Cold-pressed refined flaxseed oil and preparation method and application thereof

Abstract

This invention belongs to the field of flaxseed oil preparation technology, specifically relating to a cold-pressed refined flaxseed oil and its preparation method and application. The preparation method includes the following steps: (1) Enzymatic hydrolysis: the impurity-removed flaxseeds are washed with water, dried, and then put into an enzymatic hydrolysis tank. Water and compound enzymes are added, stirred evenly, enzymatic hydrolysis is performed, enzymes are inactivated, cooled, centrifuged, and the solid phase material is collected to obtain enzymatically hydrolyzed flaxseeds; (2) Microwave pretreatment: the moisture content of the enzymatically hydrolyzed flaxseeds is adjusted, microwaved, and allowed to stand to obtain microwave-treated flaxseeds; (3) Low-temperature pressing; (4) Initial filtration of crude oil; (5) Hydration degumming; (6) Freeze-drying and crystallization separation. The preparation method of this invention can increase the oil yield while increasing the fatty acid content in flaxseed oil. The flaxseed oil has a high content of 2-ethylhexanol and hexanol, and a rich grassy flavor, making it a high-quality flaxseed oil.

Description

Technical Field

[0001] This invention belongs to the field of flaxseed oil preparation technology, specifically relating to a cold-pressed refined flaxseed oil, its preparation method, and its application. Background Technology

[0002] Flaxseed oil is a high-quality edible vegetable oil extracted from flaxseeds. Because it is rich in unsaturated fatty acids such as alpha-linolenic acid and a variety of active nutritional components, it has broad application prospects and high nutritional value in the fields of food, health products, and cosmetics.

[0003] Currently, the main processing methods for flaxseed oil are pressing and solvent extraction. Edible-grade flaxseed oil is mostly produced using physical pressing, which can be further divided into hot pressing and cold pressing. Hot pressing requires high-temperature roasting before pressing. While this yields a higher oil output, the high temperature causes the oxidation and decomposition of unsaturated fatty acids and protein denaturation in flaxseed, destroying active ingredients such as vitamin E and producing burnt odors. Subsequent complex refining processes are required to remove impurities, further reducing nutrient content. Solvent extraction uses solvents to extract oil. Although it yields extremely high oil output, there is a risk of solvent residue, and chemical solvents can damage the natural quality of the oil. This method is only suitable for industrial applications and cannot meet the needs of high-end edible and health-related products.

[0004] Cold pressing, as an advanced physical extraction technology, typically involves directly pressing flaxseed at low temperatures. This process maximizes the preservation of the natural nutrients in flaxseed, making it a preferred method for producing high-quality flaxseed oil. For example, Chinese patent CN106147998B provides a cold-pressing method for producing flaxseed oil. The resulting flaxseed oil effectively retains the original nutrients of the flaxseed, while simplifying the extraction process and increasing the yield. Chinese patent CN103215118A provides a cold-pressing method for flaxseed oil that utilizes entirely physical methods without any chemical reactions, avoiding the chemical residues associated with chemical refining. This represents a green and healthy method for processing flaxseed oil.

[0005] Flavor is an important indicator of the quality of cold-pressed flaxseed oil. Its grassy aroma is a distinctive characteristic that sets it apart from other vegetable oils and is highly regarded by consumers. Research shows that the grassy aroma of cold-pressed flaxseed oil is mainly contributed by volatile alcohols and aldehydes, with 2-ethylhexanol and hexanol being key flavor contributors. The content of these two components is positively correlated with the intensity of the grassy aroma.

[0006] Although cold-pressed flaxseed oil has advantages such as good nutrient retention, unique flavor, and excellent quality, existing cold-pressing processes still face many technical bottlenecks. On the one hand, traditional cold-pressing processes have a low oil yield; on the other hand, existing processes do not adequately control the characteristics of flaxseed raw materials and pressing parameters, and do not pay sufficient attention to fatty acid content and flavor compound content.

[0007] Therefore, how to increase the content of 2-ethylhexanol and hexanol to obtain high-quality flaxseed oil while improving the oil yield and fatty acid retention rate has become a technical problem that urgently needs to be solved in the industry. Summary of the Invention

[0008] The purpose of this invention is to maximize the development and preservation of the unique grassy flavor of flaxseed, increase the content of 2-ethylhexanol and hexanol in the finished oil, while increasing the oil yield and the fatty acid content in flaxseed oil.

[0009] To achieve the above objectives, the present invention provides the following technical solution:

[0010] A method for preparing cold-pressed refined flaxseed oil includes the following steps:

[0011] (1) Enzymatic hydrolysis: The flax seeds after impurity removal are rinsed with water and dried. The dried flax seeds are put into an enzymatic hydrolysis tank, water and compound enzyme are added, and the mixture is stirred evenly to carry out enzymatic hydrolysis, enzyme inactivation, cooling, centrifugation, and collection of solid material to obtain enzymatic hydrolyzed flax seeds.

[0012] (2) Microwave pretreatment: Adjust the moisture content of the enzymatically hydrolyzed flaxseed, microwave it, and then let it stand at 25-30℃ for 18-20h to obtain microwave-treated flaxseed.

[0013] (3) Low-temperature pressing: Microwave-treated flaxseeds are placed into an oil press to obtain crude oil;

[0014] (4) Initial filtration of crude oil: The crude oil is filtered to obtain filtered crude oil;

[0015] (5) Hydration and degumming: The filtered crude oil is hydrated and degummed, and the upper degummed clear oil is collected;

[0016] (6) Freeze dewaxing and crystallization separation: The degummed oil is subjected to freeze dewaxing and crystallization separation to obtain cold-pressed refined flaxseed oil.

[0017] Enzymatic hydrolysis technology is increasingly used for edible oils, but existing technologies mainly focus on increasing the oil extraction rate without considering the impact of enzymatic hydrolysis on the oil's composition. Since flaxseed seed coats contain high levels of mucopolysaccharides, they can hinder the extraction efficiency of flaxseed oil. This invention improves the extraction rate of flaxseed oil by enzymatically hydrolyzing flaxseeds before cold pressing. Alpha-linolenic acid (ALA) is an essential fatty acid that the human body cannot synthesize and must obtain from food. High-quality flaxseed oil requires a higher ALA content. This invention utilizes a specific enzymatic hydrolysis process and microwave stimulation to simultaneously increase the ALA content in flaxseed oil.

[0018] Preferably, the flaxseeds after impurity removal are rinsed with water and dried to a moisture content of 8-10 wt%.

[0019] Preferably, 0.3%-0.6 wt% of a complex enzyme is added based on the weight of the dried flaxseed.

[0020] Preferably, the total enzyme activity of the complex enzyme is 8000-10000 U / g.

[0021] Preferably, the complex enzyme includes cellulase, pectinase and xylanase.

[0022] Preferably, the complex enzyme comprises cellulase, pectinase and xylanase with an enzyme activity ratio of (0.5-0.7):(1.3-1.5):1.

[0023] Preferably, the enzymatic hydrolysis conditions are: 45-55℃, enzymatic hydrolysis for 100-120 min.

[0024] Preferably, the enzymatically hydrolyzed flaxseed is adjusted to a moisture content of 18.0-18.5 wt%.

[0025] Preferably, the microwave conditions are: a thickness of 0.8-1cm, a microwave power of 550-570W, a working time of 30-40s, a pause of 30-40s, and a total cycle time of 7.0-7.5min.

[0026] Preferably, the flaxseed oil extraction rate of the preparation method is 37.67-37.92 wt%.

[0027] Existing technologies and commercially available products contain low levels of 2-ethylhexanol and hexanol in flaxseed oil, resulting in an unsatisfactory grassy flavor. This invention addresses this issue by treating enzymatically hydrolyzed flaxseed under specific microwave conditions, thereby increasing the content of 2-ethylhexanol and hexanol in flaxseed oil and enhancing its grassy flavor. Analysis shows that these two substances primarily originate from the unsaturated fatty acid metabolism pathway catalyzed by lipoxygenase. Enzymatic hydrolysis and microwave treatment disrupt the flaxseed cell structure, promoting the interaction between lipoxygenase and fatty acid precursors in the cytoplasm; simultaneously, they stimulate intracellular enzyme activity, thereby enhancing conversion efficiency and ultimately increasing the content of 2-ethylhexanol and hexanol in the oil.

[0028] Furthermore, this invention employs a pretreatment process combining enzymatic hydrolysis and microwave under specific conditions. Through the sequential synergy of biological and physical methods, it significantly improves the oil extraction rate while maximizing the protection of fatty acids in flaxseed oil. Under these conditions, the problems of heat accumulation and oxidative deterioration caused by excessive enzymatic hydrolysis and high-intensity microwave treatment can be avoided, thus preventing the destruction of fatty acids by inappropriate treatment conditions and achieving simultaneous optimization of oil extraction efficiency and oil nutritional quality.

[0029] The present invention also provides flaxseed oil prepared by the above preparation method, wherein the flaxseed oil has a grassy smell, and the flaxseed oil contains 0.50-0.53 μg / L of 2-ethylhexanol, 1.02-1.04 μg / L of hexanol, 95.57-95.95 wt% of fatty acids, and 57.1-57.4 wt% of α-linolenic acid.

[0030] A third aspect of the present invention provides the application of the preparation method in the preparation of flaxseed oil.

[0031] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows:

[0032] 1. This invention provides a method for preparing cold-pressed refined flaxseed oil. By optimizing process parameters and raw material processing methods, a cold-pressed refined flaxseed oil with high oil yield, rich grassy flavor, and high fatty acid content is obtained, meeting the market demand for high-quality flaxseed oil.

[0033] 2. This invention improves the extraction rate of flaxseed oil by enzymatically hydrolyzing flaxseeds before cold pressing.

[0034] 3. This invention increases the content of 2-ethylhexanol and hexanol in flaxseed oil by treating enzymatically hydrolyzed flaxseed under specific microwave conditions.

[0035] 4. This invention employs a specific enzymatic hydrolysis and microwave synergistic pretreatment process, which significantly improves the oil extraction rate while maximizing the protection of fatty acids in flaxseed oil. Attached Figure Description

[0036] Figure 1-5 The image shows the test report for flaxseed oil from Example 1. Detailed Implementation

[0037] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all 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.

[0038] All raw materials used in the following embodiments of the present invention are commercially available products:

[0039] Cellulase (Catalog No. S10041), pectinase (Catalog No. S10007), and xylanase (Catalog No. S23566) are all from Shanghai Yuanye Biotechnology Co., Ltd.

[0040] Example 1

[0041] This embodiment provides a method for preparing cold-pressed refined flaxseed oil, including the following steps:

[0042] (1) Raw material pretreatment: Remove dust, stems and leaves, sand, moldy seeds and discolored impurities from flaxseeds, rinse twice with clean water, and dry in a 45℃ constant temperature drying oven until the moisture content is 10wt%. Put the flaxseeds into an enzymatic hydrolysis tank, add water at a material-to-liquid ratio of 1:2 (m / v, flaxseed mass: water volume), stir to evenly disperse the flaxseeds in the water, adjust the pH of the system to 5.0 with 1wt% citric acid aqueous solution, and add 0.4wt% of the flaxseed mass of compound enzyme. The total enzyme activity of the compound enzyme is 10000U / g. The compound enzyme includes cellulase, pectinase, and xylanase with an enzyme activity ratio of 0.6:1.4:1. The system temperature was raised to 50℃ and held constant for 10 min to stabilize the system temperature and pH value before enzymatic hydrolysis. The hydrolysis conditions were: 50℃ for 110 min. After the hydrolysis was completed, the system temperature in the hydrolysis tank was raised to 90℃ and held constant for 15 min to inactivate the enzyme. After that, the system was naturally cooled to room temperature. The flaxseed suspension was centrifuged at 4000 r / min for 15 min, and the solid phase material was collected to obtain enzymatically hydrolyzed flaxseed.

[0043] (2) Microwave pretreatment: The enzymatically hydrolyzed flaxseeds were dried to a moisture content of 18wt%, placed at 4℃ for 25h, spread flat on a microwave oven with a thickness of 1cm, microwave power of 560W, working for 30s, pausing for 30s, cycling for 7min, and then placed at 27℃ for 19h to obtain microwave-treated flaxseeds.

[0044] (3) Low temperature pressing: Microwave-treated flaxseeds are put into an oil press at a pressing temperature of 20°C and a cake thickness of 3 mm. When the oil cake is firm, round, and there is no oil residue on the cake surface, it is judged as the pressing end point and crude oil is obtained.

[0045] (4) Initial filtration of crude oil: The crude oil is pumped into a plate filter, and a 5-micron precision filter bag is selected. The filter is carried out under a constant pressure of 3 kg / cm² to obtain the filtered crude oil.

[0046] (5) Hydration and degumming: Pump the filtered crude oil into a hydration tank equipped with a stirring and heating device, heat it to 60°C and maintain it, add brine for flocculation: Start the stirrer and set the speed to 60 rpm. Slowly add 3wt% brine that has been prepared and preheated to 60°C. The amount of brine added is 2wt% of the oil weight. Continue stirring for 30 min. When obvious gray flocculent phospholipid aggregates are observed to form in the oil, reduce the stirring speed to 30 rpm and continue stirring for 15 min. Maintain the oil temperature at 65°C and let it stand for sedimentation for 10 h. After standing, three clear layers will be formed in the tank: the upper layer is degummed clear oil, the middle layer is emulsion layer, and the lower layer is hydration foot. Collect the upper layer of degummed clear oil.

[0047] (6) Freezing dewaxing and crystallization separation: After drying the degummed oil to a moisture content of 0.03wt%, pump it into the crystallization tank and turn on the ethylene glycol cooling system for programmed cooling. First stage: the oil temperature is uniformly reduced from room temperature to 15℃ within 4 hours. Second stage: the oil temperature is slowly reduced from 15℃ to 5℃ within 8 hours. Third stage: the oil temperature is reduced from 5℃ to 2℃ within 4 hours. After reaching 2℃, the oil temperature is maintained at this temperature for 6 hours to allow the wax crystals to grow and stabilize. After crystal growth, the oil is filtered: it is sent to a plate and frame filter press, using 180-mesh filter paper, and cold filtered at 5℃. The pressure is increased until it stabilizes at 0.4MPa to obtain cold-pressed refined flaxseed oil.

[0048] Example 2

[0049] This embodiment provides a method for preparing cold-pressed refined flaxseed oil, including the following steps:

[0050] (1) Raw material pretreatment: Remove dust, stems and leaves, sand, moldy seeds and discolored impurities from flaxseeds, rinse twice with clean water, and dry in a 45℃ constant temperature drying oven until the moisture content is 10wt%. Put the flaxseeds into an enzymatic hydrolysis tank, add water at a material-to-liquid ratio of 1:2 (m / v, flaxseed mass: water volume), stir to evenly disperse the flaxseeds in the water, adjust the pH of the system to 5.0 with 1wt% citric acid aqueous solution, and add 0.5wt% of the flaxseed mass of compound enzyme. The total enzyme activity of the compound enzyme is 10000U / g. The compound enzyme includes cellulase, pectinase, and xylanase with an enzyme activity ratio of 0.5:1.5:1. The system temperature is raised to 55℃ and held constant for 10 min to stabilize the system temperature and pH value, and then enzymatic hydrolysis is performed. The enzymatic hydrolysis conditions are: 55℃ for 100 min. After the enzymatic hydrolysis is completed, the system temperature in the enzymatic hydrolysis tank is raised to 90℃ and held constant for 15 min to inactivate the enzyme. The system is then allowed to cool naturally to room temperature. The flaxseed suspension is centrifuged at 4000 r / min for 15 min, and the solid phase material is collected to obtain enzymatically hydrolyzed flaxseed.

[0051] (2) Microwave pretreatment: The enzymatically hydrolyzed flax seeds were dried to a moisture content of 18wt%, placed at 4℃ for 25h, spread flat on a microwave oven with a thickness of 1cm, microwave power of 600W, working for 30s, pausing for 30s, cycling for 7min, and then placed at 30℃ for 18h to obtain microwave-treated flax seeds.

[0052] (3) Low temperature pressing: Microwave-treated flax seeds are put into an oil press at a pressing temperature of 20°C and a cake thickness of 4 mm. When the oil cake is firm, round, and there is no oil residue on the cake surface, it is judged as the pressing end point and crude oil is obtained.

[0053] (4) Initial filtration of crude oil: The crude oil is pumped into a plate filter, and a 5-micron precision filter bag is selected. The filter is carried out under a constant pressure of 3 kg / cm² to obtain the filtered crude oil.

[0054] (5) Hydration and degumming: Pump the filtered crude oil into a hydration tank equipped with a stirring and heating device, heat it to 60°C and maintain the temperature, add brine for flocculation: Start the stirrer and set the speed to 60 rpm. Slowly add 3wt% brine that has been prepared and preheated to 60°C. The amount of brine added is 2wt% of the oil weight. Continue stirring for 30 min. When obvious gray flocculent phospholipid aggregates are observed to form in the oil, reduce the stirring speed to 30 rpm and continue stirring for 15 min. Maintain the oil temperature at 70°C and let it stand for sedimentation for 12 h. After standing, three clear layers will be formed in the tank: the upper layer is degummed clear oil, the middle layer is emulsion layer, and the lower layer is hydration foot. Collect the upper layer of degummed clear oil.

[0055] (6) Freezing dewaxing and crystallization separation: After drying the degummed oil to a moisture content of 0.03wt%, pump it into the crystallization tank and turn on the ethylene glycol cooling system for programmed cooling. First stage: the oil temperature is uniformly reduced from room temperature to 15℃ within 4 hours. Second stage: the oil temperature is slowly reduced from 15℃ to 5℃ within 8 hours. Third stage: the oil temperature is reduced from 5℃ to 2℃ within 4 hours. After reaching 2℃, the oil temperature is maintained at this temperature for 6 hours to allow the wax crystals to grow and stabilize. After crystal growth, the oil is filtered: it is sent to a plate and frame filter press, using 180-mesh filter paper, and cold filtered at 5℃. The pressure is increased until it stabilizes at 0.4MPa to obtain cold-pressed refined flaxseed oil.

[0056] Comparative Example 1

[0057] The difference between this comparative example and Example 1 is that the microwave power is 560W and the microwave time is 7min.

[0058] Comparative Example 2

[0059] The difference between this comparative example and Example 1 is that the microwave power is 650W, the operation time is 30s, the pause time is 30s, and the cycle time is 7min.

[0060] Comparative Example 3

[0061] The difference between this comparative example and Example 1 is that the microwave power is 450W, the operation time is 30s, the pause time is 30s, and the cycle time is 7min.

[0062] Comparative Example 4

[0063] The difference between this comparative example and Example 1 is that the microwave power is 560W, the working time is 30s, the pause time is 30s, and the cycle is 9min.

[0064] Comparative Example 5

[0065] The difference between this comparative example and Example 1 is that the microwave power is 560W, the operation time is 30s, the pause time is 30s, and the cycle time is 5min.

[0066] Comparative Example 6

[0067] The difference between this comparative example and Example 1 is that the complex enzyme includes cellulase, pectinase, and xylanase with an enzyme activity ratio of 0.4:1.6:1.

[0068] Comparative Example 7

[0069] The difference between this comparative example and Example 1 is that the complex enzyme includes cellulase, pectinase and xylanase with an enzyme activity ratio of 0.8:1.2:1.

[0070] Comparative Example 8

[0071] The difference between this comparative example and Example 1 is that the complex enzyme includes cellulase and xylanase with an enzyme activity ratio of 0.6:1.

[0072] Comparative Example 9

[0073] The difference between this comparative example and Example 1 is that the complex enzyme includes cellulase and pectinase with an enzyme activity ratio of 0.6:1.4.

[0074] Comparative Example 10

[0075] This comparative example is the product of Example 1 in the cold pressing production method of flaxseed oil provided by Chinese Patent CN106147998B.

[0076] Comparative Example 11

[0077] This comparative example is a product prepared according to a specific embodiment of the cold pressing method for flaxseed oil provided in Chinese Patent CN103215118A.

[0078] Comparative Example 12

[0079] This comparison uses commercially available cold-pressed flaxseed, brand: Brandler Flaxseed Oil.

[0080] Performance testing

[0081] Flaxseed oil was prepared using the same batch of Iya 4 flaxseeds according to the methods of Examples 1-2 and Comparative Examples 1-11, and the following performance parameters were determined.

[0082] 1. Gas chromatography-mass spectrometry was used to identify the content of 2-ethylhexanol and hexanol in flaxseed oil.

[0083] 2. Flaxseed oil extraction rate (%) = mass of flaxseed oil ÷ mass of flaxseed × 100%.

[0084] 3. Fatty acid content: Tested according to GB5009.168-2016, Method III. Fatty acids include: palmitic acid, stearic acid, oleic acid, linoleic acid, and α-linolenic acid.

[0085] The results are shown in Table 1.

[0086] Table 1 Performance Test Results

[0087]

[0088] As shown in Table 1, the flaxseed extraction rate of the preparation methods in Examples 1-2 was 37.67-37.92 wt%, the content of 2-ethylhexanol was 0.50-0.53 μg / L, the content of hexanol was 1.02-1.04 μg / L, the fatty acid content was 95.57-95.95 wt%, and the α-linolenic acid content was 57.1-57.4 wt%. The flaxseed oil of this invention has a high extraction rate, high content of 2-ethylhexanol and hexanol, a strong grassy aroma, and high fatty acid content, especially high α-linolenic acid content, which is significantly superior to existing technologies and commercially available products. The flaxseed oil prepared in Example 1 was tested, and the results are shown in the table below. Figure 1-5 It is evident that the flaxseed oil prepared by this invention meets relevant national standards and is a high-quality flaxseed oil.

[0089] In Comparative Example 1, continuous microwave treatment was performed. In Comparative Example 2, the microwave power was increased, and the levels of 2-ethylhexanol and hexanol decreased. The fatty acid content in flaxseed oil was significantly reduced, indicating that under these conditions, microwave treatment would destroy the active tissues in flaxseed and affect the conversion during the subsequent settling process.

[0090] The microwave power in Comparative Example 3 was insufficient, and the contents of 2-ethylhexanol and hexanol were low, indicating that microwaves could not effectively induce the subsequent transformation of substances in flaxseed under these conditions.

[0091] In Comparative Example 4, longer microwave time resulted in a significant decrease in the fatty acid content of flaxseed oil.

[0092] In Comparative Example 5, the microwave time was reduced, resulting in lower contents of 2-ethylhexanol and hexanol.

[0093] The changes in the composition of the complex enzymes in Comparative Examples 6-9 significantly reduced the flaxseed oil extraction rate, indicating that enzymatic hydrolysis has a significant impact on the extraction rate. Simultaneously, the contents of 2-ethylhexanol, hexanol, and α-linolenic acid were low.

[0094] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A cold-pressed refined flaxseed oil, characterized in that, The flaxseed oil has a grassy aroma. The flaxseed oil contains 0.50-0.53 μg / L of 2-ethylhexanol, 1.02-1.04 μg / L of hexanol, 95.57-95.95 wt% of fatty acids, and 57.1-57.4 wt% of α-linolenic acid. The preparation method of cold-pressed refined flaxseed oil includes the following steps: (1) Enzymatic hydrolysis: The flax seeds after impurity removal are rinsed with water and dried. The dried flax seeds, water and compound enzyme are mixed and stirred evenly for enzymatic hydrolysis. The enzyme is inactivated, cooled, centrifuged and the solid phase material is collected to obtain enzymatically hydrolyzed flax seeds. The total enzyme activity of the compound enzyme is 8000-10000 U / g. The compound enzyme includes cellulase, pectinase and xylanase with an enzyme activity ratio of (0.5-0.7):(1.3-1.5):

1. (2) Microwave pretreatment: Enzymatically hydrolyzed flax seeds are microwaved and left to stand to obtain microwave-treated flax seeds; the microwave power is 550-570W, working for 30-40s, pausing for 30-40s, and the total cycle time is 7.0-7.5min. (3) Low-temperature pressing: Microwave-treated flaxseeds are placed in an oil press and cold-pressed to obtain crude oil; (4) Initial filtration of crude oil: The crude oil is filtered to obtain filtered crude oil; (5) Hydration and degumming: The filtered crude oil is hydrated and degummed, and the upper degummed clear oil is collected; (6) Freeze dewaxing and crystallization separation: The degummed oil is subjected to freeze dewaxing and crystallization separation to obtain cold-pressed refined flaxseed oil.

2. The cold-pressed refined flaxseed oil according to claim 1, characterized in that, Rinse the cleaned flax seeds with water and dry them until the moisture content is 8-10 wt%.

3. The cold-pressed refined flaxseed oil according to claim 1, characterized in that, The amount of compound enzyme added is 0.3%-0.6 wt% of the dried flaxseed.

4. The cold-pressed refined flaxseed oil according to claim 1, characterized in that, The enzymatic hydrolysis conditions are: hydrolysis temperature of 45-55℃ and hydrolysis time of 100-120 min.

5. The cold-pressed refined flaxseed oil according to claim 1, characterized in that, When microwaved, the thickness of the enzymatically hydrolyzed flaxseeds spread out should be 0.8-1 cm.

6. The cold-pressed refined flaxseed oil according to claim 1, characterized in that, The extraction rate of flaxseed oil by the preparation method is 37.67-37.92 wt%.

Images