Hazelnut and flaxseed blend oil capable of improving oxidation resistance and preparation method of hazelnut and flaxseed blend oil

Abstract

The invention relates to the technical field of edible oil, and particularly discloses hazelnut and flaxseed blend oil capable of improving oxidation resistance and a preparation method of the hazelnut and flaxseed blend oil. The blend oil is prepared by mixing hazelnut oil and linseed oil according to a volume ratio of 1: (3-16). According to the hazelnut and flaxseed blend oil provided by the invention, the hazelnut oil and the flaxseed oil are precisely proportioned, and the Omega-6 / Omega-3 ratio in the blend oil is optimized to 1.22: 1 and is in a health interval of 1: 1 to 4: 1, so that the problem of high Omega-6 / Omega-3 ratio generally existing in common food oil is effectively corrected, and the hazelnut and flaxseed blend oil has relatively good oxidation resistance and stability and can be used for daily cooking.

Description

Technical Field

[0001] This invention relates to the field of edible oil technology, specifically to a hazelnut and flaxseed blended oil that can improve antioxidant properties and its preparation method. Background Technology

[0002] Modern blended oils commonly consumed are made from soybean oil, corn oil, and sunflower oil to balance nutrition and flavor. However, these oils have relatively weak antioxidant properties. Edible oils with poor antioxidant properties can produce harmful compounds such as aldehydes and ketones during storage. They are also more easily oxidized during metabolism in the body, generating large amounts of free radicals and toxic oxidation products such as malondialdehyde, which can promote chronic inflammation and increase the risk of cardiovascular disease. Therefore, developing a blended oil with better antioxidant properties is essential. Summary of the Invention

[0003] To develop a blended oil with a more balanced fatty acid composition, this invention provides a hazelnut-flaxseed blended oil with improved antioxidant properties and its preparation method. The hazelnut-flaxseed blended oil provided by this invention optimizes the Omega-6 / Omega-3 ratio to 1.22:1 through precise proportioning of hazelnut oil and flaxseed oil, placing it within the healthy range of 1:1 to 4:1. This effectively corrects the problem of high Omega-6 / Omega-3 ratios commonly found in blended oils, and also exhibits good antioxidant properties and stability, making it suitable for everyday cooking.

[0004] This invention provides a hazelnut and flaxseed blended oil that can improve antioxidant properties, wherein the blended oil is made by mixing hazelnut oil and flaxseed oil in a volume ratio of 1:3 to 16.

[0005] The hazelnut and flaxseed blended oil provided by this invention optimizes the Omega-6 / Omega-3 ratio to 1.22:1 by precisely proportioning hazelnut oil and flaxseed oil. This ratio falls within the healthy range of 1:1 to 4:1, effectively correcting the problem of high Omega-6 / Omega-3 ratio commonly found in blended oils. It also exhibits good antioxidant properties and stability, making it suitable for everyday cooking.

[0006] Furthermore, when the preferred volume ratio of hazelnut oil to flaxseed oil is 1:3, the ratio of Omega-6 to Omega-3 in the blended oil is 1.22:1.

[0007] Furthermore, when the volume ratio of hazelnut oil to flaxseed oil is 1:8, the ratio of Omega-6 to Omega-3 in the blended oil is 2.76:1.

[0008] Furthermore, when the volume ratio of hazelnut oil to flaxseed oil is 1:16, the ratio of Omega-6 to Omega-3 in the blended oil is 4.85:1.

[0009] Furthermore, the smoke point of the blended oil is 162℃~182℃.

[0010] The present invention also provides a method for preparing the hazelnut and flaxseed blended oil, characterized by comprising the following steps: mixing hazelnut oil and flaxseed oil at a volume ratio of 1:3~16, stirring evenly to obtain the blended oil.

[0011] Furthermore, the preferred volume ratio of the hazelnut oil to flaxseed is 1:3.

[0012] Furthermore, the hazelnut oil is cold-pressed hazelnut oil.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: The blended oil prepared by this invention meets food safety standards in terms of acid value and peroxide value, and has good antioxidant properties and stability, making it suitable for everyday cooking.

[0014] This invention optimizes the Omega-6 / Omega-3 ratio in blended oils to 1.22:1 by precisely proportioning hazelnut oil and flaxseed oil. This ratio falls within the healthy range of 1:1 to 4:1, effectively correcting the common problem of high Omega-6 / Omega-3 ratios in commonly used blended oils. Furthermore, it exhibits good antioxidant properties and stability, making it suitable for everyday cooking. Specifically, the 1:3 hazelnut oil and flaxseed oil blend has an Omega-6 / Omega-3 ratio of 1.22:1, suitable for individuals needing to enhance their Omega-3 intake, such as those at high risk of cardiovascular disease; the 1:8 blend has an Omega-6 / Omega-3 ratio of 2.76:1, suitable for a balanced daily diet; and the 1:16 blend has an Omega-6 / Omega-3 ratio of 4.85:1, close to the upper limit of the recommended ratio, suitable for generally healthy individuals. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 The percentage distribution of Omega-3, Omega-6, and Omega-9 fatty acid components in the sample oil.

[0017] Figure 2 The ratio of oleic acid to linoleic acid in the sample oil. Detailed Implementation

[0018] The specific embodiments of the present invention are described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Unless otherwise specified, the experimental methods described in the embodiments of the present invention are conventional methods, and the materials and reagents used in the following embodiments are commercially available unless otherwise specified.

[0019] Example 1: A hazelnut and flaxseed blended oil with enhanced antioxidant properties and its preparation method I. Experimental Materials and Instruments Raw materials: Cold-pressed hazelnut oil was provided by Dalian Economic Forest Research Institute, and flaxseed oil (Shengmai) and Jiusan soybean oil were purchased from supermarkets.

[0020] Reagents: Wiegand reagents were purchased from Shanghai Anpu Experimental Technology Co., Ltd.

[0021] Instrument: Agilent gas chromatograph (7890B) purchased from Agilent Technologies.

[0022] II. Test Methods 1. Preparation of blended oil The volume ratios of the blended oils are shown in Table 1. Flaxseed oil and hazelnut oil were mixed in the corresponding proportions and stirred evenly to prepare three kinds of blended oils. In addition, hazelnut oil, flaxseed oil and soybean oil were blended separately to obtain six kinds of blended oils. The volume ratios of the blended oils are shown in Table 2.

[0023] The nine blended oils prepared above were used together with hazelnut oil, flaxseed oil, and soybean oil for subsequent analysis.

[0024] Table 1. Volume ratio of flaxseed oil and hazelnut oil in each oil sample Table 2. Volume ratio of each oil sample 2. Determination of fatty acid content Weigh 60 mg each of hazelnut oil, flaxseed oil, and soybean oil into a stoppered test tube. Add 4 mL of isooctane to dissolve the oil sample. After dissolution, add 200 μL of potassium hydroxide methanol solution. Stopper the tube and shake vigorously for 30 seconds. Let it stand until clear. Add approximately 1 g of sodium bisulfate and shake vigorously to neutralize the potassium hydroxide. After the salt precipitates, transfer the supernatant to a gas chromatograph and determine the fatty acid content using gas chromatography.

[0025] Column: TR-FAME (0.25 mm × 0.2 μm × 100 μm); Carrier gas and flow rate: High-purity nitrogen, constant flow rate 1 mL / min; Injection parameters: split mode (split ratio 100:1), injection volume 1 μL, injection port temperature 260℃; Column temperature program: Initial temperature 50℃ (hold for 1 min), increase to 150℃ at 30℃ / min (hold for 1 min), then increase to 210℃ at 1.5℃ / min (hold for 5 min), and finally increase to 228℃ at 1℃ / min, and finally run at 228℃ for 3 min.

[0026] After measuring the fatty acid content of the oil sample, calculate its Omega-6 / Omega-3 ratio (linoleic acid content / α-linolenic acid content), and calculate the ratio of oleic acid to linoleic acid content to evaluate the quality of the oil sample.

[0027] 3. Determination of smoke point Measure 75 mL of each oil sample and slowly pour it into a dedicated sample cup to the calibrated mark. Place the cup in the heating chamber of the fully automated vegetable oil smoke point analyzer and seal the chamber. Use the programmed temperature rise mode: initially heat rapidly to 150℃, then continuously heat at a rate of 5℃ / min. When the oil sample first produces persistent blue smoke, the instrument automatically triggers the smoke collection system. Analyze the smoke absorbance using a photoelectric detector (detection wavelength range 380 nm to 780 nm) and simultaneously record the real-time temperature as the smoke point value.

[0028] 4. Determination of iodine value Weigh 0.25 g of each oil sample into an iodine flask, dissolve it in 10 mL of chloroform, add 25 mL of Wiegand's reagent, seal the flask, and react in the dark for 1 h. Then add 10 mL of 20% potassium iodide solution, rinse the mouth of the iodine flask with 100 mL of distilled water, and titrate with 0.1 mol / L sodium thiosulfate standard solution until a pale yellow color appears. Add 2 mL of starch indicator and continue titrating until the blue color disappears. No oil sample is added for the blank test. The calculation formula is as follows:

[0029] ; In the formula, W1 is the iodine value of the sample, expressed as the number of grams of iodine absorbed per 100 g of sample, in g / 100g. V1 represents the volume of sodium thiosulfate standard solution consumed by the blank test solution, in mL; V2 represents the volume of sodium thiosulfate standard solution consumed by the oil sample solution, in mL; c represents the concentration of the sodium thiosulfate standard titration solution, in mol / L. m represents the mass of the oil sample, expressed in grams (g).

[0030] 5. Determination of acid value Weigh 10 g of each oil sample into a conical flask. In a separate 250 mL conical flask, add 50 mL of 95% ethanol solution and 0.5 mL of phenolphthalein indicator. Shake well and heat in a water bath until it just begins to boil. Remove from the water bath and, while the ethanol solution is still above 70°C, titrate with 0.1 mol / L potassium hydroxide standard solution until the solution turns a faint pink color and remains so for 15 seconds. Pour this hot solution into each conical flask containing the oil sample. Then, heat in a water bath until it just begins to boil, gently shake, and remove from the water bath. While the solution in the conical flask is still above 70°C, titrate with potassium hydroxide standard solution until the solution turns a faint pink color and remains so for 15 seconds. This is the titration endpoint. No oil sample is added for the blank test. The calculation formula is as follows:

[0031] ; In the formula, X is the acid value, and the unit is mg / g; V represents the volume of potassium hydroxide standard titration solution consumed by the oil sample solution, in mL; V0 is the volume of potassium hydroxide standard titration solution consumed by the blank test solution, in mL; c represents the concentration of the potassium hydroxide standard titration solution used, in mol / L; 56.1 is the molar mass of potassium hydroxide, in g / mol; m represents the mass of the oil sample, expressed in grams (g).

[0032] 6. Determination of peroxide value Weigh 3 g of each oil sample and place them in a 250 mL iodine flask. Add 30 mL of chloroform-glacial acetic acid solution and gently shake until completely dissolved. Accurately add 1.00 mL of saturated potassium iodide solution, seal the flask tightly, and gently shake for 0.5 min. Place in the dark for 3 min, then remove and add 100 mL of water. Shake well and immediately titrate the precipitated iodine with 0.01 mol / L sodium thiosulfate standard titration solution. When the solution turns pale yellow, add 1 mL of starch indicator and continue titrating, shaking vigorously until the blue color disappears. No oil sample is added for the blank test. The calculation formula is as follows:

[0033] ; X represents the peroxide value, measured in mmol / kg. V represents the volume of sodium thiosulfate standard titration solution consumed by the oil sample solution, in mL; V0 is the volume of sodium thiosulfate standard titration solution consumed by the blank test solution, in mL; c represents the concentration of the sodium thiosulfate standard titration solution, in mol / L. 1000 is the conversion factor for the amount of substance from mol to mmol; 2 represents the conversion coefficient between sodium thiosulfate and reactive oxygen species; m represents the mass of the oil sample, expressed in grams (g).

[0034] 5. Data Analysis Descriptive statistical analysis, correlation analysis, and principal component analysis were performed using SPSS 25.0. Each experiment was repeated three times in triplicate, with a significance level of P < 0.05.

[0035] III. Test Results 1. Fatty acid content in hazelnut oil, flaxseed oil, and soybean oil In vegetable oils, Omega-3 fatty acids mainly come from alpha-linolenic acid, Omega-6 mainly from linoleic acid, and Omega-9 mainly from oleic acid. The fatty acid content of hazelnut oil, flaxseed oil, and soybean oil are shown in Tables 2, 3, and 4. In pure hazelnut oil, the Omega-9 (oleic acid) content was 73.44%, the Omega-6 (linoleic acid) content was 17.89%, and the Omega-3 (alpha-linolenic acid) content was almost zero at 0.4%. In pure flaxseed oil, the Omega-9 (oleic acid) content was 20.2%, the Omega-3 (alpha-linolenic acid) content reached 54.47%, and the Omega-6 (linoleic acid) content was 14.49%. In soybean oil, the Omega-9 (oleic acid) content was 23.3%, the Omega-3 (alpha-linolenic acid) content was 5.53%, and the Omega-6 (linoleic acid) content was 54.4%.

[0036] Table 2. Results of fatty acid content detection in hazelnut oil Table 3. Results of fatty acid content detection in flaxseed oil Table 4 Results of fatty acid content detection in soybean oil 2. Percentage of Omega-3, Omega-6, and Omega-9 components in the sample oil. from Figure 1It can be seen that the Omega-6 / Omega-3 ratios in the three blended oils (1-1, 1-2, and 1-3) are 1.22:1, 2.76:1, and 4.85:1, respectively. The 1-1 ratio is close to 1:1, falling within the WHO-recommended range of 4:1 to 1:1, making it more suitable for people who need to fortify their Omega-3 intake, such as those at high risk of cardiovascular disease. The 1-3 formula has a ratio close to 4:1, which meets general dietary recommendations, but its absolute Omega-3 content is lower, requiring increased oil usage to meet the needs. The 1-2 formula falls between the two, suitable for a balanced daily diet. In comparison, the Omega-6 / Omega-3 ratio of pure hazelnut oil is 44.7:1, that of pure flaxseed oil is 0.27:1, and that of soybean oil is 9.8:1. This indicates that the blended oil of this invention greatly optimizes the Omega-6 / Omega-3 ratio and is more in line with health standards.

[0037] Blended oils 2-1, 2-2, and 2-3 are made from hazelnut oil and soybean oil. Because hazelnut oil and soybean oil have low Omega-3 content, the Omega-6 / Omega-3 ratio in the resulting blends does not meet the healthy range of 4:1 to 1:1, regardless of the blending ratio. Blended oils 3-1, 3-2, and 3-3 are made from flaxseed oil and soybean oil, with Omega-6 / Omega-3 ratios of 1.15:1, 2.5:1, and 3.89:1, respectively. Although all are within the 4:1 to 1:1 range, flaxseed oil has a fishy or grassy flavor, while soybean oil has a neutral flavor with no obvious taste, making it difficult to mask the flavor of flaxseed oil, resulting in poor palatability. The three blended oils 1-1, 1-2, and 1-3 prepared by hazelnut oil to flaxseed oil volume ratios of 1:3, 1:8, and 1:16 provided by this invention not only meet the healthy range of Omega-6 / Omega-3 ratios of 4:1 to 1:1, but also allow the nutty flavor of hazelnut oil to mask the special flavor of flaxseed oil, thus balancing nutritional health and palatability. Therefore, the three blended oils 1-1, 1-2, and 1-3, along with hazelnut oil, flaxseed oil, and soybean oil, were used as sample oils for subsequent analysis.

[0038] 3. The ratio of oleic acid to linoleic acid content in the sample oil. The oleic acid to linoleic acid ratio (O / L ratio) is one of the important indicators for evaluating the quality of edible oils. Oleic acid, as a monounsaturated fatty acid, contains only one unsaturated bond in its molecule, while linoleic acid, as a polyunsaturated fatty acid, contains two unsaturated bonds. Generally, the more unsaturated bonds an oil has, the more prone it is to oxidative rancidity. Therefore, a higher O / L ratio indicates better oxidative stability of the oil.

[0039] from Figure 2 It can be seen that the O / L ratio of pure hazelnut oil is the highest among all sample oils. The O / L ratio of pure flaxseed oil is significantly lower than that of hazelnut oil and various blended oils. When the two are mixed, the O / L ratio gradually decreases as the proportion of hazelnut oil added decreases (e.g., from 1:1 to 1:3 sample oils), but the difference is not significant. This indicates that the blended oil of this invention still possesses the excellent antioxidant properties of hazelnut oil, demonstrating its unique advantage in balancing natural properties and stability.

[0040] 4. Results of oil fume point test As shown in Table 5, flaxseed oil has a lower smoke point, while hazelnut oil has a relatively higher smoke point. When flaxseed oil and hazelnut oil are mixed in different proportions, the smoke point of the mixed oil increases significantly with the increase of the proportion of hazelnut oil, making it suitable for everyday cooking.

[0041] Table 5 Results of oil fume point detection 5. Iodine value test results Iodine value is used to measure the content of unsaturated fatty acids in oils, especially reflecting the number of double bonds on the fatty acid chains. Generally speaking, the higher the iodine value, the higher the degree of unsaturation of the oil and the more double bonds it contains. As shown in Table 6, the iodine value of soybean oil is between that of hazelnut oil and flaxseed oil, indicating that its degree of unsaturation is moderate, classifying it as a semi-drying oil, and it has a good balance between oxidative stability and nutritional function among daily edible oils. Flaxseed oil, on the other hand, has an extremely high iodine value, indicating that it has a high content of polyunsaturated fatty acids and outstanding nutritional value, but it is also more prone to oxidative rancidity and requires strict storage conditions.

[0042] The iodine values ​​of blended oils 1-2 and 1-3 are lower than those of soybean oil, indicating that they have fewer double bonds and are expected to have better oxidative stability than soybean oil, making them more suitable for food systems or cooking methods that require higher oxidative stability. The iodine value of blended oil 1-1 is close to that of soybean oil, indicating that through reasonable compounding design, it is possible to obtain similar or better stability performance than soybean oil while retaining a high content of unsaturated fatty acids.

[0043] Table 6 Results of Iodine Value Tests for Sample Oil 6. Initial test results of acid value and peroxide value As shown in Table 7, the acid values ​​of all oil samples (hazelnut oil, flaxseed oil, soybean oil, and blended oils 1-1 to 1-3) were lower than the standard limit of GB5009.229-2025 "National Food Safety Standard - Determination of Acid Value in Food" (≤0.5 mg / g), and the peroxide values ​​were lower than the standard limit of GB5009.227-2023 "National Food Safety Standard - Determination of Peroxide Value in Food" (≤5 mmol / kg). This indicates that all tested oil samples met the hygienic standards for edible oils, had good initial quality, and did not undergo significant oxidative deterioration.

[0044] Table 7 Initial test results of acid value and peroxide value of sample oil The hazelnut and flaxseed blended oil provided by this invention optimizes the ratio of hazelnut oil to flaxseed oil, achieving an optimized Omega-6 / Omega-3 ratio. Both the acid value and peroxide value meet food safety standards, and it exhibits good antioxidant properties and stability, making it suitable for everyday cooking. When flaxseed oil and hazelnut oil are mixed at a volume ratio of 1:3, the Omega-6 / Omega-3 ratio is 1.22:1, which is closest to the optimal 1:1 ratio and suitable for individuals with Omega-3 fortification needs.

[0045] Although preferred embodiments of the invention have been described, those skilled in the art, once they have learned the basic inventive concept, can make other changes and modifications to these embodiments.

[0046] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A hazelnut and flaxseed blended oil that enhances antioxidant properties, characterized in that, The blended oil is made by mixing hazelnut oil and flaxseed oil in a volume ratio of 1:3 to 16.

2. The hazelnut and flaxseed blended oil according to claim 1, characterized in that, When the volume ratio of hazelnut oil to flaxseed oil is 1:3, the ratio of Omega-6 to Omega-3 in the blended oil is 1.22:

1.

3. The hazelnut and flaxseed blended oil according to claim 1, characterized in that, When the volume ratio of hazelnut oil to flaxseed oil is 1:8, the ratio of Omega-6 to Omega-3 in the blended oil is 2.76:

1.

4. The hazelnut and flaxseed blended oil according to claim 1, characterized in that, When the volume ratio of hazelnut oil to flaxseed oil is 1:16, the ratio of Omega-6 to Omega-3 in the blended oil is 4.85:

1.

5. The hazelnut and flaxseed blended oil according to claim 1, characterized in that, The smoke point of the blended oil is 162℃~182℃.

6. A method for preparing the hazelnut and flaxseed blended oil according to claim 1, characterized in that, Includes the following steps: Hazelnut oil and flaxseed oil are mixed at a volume ratio of 1:3 to 16 and stirred evenly to obtain the blended oil.

7. The method for preparing hazelnut and flaxseed blended oil according to claim 6, characterized in that, The volume ratio of hazelnut oil to flaxseed is 1:

3.

8. The method for preparing hazelnut and flaxseed blended oil according to claim 6, characterized in that, The hazelnut oil mentioned is cold-pressed hazelnut oil.

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