High-efficiency fermentation preparation method of Badam vegetable oil, Badam fermented oil and application of Badam fermented oil
Through the fermentation and preparation method of Badanmu vegetable oil with synergistic metabolism and dynamic regulation of complex bacteria, the problems of low oil yield and loss of active ingredients in the prior art are solved, and the efficient extraction of highly active vegetable oil is achieved, which is suitable for the food, medicine and cosmetics fields.
Patent Information
- Application Number
- CN202510558174.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-29
- Publication Date
- 2025-08-22
AI Technical Summary
The existing badan wood oil extraction technology has problems such as low oil yield, oxidation of unsaturated fatty acids, serious waste of resources, and destruction of residual toxic substances and active ingredients. Traditional methods cannot efficiently extract highly active vegetable oil.
The coordinated metabolism of the complex bacterial flora (Cans tropical, Aspergillus niger, Lactobacillus plantarum) and three-stage dynamic dissolved oxygen regulation are adopted, combined with pulse feeding strategies and membrane separation-molecular distillation technology to achieve efficient conversion of badanmu kernel residue into highly active vegetable oil.
It significantly improves oil yield and functional component retention rate, is suitable for the production of high-value-added oil and fats in the food, pharmaceutical and cosmetics industries, and improves oil yield and functional activity.
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of plant oil extraction, and specifically relates to a method for preparing almond plant oil by efficient fermentation based on the coordinated metabolism and dynamic regulation of a composite bacterial community, as well as almond fermented oil and its application. Background Art
[0002] Almond kernels, the fruit of the Rosaceae plant (Amygdalus communis L.), are primarily produced in the Xinjiang Uyghur Autonomous Region. They are a nutritious, world-renowned, and highly prized fruit and a renowned Xinjiang specialty. Analysis shows that almond kernels contain 55-66% fatty oil (over 90% of which is unsaturated fatty acids), 28% protein, 10% sugar, and 18 trace elements, including Fe, Ca, Zn, and Se. Almond kernels also contain 18 amino acids, boasting high nutritional value and long considered a longevity fruit by the Uyghur people. Recent medical research has shown that almond kernels have anti-aging, antioxidant, immune-enhancing properties, and are rich in trace elements, making them a high-quality source of essential fatty acids and protein. Research and analysis indicate that almond kernel extracts can be used in traditional medicine, food and health supplements, and cosmetics and skincare products. In particular, almond kernel extract, rich in vitamin E and antioxidants, has been incorporated into anti-aging and moisturizing products.
[0003] However, traditional almond oil extraction relies on physical pressing, solvent extraction or single-strain fermentation, which has the following defects: (1) The oil yield of the pressing method is low (≤40%), and high temperature (>60°C) leads to oxidation of unsaturated fatty acids (peroxide value ≥3.0meq / kg); the residual oil in the residue (about 15-20%) cannot be effectively extracted, resulting in serious waste of resources; (2) The solvent extraction method requires the use of organic solvents such as n-hexane, which leaves residual toxic substances (such as n-hexane ≤10ppm), high purification costs, and damage to natural antioxidant components (such as tocopherol loss rate >30%); (3) Existing fermentation methods for preparing vegetable oils mostly use a single strain (such as Aspergillus oryzae), with low oil synthesis efficiency (yield ≤50%), long fermentation cycle (≥200h), and inability to retain active ingredients. Summary of the Invention
[0004] In order to solve the above-mentioned defects of the existing almond oil extraction technology, the present invention proposes an efficient fermentation preparation method of almond vegetable oil and almond fermented oil and its application, which can significantly improve the oil yield and functional activity.
[0005] To achieve the above object, the present invention adopts the following technical solutions:
[0006] The first aspect of the present invention is to provide a method for efficiently fermenting and preparing almond vegetable oil, comprising the following steps:
[0007] (1) Raw material pretreatment: Almond kernels were low-temperature pressed to obtain crude oil, and the residue was treated with cellulase (0.5-1.5% w / w) and ultrasonic wave (20-40 kHz, 200-500 W) to break the wall of the kernels, and the solid-liquid ratio was controlled to be 1:3-1:5 to obtain a residue mixture;
[0008] (2) Inoculation of composite flora: Candida tropicalis CGMCC 2.1776, Aspergillus niger CCTCCAF 200037, and Lactobacillus plantarum CICC 23121 were inoculated into the residue mixture in proportion to obtain a fermentation mixture;
[0009] (3) Three-stage dynamic fermentation: The fermentation mixture is fermented in the following three stages:
[0010] Stage I: The fermentation mixture is subjected to anaerobic fermentation at pH 5.5-6.0, temperature 32-35°C, and stirring speed 50-100 rpm for 30-42 hours;
[0011] Phase II: pH 6.5-7.0, temperature 28-30°C, and pulse feeding (carbon-nitrogen ratio 20:1) were then used for microaerobic fermentation (DO 5-15%) for 54-66 hours.
[0012] Stage III: Finally, the pH is controlled at 7.2-7.5, the temperature is 25-28°C, and 0.1-0.3% biosurfactant is added for aerobic fermentation (DO>30%) for 12-24 hours to obtain the fermentation broth;
[0013] (4) Product purification: The fermentation broth is ultrafiltered using a ceramic membrane and then molecularly distilled at a temperature of 80-100°C and a vacuum of 0.1-1 mbar to obtain high-purity almond oil.
[0014] Preferably, in step (1), the cellulase treatment conditions are: enzymatic hydrolysis temperature 45-50°C, time 2-4h, and ultrasonic treatment interval 10s on / 5s off.
[0015] Preferably, in step (1), the almond kernels are pre-cleaned and then dried to a moisture content of ≤8%; a twin-screw press is used for low-temperature pressing with the following parameters: screw speed 25 rpm, pressing pressure 25 MPa, oil outlet temperature ≤45°C; the crude oil is filtered through diatomaceous earth (pore size 5 μm), and the residue is collected for later use.
[0016] Preferably, in step (1), the residue is mixed with deionized water at a ratio of 1:4, and the pH is adjusted to 5.0 (citrate buffer); 1.0% cellulase (Novozymes Cellic CTec3) is added, and the mixture is stirred at a constant temperature of 50°C (150 rpm) for 3 hours; the enzymatic hydrolyzate is centrifuged (4000 rpm, 15 minutes), and the supernatant is taken for later use.
[0017] Preferably, in step (1), the enzymatically hydrolyzed material is transferred to an ultrasonic reaction tank (capacity 50 L); the parameters are set as follows: frequency 35 kHz, power density 8 W / L, pulse mode (10 seconds on / 5 seconds off), and treatment for 30 minutes; verification of cell wall breaking efficiency: scanning electron microscopy (SEM) shows that the cell wall rupture rate is >90%.
[0018] More preferably, in step (1), the process of pre-treating the raw materials comprises the following steps:
[0019] (11) Low temperature pressing: Almond kernels are pressed through a twin-screw press (pressure 25 MPa, temperature ≤ 45°C) to extract crude oil, with the residue containing 18-22% oil;
[0020] (12) Enzymatic hydrolysis of residue: the residue was mixed with deionized water at a ratio of 1:4 (w / w), 1.0% cellulase (activity ≥ 2000 U / g) was added, and enzymatic hydrolysis was carried out at pH 5.0 and 50°C for 3 h;
[0021] (13) Ultrasonic wall breaking: After enzymatic hydrolysis, the material was transferred into an ultrasonic reactor (frequency 35 kHz, power 400 W) and treated in pulse mode (10 seconds on / 5 seconds off) for 30 minutes.
[0022] Preferably, in step (2), each bacterial strain is activated using the following process before inoculation:
[0023] The tropical yeast Candida was cultured in YPD medium (1% yeast powder, 2% peptone, 2% glucose) at 30° C. on a shaking platform for 24 hours.
[0024] The Aspergillus niger was cultured in PDA medium at 28°C for 5 days, with a spore suspension concentration of 1×106 CFU / mL;
[0025] The plant lactobacillus was cultured anaerobically at 37° C. for 48 hours using MRS culture medium.
[0026] Preferably, in step (2), the inoculation ratio of Candida tropicalis, Aspergillus niger and Lactobacillus plantarum is (2-5):(1-3):1 (v / v); and the total inoculation amount is 8% of the volume of the fermentation broth.
[0027] Preferably, in step (3), the pulse feeding in stage II is to add glucose and soybean meal hydrolysate or glucose and cottonseed protein hydrolysate every 2 hours, with a mass ratio of 2-4:1, and the total addition amount is 15-25% of the initial substrate.
[0028] Preferably, in step (3), the biosurfactant used in stage III is a mixture of rhamnolipid and sophorolipid in a mass ratio of 2:1.
[0029] More preferably, in step (3), the three-stage dynamic fermentation process comprises the following steps:
[0030] (31) Stage I (anaerobic fermentation):
[0031] Conditions: pH 5.8, temperature 34°C, dissolved oxygen (DO) ≤ 0.5% (nitrogen replacement), stirring 80 rpm, time 36 hours;
[0032] Monitoring: Samples were taken every 6 hours to detect biomass (OD600) and residual sugar content (DNS method).
[0033] (32) Phase II (microaerobic pulse feeding):
[0034] Feed solution: glucose and soybean meal hydrolyzate (mass ratio 3:1), C / N = 20:1;
[0035] Feeding method: pulse addition of 5% of the total feed amount every 2 hours, and the total feed amount is 20% of the initial substrate;
[0036] Conditions: DO 10%, pH 6.8, temperature 28°C, stirring 150 rpm, time 60 hours.
[0037] (33) Stage III (aerobic refining):
[0038] Add 0.2% rhamnolipid (purity ≥90%);
[0039] Conditions: DO 35%, pH 7.4, temperature 25°C, stirring 200 rpm, time 18 hours.
[0040] Preferably, in step (4), the ceramic membrane is made of zirconium oxide, has a pore size of 0.02-0.1 μm, and a transmembrane pressure of 0.2-0.5 MPa.
[0041] More preferably, in step (4), the process for refining the product comprises the following steps:
[0042] (41) Ceramic membrane ultrafiltration: 0.05 μm zirconium oxide membrane (Inopor, Germany), transmembrane pressure 0.3 MPa, temperature 25 °C, removal of large molecular impurities (protein retention rate > 99%);
[0043] (42) Molecular distillation: temperature 90 °C, vacuum degree 0.5 mbar, the light phase collects oil, and the heavy phase (glycerol, free fatty acids) is recycled to the fermentation system.
[0044] The second aspect of the present invention is to provide an almond fermented oil prepared by the method described in any of the above items, wherein the unsaturated fatty acid content is ≥88% (including 65-75% oleic acid and 12-18% linoleic acid), the free sterol retention rate is ≥95%, and the peroxide value is ≤1.0meq / kg (tested according to GB 5009.227).
[0045] Preferably, the DPPH free radical scavenging rate IC 50 ≤50μg / mL, ABTS cation clearance rate ≥90% (at concentration 100μg / mL).
[0046] The third aspect of the present invention is to provide a use of the almond fermented oil as described in any one of the above items in anti-aging cosmetics, with an addition amount of 0.5-5%, and it is used in combination with ceramide or hyaluronic acid.
[0047] The present invention adopts the above technical solution, which has the following technical effects compared with the prior art:
[0048] The present invention provides an efficient fermentation method for preparing almond vegetable oil, which realizes an innovative process for efficiently converting almond kernel residue into highly active vegetable oil through the synergistic action of a composite bacterial community (Candida tropicalis, Aspergillus niger, and Lactobacillus plantarum), combined with three-stage dynamic dissolved oxygen regulation, a pulse feeding strategy, and membrane separation-molecular distillation combined technology. The method of the present invention can significantly improve the oil yield and functional ingredient retention rate, and is suitable for the production of high-value-added oils in the food, medicine, and cosmetics industries. DETAILED DESCRIPTION
[0049] The core solution of this invention is based on the synergistic metabolism of complex bacterial communities and dynamic environmental regulation technology. Through the phased dissolved oxygen-feeding strategy and membrane separation coupling technology, it significantly improves the oil yield and functional activity, and is suitable for the production of high-end food, medicine and cosmetic raw materials.
[0050] Specifically, (1) a composite bacterial community synergistic metabolic process is adopted: tropical yeast is used to efficiently convert sugars into triglycerides, Aspergillus niger secretes lipase to promote substrate hydrolysis, and Lactobacillus plantarum is used to inhibit miscellaneous bacteria and synthesize antioxidant peptides. (2) A dynamic fermentation control process is adopted: a three-stage dissolved oxygen strategy is used to match the metabolic characteristics of the bacterial community (anaerobic-microaerobic-aerobic), and pulse feeding is used to avoid substrate inhibition and maintain carbon-nitrogen balance. (3) A green refining process is adopted: ceramic membrane ultrafiltration is used to remove large molecular impurities (proteins, polysaccharides), and low-temperature molecular distillation is used to retain heat-sensitive active ingredients.
[0051] The present invention will be described in detail and specifically below through specific examples to provide a better understanding of the present invention, but the following examples do not limit the scope of the present invention.
[0052] Example 1 (standard process)
[0053] A method for preparing almond vegetable oil by efficient fermentation, comprising the following steps:
[0054] (1) Raw material pretreatment: 10 kg of almond kernels (oil content 52%) were subjected to low-temperature pressing to obtain 4.3 kg of crude oil; the residue after pressing was treated with cellulase (1.0% w / w) and ultrasonic wave (35 kHz, 400 W) to break the cell wall, and the solid-liquid ratio was controlled to 1:4 to obtain a residue mixture;
[0055] (2) Inoculation of composite flora: Candida tropicalis (CGMCC 2.1776), Aspergillus niger (CCTCCAF 200037), and Lactobacillus plantarum (CICC 23121) were inoculated into the residue mixture in proportion. The inoculation amount of each species was 6% for Candida tropicalis, 4% for Aspergillus niger, and 2% for Lactobacillus plantarum.
[0056] (3) Three-stage dynamic fermentation: The fermentation mixture is fermented in the following three stages:
[0057] Phase I: The mixture was subjected to anaerobic fermentation (DO = 0%) at pH 5.8, temperature 34°C, and stirring speed 80 rpm for 36 h;
[0058] Phase II: pH 6.8, temperature 28°C, and glucose to soybean meal hydrolysate mass ratio of 3:1 were then added every 2 h for microaerobic fermentation (DO 10%) for 60 h.
[0059] Stage III: Finally, the pH was controlled at 7.4 and the temperature was 25°C. 0.2% biosurfactant was added for aerobic fermentation (DO 35%). The biosurfactant used was rhamnolipid and sophorolipid at a mass ratio of 2:1. The fermentation was continued for 18 hours to obtain the fermentation broth.
[0060] (4) Product purification: The fermentation broth was ultrafiltered using a 0.05 μm ceramic membrane (molecular weight cutoff 10 kDa), and then molecularly distilled at a temperature of 90°C and a vacuum of 0.5 mbar to obtain high-purity almond oil.
[0061] Testing showed a total oil yield of 91.2% (residual oil + fermented synthetic oil) (testing standard: GB 5009.6); oleic acid content of 71.3% (testing standard: AOCS Ce 1h-05); and a peroxide value of 0.8 meq / kg (testing standard: GB 5009.227). The fermentation cycle was 114 hours (the traditional method requires at least 200 hours).
[0062] Example 2 (optimization of feeding)
[0063] The difference from the above-mentioned Example 1 is that in step (3) of the three-stage dynamic fermentation, the feed ratio of stage II is adjusted to glucose: cottonseed protein hydrolysate = 4:1, and the rest is the same as in Example 1.
[0064] After testing, it was found that after optimizing the feeding process, the oil yield increased to 94.5% and the free sterol content increased by 12%.
[0065] Comparative Example 1 (single strain)
[0066] The difference from the above-mentioned Example 1 is that in step (2) of inoculating the composite flora, only Candida tropicalis is inoculated, and the rest is the same as in Example 1.
[0067] After testing, the oil yield was 58.7% and the fermentation period was extended to 210h.
[0068] Comparative Example 2 (constant dissolved oxygen)
[0069] The difference from the above-mentioned Example 1 is that the DO is maintained at 20% throughout the three-stage dynamic fermentation in step (3). Other steps are the same as those in Example 1.
[0070] After testing, the oxidation rate of polyunsaturated fatty acids in the oil reached 15%, and the peroxide value rose to 2.3meq / kg.
[0071] Example 3 (Optimizing the ratio of bacterial strains)
[0072] The difference from the above-mentioned Example 1 is that the ratio of bacterial species in the composite bacterial consortium inoculation in step (2) is changed to 4:1:1 (Candida tropicalis:Aspergillus niger:Lactobacillus plantarum), and the other parameters are the same as those in Example 1.
[0073] After testing, the oil yield was increased to 94.8% (originally 91.2%); the fermentation cycle was shortened to 102 hours (originally 114 hours).
[0074] Comparative Example 3 (without dynamic regulation)
[0075] The difference from the above-mentioned Example 1 is that the three-stage fermentation is omitted in step (3), and DO=10%, pH 6.5, and temperature 30° C. are maintained throughout the whole process; other parameters are the same as in Example 1.
[0076] After testing, the oil yield dropped to 68.3%; the peroxide value increased to 1.9 meq / kg (originally 0.8 meq / kg).
[0077] Example 4 (Industrial Scale-up)
[0078] A method for preparing almond vegetable oil by efficient fermentation, comprising the following steps:
[0079] (1) Raw material pretreatment: 500L three-stage fermentation system (Jiangsu Saideli), membrane separation unit (membrane area 20m 2 ); 1 ton of almond kernel residue (oil content 18%) was treated with cellulase (1.0% w / w) and ultrasonic-assisted (35kHz, 400W) cellulase to control the solid-liquid ratio to 1:4 to obtain a residue mixture;
[0080] (2) Inoculation of composite flora: Candida tropicalis (CGMCC 2.1776), Aspergillus niger (CCTCCAF 200037), and Lactobacillus plantarum (CICC 23121) were inoculated into the residue mixture in proportion. The inoculation amount of each species was 6% for Candida tropicalis, 4% for Aspergillus niger, and 2% for Lactobacillus plantarum.
[0081] (3) Three-stage dynamic fermentation: The fermentation mixture is fermented in the following three stages:
[0082] Phase I: The mixture was subjected to anaerobic fermentation (DO = 0%) at pH 5.8, temperature 34°C, and stirring speed 50-100 rpm for 36 h;
[0083] Phase II: pH 6.8, temperature 28°C, and pulse feeding (carbon-nitrogen ratio 20:1) were then used for microaerobic fermentation (DO 12%), with a total sugar addition of 200 kg for 60 h.
[0084] Stage III: Finally, the pH was controlled at 7.4, the temperature was 25°C, and 0.2% biosurfactant was added for aerobic fermentation (DO 35%) for 20 h to obtain the fermentation broth;
[0085] (4) Product purification: The fermentation broth was ultrafiltered using a 0.05 μm ceramic membrane (molecular weight cutoff 10 kDa), and then molecularly distilled at a temperature of 90°C and a vacuum of 0.5 mbar to obtain high-purity almond oil.
[0086] After testing, the total oil output is: 162kg (residual oil + fermentation synthetic oil); oleic acid content: 73.5%, peroxide value: 0.7meq / kg; energy consumption: 1.2kW·h / kg oil (traditional method: 2.8kW·h / kg).
[0087] Comparative Example 4 (no membrane separation)
[0088] The difference from the above-mentioned Example 4 is that in the product purification process of step (4), centrifugation (8000 rpm, 30 min) is used instead of ceramic membrane separation. The rest is the same as Example 4.
[0089] After testing, the oil turbidity (NTU): 35 → NTU = 2 after membrane separation; free fatty acid content: 0.8% → 1.5% after centrifugation.
[0090] Example 5 (Industrial Continuous Production)
[0091] A method for preparing almond vegetable oil by efficient fermentation, comprising the following steps:
[0092] (1) Raw material pretreatment: Raw material pretreatment: 1000L three-stage fermentation system (Jiangsu Saideli), membrane separation unit (membrane area 50m 2 ); 2 tons of almond kernel residue (oil content 19%) was treated with cellulase (1.0% w / w) and ultrasonic-assisted (35kHz, 400W) cellulase to control the solid-liquid ratio to 1:4 to obtain a residue mixture;
[0093] (2) Inoculation of composite flora: Candida tropicalis (CGMCC 2.1776), Aspergillus niger (CCTCCAF 200037), and Lactobacillus plantarum (CICC 23121) were inoculated into the residue mixture in proportion. The inoculation amount of each species was 6% for Candida tropicalis, 4% for Aspergillus niger, and 2% for Lactobacillus plantarum.
[0094] (3) Three-stage dynamic fermentation: The fermentation mixture is fermented in the following three stages:
[0095] Phase I: The mixture was subjected to anaerobic fermentation (DO = 0%) at pH 5.8, temperature 34°C, and stirring speed 50-100 rpm for 36 h;
[0096] Phase II: pH 6.8, temperature 28°C, and pulse feeding (carbon-nitrogen ratio 20:1) were then used for microaerobic fermentation (DO 12%) with a feed rate of 400 kg (glucose:soybean meal hydrolysate = 3:1) for 60 h.
[0097] Stage III: Finally, the pH was controlled at 7.4, the temperature was 25°C, and 40 kg of biosurfactant was added for aerobic fermentation (DO 35%) for 18 h to obtain the fermentation broth;
[0098] (4) Product purification: The fermentation broth was ultrafiltered using a 0.05 μm ceramic membrane with a filtration flow rate of 500 L / h. Molecular distillation was then performed at a temperature of 90°C and a vacuum of 0.5 mbar to obtain high-purity almond oil.
[0099] After testing, the total oil production was 342 kg (yield 89.5%); the unit energy consumption was 1.1 kW·h / kg (2.8 kW·h / kg for the traditional method).
[0100] While the specific embodiments of the present invention have been described in detail above, these are merely exemplary and the present invention is not limited thereto. For those skilled in the art, any equivalent modifications and substitutions to the present invention are also within the scope of the present invention. Therefore, any equivalent changes and modifications made without departing from the spirit and scope of the present invention are intended to be encompassed within the scope of the present invention.
Claims
1. A method for preparing almond vegetable oil by efficient fermentation, characterized in that: The following steps are involved: (1) Raw material pretreatment: Almond kernels were low-temperature pressed to obtain crude oil, and the residue was treated with cellulase (0.5-1.5% w / w) and ultrasonic wave (20-40 kHz, 200-500 W) to break the wall of the kernels, and the solid-liquid ratio was controlled to be 1:3-1:5 to obtain a residue mixture; (2) Inoculation of composite flora: Candida tropicalis (CGMCC 2.1776), Aspergillus niger (CCTCCAF 200037) and Lactobacillus plantarum (CICC 23121) were inoculated into the residue mixture in proportion to obtain a fermentation mixture; (3) Three-stage dynamic fermentation: The fermentation mixture is fermented in three stages: Stage I: The fermentation mixture is subjected to anaerobic fermentation at pH 5.5-6.0, temperature 32-35°C, and stirring speed 50-100 rpm for 30-42 hours; Phase II: pH 6.5-7.0, temperature 28-30°C, and pulse feeding (carbon-nitrogen ratio 20:1) were then used for microaerobic fermentation (DO 5-15%) for 54-66 hours. Stage III: Finally, the pH is controlled at 7.2-7.5, the temperature is 25-28°C, and 0.1-0.3% biosurfactant is added for aerobic fermentation (DO>30%) for 12-24 hours to obtain the fermentation broth; (4) Product purification: The fermentation broth is ultrafiltered using a ceramic membrane and then molecularly distilled at a temperature of 80-100°C and a vacuum of 0.1-1 mbar to obtain high-purity almond oil.
2. The method for preparing almond vegetable oil by efficient fermentation according to claim 1, characterized in that: In step (1), the cellulase treatment conditions are: enzymatic hydrolysis temperature 45-50°C, time 2-4h, and ultrasonic treatment interval 10s on / 5s off.
3. The method for preparing almond vegetable oil by efficient fermentation according to claim 1, characterized in that: In step (2), each strain is activated using the following process before inoculation: The tropical yeast Candida was cultured in YPD medium (1% yeast powder, 2% peptone, 2% glucose) at 30° C. on a shaking platform for 24 hours. The Aspergillus niger was cultured in PDA medium at 28°C for 5 days, with a spore suspension concentration of 1×106 CFU / mL; The plant lactobacillus was cultured anaerobically at 37° C. for 48 hours using MRS culture medium.
4. The method for preparing almond vegetable oil by efficient fermentation according to claim 1, characterized in that: In step (2), the inoculation ratio of the Candida tropicalis, Aspergillus niger and Lactobacillus plantarum is (2-5):(1-3):1 (v / v); and the total inoculation amount is 8% of the volume of the fermentation broth.
5. The method for preparing almond vegetable oil by efficient fermentation according to claim 1, characterized in that: In step (3), the pulse feeding in stage II is to add glucose and soybean meal hydrolysate or glucose and cottonseed protein hydrolysate every 2 hours, with a mass ratio of 2-4:1, and the total addition amount is 15-25% of the initial substrate.
6. The method for preparing almond vegetable oil by efficient fermentation according to claim 1, characterized in that: In step (3), the biosurfactant used in stage III is a mixture of rhamnolipid and sophorolipid, with a mass ratio of 2:
1.
7. The method for preparing almond vegetable oil by efficient fermentation according to claim 1, characterized in that: In step (4), the ceramic membrane is made of zirconium oxide, has a pore size of 0.02-0.1 μm, and a transmembrane pressure of 0.2-0.5 MPa.
8. An almond fermented oil prepared by the method according to any one of claims 1 to 7, characterized in that: The unsaturated fatty acid content is ≥88% (of which oleic acid is 65-75% and linoleic acid is 12-18%), the free sterol retention rate is ≥95%, and the peroxide value is ≤1.0 meq / kg.
9. The fermented almond oil according to claim 8, characterized in that DPPH free radical scavenging rate IC 50 ≤50μg / mL, ABTS cation clearance rate ≥90% (at concentration 100μg / mL).
10. Use of the fermented almond oil according to claim 8 or 9 in anti-aging cosmetics, characterized in that: The added amount is 0.5-5%, and it is used in combination with ceramide or hyaluronic acid.