides a method for preparing a phospholipid flavor base material by enzymatic oxidation, which can effectively achieve enzymatic oxidation of phospholipids under relatively low temperature conditions, and can also effectively enrich the key flavor substances of phospholipids, so that the phospholipids have a better fat taste and a refreshing floral and vanilla aroma, so that the final base material mainly presents a "clear stew" taste.

[0008] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0009] A method for preparing a phospholipid flavor base material by enzymatic oxidation, the method for preparing a phospholipid flavor base material comprising the following steps:

[0010] S1. Obtaining phospholipids: using tuna as raw material, column chromatography is used to prepare dry phospholipid raw materials;

[0011] S2, re-dissolution: take the dry phospholipid raw material mixed solvent and fill it with nitrogen in a sealed container, stir and dissolve it, then filter and remove the solvent to obtain the precipitated phospholipid for use:

[0012] S3, drying: drying the precipitated phospholipids in an ice-water bath by nitrogen purge to remove the remaining solvent, and obtaining dry phospholipids for later use;

[0013] S4, enzyme solution preparation: dissolve lipoxygenase in distilled water, and then adjust the pH to 6 to obtain an enzyme solution for use;

[0014] S5, pressure oxidation treatment: add the enzyme solution to the above-mentioned dry phospholipids, stir evenly, seal and heat to 37°C, keep warm for 1 hour, then seal and pressurize and fill with supercritical carbon dioxide, keep warm for 40 minutes, then release the pressure to discharge carbon dioxide, continue to heat to 45°C and keep warm for 1 hour to obtain oxidized phospholipids for use;

[0015] S6. Refrigeration: Cool the oxidized phospholipid in an ice-water bath and then refrigerate to obtain a phospholipid flavor base.

[0016] Preferably, the method for obtaining phospholipids comprises the following steps:

[0017] S1-1, washing: washing the raw materials to obtain clean tuna heads and tuna viscera for later use;

[0018] S1-2, crushing: crush the clean tuna head and tuna viscera to obtain crushed material for later use;

[0019] S1-3. Extraction: Column chromatography is used to extract phospholipids from the crushed tuna raw material.

[0020] Preferably, the specific operation method in step S1-3 includes the following steps:

[0021] S1-3-1. Add the crushed material to a methanol-chloroform solution and 0.05% BHT in a volume ratio of 1:2, mix thoroughly and let stand for 1 hour; after filtering, add 0.9% physiological saline to the filtrate and shake thoroughly, centrifuge, and obtain total lipids for later use;

[0022] S1-3-2, adding chloroform to the total lipids, mixing well, and then adding to the aminopropyl solid phase extraction column activated by n-hexane for elution;

[0023] S1-3-3. Collect the methanol eluate from the above extraction column, blow it with nitrogen and then vacuum dry it to obtain phospholipids.

[0024] Preferably, the solvent in step S2 is diethyl ether, and the volume ratio of the phospholipid raw material mixed solvent is 1:10-20.

[0025] Preferably, the pressure during nitrogen filling, stirring and dissolving in step S2 is controlled to be 0.2-0.3 MPa.

[0026] Preferably, in step S4, the volume ratio of lipoxygenase mixed with distilled water is 1:3-5, and the enzyme activity of lipoxygenase is 1.5×10 7 -7.5×10 7 UNITS.

[0027] Preferably, in step S4, 0.1 mol / L sodium citrate buffer is used to adjust the pH.

[0028] Preferably, when the enzyme solution is added to the dry phospholipid in step S5, the mass ratio of the lipoxygenase contained in the enzyme solution to the precipitated phospholipid is 0.03-0.05:1.

[0029] Preferably, the pressure increased in step S5 is 7.5-8.0 MPa, and the amount of supercritical carbon dioxide charged is 3-5 times the total mass of the dry phospholipids.

[0030] Preferably, the refrigeration temperature in step S6 is 4°C.

[0031] The present invention provides a method for preparing a phospholipid flavor base material by enzymatic oxidation, which has the following advantages compared with the prior art:

[0032] (1) The present invention uses lipoxygenase (LOX enzyme) to prepare the flavor base, because LOX specifically catalyzes fatty acids with a 1,4-pentadiene structure, avoiding nonspecific oxidation. More ω-6 fatty acids are degraded to produce flavor substances (hexanal, (E)-2-hexenal, (E)-2-octenal, 2-pentylfuran), maintaining the accuracy and controllability of the reaction, and the phospholipid flavor base mainly presents a "clear stew" taste;

[0033] (2) In the present invention, the phospholipids are initially subjected to solvent pressure dissolution and washing to remove most impurities, and then an enzymatic oxidation treatment is performed by keeping the lipoxygenase solution at pH 6 at 37°C, and then the oxidation is interrupted by increasing the pressure and adding supercritical carbon dioxide to promote the uniformity of various substances, and then the temperature is raised to 45°C to continue the oxidation treatment, so that the key flavor substances of the final product are hexanal (fatty, fishy, ​​and grassy), heptaldehyde, (E)-2-hexenal (fatty, cheese-like), octanal, nonanal, (E,E)-2,4-hexadienal (floral, Fruity aroma), (E,Z)-2,6-nonadienal, (E)-2-octenal (floral, fruity aroma), benzaldehyde (floral, vanilla and almond aroma), (E)-2-decenal (spicy, woody and fresh), (E,E)-2,4-decadienal, 1-octen-3-ol, 7-tetradecanol (honey aroma, floral aroma), 2-ethylfuran (caramel, sweetness) and 2-pentylfuran (grassy, ​​earthy, metallic taste), etc. The main body is the fresh aroma of fat, floral, fruity and woody, which meets the market demand for food flavor additives. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 Schematic diagram of fatty acid determination after enzymatic phospholipid thermal oxidation of the present invention; wherein, (a) is a heat map of fatty acid content; (b) is a stacking map of fatty acid content; (c) is a bar graph of fatty acid component content

[0035] Figure 2 This is a schematic diagram of the change of TBA value before and after enzymatic phospholipid oxidation of the present invention;

[0036] Figure 3 is the spectrum of the main acyl groups of the enzymatic oxidation of phospholipids in CDCl3 of the present invention;

[0037] Figure 4 For the present invention 1 H NMR monitors the extended region of the spectrum of oxidation products produced during the enzymatic oxidation of phospholipids;

[0038] Figure 5 Schematic diagram of the changes in volatile flavor substances before and after phospholipid enzyme oxidation according to the present invention. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention is clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] The lipoxygenase used in the following examples was purchased from Merck KGaA, Darmstadt, Germany, and the enzyme activity was 1.5×10 7 UNITS.

[0041] Embodiment 1:

[0042] Preparation of phospholipid materials:

[0043] (1) selecting tuna as raw material, cleaning it, and obtaining clean tuna heads and tuna viscera for later use;

[0044] (2) Crush the clean tuna head and tuna viscera to obtain crushed material for later use;

[0045] (3) Add the crushed material to a methanol-chloroform solution and 0.05% BHT in a volume ratio of 1:2, mix thoroughly and let stand for 1 hour; after filtering, add 0.9% physiological saline to the filtrate and shake thoroughly, centrifuge, and obtain total lipids for later use;

[0046] (4) adding chloroform to the total lipids and mixing well, and then adding the mixture to an aminopropyl solid phase extraction column activated with n-hexane for elution; wherein elution with chloroform-isopropanol solution (2:1, v / v) can obtain neutral triglycerides, elution with 2% acetic acid-ether solution (v / v) can obtain free fatty acids, and elution with methanol can obtain phospholipids;

[0047] (5) collecting the methanol eluate from the extraction column, blowing with nitrogen and then vacuum drying to obtain phospholipids.

[0048] Embodiment 2:

[0049] Preparation of lecithin flavor base:

[0050] (1) The phospholipids in Example 1 above were taken as raw materials and mixed with ether in a volume ratio of 1:15 in a sealed container, and nitrogen was filled to adjust the pressure to 0.25±0.05 MPa. The phospholipids were dissolved by magnetic stirring for 15 minutes, and then filtered to remove the solvent to obtain the precipitated phospholipids for use;

[0051] (2) drying the precipitated phospholipids in an ice-water bath by nitrogen purge to remove the remaining solvent, thereby obtaining dry phospholipids for later use;

[0052] (3) pH adjustment: dissolve lipoxygenase in distilled water at a volume ratio of 1:4, and then adjust the pH to 6 with 0.1 mol / L sodium citrate buffer to obtain an enzyme solution for use;

[0053] (4) Oxidation treatment: add the enzyme solution to the above-mentioned dry phospholipids (the mass ratio of lipoxygenase to dry phospholipids is 0.04:1), stir evenly, seal and heat to 37°C, keep warm for 1 hour, then seal and pressurize to 8.0 MPa and fill with supercritical carbon dioxide 4 times the total mass of the dry phospholipids, keep warm for 40 minutes, then release the pressure to discharge the carbon dioxide, continue to heat to 45°C, keep warm and stir magnetically for 1 hour, and obtain oxidized phospholipids for use;

[0054] (5) Cool the oxidized phospholipids in an ice water bath and then refrigerate at 4° C. to obtain a phospholipid flavor base.

[0055] Detection:

[0056] Referring to the preparation method of Example 2 above, the following experimental groups were set by controlling and adjusting different pH values ​​and oxidation treatment process conditions, and a blank group was set up, i.e., the phospholipids prepared in Example 1 were not treated:

[0057] Table 1

[0058]

[0059] In the table, when the pH value is 6, 0.1 mol / L sodium citrate buffer is used for adjustment; when the pH value is 9, 0.2 mol / L borate buffer is used for adjustment; 37°C and 45°C are used for magnetic stirring, 95°C is used for water bath heating, and in experimental group 1, dry phospholipids are directly oxidized by water bath heating.

[0060] 1. Determination of fatty acid composition: Accurately weigh 50 mg of the final product of each group into a centrifuge tube, first add 2 mL of n-heptane to dissolve, then add 4 mL of 2 mol / L potassium hydroxide-methanol solution, vortex for 30 seconds and let stand to separate. Take 1 mL of the n-heptane layer solution and dilute it to 10 mL. The dilution is filtered through a 0.22 μm pore size organic phase filter with an injection volume of 1 μL.

[0061] The results are as follows Figure 1 As shown, 37 kinds of FA were detected in the enzymatic oxidation of phospholipids in the experimental group, with contents of SFA (235.31±18.41), MUFA (9.64±0.65), and PUFA (276.43±15.25) mg / g. DHA (C22:6n3) had the highest content (28%), followed by palmitic acid (C16:0) (19.90%) and linoleic acid (C18:2n6c) (10.16%). The enzymatic oxidation of SFA and PUFA at pH=6 decreased significantly, and the DHA content in PUFA decreased by nearly 50%, and C18:2n6c and linolenic acid (C18:3n6) also decreased by about 40%. That is, the oxidation effect was best in experimental group 2.

[0062] 2. Determination of conjugated diene and conjugated triene values: Weigh 50 mg of phospholipid flavor base into a 10 mL volumetric flask, add a small amount of isooctane to dissolve the phospholipid, and then adjust the volume with isooctane, and measure the absorbance at 233 nm and 268 nm respectively. The results are expressed by the following equation.

[0063]

[0064] In the formula, ——Extinction value, A λ ——Absorbance, c PL ——phospholipid concentration (g / 100mL), l——cuvette width (cm).

[0065] The results are shown in Table 2. In experimental groups 1 and 2, the CD and CT values ​​were higher, and the content of conjugated diene and conjugated triene structures in phospholipids was relatively high. The CD and CT values ​​were arranged in the order of experimental group 1> experimental group 2> experimental group 4> experimental group 3> experimental group 5> blank group.

[0066] Table 2

[0067] Group Blank group Experimental Group 1 Experimental Group 2 Experimental Group 3 Experimental Group 4 Experimental Group 5 CD 12.71±1.52 28.93±0.39 24.44±1.96 19.87±0.33 20.99±0.20 16.23±0.23 CT 9.23±1.39 16.20±0.08 14.28±0.51 12.53±0.33c 14.09±0.0 12.68±0.20

[0068] 3. Determination of TBA value: Weigh 0.15g of each group of phospholipid flavor base into a 25mL volumetric flask, add a small amount of 1-butanol to dissolve the phospholipids, and then use 1-butanol to make up the volume. Take 5mL of sample solution and 5mL of 0.2% 2-thiobarbituric acid 1-butanol solution (TBA reagent) and mix well. After cooling to room temperature in a 95℃ water bath for 2h, measure the absorbance at 532nm with a UV-visible spectrophotometer. The result is expressed as the TBA value using the following equation.

[0069]

[0070] Where, 50 is the coefficient based on the volume of the volumetric flask and the width of the cuvette, A532 ——absorbance, m——sample mass (g).

[0071] The results are as follows Figure 2 As shown, the blank group and experimental group 1 were 107.02±7.07 and 131.25±10.73, respectively, and the experimental groups 2-5 were 126.39±5.80, 117.22±8.83, 160.44±4.96 and 149.16±4.71, respectively. The TBA value of phospholipids in experimental group 4 was the highest, followed by experimental group 5, indicating that the phospholipids in these two groups produced more secondary oxidation products, including volatile aldehydes, during the oxidation process.

[0072] 4. Determination of fatty acyl groups: Take 0.1g of each group of phospholipid flavor base samples, dissolve in 0.4mL CDCl3 and 0.4mL methanol-EDTA solution, mix well, and transfer to a 5mm NMR tube. Use a 500MHz spectrometer with a 5mm low-temperature probe, and the acquisition parameters are: test temperature 4℃; pulse angle 30°; acquisition time 3.2768s; relaxation time 3s; scan number 128 times; total acquisition time 13min 20s.

[0073] The calculation formula of main fatty acyl groups:

[0074]

[0075] Wherein: x(i)——percentage of fatty acyl to be measured, %; I(i)——integral conversion value of acyl to be measured; I(FA)——integral conversion value of total fatty acids.

[0076] The results are as follows Figure 3 And as shown in Table 3. Figure 3 Shows 1 In the H NMR spectrum between 0.5 and 5.5 ppm, the signal at 0.97 ppm is assigned to unsaturated ω-3 acyl (signal C), the signal at 1.66 to 1.70 ppm is assigned to EPA and ARA acyl (signal F), the signal at 1.94 to 2.14 ppm is assigned to allyl groups on unsaturated acyl groups except DHA (signal G), the signal between 2.36 and 2.46 ppm is assigned to DHA acyl (signal I), and the signal at 2.76 ppm is assigned to di-unsaturated ω-6 acyl (signal J).

[0077] Table 3

[0078]

[0079] In the above table, ω-3 represents total ω-3 unsaturated fatty acid acyl groups, DHA represents docosahexaenoic acid, EPA+ARA represents eicosapentaenoic acid and arachidonic acid, ω-6 represents diunsaturated ω-6 acyl groups, and S+M represents saturated plus modified fatty acid acyl groups.

[0080] As shown in Table 3, the contents of ω-3, DHA, EPA+ARA, ω-6 and S+M in the blank group were (8.09±0.21)%, (6.61±0.07)%, (4.32±0.12)%, (15.05±0.35)% and (40.47±1.46)%, respectively. In experimental group 1, the contents of all fatty acyl groups decreased significantly. In experimental group 2, the contents of ω-3 and ω-6 unsaturated fatty acids (signals C and J) were significantly reduced compared with those in experimental group 1 (P<0.05). In experimental group 3, except for the significant decrease in the content of DHA acyl group, the oxidation degree of other acyl groups was not as good as that in experimental group 2, and even the content was higher than that in experimental group 5.

[0081] 5. Determination of oxidation products: Take 0.1g of each group of phospholipid flavor base samples and dissolve them in 0.4mL CDCl3 and 0.4mL methanol-EDTA solution, mix well, and transfer to a 5mm NMR tube. Use a 500MHz spectrometer with a 5mm cryogenic probe. Acquisition parameters: The internal temperature is set to 20℃. Perform a single pulse experiment with the following experimental parameters: 64 scans, 1s relaxation time, and 3.744s acquisition time.

[0082] The results are as follows Figure 4 As shown, Figure 4 It shows that less hydroperoxides were detected in experimental group 1. More dienal signals were found in experimental group 4, indicating that a certain amount of dienals were generated after phospholipid oxidation. However, only normal alkanals (signal m) were found in experimental group 5, because under pH = 6, LOX catalyzed phospholipids to generate (E, Z)-2,4-decadienal, while normal alkanals such as hexanal were generated under pH = 9.

[0083] 6. Determination of volatile flavor substances in oxidized phospholipids: Use headspace solid phase microextraction (HS-SPME), weigh 0.01g of each group of phospholipid flavor base samples into a sample bottle, add 4mL of ultrapure water. Place the sample bottle on a magnetic stirring table, stir magnetically at 60℃ for 20min, insert the extraction head into the headspace sample bottle, extract at the same temperature for 40min, insert the extraction head into the GC-MS during injection, and analyze for 5min. Results Figure 5 and Table 4.

[0084] Table 4:

[0085]

[0086]

[0087]

[0088] like Figure 5As shown: the volatile flavor substances aldehydes accounted for the highest proportion in experimental groups 2-5, and the types of phospholipid flavor compounds increased significantly after enzymatic oxidation.

[0089] Based on the above tests, it can be seen that the enzymatic oxidation effect in experimental group 2 is the best.

[0090] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a phospholipid flavor base by enzymatic oxidation, characterized in that: The method for preparing the phospholipid flavor base comprises the following steps: S1. Obtaining phospholipids: using tuna as raw material, column chromatography is used to prepare dry phospholipid raw materials; S2, re-dissolution: take the dry phospholipid raw material mixed solvent and fill it with nitrogen in a sealed container, stir and dissolve it, then filter and remove the solvent to obtain the precipitated phospholipid for use: S3, drying: drying the precipitated phospholipids in an ice-water bath by nitrogen purge to remove the remaining solvent, and obtaining dry phospholipids for later use; S4, enzyme solution preparation: dissolve lipoxygenase in distilled water, and then adjust the pH to 6 to obtain an enzyme solution for use; S5, pressure oxidation treatment: add the enzyme solution to the above-mentioned dry phospholipids, stir evenly, seal and heat to 37°C, keep warm for 1 hour, then seal and pressurize and fill with supercritical carbon dioxide, keep warm for 40 minutes, then release the pressure to discharge carbon dioxide, continue to heat to 45°C and keep warm for 1 hour to obtain oxidized phospholipids for use; S6. Refrigeration: Cool the oxidized phospholipid in an ice-water bath and then refrigerate to obtain a phospholipid flavor base.

2. The method for preparing a phospholipid flavor base by enzymatic oxidation according to claim 1, characterized in that: The method for obtaining the phospholipids comprises the following steps: S1-1, washing: washing the raw materials to obtain clean tuna heads and tuna viscera for later use; S1-2, crushing: crush the clean tuna head and tuna viscera to obtain crushed material for later use; S1-3. Extraction: Column chromatography is used to extract phospholipids from the crushed tuna raw material.

3. The method for preparing a phospholipid flavor base by enzymatic oxidation according to claim 2, characterized in that: The specific operation method in step S1-3 includes the following steps: S1-3-1. Add the crushed material to a methanol-chloroform solution and 0.05% BHT in a volume ratio of 1:2, mix thoroughly and let stand for 1 hour; after filtering, add 0.9% physiological saline to the filtrate and shake thoroughly, centrifuge, and obtain total lipids for later use; S1-3-2, adding chloroform to the total lipids, mixing well, and then adding to the aminopropyl solid phase extraction column activated by n-hexane for elution; S1-3-3. Collect the methanol eluate from the above extraction column, blow it with nitrogen and then vacuum dry it to obtain phospholipids.

4. The method for preparing a phospholipid flavor base by enzymatic oxidation according to claim 1, characterized in that: In step S2, the solvent is ether, and the volume ratio of the phospholipid raw material mixed solvent is 1:10-20.

5. The method for preparing a phospholipid flavor base by enzymatic oxidation according to claim 1, characterized in that: In the step S2, the pressure is controlled to be 0.2-0.3 MPa during nitrogen filling, stirring and dissolving.

6. The method for preparing a phospholipid flavor base by enzymatic oxidation according to claim 1, characterized in that: In step S4, the volume ratio of lipoxygenase mixed with distilled water is 1:3-5, and the enzyme activity of lipoxygenase is 1.5×10 7 -7.5×10 7 UNITS.

7. The method for preparing a phospholipid flavor base by enzymatic oxidation according to claim 1, characterized in that: In step S4, 0.1 mol / L sodium citrate buffer is used to adjust the pH.

8. The method for preparing a phospholipid flavor base by enzymatic oxidation according to claim 1, characterized in that: In the operation of adding the enzyme solution to the dry phospholipid in step S5, the mass ratio of the lipoxygenase contained in the enzyme solution to the precipitated phospholipid is 0.03-0.05:

1.

9. The method for preparing a phospholipid flavor base by enzymatic oxidation according to claim 1, characterized in that: The pressure of the boost in step S5 is 7.5-8.0 MPa, and the amount of supercritical carbon dioxide charged is 3-5 times the total mass of the dry phospholipids.

10. The method for preparing a phospholipid flavor base by enzymatic oxidation according to claim 1, characterized in that: The refrigeration temperature in step S6 is 4°C.

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