Application of ultra-long-chain saturated fatty acid or detection reagent thereof in prediction of disease risk of metabolic syndrome

Abstract

The invention provides application of super-long-chain saturated fatty acid or a detection reagent thereof in prediction of the disease risk of metabolic syndrome, and particularly, it is determined that the super-long-chain saturated fatty acid has significant negative correlation with the metabolic syndrome, the super-long-chain saturated fatty acid is reduced along with reduction of the score of the metabolic syndrome, and the super-long-chain saturated fatty acid can be used for predicting the disease risk of the metabolic syndrome. According to the level of the super-long-chain fatty acid, on one hand, the risk of suffering from the metabolic syndrome can be predicted, and on the other hand, early prediction or disease intervention can be performed on the metabolic syndrome through dietary strengthening of the super-long-chain fatty acid or taking of a super-long-chain fatty acid supplement.

Description

[0001] This application is a divisional application of the patent application No. 201710322708.2, filed on May 9, 2017, and entitled "Application of very long chain saturated fatty acid or its detection reagent in predicting the risk of metabolic syndrome". TECHNICAL FIELD

[0002] The present application relates to the field of biomedicine, in particular, to the application of very long chain saturated fatty acid or its detection reagent in predicting the risk of metabolic syndrome. BACKGROUND

[0003] With the development of China's economy, the dietary structure and disease trend of residents have changed greatly. According to the 2002 China Nutrition and Health Survey, the consumption of animal food and oil in the diet of urban residents and wealthy rural residents has increased too much. From 1992 to 2002, the dietary fat energy ratio increased sharply from 22% to 29.8%. This change in dietary structure is likely to affect the balance of fatty acids in the body and their metabolic processes in the body, and thus affect the occurrence and development of diseases. At the same time, the prevalence of obesity has spread from Western countries to Asian regions, becoming a major threat to global public health. The rate of obesity and overweight in China increased from 22.8% and 7.1% in 2002 to 30.6% and 12.0% in 2010. Obesity can cause a series of metabolic abnormalities, including hyperglycemia, hyperlipidemia, and hypertension, by affecting the secretion of insulin, sex hormones, and adipokines. Excessive intake of palmitic acid (C16:0) can reduce insulin sensitivity, increase blood lipids and blood pressure.

[0004] There is an urgent need in the art to study the relationship between very long chain saturated fatty acid and metabolic syndrome, so as to establish a simple and reliable model for predicting the risk of metabolic syndrome. SUMMARY

[0005] The present application provides the application of very long chain saturated fatty acid or its detection reagent in predicting the risk of metabolic syndrome.

[0006] The first aspect of the present application provides the use of very long chain saturated fatty acid or its detection reagent for preparing a kit for detecting the susceptibility or risk of metabolic syndrome. In the present application, the very long chain saturated fatty acid is a very long chain saturated fatty acid with a carbon atom number of ≥20.

[0007] In another preferred embodiment, the carbon atom number of the very long chain saturated fatty acid is 20-24, preferably 20-23.

[0008] In another preferred embodiment, the ultra-long chain saturated fatty acid is selected from the group consisting of C20:0, C22:0, C23:0, C24:0, or a combination thereof.

[0009] In another preferred embodiment, the ultra-long chain saturated fatty acid is selected from the group consisting of C20:0, 0.18 (0.13, 0.25), C22:0, 0.26 (0.18, 0.35), C24:0, 0.19 (0.13, 0.26), or a combination thereof.

[0010] In another preferred embodiment, the ultra-long chain saturated fatty acid is an ultra-long chain saturated fatty acid present in the blood of a mammal (e.g., a human) or an ultra-long chain saturated fatty acid detectable in the blood of a mammal (e.g., a human).

[0011] In another preferred embodiment, the metabolic syndrome comprises a metabolic disorder related disease.

[0012] In another preferred embodiment, the metabolic disorder related disease is selected from the group consisting of obesity, hypertension, hyperlipidemia, hyperglycemia, coronary heart disease, myocardial infarction, ischemic stroke, diabetes, or a combination thereof.

[0013] In another preferred embodiment, the detection comprises an assisted detection and / or an early detection.

[0014] In another preferred embodiment, the detection is a blood detection, a plasma detection, or a serum detection.

[0015] In another preferred embodiment, the detection is directed to a detection sample comprising a blood sample, a plasma sample, or a serum sample.

[0016] In another preferred embodiment, the detection is a comparison of a certain ultra-long chain saturated fatty acid content Al in a sample from a test subject with a corresponding ultra-long chain saturated fatty acid content A0 in a normal population, and if Al is significantly higher than A0, it indicates that the test subject has a lower susceptibility (or risk) to the metabolic syndrome.

[0017] In another preferred embodiment, the "significantly higher" means that Al / A0≥2, preferably Al / A0≥3, and more preferably Al / A0≥4.

[0018] In another preferred embodiment, if Al is significantly lower than A0, it indicates that the test subject has a higher susceptibility (or risk) to the metabolic syndrome.

[0019] In another preferred embodiment, the "significantly lower" means that Al / A0≤1 / 2, preferably Al / A0≤1 / 3, and more preferably Al / A0≤1 / 4.

[0020] In another preferred embodiment, the number of normal individuals is at least 100; more preferably at least 300; more preferably at least 500; and most preferably at least 1000.

[0021] In another preferred embodiment, the detection reagent comprises a mass spectrometry detection reagent.

[0022] In another preferred embodiment, the mass spectrometry detection reagent is selected from the group consisting of fatty acid standards (C20:0, C22:0, C23:0, C24:0, or combinations thereof), 1,2-dihenarachidoyl-sn-glycero-3-phosphocholine, methanol, dichloromethane, isooctane, n-hexane, concentrated sulfuric acid, or combinations thereof.

[0023] In another preferred embodiment, the detection reagent comprises a long chain saturated fatty acid specific antibody.

[0024] In another preferred embodiment, the long chain saturated fatty acid specific antibody is conjugated or otherwise associated with a detectable label.

[0025] In another preferred embodiment, the detectable label is selected from the group consisting of a chromophore, a chemiluminescent group, a fluorophore, an isotope, or an enzyme.

[0026] In another preferred embodiment, the long chain saturated fatty acid specific antibody is a monoclonal antibody or a polyclonal antibody.

[0027] In another preferred embodiment, the kit further comprises the detection reagent spotted on the test plate and instructions for use.

[0028] In another preferred embodiment, the kit further comprises a detection kit of sample pre-treatment reagents and instructions for use.

[0029] In another preferred embodiment, the instructions set forth a method of detecting and a method of predicting the risk of metabolic syndrome based on the A1 value.

[0030] In another preferred embodiment, the instructions indicate the following: (i) a plasma very long chain saturated fatty acid level of 0.1-1%, more preferably 0.15-0.9%, and more preferably 0.17-0.6% by total weight of fatty acids in the plasma indicates a lower susceptibility (or risk of developing) metabolic syndrome when the metabolic syndrome risk score is ≤2 (more preferably 1-2); and (ii) when the level of plasma very long chain saturated fatty acids is 0.1-1%, preferably 0.13-0.9%, more preferably 0.15-0.7% by total weight of fatty acids in plasma, the metabolic syndrome risk score is < 3 (preferably 2-3), indicating a lower susceptibility (or risk of developing) metabolic syndrome; (iii) when the level of plasma very long chain saturated fatty acids is 0.1-1%, preferably 0.14-0.9%, more preferably 0.15-0.8% by total weight of fatty acids in plasma, the metabolic syndrome risk score is < 4 (preferably 3-4), indicating a higher susceptibility (or risk of developing) metabolic syndrome; (iv) when the level of plasma very long chain saturated fatty acids is 0.1-1%, preferably 0.13-0.9%, more preferably 0.15-0.8% by total weight of fatty acids in plasma, the metabolic syndrome risk score is < 5 (preferably 4-5), indicating a higher susceptibility (or risk of developing) metabolic syndrome.

[0031] In another preferred embodiment, the kit further comprises a standard of very long chain fatty acids.

[0032] In another preferred embodiment, the standard is selected from the group consisting of C20:0, C22:0, C23:0, C24:0, or a combination thereof.

[0033] In another preferred embodiment, the detecting comprises gas chromatography (GC)-cation flame method (GC-FID) detection.

[0034] The second aspect of the present application provides a kit for detecting the risk of developing metabolic syndrome, comprising: (a) a reagent for detecting the content of very long chain saturated fatty acids in a sample, wherein the sample comprises a blood sample, a plasma sample, or a serum sample, and the very long chain saturated fatty acids comprise very long chain saturated fatty acids with carbon number ≥ 20; (b) a standard of very long chain saturated fatty acids; (c) an instruction manual.

[0035] In another preferred embodiment, the instruction manual indicates the method of the third aspect of the present application.

[0036] In another preferred embodiment, the standard is selected from the group consisting of C20:0, C22:0, C23:0, C24:0, or a combination thereof.

[0037] The third aspect of the present application provides a method for detecting the risk of developing metabolic syndrome, comprising the steps of: (a) providing a test sample of a subject; (b) determining the content of the very long chain saturated fatty acid in the sample as A1; (c) comparing step (b) with the content of the very long chain saturated fatty acid in a normal population sample A0, if A1 is significantly higher than A0, it indicates that the test group has a lower risk of metabolic syndrome; wherein the very long chain saturated fatty acid is a very long chain saturated fatty acid with carbon number ≥20.

[0038] In another preferred embodiment, the detection method is selected from the group consisting of gas chromatography cation flame method (GC-FID).

[0039] In another preferred embodiment, the sample for detection comprises a blood sample, a plasma sample, or a serum sample.

[0040] In another preferred embodiment, the method is non-therapeutic and non-diagnostic.

[0041] The fourth aspect of the present application provides a method for producing a blended oil, comprising the steps of: (i) providing a base oil; (ii) detecting the content of the very long chain saturated fatty acid in the base oil, wherein the very long chain saturated fatty acid has carbon number ≥20; and (iii) adding a predetermined content of the very long chain saturated fatty acid to the base oil based on the content of the very long chain saturated fatty acid in step (iii), thereby obtaining the blended oil.

[0042] In another preferred embodiment, the predetermined content refers to the amount of the very long chain saturated fatty acid added to the total weight of the blended oil, which is 0.5-20%, preferably 1-15%, and more preferably 2-10%.

[0043] In another preferred embodiment, the base oil is selected from the group consisting of peanut oil, canola oil, lotus seed oil, or a combination thereof.

[0044] In another preferred embodiment, the very long chain saturated fatty acid with carbon number ≥20 is selected from the group consisting of C20:0, C22:0, C23:0, C24:0, or a combination thereof.

[0045] It should be understood that, within the scope of the present application, the above technical features of the present application and the technical features specifically described in the following (such as the examples) can be combined with each other to form new or preferred technical solutions. Due to the limited space, they will not be listed one by one here. BRIEF DESCRIPTION OF DRAWINGS

[0046] Figure 1The relationship between plasma ultra-long chain saturated fatty acids and metabolic syndrome risk was shown, using restricted cubic spline analysis, adjusted for gender, age and physical activity in the model.

[0047] Figure 2 The relationship between plasma ultra-long chain saturated fatty acids and metabolic syndrome score was shown, using box-plot method.

[0048] Figure 3 The interaction between plasma ultra-long chain saturated fatty acids and other factors was shown. The OR value represents the size of the risk of metabolic syndrome increased by one standard deviation of fatty acids. The model was adjusted for gender, age and physical activity. DETAILED DESCRIPTION

[0049] The inventors have made extensive and in-depth research, and for the first time found that the ultra-long chain saturated fatty acids can be used as an effective marker for predicting the risk of metabolic syndrome (such as diabetes, coronary heart disease and arteriosclerosis, etc.). Through a 2-year tracking study of 2008 residents, the inventors determined that the ultra-long chain saturated fatty acids have a significant negative correlation with metabolic syndrome, and the ultra-long chain saturated fatty acids decrease with the decrease of metabolic syndrome score, and the level of the ultra-long chain fatty acids can be used to predict the risk of metabolic syndrome on one hand, and on the other hand, the metabolic syndrome can be early predicted or intervened by dietary fortification of the ultra-long chain fatty acids or taking the ultra-long chain fatty acid supplements. On this basis, the inventors completed the present application.

[0050] Ultra-long chain saturated fatty acids As used herein, the term "ultra-long chain saturated fatty acids" refers to straight-chain saturated fatty acids with carbon atom number ≥ 20, such as C20:0, C22:0, C24:0 saturated fatty acids detectable in plasma.

[0051] Metabolic syndrome In the present application, the "metabolic syndrome" refers to a pathological state of metabolic disorder of protein, fat, carbohydrate and other substances in the human body, which is a complex metabolic disorder syndrome and a risk factor for diabetes and cardiovascular and cerebrovascular diseases.

[0052] Specifically, according to the National Education Program's Adult Treatment Panel III (ATPIII), the metabolic syndrome criteria for Asian Americans are as follows: 1. Waist circumference ≥ 90 cm (male), ≥ 80 cm (female) 2. Triglycerides ≥ 1.7 mmol / L 3. High-density lipoprotein <1.03 mmol / L (males), <1.29 mmol / L (females) 4. Systolic blood pressure ≥ 130 or diastolic blood pressure ≥ 85 mm Hg or taking antihypertensive medication 5. Fasting plasma glucose ≥ 5.6 mmol / L or taking antihyperglycemic medication or insulin A patient can be diagnosed as having metabolic syndrome if he or she has three or more of the above five conditions.

[0053] In a preferred embodiment, the metabolic syndrome comprises a metabolic disorder-related disease.

[0054] In a preferred embodiment, the metabolic disorder-related disease is selected from the group consisting of obesity, hypertension, hyperlipidemia, hyperglycemia, coronary heart disease, myocardial infarction, ischemic stroke, diabetes, or a combination thereof.

[0055] Detection reagent and detection method The present application relates to quantitative and qualitative detection of the level of ultra-long chain saturated fatty acids in human body. These tests are well known in the art. The level of ultra-long chain saturated fatty acids in human body detected in the test can be used to predict the risk of prevalence of metabolic syndrome.

[0056] In the present application, various methods can be used to qualitatively or quantitatively detect the reaction between the detection reagent and the sample, and the preferred method is gas chromatography (GC) - hydrogen flame ionization detector. In the present application, the detection reagent of the ultra-long chain saturated fatty acid comprises a mass spectrometry detection reagent (such as 1,2-dihenarachidoyl-sn-glycero-3-phosphocholine, dichloromethane, methanol, concentrated sulfuric acid, isooctane).

[0057] One method for detecting the content of ultra-long chain saturated fatty acids in a sample is to qualitatively and quantitatively analyze the ultra-long chain saturated fatty acids by using the above-mentioned chromatographic analysis method.

[0058] Kit The present application also provides a kit for predicting the risk of metabolic syndrome. The kit used in the present application generally comprises a detection reagent, standard samples of ultra-long chain saturated fatty acids of various concentrations, and / or instructions for judging the risk of metabolic syndrome.

[0059] The instructions therein record the detection method and related instructions for judging the risk of metabolic syndrome according to the determination value Al of different samples.

[0060] A typical kit of the present application can be used to detect human blood samples, plasma samples.

[0061] It should be understood that after the present application first discloses the correlation between the specific ultra-long chain saturated fatty acids and the risk of metabolic syndrome, the person skilled in the art can easily predict the metabolic syndrome in early stage or intervene the disease, or guide the taking of dietary supplements of the ultra-long chain saturated fatty acids or food or related drugs thereof according to the above correlation.

[0062] The main advantages of the present application include: (1) The present application first discovers that the plasma ultra-long chain saturated fatty acids are significantly negatively correlated with the risk of metabolic syndrome.

[0063] (2) The present application first analyzes the relationship between the plasma ultra-long chain saturated fatty acids and metabolic syndrome, and the interaction of the fatty acids with the risk factors such as age, exercise, and hypertension.

[0064] (3) The present application first discovers that the plasma C20:0 level is significantly interacted with gender and drinking, and drinking is a risk factor of metabolic syndrome, thus it is inferred that for the population who drinks a lot for a long time, the dietary supplement of C20:0 or the taking of the corresponding supplement can be considered to reduce the risk of metabolic syndrome.

[0065] (4) The present application first discovers that the ultra-long chain saturated fatty acids decrease with the decrease of the metabolic syndrome score.

[0066] (5) The first discovery of the present application can be used to predict the risk of metabolic syndrome, and on the other hand, through the dietary fortification of the ultra-long chain fatty acids or the taking of the ultra-long chain fatty acid supplements, the metabolic syndrome can be predicted in early stage or intervened.

[0067] The present application will be further described below in conjunction with specific examples. It should be understood that these examples are only used to illustrate the present application and not used to limit the scope of the present application. The experimental methods in the following examples are not specified, and the methods are usually carried out according to the conventional conditions, for example, the conditions described in Sambrook et al., Molecular Cloning: A Laboratory Manual (New York: Cold Spring Harbor Laboratory Press, 1989), or the conditions suggested by the manufacturers. Unless otherwise specified, the percentages and parts are weight percentages and weight parts.

[0068] Unless otherwise specified, the materials and reagents used in the specification of the present application are commercially available products.

[0069] 1. Investigation subjects In a 2-year follow-up experiment, 2008 residents living in Beijing Shunyi were detected at baseline of fatty acids, blood lipids, blood sugar, blood pressure, waist circumference, height and weight, and the information of life habits such as smoking, drinking and exercise was collected. After excluding data missing, excluding people with cardiovascular disease, malignant tumor, and other major diseases, finally 1729 people were used to analyze the relationship between blood very long chain saturated fatty acids and metabolic syndrome.

[0070] 2. Ethical review Ethical Review Committee of the Center for Chronic Non-communicable Disease Prevention and Control, China Center for Disease Control and Prevention.

[0071] 3. Steps of the specific experiment 3.1 Collecting blood samples of the population, detecting total cholesterol, triglyceride, high-density lipoprotein, fasting blood glucose and other indicators.

[0072] 3.2 Detection of fatty acids: after extraction of fatty acids by Folch method and methylation, gas chromatography (GC)-hydrogen flame ionization detection (FID) method is used to determine the composition and content of fatty acids.

[0073] 1,2-dihenarachidoyl-sn-glycero-3-phosphocholine was added to 100 ul of plasma as an internal standard, and dichloromethane / methanol was used to extract lipids, and the solvent was blown dry by nitrogen, and methanol / sulfuric acid was used for fatty acid methylation to produce FAMEs. FAMEs were extracted with n-hexane, the solvent was blown dry by nitrogen, and then isooctane was used for dissolution. Agilent 6890 GC / FID was used for detection, and the chromatographic column was Supelco SP-2560 (100m*0.25mm inside diameter*0.20um thickness), and the results were expressed as weight percentage.

[0074] 3.3 Definition of metabolic syndrome: the latest diagnostic criteria of metabolic syndrome of the International Diabetes Federation, sampling for metabolic syndrome: plus three or more of the following five factors: Central obesity: waist circumference ≥ 90 cm (male), waist circumference ≥ 80 cm (female) Triglycerides: ≥ 1.7 mmol / L or receiving special treatment for adjusting blood lipids High-density lipoprotein: <1.03 mmol / L (male) and <1.29 mmol / L (female) or receiving special treatment for adjusting blood lipids Blood pressure: systolic blood pressure ≥ 130 mm Hg or diastolic blood pressure ≥ 85 mm Hg or taking antihypertensive drugs Fasting blood glucose: > 100 mg / dL (5.6 mmol / L) or previously diagnosed as type II diabetes 3.5 Data analysis: Rank sum test and Chi-square test were used to detect the difference of basic variables among three genotypes. Logistic regression was used to analyze the association between plasma very long chain saturated fatty acids and metabolic syndrome risk. In addition, we also used generalized linear regression to analyze the relationship between plasma very long chain saturated fatty acids and metabolic syndrome, and the interaction between fatty acids and risk factors such as age, exercise, hypertension, etc.

[0075] 4 Experimental results 4.1 Plasma very long chain saturated fatty acids and metabolic syndrome risk High levels of plasma very long chain saturated fatty acids in plasma were significantly negatively associated with the risk of metabolic syndrome. ORs (odds ratios) values were C20:0, 0.18 (0.13, 0.25); C22:0, 0.26 (0.18, 0.35); C24:0, 0.19 (0.13, 0.26); total very long chain saturated fatty acids 0.16 (0.11, 0.22). Figure 1 4.2 Relationship between plasma very long chain saturated fatty acids and metabolic syndrome score Plasma very long chain saturated fatty acid levels decreased linearly with the increase of metabolic syndrome score. Figure 2 With metabolic syndrome score ≤2, 3, 4, 5, the plasma very long chain saturated fatty acid levels were (expressed as median (Q1-Q4)): C20:0: 0.18 (0.20-0.23), 0.16 (0.18-0.20), 0.15 (0.17-0.20), 0.15 (0.17-0.20) C22:0: 0.59 (0.70-0.84), 0.47 (0.59-0.70), 0.56 (0.67-0.79), 0.51 (0.62-0.71) C24:0: 0.46 (0.61-0.73), 0.47 (0.57-0.68), 0.26 (0.34-0.46), 0.26 (0.34-0.43) 4.3 Interaction between plasma very long chain saturated fatty acids and other factors Plasma C20:0 levels had significant interaction with gender and alcohol consumption. P value <0.01. Figure 3 5. Experimental conclusion ​​The results of the present application show that there is a significant negative correlation between plasma very long chain saturated fatty acids and metabolic syndrome. And the very long chain saturated fatty acids decrease with the decrease of metabolic syndrome score. That is, if the plasma very long chain saturated fatty acids are used to predict metabolic syndrome, the lower the concentration is, the more serious the metabolic syndrome may be. In stratified analysis, it is found that the level of C20:0 interacts with alcohol drinking, and alcohol drinking is a risk factor of metabolic syndrome, thus it is inferred that for the population who drinks a lot of alcohol for a long time, dietary supplement of C20:0 or taking corresponding supplements can be considered to reduce the risk of metabolic syndrome.

[0076] In summary, the findings of the present application suggest that the level of plasma very long chain fatty acids can be used to predict the risk of metabolic syndrome on the one hand, and on the other hand, through dietary fortification of very long chain fatty acids or taking very long chain fatty acid supplements, early prediction or disease intervention of metabolic syndrome can be achieved.

[0077] All the documents mentioned in the present application are cited as references in the present application as if each document is cited as a reference individually. In addition, it should be understood that various modifications or changes can be made to the present application by those skilled in the art after reading the above teaching of the present application, and these equivalent forms also fall within the scope defined by the claims attached to the present application.

Claims

1. Use of an ultra-long chain saturated fatty acid or a detection reagent thereof, characterized in that, A kit for detecting susceptibility to or risk of developing metabolic syndrome; wherein the ultra-long chain saturated fatty acid is an ultra-long chain saturated fatty acid having a carbon number of ≥20.

2. Use according to claim 1, characterized in that, The ultra-long chain saturated fatty acid has a carbon number of 20-24, preferably 20-23.

3. Use according to claim 1, characterized in that, The ultra-long chain saturated fatty acid is selected from the group consisting of C20:0, C22:0, C23:0, C24:0, or a combination thereof.

4. The use according to claim 1, characterized in that, The detection is blood detection, plasma detection, or serum detection.

5. The use according to claim 1, characterized in that, The detection is comparing the content of a certain ultra-long chain saturated fatty acid in the sample from the test subject A1 with the corresponding content of the ultra-long chain saturated fatty acid in the normal population A0, if A1 is significantly higher than A0, it indicates that the test subject has a lower susceptibility to metabolic syndrome.

6. The use according to claim 1, characterized in that, The detection reagent includes mass spectrometry detection reagent.

7. A kit for detecting the risk of developing metabolic syndrome, characterized by, Comprising: (a) a reagent for detecting the content of ultra-long chain saturated fatty acid in a sample, wherein the sample includes blood sample, plasma sample, or serum sample, and the ultra-long chain saturated fatty acid includes an ultra-long chain saturated fatty acid having a carbon number of ≥20; (b) an ultra-long chain saturated fatty acid standard; (c) an instruction manual.

8. A method of detecting the risk of developing metabolic syndrome, characterized by, Comprising steps: (a) providing a test sample of a subject; (b) determining the content of ultra-long chain saturated fatty acid in the sample as A1; (c) comparing step (b) with the content of ultra-long chain saturated fatty acid in the sample of the normal population A0, if A1 is significantly higher than A0, it indicates that the test group has a lower risk of developing metabolic syndrome; wherein the ultra-long chain saturated fatty acid is an ultra-long chain saturated fatty acid having a carbon number of ≥20.

9. A method of producing a blend oil, characterized by, Comprising steps: (i) providing a base oil; (ii) detecting the content of ultra-long chain saturated fatty acid in the base oil, wherein the ultra-long chain saturated fatty acid has a carbon number of ≥20; and (iii) based on the content of the ultra-long chain saturated fatty acid in step (iii), adding a predetermined content of ultra-long chain saturated fatty acid to the base oil to obtain the blended oil.

10. The method of claim 9, wherein, The predetermined content refers to the addition amount of the ultra-long chain saturated fatty acid being 0.5-20%, preferably 1-15%, more preferably 2-10%, based on the total weight of the blended oil.

Images