Direct drinking tea seed oil and preparation process thereof

Abstract

The invention discloses direct drinking tea seed oil and a preparation process thereof, and relates to the technical field of grease processing. The method adopts a pure physical squeezing and whole-course low-temperature treatment technology, and comprises the following steps: screening fresh tea seeds, performing low-temperature drying treatment, and performing mechanical shelling and crushing to obtain a tea seed kernel and tea seed shell composite squeezed material in a specific proportion; and finally, obtaining virgin grease by adopting a low-temperature physical spiral squeezing process. The obtained crude oil is sequentially subjected to rough filtration, sedimentation and vacuum suction filtration, and then is subjected to the steps of ultrasonic-assisted hydration degumming, low-temperature winterization wax removal, vacuum low-temperature drying and the like, so that non-triglyceride components such as impurities, moisture, phospholipid and waxiness in the grease are effectively removed. According to the process, chemical reagents are not needed, high-temperature damage and generation of harmful substances are avoided, nutritional active ingredients such as unsaturated fatty acid, tocopherol, phytosterol and squalene in the tea seed oil are effectively reserved, and the finished product oil is clear, transparent, pure in flavor, safe, capable of being directly drunk and suitable for development of high-end nutritional oil and functional vegetable oil.

Description

Technical Field

[0001] The present invention relates to the technical field of oil processing, and in particular to direct drinking tea seed oil and a preparation process thereof. Background Art

[0002] Tea seed oil, a high-quality vegetable oil pressed or extracted from the seeds of the Camellia sinensis plant (Theaceae), boasts a distinctive, fragrant flavor and rich nutritional profile. As an emerging, high-end woody edible oil, tea seed oil is gaining increasing market attention and consumer favor due to its superior fatty acid profile and significant health benefits.

[0003] Tea seed oil contains over 80% unsaturated fatty acids, particularly oleic and linoleic acids, with linoleic acid being particularly prominent (≥20%), surpassing similar oils like camellia oil and olive oil. Furthermore, tea seed oil is rich in lipid concomitants such as polyphenols, tocopherols, phytosterols, and squalene. These active substances have numerous health benefits, including lowering blood lipids, preventing atherosclerosis, regulating immunity, slowing aging, and providing antioxidant benefits. Tea seed oil holds great promise as a daily nutritional oil supplement.

[0004] However, the tea seed oil currently available on the market is primarily intended for general cooking uses, and its production processes are largely based on traditional vegetable oil refining methods. Common oil extraction methods include pressing and solvent extraction, followed by refining processes such as degumming, deacidification, bleaching, deodorization, and defatting to produce the finished oil. The chemical solvents and high temperatures used in these processes not only result in residual organic solvents and environmentally unfriendly wastewater discharge, but also lead to the loss of tea seed oil's fragrant aroma and nutrients such as tocopherol, squalene, and sterols. Higher temperatures also produce more harmful substances such as benzopyrene, trans fatty acids, and chloropropane esters.

[0005] Therefore, existing tea seed oil preparation technologies are still unable to meet the high standards for safety, purity, nutrient retention, and flavor fidelity required for its use as a "drinking oil." Developing a tea seed oil preparation process for direct drinking, centered around pure physical, low-temperature, and environmentally friendly purification, is a key technological breakthrough for enhancing the functional applications and industrial value of tea seed oil. Summary of the Invention

[0006] The purpose of the present invention is to solve at least one of the technical problems existing in the prior art, provide a direct drinking tea seed oil and a preparation process thereof, and specifically provide a method for preparing direct drinking tea seed oil by purely physical, fully low-temperature, and multi-stage filtration of preferred tea seed raw materials. The present invention adopts technical means such as full low-temperature, purely physical pressing, and moderate refining to maximize the retention of natural nutrients and flavor substances in tea seed oil while ensuring the safety of the oil, overcoming the problems of nutrient loss and harmful component generation during traditional high-temperature extraction and chemical refining.

[0007] The technical solutions of the present invention are as follows: In a first aspect, the present invention provides a preparation process for direct drinking tea seed oil, comprising the following steps: S1, shelling the dried tea seeds, then crushing the obtained tea seed kernels and tea seed shells, and then uniformly mixing the crushed tea seed kernels and tea seed shells according to a set mass ratio to prepare a pressing material; S2, physically pressing the material to obtain crude oil; S3, subjecting the crude oil to coarse filtration, sedimentation and vacuum fine filtration to obtain fine filtered oil; S4, heating the refined filtered oil, slowly adding isothermal deionized water, stirring and emulsifying, and then turning on the ultrasonic equipment to degumming, and after completion, removing the colloid by centrifugation to obtain degummed oil; S5, slowly cooling the degummed oil, placing it in a low temperature environment for crystallization, and then removing crystalline impurities and wax by centrifugation to obtain winterized oil; S6. Vacuum-drying the winterized oil to obtain direct-drinking tea seed oil.

[0008] Preferably, S1 further comprises hot air drying the fresh tea seeds at a hot air drying temperature of 30° C.-40° C., and stopping the drying when the moisture content in the tea seeds reaches 10%-15%.

[0009] Preferably, S1 includes the following specific steps: The dried tea seeds are shelled, and the residual shell rate in the tea seed kernels is controlled to be no more than 2%. The tea seed kernels and tea seed shells are then crushed to a fineness of 60-80 mesh respectively, and the crushed tea seed kernels and tea seed shells are evenly mixed in a mass ratio of 95:4-6 to prepare the pressing material.

[0010] Preferably, in S2, the temperature of physical pressing does not exceed 60°C.

[0011] Preferably, in S3, solid impurities in the crude oil are initially filtered out using a 100-mesh sieve, and then the crude oil is allowed to settle. Vacuum filtration is then performed using precision filter paper to separate and remove moisture and impurities in the oil. The settling temperature is 4-8° C., and the settling time is 12-18 h.

[0012] Preferably, in S4, the refined filtered oil is heated to 60° C., isothermal deionized water is slowly added, and after stirring and emulsifying for 10 minutes, an ultrasonic device is turned on for degumming while stirring continuously. After completion, the colloid is removed by centrifugation.

[0013] Preferably, in S4, the amount of deionized water added is 5.5%-6.5% of the weight of the oil, the ultrasonic temperature is 40-50°C, the ultrasonic time is 15-20 min, and the ultrasonic power is 80-100 W.

[0014] Preferably, in S5, the winterization temperature is maintained at 0-5°C and the crystallization time is 24-36 h.

[0015] Preferably, a preparation process for direct drinking tea seed oil comprises the following specific steps: (1) Raw material screening and low-temperature drying treatment Pick fresh tea seeds, remove impurities such as branches, leaves, peels, iron, sand and gravel, mildewed or insect-infested tea seeds, clean and disinfect them, spread the cleaned tea seeds evenly on the tray, use hot air drying, turn them over every 3 hours, and test the moisture content in the tea seeds at the same time.

[0016] (2) Shelling and crushing The dried tea seeds are shelled, and the residual shell rate in the kernels is controlled to be no more than 2%. The tea seed kernels and tea seed shells are then crushed to a fineness of 60-80 mesh respectively. The crushed tea seed kernels and tea seed shells are evenly mixed according to a set mass ratio to prepare the pressing material.

[0017] (3) Low temperature screw pressing The material is fed into a screw press and subjected to a one-time physical pressing process to obtain the crude oil.

[0018] (4) Crude oil coarse filtration, sedimentation and vacuum fine filtration First, use a 100-mesh sieve to preliminarily filter out solid impurities in the crude oil and allow it to settle. Then use precision filter paper for vacuum filtration to separate and remove moisture and impurities in the oil.

[0019] (5) Ultrasonic-assisted hydration degumming Heat the refined filtered oil to 60°C, slowly add isothermal deionized water, stir and emulsify for 10 minutes, then turn on the ultrasonic equipment for degumming while stirring continuously. After completion, remove the colloid by centrifugation.

[0020] (6) Winterization and wax removal treatment After the degummed oil is slowly cooled to 10°C, it is placed in a low-temperature environment to crystallize, and then high-speed centrifugation is used to remove crystalline impurities and wax to improve the clarity and purity of the oil.

[0021] (7) Vacuum low temperature drying The winterized oil is placed in a vacuum dryer and subjected to negative pressure drying at 65°C to control the final moisture content below 0.2%, thereby obtaining a high-purity tea seed oil product that can be drunk directly.

[0022] In a second aspect, the present invention provides a direct-drinking tea seed oil obtained by adopting the preparation process.

[0023] Preferably, in the direct drinking tea seed oil, the content of linoleic acid is 22.18.18±0.04 g / 100 g, the content of α-tocopherol is 262.92±2.81 g / 100 g, and the content of squalene is 315.81±17.32 mg / kg.

[0024] The present invention has at least one of the following beneficial effects: 1. The present invention adopts full physical cold pressing and low-temperature treatment, which effectively protects the unsaturated fatty acids, tocopherol, squalene and other nutritional active ingredients in tea seed oil, thereby making the content of unsaturated fatty acids, tocopherol, squalene and other nutritional active ingredients in direct drinking tea seed oil high.

[0025] 2. The present invention has no chemical additives and no solvent residue, thus ensuring the safety of the oil and the high purity requirement suitable for direct drinking.

[0026] 3. The present invention improves the flavor and taste of tea seed oil when it is drunk directly, and the oil is clear and bright with a fresh and fragrant smell.

[0027] 4. The present invention is green and environmentally friendly, has a simple process, is easy to industrialize and promote, and is suitable for the development of high-end edible vegetable oils and functional nutritional oil products. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The present invention is a preparation flow chart of the direct drinking tea seed oil. DETAILED DESCRIPTION

[0029] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0030] Example 1 like Figure 1 As shown, a preparation process for direct drinking tea seed oil comprises the following steps: (1) Raw material screening and low-temperature drying treatment Choose fresh tea seeds picked in season, manually select and remove peels, branches and leaves, insect-eaten or moldy tea seeds, etc., wash with clean water and place in a drying tray, use 37℃ hot air to dry, turn over every 3 hours, and stop drying when the moisture content of the tea seeds drops to 10%.

[0031] (2) Shelling and crushing The dried tea seeds are shelled, and the residual shell rate in the seed kernels is controlled to be no more than 2%. The seed kernels are mixed with 5% seed shells and then crushed to 60 mesh to prepare the pressing material.

[0032] (3) Low temperature screw pressing The material is sent to the screw press for pressing, the temperature is controlled at 60℃, and the crude oil is obtained by one low-temperature pressing.

[0033] (4) Crude oil coarse filtration, sedimentation and vacuum fine filtration The crude oil was coarsely filtered through a 100-mesh stainless steel sieve, refrigerated and settled at 6°C for 16 hours, and then filtered through a vacuum filter with precision filter paper to remove impurities and free water.

[0034] (5) Ultrasonic-assisted hydration degumming The refined filtered oil was heated to 60°C, and isothermal deionized water (6.5% of the oil weight) was slowly added. After emulsification for 10 minutes, an ultrasonic generator (power of 90 W) was turned on and ultrasonicated at 40°C for 20 minutes, followed by high-speed centrifugation.

[0035] (6) Winterization and wax removal treatment The degummed oil was slowly cooled to 10°C and then transferred to a refrigerator (2°C) for crystallization for 36 hours. After crystallization, the crystalline wax was separated using a low-temperature high-speed centrifuge.

[0036] (7) Vacuum low temperature drying Finally, the oil sample was placed in a vacuum dryer and dried at 65°C for 3.5 hours. The water content in the oil was reduced to 0.1%, and a clear golden yellow, pure flavor direct drinking tea seed oil was obtained.

[0037] Example 2 like Figure 1 As shown, a preparation process for direct drinking tea seed oil comprises the following steps: (1) Raw material screening and low-temperature drying treatment Select fresh tea seeds picked in the season, manually select and remove peels, branches and leaves, insect-eaten or moldy tea seeds, etc., wash with clean water and place in a drying tray, use 35℃ hot air to dry, turn over every 3 hours, and stop drying after about 14 hours when the moisture content of the seeds drops to 12%.

[0038] (2) Shelling and crushing The dried tea seeds are shelled, and the residual shell rate in the seed kernel is controlled to be no more than 1.5%. The seed kernel is mixed with 5% seed shell and then crushed to 80 mesh to prepare the pressing material.

[0039] (3) Low temperature screw pressing The material is sent to the screw press for pressing, the temperature is controlled at 55℃, and the crude oil is obtained by one low-temperature pressing.

[0040] (4) Crude oil coarse filtration, sedimentation and vacuum fine filtration The crude oil was coarsely filtered through a 100-mesh stainless steel sieve, refrigerated and settled at 4°C for 15 hours, and then vacuum filtered through precision filter paper to remove impurities and free water.

[0041] (5) Ultrasonic-assisted hydration degumming The refined filtered oil was heated to 60°C, and isothermal deionized water (6% of the oil weight) was slowly added. After emulsification for 10 minutes, an ultrasonic generator (power 80 W) was turned on and ultrasonicated at 50°C for 18 minutes, followed by high-speed centrifugation.

[0042] (6) Winterization and wax removal treatment The degummed oil was slowly cooled to 10°C, and then transferred to a refrigerator (2°C) for crystallization for 30 hours. After crystallization, the crystalline wax was separated using a low-temperature high-speed centrifuge.

[0043] (7) Vacuum low temperature drying Finally, the oil sample was placed in a vacuum dryer and dried at 65°C for 2 hours. The water content in the oil was reduced to 0.15%, and a clear golden yellow, pure flavor direct drinking tea seed oil was obtained.

[0044] Example 3 like Figure 1 As shown, a preparation process for direct drinking tea seed oil comprises the following steps: (1) Raw material screening and low-temperature drying treatment Select fresh tea seeds picked in the season, manually select and remove peels, branches and leaves, insect-eaten or moldy tea seeds, etc., wash with clean water, place in a drying tray, use 40℃ hot air to dry, turn over every 3 hours, and stop drying after about 10 hours when the moisture content of the seeds drops to 13%.

[0045] (2) Shelling and crushing The dried tea seeds are shelled, and the residual shell rate in the seed kernels is controlled to be no more than 2%. The seed kernels are mixed with 5% seed shells and then crushed to 80 mesh to prepare the pressing material.

[0046] (3) Low temperature screw pressing The material is sent to the screw press for pressing, the temperature is controlled at 60℃, and the crude oil is obtained by one low-temperature pressing.

[0047] (4) Crude oil coarse filtration, sedimentation and vacuum fine filtration The crude oil was coarsely filtered through a 100-mesh stainless steel sieve, refrigerated and settled at 8°C for 12 hours, and then filtered through a vacuum filter with precision filter paper to remove impurities and free water.

[0048] (5) Ultrasonic-assisted hydration degumming The refined filtered oil was heated to 60°C, and isothermal deionized water (5.5% of the oil weight) was slowly added. After emulsification for 10 minutes, an ultrasonic generator (power 99 W) was turned on and ultrasonicated at 45°C for 15 minutes, followed by high-speed centrifugation.

[0049] (6) Winterization and wax removal treatment The degummed oil was slowly cooled to 10°C, then transferred to a refrigerator (0°C) and allowed to crystallize for 24 hours. After crystallization, the crystalline wax was separated using a low-temperature high-speed centrifuge.

[0050] (7) Vacuum low temperature drying Finally, the oil sample was placed in a vacuum dryer and dried at 65°C for 2 hours. The water content in the oil was reduced to 0.18%, and a clear golden yellow, pure flavor direct drinking tea seed oil was obtained.

[0051] Comparative Example 1 Comparative Example 1 provides a preparation process of camellia oil, which differs from Example 1 in that the raw material "tea seeds" is replaced with "camellia seeds", and the preparation process is the same as that of Example 1.

[0052] Comparative Example 2 A process for preparing tea seed oil differs from that of Example 1 in that, in step (2), 5% of tea seed shells are not added, and only the seed kernels are crushed to 80 mesh to prepare the pressed material. The other steps are the same as those of Example 1.

[0053] Comparative Example 3 A preparation process for tea seed oil is provided, which differs from Example 1 in that: in step (5), no ultrasonic treatment is performed, and only hydration degumming is performed. The specific steps of step (5) are: heating the refined filtered oil to 60° C., slowly adding isothermal deionized water (5.5% of the weight of the oil), emulsifying for 10 minutes, and settling for 3 hours to obtain degummed tea oil. The other steps are the same as those in Example 1.

[0054] test: The tea seed oil prepared in Examples 1 to 3 and the tea seed oil prepared in Comparative Examples 1 to 3 were tested for various indicators. The testing method is as follows: (1) The determination of acid value in tea seed oil / camellia oleifera oil shall refer to the cold solvent indicator titration method in GB 5009.229-2025, the determination of peroxide value shall refer to the indicator titration method in GB 5009.227-2023, the determination of iodine value shall refer to GB / T 5532-2022, the determination of saponification value shall refer to GB / T 5534-2024, the determination of fatty acids shall refer to GB 5009.168-2016 "National Food Safety Standard for the Determination of Fatty Acids in Foods", the determination of α-tocopherol shall refer to GB / T 26635-2011 "Determination of Tocopherols and Tocotrienols in Animal and Vegetable Oils and Fats by High Performance Liquid Chromatography", the determination of squalene shall refer to T / ZNZ 027-2020 "Determination of Squalene in Edible Vegetable Oils by Gas Chromatography-Tandem Mass Spectrometry", the determination of aflatoxin B1 and benzo(a)pyrene shall refer to GB5009.22-2016 and GB 5009.265-2021, determination of phospholipid content refers to GB / T 5537-2008.

[0055] The test results are shown in Table 1.

[0056] Table 1 Comparison of various indicators of tea seed oil and camellia oil As shown in Table 1, compared to Comparative Examples 1-3, the tea seed oils prepared in Examples 1-3 exhibit higher unsaturated fatty acid content (linoleic acid reaching 22%) and richer nutritional value (α-tocopherol exceeding 260 mg / kg and squalene exceeding 310 mg / kg), showing broad prospects for the development of high-end nutritious edible oils. Analysis of Comparative Examples 1-3 demonstrates that the addition of 5% seed shells to the pressed material significantly increases the content of nutritionally active ingredients such as squalene and α-tocopherol in the oil. Furthermore, the ultrasonic-assisted hydration degumming process, compared to traditional static degumming methods, more effectively removes phospholipids, improves oil purity and clarity, and further enhances the retention of squalene and tocopherol, ultimately improving both oil quality and safety.

[0057] (2) Evaluate the taste, smell and appearance of tea seed oil. The evaluation method is as follows: Place an equal amount of oil sample in a 10mL sealed colorless transparent glass bottle, first observe its color, transparency and whether there are impurities; gently shake the glass bottle, open the cork, take a slow and deep breath, carefully identify the characteristics and intensity of the smell, and judge whether there is any bad smell; use a clean tasting spoon to take a small amount of direct drinking tea oil, put it in the mouth, and slide the tongue to make the tea oil flow from the tip of the tongue to the root of the tongue, filling the entire mouth. During this process, pay attention to the taste characteristics of the tea oil (such as whether it is smooth or greasy), flavor characteristics (such as whether the taste is light, rich, and whether there is any peculiar smell), and whether it produces any irritation. The specific sensory evaluation scoring standards are as follows: Table 2 Sensory evaluation scoring criteria The results are shown in Table 3.

[0058] Table 3 Sensory evaluation scores of tea seed oil and camellia oil As can be seen from Table 2, the tea seed oils prepared in Examples 1 to 3 all performed well in terms of taste, aroma, and appearance. They had a smooth, delicate taste, a soft, low-greasy feel, and a pure, natural flavor, with average scores exceeding 4.5. They also had a pleasant, fresh aroma with no odor or oily taste, scoring between 4.57 and 4.67. The oils were clear and bright, light yellow in color, and free of visible impurities, with an appearance score of 4.83, indicating excellent overall sensory quality. In comparison, the tea seed oils prepared in Comparative Examples 1 to 3 were slightly inferior in terms of sensory performance, with a slightly thick or greasy taste, a slightly strong aroma, and a darker oil color.

[0059] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A preparation process for direct drinking tea seed oil, characterized in that: The following steps are involved: S1, shelling the dried tea seeds, then crushing the obtained tea seed kernels and tea seed shells, and then uniformly mixing the crushed tea seed kernels and tea seed shells according to a set mass ratio to prepare a pressing material; S2, physically pressing the material to obtain crude oil; S3, subjecting the crude oil to coarse filtration, sedimentation and vacuum fine filtration to obtain fine filtered oil; S4, heating the refined filtered oil, slowly adding isothermal deionized water, stirring and emulsifying, and then turning on the ultrasonic equipment to degumming, and after completion, removing the colloid by centrifugation to obtain degummed oil; S5, slowly cooling the degummed oil, placing it in a low temperature environment for crystallization, and then removing crystalline impurities and wax by centrifugation to obtain winterized oil; S6. Vacuum-drying the winterized oil to obtain direct-drinking tea seed oil.

2. The preparation process according to claim 1, characterized in that S1 also includes hot air drying the fresh tea seeds. The hot air drying temperature is 30° C.-40° C., and the drying is stopped when the moisture content in the tea seeds reaches 10%-15%.

3. The preparation process according to claim 1, characterized in that S1 includes the following specific steps: The dried tea seeds are shelled, and the residual shell rate in the tea seed kernels is controlled to be no more than 2%. The tea seed kernels and tea seed shells are then crushed to a fineness of 60-80 mesh respectively, and the crushed tea seed kernels and tea seed shells are evenly mixed in a mass ratio of 95:4-6 to prepare the pressing material.

4. The preparation process according to claim 1, characterized in that In S2, the temperature of physical pressing does not exceed 60°C.

5. The preparation process according to claim 1, characterized in that: In S3, solid impurities in the crude oil are initially filtered out using a 100-mesh sieve, and then the crude oil is allowed to settle. Vacuum filtration is then performed using precision filter paper to separate and remove moisture and impurities in the oil. The settling temperature is 4-8°C, and the settling time is 12-18 hours.

6. The preparation process according to claim 1, characterized in that In S4, the refined filtered oil is heated to 60° C., isothermal deionized water is slowly added, and after stirring and emulsifying for 10 minutes, an ultrasonic device is turned on for degumming while stirring continuously. After degumming, the colloid is removed by centrifugation.

7. The preparation process according to claim 1, characterized in that In S4, the amount of deionized water added is 5.5%-6.5% of the oil weight, the ultrasonic temperature is 40-50°C, the ultrasonic time is 15-20 min, and the ultrasonic power is 80-100 W.

8. The preparation process according to claim 1, characterized in that: In S5, the winterization temperature was maintained at 0-5 °C and the crystallization time was 24-36 h.

9. A direct drinking tea seed oil, characterized in that The method is obtained by using the preparation process according to any one of claims 1 to 8.

10. The direct drinking tea seed oil according to claim 9, characterized in that In the direct drinking tea seed oil, the content of linoleic acid is 22.18.18±0.04g / 100g, the content of α-tocopherol is 262.92±2.81g / 100g, and the content of squalene is 315.81±17.32mg / kg.

Images