Method for controlling the oil consumption of tea seed oil and application thereof

Abstract

This invention belongs to the field of cosmetics, specifically relating to a method and application for controlling the rancidity of tea seed oil. The technical solution of this invention involves adding an appropriate amount of one or more selected from α-tocopherol, 2-hydroxypropane-1,2,3-tricarboxylic acid, or freeze-dried tea extract powder to tea seed oil, which can effectively control the rancidity of tea seed oil, significantly improve the user experience, and thus solve the technical problem of limiting the amount of tea seed oil added to cosmetic formulations.

Description

Technical Field

[0001] This invention belongs to the field of natural product chemistry, specifically relating to a method and application for controlling the rancidity of tea seed oil. Background Technology

[0002] Tea (Camellia sinensis) is a plant belonging to the genus Camellia in the family Theaceae. It originated in China and northern India, and thrives in warm, humid climates, especially in tropical and subtropical regions. Its fruit is a capsule containing 1-3 seeds, known as tea seeds. Statistics show that my country currently has 2.13 million hectares of tea gardens, producing approximately 840,000 tons of tea seeds. Tea seeds are rich in fatty acids, starch, protein, tea saponins, soluble sugars, and hemicellulose, with an oil content of 25%-35%. Tea seed oil is an oil extracted from tea seeds. It differs from "oil-tea seed oil" and "camellia seed oil." Oil-tea seed oil is extracted from the seeds of the Camellia oleifera species in the genus Camellia of the family Theaceae; camellia seed oil is extracted from the Camellia genus of the genus Camellia of the family Theaceae. Tea seed oil is also often called "Oriental olive oil," as it is rich in trace elements and has a fatty acid composition similar to olive oil, containing abundant nutrients beneficial to the human body. Tea seed oil mainly contains five fatty acids: palmitic acid, oleic acid, linoleic acid, linolenic acid and stearic acid. Its unsaturated fatty acids can reach about 80%, mainly oleic acid. The ratio of polyunsaturated fatty acids to monounsaturated fatty acids is as high as 3.5-4:1.

[0003] Currently, camellia oils, containing fatty acids, squalene, α-tocopherol, and tea polyphenols, are widely used in cosmetics due to their antioxidant and repairing effects. However, the high content of unsaturated fatty acids in camellia oil makes it susceptible to hydrolysis and rancidity under the influence of light and temperature, generating free fatty acids that further decompose into simple, odorous aldehydes, ketones, and acids, producing an unpleasant rancid smell. Adding even 0.5% to a formula can significantly affect the scent of the finished cosmetic product, making it difficult to mask even with natural or artificial fragrances. This greatly limits the development and utilization of camellia oil in skincare product formulations.

[0004] In existing technologies, such as the patent with publication number CN210736689U entitled "A Deodorizing and Deodorizing Device for Camellia Seed Oil Production Process," it is pointed out that by improving the deodorizing and deodorizing device in the camellia seed oil production process, the deodorizing and deodorizing efficiency can be improved, thereby enhancing the quality of the finished camellia seed oil. However, this method can only reduce off-odors during the production stage of camellia seed oil and cannot effectively suppress the newly generated rancid odor during subsequent storage. Furthermore, this technology requires significant modifications to the production equipment, substantially increasing production costs and limiting its widespread application in actual production.

[0005] Therefore, there is an urgent need in the existing technology for a method that can effectively inhibit the hydrolysis and rancidity of tea seed oil, prolong its stability and improve its odor, so as to expand its application in cosmetics and other fields. Summary of the Invention

[0006] This invention belongs to the field of cosmetics, specifically relating to a method and application for controlling the rancidity of tea seed oil. By adding an appropriate amount of one or more selected from α-tocopherol, 2-hydroxypropane-1,2,3-tricarboxylic acid, or freeze-dried tea extract powder to tea seed oil, the rancidity of tea seed oil can be controlled, significantly improving the user experience and thus solving the problem of limiting the amount of tea seed oil added to cosmetic formulations.

[0007] Furthermore, based on the weight of tea seed oil, the amount of α-tocopherol added is at least 0.025 wt%, the amount of 2-hydroxypropane-1,2,3-tricarboxylic acid added is at least 0.005 wt%, and the amount of tea extract freeze-dried powder added is at least 0.005 wt%.

[0008] Further, the α-tocopherol is 0.02-0.055 wt%, the 2-hydroxypropane-1,2,3-tricarboxylic acid is 0.005-0.02 wt%, and the lyophilized tea extract powder is 0.045-0.55 wt%.

[0009] Furthermore, the tea seed oil contains any one of the following components selected from the ingredients: 0.03-0.05 wt% α-tocopherol or 0.02-0.04 wt% α-tocopherol + 0.005-0.015 wt% 2-hydroxypropane-1,2,3-tricarboxylic acid or 0.045%-0.55 wt% lyophilized tea extract powder.

[0010] Furthermore, the tea seed oil can be prepared by any method in the prior art, and the preparation of the tea seed oil includes the following steps: 1) Collect tea seeds, dry them in the sun, and remove impurities to obtain dried tea seeds; 2) The dried tea seeds are mechanically dehulled and crushed, steamed at 50℃-60℃ for 30-60 minutes, then pressed by gears, and centrifuged at 1000-3000 rpm to obtain crude tea seed oil. 3) Refining: Heat the crude tea seed oil in hot water, then vacuum deodorize for 1-2 hours, crystallize for 24-48 hours, add silica gel to decolorize and remove impurities, filter and take the supernatant oil, which is the finished tea seed oil.

[0011] Furthermore: the centrifugation is plate centrifugation; Furthermore, the hot water cleaning is 80°C hot water, and the cleaning time is 5 minutes.

[0012] Furthermore, the filtration is performed using a 0.2 μM membrane.

[0013] The tea seed oil prepared using the above method contains less than 10 mg / kg of hexanal and less than 3 mg / kg of nonanal.

[0014] Furthermore, the freeze-dried tea extract powder is prepared by the following steps: taking green tea leaves, air-drying them naturally, and removing impurities; adding water at a mass ratio of 1:20-1:50, extracting at 75-95℃ for 1-3 hours, centrifuging and filtering to obtain the filtrate, concentrating the filtrate by reverse osmosis to 30%-50% of the original liquid volume, and then freeze-drying at a freezing temperature of -45℃ and a freezing discharge temperature of 40℃ for 48-72 hours to obtain the freeze-dried tea extract powder. The tea polyphenol content of the freeze-dried tea extract powder obtained by this method is above 25%.

[0015] This invention also provides a tea seed oil, wherein the tea seed oil contains appropriate amounts of one or more components selected from the following: α-tocopherol, 2-hydroxypropane-1,2,3-tricarboxylic acid, and freeze-dried tea extract powder. This tea seed oil exhibits good storage stability, and during storage, it effectively controls the rancid odor of the tea seed oil, thus solving the technical problem of limiting the amount of tea seed oil added to cosmetic formulations due to its rancid odor.

[0016] Furthermore, based on the weight of tea seed oil, the amount of α-tocopherol added is at least 0.025 wt%, the amount of 2-hydroxypropane-1,2,3-tricarboxylic acid added is at least 0.005 wt%, and the amount of tea extract freeze-dried powder added is at least 0.005 wt%.

[0017] Further, the content of α-tocopherol is 0.025%-0.055 wt%, the content of 2-hydroxypropane-1,2,3-tricarboxylic acid is 0.005-0.02 wt%, and the content of lyophilized tea extract powder is 0.045-0.55 wt%.

[0018] Furthermore, the tea seed oil contains 0.03-0.05 wt% α-tocopherol or 0.02-0.04 wt% α-tocopherol + 0.005-0.015 wt% 2-hydroxypropane-1,2,3-tricarboxylic acid or 0.095%-0.55 wt% lyophilized tea extract powder.

[0019] The present invention also provides a product containing camellia seed oil, characterized in that it contains the aforementioned camellia seed oil for controlling oil rancidity: (1) Additives; (2) Cosmetics; (3) Health products; (4) Food; (5) Medicines.

[0020] This invention also provides an application of the aforementioned controlled-flavor tea seed oil, characterized in that it is used to prepare the following products: (1) Additives; (2) Cosmetics; (3) Health products; (4) Food; (5) Medicines.

[0021] The cosmetics described in this invention refer to daily chemical industrial products applied to the skin, hair, nails, lips, and other human body surfaces by rubbing, spraying, or other similar methods for the purpose of cleaning, protecting, beautifying, and modifying. As cosmetics, they can be categorized according to their efficacy into: cleansing cosmetics (used to cleanse the skin), skincare cosmetics (such as cleansing creams, facial cleansers, bath products, shampoos and conditioners, shaving creams, etc.), basic cosmetics (basic treatments for the face and hair before makeup, such as various face creams, lotions, toners, masks, hair creams, hairsprays, etc.), beauty cosmetics (beautification products for the face and hair, such as blush, lipstick, eyeshadow, hair dyeing, perming, styling, and fixing products), and therapeutic cosmetics (daily chemical products that fall between pharmaceuticals and cosmetics, such as cooling and deodorizing products). According to their external form, products can be categorized as follows: odor-removing, spot-removing, sun protection, body shaping, hair growth, hair removal, hair dyeing, insect repellent, olive extract, etc.; liquids (such as facial cleanser, bath gel, shampoo, toner, perfume, cleansing water, makeup remover, serum, essence, etc.); lotions (such as honey, milk, hair conditioner, essence lotion); creams (such as face cream, foundation cream, shampoo, concealer, hair treatment cream, essence cream, makeup primer); powders (such as face powder, talcum powder, loose powder, cleansing powder, setting powder); block powders (such as pressed powder, blush powder, lipstick, hair wax); and oils (such as makeup remover oil, body oil, hair oil, essence oil).

[0022] The health products described in this invention can be prepared into powders, tablets, capsules, liquid preparations, gels, etc., and can also be prepared into tea bags, beverages, candies, etc.

[0023] The pharmaceutical products described in this invention can be classified according to their dispersion systems into: solution type (a homogeneous dispersion system in which the drug is dispersed in a dispersion medium in a molecular or ionic state (particle diameter less than 1 nm), also known as a low molecular weight solution, such as aromatic aqueous solutions, solutions, syrups, glycerin preparations, liniments, injections, etc.); colloidal solution type (a homogeneous dispersion system mainly composed of high molecular weight substances (particle diameter between 1 and 100 nm) dispersed in a dispersion medium, also known as a high molecular weight solution, such as colloids, collodion preparations, coatings, etc.); and emulsion type (a non-homogeneous dispersion system in which oil-based drugs or drug oil solutions are dispersed in a dispersion medium in a droplet state). 4. Suspension type: Non-uniform dispersion system formed by solid drugs being dispersed in a dispersion medium in the form of particles, such as mixtures, lotions, suspensions, etc.); gas dispersion type (dispersion system formed by liquid or solid drugs being dispersed in a gaseous dispersion medium in the form of particles, such as aerosols); particulate dispersion type (drugs dispersed in liquid or solid states as particles of different sizes, such as microspheres, microcapsules, nanocapsules, etc.); solid dispersion type (dispersion system in which solid drugs exist in aggregate state, such as tablets, powders, granules, capsules, pills, etc.).

[0024] Beneficial effects: This invention significantly improves the component stability of tea seed oil under light and temperature conditions by adding appropriate amounts of α-tocopherol, 2-hydroxypropane-1,2,3-tricarboxylic acid, a mixture of α-tocopherol and 2-hydroxypropane-1,2,3-tricarboxylic acid, or freeze-dried tea extract powder to tea seed oil. This effectively inhibits the occurrence of oil hydrolysis and rancidity, thereby controlling the rancidity of tea seed oil from the source.

[0025] This technological breakthrough has solved the problem of limited addition of camellia seed oil in cosmetic formulations due to odor issues, significantly expanding the application scope of camellia seed oil in cosmetics and other fields.

[0026] This invention not only meets the needs of cosmetics production, but also provides a new technological path for the high-value utilization of camellia seed oil by improving its quality and stability, resulting in significant economic benefits and market prospects. Furthermore, this invention employs a physical compounding process, eliminating the need for high-temperature, high-pressure, or chemical modification treatments, and is fully compatible with existing oil refining production lines, enabling rapid commercialization. Detailed Implementation

[0027] The present invention will now be described in detail with reference to specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0028] 1. Preparation of experimental samples 1.1 Preparation of Camellia Seed Oil The preparation of tea seed oil involves three steps: After harvesting tea seeds, they are dried and cleaned to obtain dried tea seeds. The dried tea seeds were mechanically dehulled and crushed, softened with steam at 55℃ for 50 minutes, then pressed by gears, and the crude tea seed oil was obtained after centrifugation at 2000 rpm. Refining: The crude tea seed oil is washed twice with 80℃ hot water for 5 minutes each time, followed by vacuum deodorization for 2 hours, crystal growth for 24 hours, decolorization and impurity removal with silica gel, and filtration through a 0.2μm membrane. The supernatant oil is then collected as the finished tea seed oil. The tea seed oil contains 6.99 mg / kg of hexanal and 2.38 mg / kg of nonanal. Preliminary visual and olfactory evaluation shows that it has a fragrant aroma, no obvious rancid smell, and a bright color, meeting the requirements for use.

[0029] 1.2 Preparation of freeze-dried tea extract powder Green tea leaves from Nyingchi, Tibet, are naturally air-dried and impurities are removed. The selected tea leaves are then mixed with water at a ratio of 1:30-50 and extracted at 80°C for 2 hours. After centrifugation at 1000 rpm, the filtrate is collected and concentrated using reverse osmosis to 40% of its original volume. This concentrate is then freeze-dried at -45°C and 40°C for 60 hours to obtain the freeze-dried tea extract powder. Testing shows that the freeze-dried tea extract powder contains more than 25% tea polyphenols.

[0030] 1.3. Preparation of Camellia Seed Oil with Different Additives 50g of tea seed oil was placed in a glass bottle. A blank control group, a model group, and an experimental group were set up. Before and after washing the tea seed oil or after preparation, α-tocopherol, pentaerythritol tetra(bis-tert-butylhydroxyhydrocinnamic acid) ester (TT), 2-hydroxypropane-1,2,3-tricarboxylic acid (CA), or tea extract lyophilized powder (CE) were added individually or in combination as shown in Table 1. The bottles were placed in a light environment at 25℃ or a high-temperature environment at 50℃. The original blank control was set at 4℃ in the dark without adding any samples. The tea seed oil in the light environment at 25℃ or the high-temperature environment at 50℃ was used as the model group. After 2 months, the content of nonanal and hexanal, peroxide value, and sensory evaluation related to the odor change of tea seed oil were tested to comprehensively derive the method for controlling the odor loss of tea seed oil.

[0031] Among them, 2-hydroxypropane-1,2,3-tricarboxylic acid was ground and added to tea seed oil, pentylenetetradecyl tetra(bis-tert-butylhydroxyhydrocinnamic acid) ester was heated and dissolved in tea seed oil, α-tocopherol and freeze-dried tea extract powder were added to tea seed oil and stirred evenly.

[0032] After adding the tea seed oil, cool it to room temperature, place it in a 4°C refrigerator for 4-6 hours, and then conduct accelerated testing.

[0033] Table 1. Mass percentage of different added ingredients

[0034] 1.4 Determination of nonanal and hexanal content in camellia seed oil under high temperature or light conditions Hexanal and nonanal are the "odor fingerprints" of tea seed oil. Their formation dynamics and odor characteristics not only reflect the degree of oil deterioration but also provide key targets for quality control. Their formation is closely related to the reaction of unsaturated fatty acids (such as linoleic acid and oleic acid).

[0035] Hexanal: Primarily derived from the decomposition of components converted from linoleic acid (C18:2) (such as 13-HPODE) in a β-cleavage reaction, generating short-chain aldehydes such as hexanal and hexenal. Its odor is characterized by a combination of grassy and pungent notes: at low concentrations (<5 mg / kg), it exhibits a fresh grassy or green leafy aroma, similar to freshly cut plant stems and leaves; however, at higher concentrations (>10 mg / kg), the pungent odor intensifies, accompanied by a metallic, fishy smell. Rancidity marker: Hexanal and trans-2-hexenal synergistically produce a raw, green odor similar to raw potatoes or unripe fruit, a sensitive indicator of early oil deterioration. Furthermore, the synergistic effect of hexanal and trans-2-decenal at low concentrations produces a metallic, fishy smell similar to rusty nails (hexanal contributes a grassy base, while trans-2-decenal enhances the metallic feel); at high concentrations, it is combined with the musty, damp odor of 1-octen-3-one, forming a pungent, greasy smell similar to machine lubricating oil.

[0036] Nononal: Primarily produced by the decomposition of components derived from the conversion of oleic acid (C18:1) (such as 10-HPOME), and may also be generated through secondary reactions of linoleic acid. Its characteristic odor is a fatty, rancid smell: a typical waxy and fatty oxidation odor, similar to stale nuts or the rancid smell of fried foods. It can be detected by the sense of smell at concentrations above 0.5 mg / kg. Sources of complex off-odors: When present with unsaturated aldehydes such as 2-nonenal, it produces a fishy or rotten meat-like odor; at high temperatures, it may further degrade into nonanoic acid, intensifying the rancid smell. The synergistic effect of hexanal and nononal accelerates the overall flavor deterioration.

[0037] The experiment quantitatively assessed the odor of tea seed oil by measuring the changes in the content of nonanal and hexanal after tea seed oil containing α-tocopherol, pentaerythritol tetra(bis-tert-butylhydroxyhydrocinnamic acid) ester (TT), 2-hydroxypropane-1,2,3-tricarboxylic acid (CA) or lyophilized tea extract powder (CE) was placed in a light incubator (TL84 and UV standard light source, Shanghai Yiheng Scientific Instruments Co., Ltd.) or a constant temperature test chamber (Jiangsu Emerson Test Instruments Technology Co., Ltd.) for 2 months.

[0038] Nononal and hexanal GC-MS determination methods: The contents of hexanal and nonanal in camellia seed oil were determined by gas chromatography-mass spectrometry (GC-MS). Camellia seed oil was pretreated and extracted with n-hexane before analysis. Hexanal and nonanal were separated in the oil using a Thermo Fisher capillary TG-5MS column (30 m × 0.25 mm × 0.25 μm) with a temperature-programmed method. Mass spectrometry was used for detection, and qualitative analysis was based on retention time and characteristic ion abundance ratio. The contents were calculated using the external standard method. The established GC-MS method is rapid, accurate, and sensitive for the quantitative analysis of hexanal and nonanal components in camellia seed oil. Simultaneously, the odor of the camellia seed oil samples before and after light exposure was evaluated using olfactory methods. ++++ Very strong rancid smell; +++ Strong rancid smell; ++ Slight rancid smell; + Slight rancid smell.

[0039] The test results are shown in Tables 2 and 3.

[0040] Table 2. Changes in nonanal and hexanal content in tea seed oil under light conditions

[0041] As shown in Table 2, in the blank control, the content of hexanal in tea seed oil increased from 6.99 mg / kg to 10.02 mg / kg and the content of nonanal increased from 2.38 mg / kg to 3.06 mg / kg after 2 months of light exposure. This indicates that the content of hexanal and nonanal in tea seed oil increases significantly under light exposure, resulting in a strong rancid odor.

[0042] The addition of 0.05wt%TT, 0.03wt%-0.05wt%α-tocopherol, 0.1wt%-0.5wt%CE, 0.05wt%TT+0.01wt%α-tocopherol, 0.05wt%TT+0.01wt%CA, 0.03wt%α-tocopherol+0.01wt%CA, and 0.03wt%TT+0.01wt%α-tocopherol+0.01wt%CA resulted in a total content of hexanal and nonanal in tea seed oil below 9mg / kg. This inhibits the production of hexanal and acetaldehyde after exposure to light and reduces the rancid taste in the system.

[0043] Preferably, when 0.03wt%-0.05wt% α-tocopherol, 0.03wt% α-tocopherol + 0.01wt% CA, and 0.1wt%-0.5wt% CE are added to tea seed oil, the content of acetaldehyde and hexanal in the tea seed oil can be controlled to below 8 mg / kg. This indicates that the addition of these components can more significantly inhibit the production of hexanal and nonanal in tea seed oil under light, thereby reducing the rancid odor in the system. Furthermore, the content of hexanal and nonanal is consistent with the intensity of the rancid odor in the olfactory assessment.

[0044] Table 3. Changes in nonanal and hexanal content in tea seed oil under high temperature conditions of 50℃

[0045] As shown in Table 3, compared with the blank control, the content of hexanal in tea seed oil increased from 6.99 mg / kg to 15.73 mg / kg and the content of nonanal increased from 2.38 mg / kg to 4.3 mg / kg after 2 months at 50℃. This indicates that tea seed oil is more likely to produce a strong rancid odor at high temperatures, and that high temperature has a greater impact on the production of hexanal and acetaldehyde in tea seed oil than light.

[0046] Suppressing the odor produced by tea seed oil at high temperatures is more difficult. Adding 0.03wt%-0.05wt% α-tocopherol, 0.03wt% α-tocopherol + 0.01wt% CA, and 0.1wt%-0.5wt% CE can significantly inhibit the production of hexanal and nonanal at high temperatures. Among them, 0.03wt% α-tocopherol + 0.01wt% CA has the strongest inhibitory effect. However, adding other ingredients cannot effectively control the production of acetaldehyde and hexanal in tea seed oil at high temperatures. This indicates that adding only 0.03wt%-0.05wt% α-tocopherol, 0.03wt% α-tocopherol + 0.01wt% CA, and 0.1wt%-0.5wt% C can significantly control the odor caused by the decomposition of tea seed oil at high temperatures.

[0047] 1.5 Determination of iodine value Iodine value (IV) is a core indicator for measuring the number of double bonds in unsaturated fatty acids in oils (the number of grams of iodine absorbed per 100g of oil). It indicates the content of unsaturated fatty acids in the oil; the higher the iodine value, the higher the content of unsaturated fatty acids. The double bonds (C=C) of unsaturated fatty acids are the main targets for oxidation. Changes in the chemical state of the double bonds directly affect the iodine value. Free radical attacks trigger double bond breakage, conjugation, polymerization, or epoxidation to form peroxides, leading to a reduction in the number of additive double bonds and a significant decrease in the iodine value.

[0048] Changes in iodine value can reflect the degree of oxidation of tea seed oil to some extent. Therefore, the change in the degree of unsaturation of the oil can be evaluated based on the iodine value, that is, the degree of oxidation. The greater the decrease in iodine value, the greater the degree of oxidation.

[0049] Methods for determining iodine value The iodine value of tea seed oil samples was determined according to the national standard GB / T 5532-2008, and the iodine value W1 of tea seed oil was calculated according to the following formula.

[0050]

[0051] Note: W1 - the number of grams of iodine absorbed per 100 g of oil sample, g / 100 g V1 - The volume of Na2S2O3 standard solution consumed by the blank, in mL V2 - The volume of Na2S2O3 standard solution consumed by the sample, in mL c-Na2S2O3 concentration, mol / L m - Oil mass, g The results are shown in Table 4.

[0052] Table 4. Changes in iodine value of tea seed oil under different conditions (g / 100g)

[0053] As shown in Table 4 above, compared with the blank control, the iodine value of tea seed oil decreased after two months of exposure to light or high temperature. After adding different concentrations of α-tocopherol, pentaerythritol tetra(bis-tert-butylhydroxyhydrocinnamic acid) ester (TT), 2-hydroxypropane-1,2,3-tricarboxylic acid (CA), or lyophilized tea extract powder (CE) or compound ingredients, except for the 0.05wt%-0.5wt% CE group which could not control the decrease in iodine value under light, the other experimental groups could control the change in iodine value to a certain extent. This indicates that the addition of α-tocopherol, TT, CA or their combinations can enhance the antioxidant effect of tea seed oil.

[0054] 1.6 Sensory evaluation of camellia seed oil This experiment conducted a sensory evaluation of tea seed oil after a 2-month accelerated test.

[0055] Ten volunteers aged 20-50 years were selected to evaluate and score the aroma of camellia seed oil under different experimental conditions in a constant temperature and humidity chamber. The scoring criteria were based on the pleasantness of the aroma, with a maximum score of 10. Severe rancidity and unpleasant aroma (1 point); rancidity odor, acceptable (5 points); rich camellia seed aroma, mild oil aroma, pleasant aroma (10 points). Higher scores indicated better aroma, and lower scores indicated worse aroma and stronger rancidity. The scores of the 10 volunteers were summed, and the average score was calculated as the sensory score. The scores under light and high temperature conditions were added together to obtain the total sensory score. The comprehensive results are shown in Table 5.

[0056] Table 5. Sensory evaluation results of tea seed oil under different conditions

[0057] As shown in the table above, compared with the blank control, the sensory score of camellia seed oil decreased from 7.11 to 4.13 and 4.22 under light and high temperature of 50℃, respectively, indicating that both light and high temperature can accelerate the production of unpleasant odor in camellia seed oil. Under light conditions, adding 0.05wt%TT, 0.03wt%-0.05wt%α-tocopherol, 0.01wt%CA, 0.05wt%TT+0.01wt%α-tocopherol, 0.03wt%α-tocopherol+0.01wt%CA, and 0.1wt%-0.5wt%CE to tea seed oil can control its unpleasant odor, with scores all higher than the model group (4.13 points). At a high temperature of 50℃, adding 0.01wt%-0.05wt%α-tocopherol, 0.03wt%α-tocopherol+0.01wt%CA, and 0.05wt%-0.1wt%CE to tea seed oil can control its unpleasant odor, with scores all higher than the model group (4.22 points).

[0058] In summary, preferably, from the perspective of the total sensory score, 0.03wt%-0.05wt% α-tocopherol, 0.03wt% α-tocopherol + 0.01wt% CA and 0.05wt%-0.5wt% CE have higher scores than the model group, and are the optimal options for controlling odor.

[0059] 1.7 Sensory evaluation of skincare formulas containing tea seed oil The tea seed oil samples prepared according to the formulation and preparation method in Table 6 below were added with 0.03wt%-0.05wt% α-tocopherol, 0.03wt% α-tocopherol + 0.01wt% CA and 0.05wt%-0.5wt% CE, and the model group tea seed oil sample without any added reagents. After 3 months of accelerated testing at 50℃, the degree of oiliness was evaluated.

[0060]

[0061] The tea seed oil containing 0.03wt%-0.05wt% α-tocopherol, 0.03wt% α-tocopherol + 0.01wt% CA, and 0.05wt%-0.5wt% CE maintained a stable odor, without any rancid smell, consistent with the initial odor results. However, the formulation containing the tea seed oil sample from the model group exhibited a noticeable rancid smell, which was unpleasant. Therefore, the addition of the tea seed oil disclosed in this invention can significantly suppress the rancid smell of tea seed oil and increase its potential for inclusion in cosmetics.

[0062] It should be understood that the Detailed Description section, not the Summary of the Invention section and the Abstract of the Specification section, is intended to interpret the claims. The Summary of the Invention section and the Abstract of the Specification section may provide one or more, but not all, exemplary embodiments of the invention conceived by the inventors, and are therefore not intended to limit the invention and the appended claims in any way.

Claims

1. A method for controlling the rancidity of tea seed oil, characterized in that, The method includes the following steps: adding one or more of α-tocopherol, 2-hydroxypropane-1,2,3-tricarboxylic acid, or freeze-dried tea extract powder to tea seed oil.

2. The method as described in claim 1, characterized in that, Based on the weight of tea seed oil, the α-tocopherol is at least 0.025 wt%, the 2-hydroxypropane-1,2,3-tricarboxylic acid is at least 0.005 wt%, and the freeze-dried tea extract powder is at least 0.005 wt%.

3. The method as described in claim 2, characterized in that, The α-tocopherol is 0.02-0.055 wt%, 2-hydroxypropane-1,2,3-tricarboxylic acid is 0.005-0.02 wt%, and the lyophilized tea extract powder is 0.045-0.55 wt%.

4. The method as described in claim 1, characterized in that, The tea seed oil contains any one of the following components: α-tocopherol 0.03-0.05 wt% or α-tocopherol 0.02-0.04 wt% + 2-hydroxypropane-1,2,3-tricarboxylic acid 0.005-0.015 wt% or tea extract freeze-dried powder 0.045%-0.55 wt%.

5. The method according to any one of claims 1-3, characterized in that, The preparation of the tea seed oil includes the following steps: 1) Collect tea seeds, dry them in the sun, and remove impurities to obtain dried tea seeds; 2) The dried tea seeds are mechanically dehulled and crushed, steamed at 50℃-60℃ for 30-60 minutes, then pressed, and centrifuged at 1000-3000 rpm to obtain crude tea seed oil. 3) Refining: Wash the crude tea seed oil with hot water, then vacuum deodorize for 1-2 hours, crystallize for 24-48 hours, add silica gel to decolorize and remove impurities, filter and take the supernatant oil, which is the finished tea seed oil. The content of hexanal in the tea seed oil is less than 10mg / Kg and the content of nonanal is less than 3mg / Kg.

6. The method according to any one of claims 1-4, characterized in that, The freeze-dried tea extract powder is prepared by the following steps: green tea leaves are taken, naturally dried, and impurities are removed; water is added at a mass ratio of 1:20-1:50, and extracted at 75-95℃ for 1-3 hours; after centrifugation, the filtrate is filtered and concentrated by reverse osmosis to 30%-50% of the original liquid volume; and then freeze-dried for 48-72 hours to obtain the freeze-dried tea extract powder, wherein the tea polyphenol content of the obtained freeze-dried tea extract powder is above 25%.

7. A type of tea seed oil, characterized in that, The tea seed oil contains an appropriate amount of one or more of the following components: α-tocopherol, 2-hydroxypropane-1,2,3-tricarboxylic acid, and freeze-dried tea extract powder.

8. The tea seed oil as described in claim 7, characterized in that: The α-tocopherol is 0.02-0.055 wt%, 2-hydroxypropane-1,2,3-tricarboxylic acid is 0.005-0.02 wt%, and the lyophilized tea extract powder is 0.045-0.55 wt%.

9. At least one of the following products containing camellia seed oil, characterized in that, Camellia seed oil containing the controlled rancidity flavor as described in any one of claims 7-8: (1) Additives; (2) Cosmetics; (3) Health products; (4) Food; (5) Medicines.

10. The application of tea seed oil as described in any one of claims 7-8, characterized in that, Used to prepare the following products: (1) Additives; (2) Cosmetics; (3) Health products; (4) Food; (5) Medicines.

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