A kind of processing method of strong-flavor tea seed oil

Abstract

The present application discloses a method for processing strong-flavor tea seed oil, which belongs to the technical field of edible oil processing. It includes: pretreatment of raw materials, obtaining tea seed kernel powder, obtaining freeze-dried powder of oil camellia and ethanol aqueous solution extract of oil camellia; using two mixed formulas, each mixed formula is respectively rolled, steamed, fried, and filtered by sedimentation, and then the obtained tea seed oil I and tea seed oil II are mixed in a certain proportion range to obtain the strong-flavor tea seed oil provided by the present invention. The preparation method of the tea seed oil is simple and easy to operate. The strong-flavor tea seed oil obtained by the processing method can ensure a high polyphenol content and reduce the content of polycyclic aromatic hydrocarbons, so as to solve the contradiction that the existing processing methods cannot simultaneously meet the high polyphenol content and low polycyclic aromatic hydrocarbon content.

Description

Technical Field

[0001] The invention belongs to the technical field of edible oil processing, and specifically relates to a method for processing strong-flavor tea seed oil, and in particular to a method for processing strong-flavor tea seed oil by inhibiting polycyclic aromatic hydrocarbons through polyphenols. Background Art

[0002] Camellia oleifera is a woody oil plant unique to my country. It is known as one of the "four major woody oil plants in the world" along with olive, coconut and oil palm. It is also known as one of the "four major woody oil plants in my country" along with tung, Chinese tallow tree and walnut. Camellia oleifera seeds consist of kernels and shells. The oil content of the whole seed is 25% to 40%. The oil is mainly concentrated in the kernel, and the shell contains very little oil, only about 0.5%. The oil extracted from camellia oleifera seeds is called camellia oleifera oil. Camellia oleifera oil contains four main fatty acids: palmitic acid, stearic acid, oleic acid and linoleic acid. Its fatty acid composition and physiological activity are extremely similar to those of olive oil, and it is known as the "Chinese olive oil".

[0003] The fragrant tea seed oil prepared by hot pressing has both unique flavor and high nutritional value. Studies have found that higher hot pressing temperatures give tea seed oil a unique flavor. However, the content of benzo[α]pyrene in hot pressed tea seed oil is relatively high, exceeding the limit value (10μg / kg) of the national standard GB2762-2017, and as the temperature increases, the accumulated benzo[α]pyrene content in the oil further increases. The unique flavor of fragrant tea seed oil depends on higher hot pressing temperatures, but higher temperatures lead to the enrichment of polycyclic aromatic hydrocarbons such as benzo[α]pyrene, leading to food safety risks. Therefore, in the context of high-temperature hot pressing to produce tea seed oil, it is urgent to find a processing method for fragrant tea seed oil that inhibits polycyclic aromatic hydrocarbons. Summary of the invention

[0004] According to the present invention, a method for processing strong-flavor tea seed oil by inhibiting polycyclic aromatic hydrocarbons through polyphenols is provided. The preparation method of the tea seed oil is simple and easy to operate. The strong-flavor tea seed oil obtained by the processing method can ensure a high polyphenol content and reduce the content of polycyclic aromatic hydrocarbons, so as to solve the contradiction that the existing processing methods cannot simultaneously meet the requirements of high polyphenol content and low polycyclic aromatic hydrocarbon content.

[0005] The purpose of this section is to provide a method for processing strong-flavor tea seed oil by inhibiting polycyclic aromatic hydrocarbons through polyphenols and to briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and title of the present application to avoid blurring the purpose of this section, the abstract and the title of the invention, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0006] In view of the above-mentioned related technologies, there are problems of polyphenol loss and excessive polycyclic aromatic hydrocarbons in the process of high-temperature hot pressing to produce tea seed oil, the present invention provides a method for processing rich-flavor tea seed oil, and the specific technical scheme is as follows:

[0007] Raw material pretreatment: Select high-quality tea seeds, dry and shell them to obtain tea seed kernels and tea seed shells;

[0008] Obtaining tea seed kernel powder: crushing the tea seed kernel to obtain tea seed kernel powder;

[0009] Obtaining Camellia oleifera freeze-dried powder and Camellia oleifera ethanol aqueous solution extract;

[0010] Mixing formula 1: The tea seed kernel powder, the tea seed shell, and the freeze-dried camellia oleifera powder are mixed evenly according to the mass percentages of 88% to 90%, 9% to 11%, and 1% to 3%, respectively, to obtain a mixture I;

[0011] When the proportion of tea seed shells is too low, it is difficult to establish pressing pressure in the press chamber during the pressing process, that is, the elasticity is low, the intermediate deformation stage of elastic-plastic deformation of the pressed material is shorter, the effective oil output time is reduced, and thus the oil output rate is low; when the proportion of tea seed shells is too high, the oil circuit is easily blocked, which also leads to a low oil output rate.

[0012] When the proportion of Camellia oleifera freeze-dried powder is too low, the total amount of polyphenols in the embryo is too low, and a satisfactory PAH inhibition effect cannot be obtained; when the proportion of Camellia oleifera freeze-dried powder is too high, the oil path is easily blocked, resulting in a low oil yield.

[0013] First flaking: flaking the mixture I until the surface is uniform and oil-free, and the obtained flaking A is about 0.4-0.6 mm thick;

[0014] After the material embryo A is steamed and fried for the first time, it is pressed for the first time to obtain the first pressed oil;

[0015] First sedimentation and filtration: the first pressed oil is allowed to settle at a temperature of 10°C to 20°C, and filtered to obtain tea seed oil I;

[0016] Mixing formula II: mixing the tea seed kernel powder and the tea seed shell, and then evenly spraying the extract, the spraying amount being 1 to 5% of the total mass of the tea seed kernel powder and the tea seed shell, to obtain mixture II;

[0017] When the amount of the extract sprayed is too low, the polyphenol content is insufficient and a satisfactory PAH inhibition effect cannot be obtained; when the amount of the extract sprayed is too high, the original moisture content of the material will be destroyed, resulting in poor plasticity of the subsequent embryo and low oil yield.

[0018] In some optional embodiments, in the second mixing formula, the mass percentages of the tea seed kernel powder and the tea seed shell are 88% to 92% and 8% to 12%, respectively.

[0019] When the proportion of tea seed shells is too low, it is difficult to establish pressing pressure in the press chamber during the pressing process, that is, the elasticity is low, the intermediate deformation stage of elastic-plastic deformation of the pressed material is shorter, the effective oil output time is reduced, and thus the oil output rate is low; when the proportion of tea seed shells is too high, the oil circuit is easily blocked, which also leads to a low oil output rate.

[0020] Second flaking: flaking the mixture II until the surface is uniform and oil-free, and the obtained flaking material B is about 0.3-0.5 mm thick;

[0021] After the material embryo B is steamed and fried for the second time, it is pressed for the second time to obtain the second pressed oil;

[0022] Second sedimentation and filtration: the second pressed oil is allowed to settle at a temperature of 10°C to 20°C, and filtered to obtain tea seed oil II;

[0023] Blending in proportion: mixing the tea seed oil I and the tea seed oil II to obtain a strong-flavored tea seed oil.

[0024] In some optional embodiments, the high-quality tea seeds can be selected from fresh tea seeds of the season, and the sundries such as stones and debris, as well as bad seeds such as broken, moldy, and smelly seeds can be removed manually or by screening machines.

[0025] In some optional embodiments, the drying conditions are: setting the drying temperature to 55°C to 65°C, the drying time to 18 to 20 hours, starting continuous dehumidification 3 hours after the program starts, maintaining the air humidity in the dryer at 20% to 40%, and obtaining tea seeds with a moisture content of 9% to 13%.

[0026] The dried tea seeds are shelled, and then the tea seed shells are blown out and separated by wind to obtain tea seed kernels and tea seed shells.

[0027] In some optional embodiments, the Camellia oleifera freeze-dried powder is obtained by selecting Camellia oleifera varieties with red flowers and large fruits that are in full bloom from October to November, freeze-drying, crushing into powder, and sealing and refrigerating for later use.

[0028] The red-flowered and large-fruited Camellia oleifera variety, which blooms most in October and November, was chosen because the polyphenol content in the material is highest at this time.

[0029] Freeze-drying is chosen because there is a time difference between the flowering of tea trees and the pressing of tea seeds. After cold pressing and drying, it is easier to preserve and can be used all year round.

[0030] In some optional embodiments, obtaining an ethanol-water extract of Camellia oleifera comprises: soaking the Camellia oleifera freeze-dried powder in an ethanol-water solution having a volume fraction of 40% to 50% at a solid-liquid ratio of 1:30 g / mL to 1:40 g / mL; after soaking for 12 to 24 hours, filtering out the solid residue, and refrigerating the extract for later use.

[0031] In some optional embodiments, due to the additional addition of Camellia oleifera freeze-dried powder to the embryo A, the first steaming and frying temperature is re-optimized to 130°C to 150°C and the steaming and frying time is 40 to 60 min according to the oil yield and the polyphenol and polycyclic aromatic hydrocarbon contents of the obtained oil.

[0032] When the steaming and frying temperature is too low, the tea seed cells are not fully destroyed, the protein denaturation degree is low, and the oil cannot be fully condensed, resulting in a low oil yield. At the same time, too low a temperature will also make the aroma of the produced oil not strong. When the steaming and frying temperature is too high, the embryo is easy to coke, the cake is difficult to shape, and the oil path is blocked, resulting in a low oil yield. At the same time, too high a temperature will also lead to the generation and accumulation of excessive polycyclic aromatic hydrocarbons.

[0033] When the steaming and frying time is too short, the steaming and frying is not sufficient, the protein denaturation is insufficient, the elasticity and plasticity of the tea seeds are poor, resulting in a low oil yield; when the steaming and frying time is too long, the steaming and frying is excessive, the embryo produces more powder during the pressing process, and the cake is easy to collapse when the pressure is high, which also leads to a low oil yield. In addition, the appropriate steaming and frying time will also affect the rich flavor of tea seed oil.

[0034] In some optional embodiments, the pressure of the first pressing is 7-9 MPa.

[0035] When the pressing pressure is too low, the oil cannot be squeezed for the first time, resulting in a low oil yield; when the pressing pressure is too high, the tea seed cake collapses and cracks, causing the cake powder to mix with the oil, which also leads to a low oil yield.

[0036] In some optional embodiments, the first sedimentation filtration is to stand the first pressed oil at a temperature of 10°C to 20°C for 3 days. The filtration can remove a large amount of phospholipids and waxes to obtain a clear and more stable tea seed oil I. Tea seed oil I has the characteristics of rich aroma, low polycyclic aromatic hydrocarbon content but low polyphenol content.

[0037] In some optional embodiments, since the embryo material is additionally sprayed with camellia oleifera extract, the second steaming and frying temperature is re-optimized to 120°C to 140°C and the steaming and frying time is 40 to 60 min according to the oil yield and the polyphenol and polycyclic aromatic hydrocarbon contents of the obtained oil.

[0038] Compared with steaming and frying parameter one, the steaming and frying temperature is set lower and the steaming and frying time is longer. This is because after the extract is sprayed, the polyphenol content of the embryo is relatively high and the moisture content is easy to adjust, which can ensure a higher oil yield and retain richer polyphenols.

[0039] In some optional embodiments, the pressure of the second pressing is 8-10 MPa.

[0040] Compared with the pressure of the first pressing, the pressing pressure set for the second pressing is higher. Under this formula, the oil path is smoother. In the absence of Camellia oleifera freeze-dried powder interfering with the oil output, a higher oil yield can be obtained by increasing the pressing pressure.

[0041] In some optional embodiments, the first sedimentation filtration is to let the first pressed oil stand for 3 days at a temperature of 10°C to 20°C. Filtration can remove a large amount of phospholipids and waxes to obtain a clear and more stable tea seed oil I. In view of the fact that a large amount of Camellia oleifera freeze-dried powder in the embryo will interfere with the normal patency of the oil path, the comprehensive oil yield of this method is low. The tea seed oil I has the characteristics of low polycyclic aromatic hydrocarbon content, low polyphenol content, low oil yield, and strong aroma.

[0042] In some optional embodiments, the second sedimentation filtration is to stand the second pressed oil at a temperature of 10°C to 20°C for 3 days, and the filtration can remove a large amount of phospholipids and waxes to obtain a clear and more stable tea seed oil II. The tea seed oil II has the characteristics of low polycyclic aromatic hydrocarbon content, high polyphenol content, high oil yield, and light fragrance.

[0043] In some optional embodiments, the blending is carried out in proportion, wherein the mass proportion of the tea seed oil I is 20% to 80%, and after mixing, a strong-flavor tea seed oil with low polycyclic aromatic hydrocarbons content and high polyphenol content is obtained. This tea seed oil has the advantages of both tea seed oil I and tea seed oil II, and has better storage stability than ordinary strong-flavor tea seed oil.

[0044] If the proportion of tea seed oil I is too low, the final oil will not have a strong aroma; if the proportion of tea seed oil I is too high, the polyphenol content contained in the final oil will be insufficient, and considering the actual situation of low oil yield of this line, the factory processing cost will be too high.

[0045] The present invention has at least the following beneficial effects: the processing method provided by the present invention comprehensively considers four factors in the processing of tea seed oil: polyphenols, polycyclic aromatic hydrocarbons, strong-flavor flavor, and oil yield. The present invention improves the traditional hot pressing method, innovatively adds freeze-dried powder of Camellia oleifera or sprays the extract, obtains two tea seed oils with different characteristics, and after mixing, the tea seed oil has both strong-flavor flavor and high content of polyphenols, and the content of polycyclic aromatic hydrocarbons does not exceed the standard. This is achieved by setting a high-concentration polyphenol to act on the key section of high-temperature pressing of oil and fat, and using the principle of high-concentration polyphenol to reduce free radicals and inhibit polycyclic aromatic hydrocarbons. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0047] Figure 1 The present invention is a simplified flow chart of a method for processing strong-flavor tea seed oil by inhibiting polycyclic aromatic hydrocarbons through polyphenols. DETAILED DESCRIPTION

[0048] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with specific embodiments.

[0049] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0050] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0051] Example 1: Obtaining tea seed kernel powder and tea seed shell

[0052] like Figure 1 As shown, the tea seed raw material is pre-treated, including seed selection, impurity removal, etc., and then dried at 55°C to 65°C, shelled, to obtain tea seed kernels and tea seed shells, and then subjected to a crushing process to obtain tea seed kernel powder with a mesh size of 10 to 20 meshes.

[0053] Tea seed kernels are crushed into powder to increase the surface area, promote temperature and moisture transfer, and maintain smooth oil passages. If the tea seed kernel powder is too fine, it will easily cause adhesion and block the oil passage; if it is too coarse, uneven moisture or temperature distribution will also block the oil passage.

[0054] Example 2

[0055] Camellia oleifera of the red-flowered and large-fruited variety that blooms most in October to November is freeze-dried and ground into powder to obtain Camellia oleifera freeze-dried powder, which is then sealed and refrigerated for later use.

[0056] The Camellia oleifera freeze-dried powder was soaked in a 40% ethanol aqueous solution at a solid-liquid ratio of 1:30 g / mL. After soaking for 24 hours, the solid residue was filtered out and the extract was refrigerated for later use.

[0057] Example 3

[0058] The Camellia oleifera freeze-dried powder in Example 2 was soaked in a 50% by volume ethanol aqueous solution at a solid-liquid ratio of 1:40 g / mL. After soaking for 24 hours, the solid residue was filtered out to obtain an extract that was refrigerated for later use.

[0059] Example 4 Preparation of tea seed oil I

[0060] Example 4.1

[0061] Route 1: According to mixing formula 1, tea seed kernel powder, tea seed shell, and freeze-dried camellia oleifera powder obtained in Example 2 are uniformly mixed in mass proportions of 89%, 9%, and 2%, respectively. The mixture I prepared above is rolled into embryos until the surface is uniform and no oil is exposed. The embryos are steamed for the first time at a steaming temperature of 130 to 150° C. for 30 to 50 min. Then, the first pressing is performed at a pressure of 7 MPa at 20° C. After the first sedimentation and filtration, tea seed oil I is obtained.

[0062] Example 4.2

[0063] Route 1: According to the mixing formula 1, tea seed kernel powder, tea seed shell and the freeze-dried powder of Camellia oleifera obtained in Example 2 are uniformly mixed, and the mass proportions thereof are 88%, 11% and 1%, respectively. The mixture I prepared above is rolled into embryos until the surface is uniform and no oil is exposed. The embryos are steamed for the first time at a steaming temperature of 130 to 150° C. for 30 to 50 min. Then, the first pressing is performed at a pressure of 9 MPa. After the first sedimentation and filtration at 10° C., tea seed oil I is obtained.

[0064] Example 4.3

[0065] Route 1, according to mixing formula 1, tea seed kernel powder, tea seed shell, and the freeze-dried powder of Camellia oleifera obtained in Example 2 are uniformly mixed, and the mass proportions thereof are 88%, 11%, and 1%, respectively. The mixture I prepared above is rolled into embryos until the surface is uniform and no oil is exposed. The embryos are steamed for the first time at a steaming temperature of 100 to 110° C. for 70 to 90 min. Then, the first pressing is performed at a pressure of 9 MPa. After the first sedimentation and filtration at 10° C., tea seed oil I is obtained.

[0066] According to "GB 5009.265-2021 Determination of Polycyclic Aromatic Hydrocarbons in Food", the content of polycyclic aromatic hydrocarbon benzo[a]pyrene is determined.

[0067] According to “LS / T 6119-2017 Grain and Oil Inspection-Determination of Polyphenols in Vegetable Oils-Spectrophotometric Method”, the content of polyphenols was determined.

[0068] According to "Han Xiaomiao, Wu Suxi, Wu Meifang, Liu Qiong. Analysis of volatile flavor components of tea seed oil produced by different processes [J]. China Oils and Fats, 2018, 43(01): 39-42.", the flavor substances were determined based on the headspace gas chromatography-mass spectrometry method.

[0069] According to GB / T 14488.1-2008 Determination of Oil Content of Vegetable Oils, the oil content of the residual cake after pressing is determined.

[0070] The tea seed oil I obtained in Example 4.1 and Example 4.2 has the characteristics of low polycyclic aromatic hydrocarbons content (benzo[a]pyrene content 4μg / kg), low polyphenol content (5mg / g), strong aroma (octanal and hexanal content higher than 25%, sensory evaluation), and low oil yield (cake residual oil rate 12%). The low polycyclic aromatic hydrocarbons are given by the inhibitory effect of polyphenols after the addition of camellia oleifera freeze-dried powder to the embryo, the low polyphenol content and strong aroma are caused by the higher hot pressing temperature, and the low oil yield is caused by the partial blocking of the oil path by the camellia oleifera freeze-dried powder; while the tea seed oil I obtained in Example 4.3 has the characteristics of low polycyclic aromatic hydrocarbons content (benzo[a]pyrene content 5μg / kg), low polyphenol content (6mg / g), light aroma (octanal and hexanal content less than 10%, sensory evaluation), and low oil yield (cake residual oil rate 14%). The lower heat treatment temperature leads to insufficient Maillard reaction and insufficient concentration of generated aroma substances.

[0071] Example 5 Preparation of tea seed oil II

[0072] Example 5.1

[0073] Route 2, according to the mixing formula 2, tea seed kernel powder and tea seed shell are uniformly mixed, and the mass ratios thereof are 90% and 10%, respectively, and then the ethanol aqueous solution extract of the oil camellia in Example 2 or Example 3 is uniformly sprayed, and the spraying amount is 1% of the total mass of the tea seed kernel powder and the tea seed shell, to obtain a mixture II. After the mixture II prepared above is rolled, it is steamed and fried for the second time, and the steaming and frying temperature is 120-140°C, and the steaming and frying time is 40-60min, and then it is pressed for the second time, and the pressure is set to 10MPa. After the second sedimentation and filtration, tea seed oil II is obtained.

[0074] Example 5.2

[0075] Route 2, according to the mixing formula 2, tea seed kernel powder and tea seed shell are uniformly mixed, and the mass ratios are 92% and 8%, respectively, and then the ethanol aqueous solution extract of the oil camellia in Example 2 or Example 3 is uniformly sprayed, and the spraying amount is 0.9% of the total mass of the tea seed kernel powder and the tea seed shell to obtain a mixture II. After the mixture II prepared above is rolled, it is steamed for the second time, and the steaming temperature is 120-140°C, and the steaming time is 40-60min, followed by a second pressing, and the pressure is set to 10MPa. After the second sedimentation and filtration, tea seed oil II is obtained.

[0076] Example 5.3

[0077] Route 2, according to the mixing formula 2, tea seed kernel powder and tea seed shell are uniformly mixed, and the mass ratios are 88% and 12% respectively, and then the ethanol aqueous solution extract of the oil camellia in Example 2 or Example 3 is uniformly sprayed, and the spraying amount is 5% of the total mass of the tea seed kernel powder and the tea seed shell to obtain a mixture II. After the mixture II prepared above is rolled, it is steamed for the second time, and the steaming temperature is 120-140°C, and the steaming time is 40-60min, followed by a second pressing, and the pressure is set to 10MPa. After the second sedimentation and filtration, tea seed oil II is obtained.

[0078] Example 5.4

[0079] Route 2, according to the mixing formula 2, tea seed kernel powder and tea seed shell are uniformly mixed, and the mass ratios are 98% and 2%, respectively, and then the ethanol aqueous solution extract of the oil camellia in Example 2 or Example 3 is uniformly sprayed, and the spraying amount is 5% of the total mass of the tea seed kernel powder and the tea seed shell to obtain a mixture II. After the mixture II prepared above is rolled, it is steamed for the second time, and the steaming temperature is 120-140°C, and the steaming time is 40-60min, followed by a second pressing, and the pressure is set to 10MPa. After the second sedimentation and filtration, tea seed oil II is obtained.

[0080] Example 5.5

[0081] Route 2, according to the mixing formula 2, tea seed kernel powder and tea seed shell are uniformly mixed, and the mass ratios are 80% and 20%, respectively, and then the ethanol aqueous solution extract of the oil camellia in Example 2 or Example 3 is uniformly sprayed, and the spraying amount is 5% of the total mass of the tea seed kernel powder and the tea seed shell to obtain a mixture II. After the mixture II prepared above is rolled, it is steamed for the second time, and the steaming temperature is 120-140°C, and the steaming time is 40-60min, followed by a second pressing, and the pressure is set to 10MPa. After the second sedimentation and filtration, tea seed oil II is obtained.

[0082] The tea seed oil II obtained in Example 5.2 cannot obtain a satisfactory PAH inhibition effect because the amount of extract sprayed is too low and the polyphenol content is insufficient. The amount of tea seed oil II obtained in Example 5.4 is less than that obtained in Example 5.1 and Example 5.3. This is because the proportion of tea seed shells is too low, and it is difficult for the pressing chamber to establish pressing pressure during the pressing process, that is, the elasticity is low, and the intermediate deformation stage of elastic-plastic deformation of the pressed material is short, and the effective oil output time is reduced, so the oil output rate is low. The amount of tea seed oil II obtained in Example 5.5 is also less than that obtained in Example 5.1 and Example 5.3. This is because when the proportion of tea seed shells is too high, it is easy to block the oil circuit, which also leads to a low oil output rate.

[0083] The tea seed oil II obtained in Example 5 has the characteristics of low polycyclic aromatic hydrocarbon content (benzo[a]pyrene content 5 μg / kg), high polyphenol content (23 mg / g) but insufficient rich flavor (octanal and hexanal content less than 8%, sensory evaluation).

[0084] Example 6 Preparation of Luzhou-flavor Tea Seed Oil

[0085] Example 6.1

[0086] The tea seed oil I obtained in Example 4.1 and the tea seed oil II obtained in Example 5.1 were mixed in a proportion such that the mass proportion of the tea seed oil I was 20%, and a strong-flavored tea seed oil was obtained after mixing.

[0087] Example 6.2

[0088] The tea seed oil I obtained in Example 4.2 and the tea seed oil II obtained in Example 5.3 were mixed in a proportion such that the mass proportion of the tea seed oil I was 50%, and a strong-flavored tea seed oil was obtained after mixing.

[0089] Example 6.3

[0090] The tea seed oil I obtained in Example 4.1 and the tea seed oil II obtained in Example 5.3 were mixed in a proportion such that the mass proportion of the tea seed oil I was 80%, and a strong-flavored tea seed oil was obtained after mixing.

[0091] Example 6.4

[0092] The tea seed oil I obtained in Example 4.2 and the tea seed oil II obtained in Example 5.3 were mixed in proportion, with the mass proportion of tea seed oil I being 95%, and a strong-flavored tea seed oil was obtained after mixing.

[0093] Example 6.5

[0094] The tea seed oil I obtained in Example 4.2 and the tea seed oil II obtained in Example 5.3 were mixed in a proportion such that the mass proportion of the tea seed oil I was 5%, and a strong-flavored tea seed oil was obtained after mixing.

[0095] Examples 6.1 to 6.3 obtain tea seed oil with low polycyclic aromatic hydrocarbon content (benzo[a]pyrene content <8μg / kg), high polyphenol content (>15mg / g), and sufficient strong aroma (octanal and hexanal content greater than 15%, sensory evaluation). This tea seed oil has the advantages of both tea seed oil I and tea seed oil II, and its nutritional value and storage stability are better than ordinary strong-flavor tea seed oil. Example 6.4, the proportion of tea seed oil I is too high, and the freeze-dried powder of Camellia oleifera in the embryo hinders the smooth oil path of the pressing process, resulting in too low oil yield and too high processing cost. Example 6.5, the proportion of tea seed oil I is too low, resulting in insufficient strong aroma flavor.

[0096] It should be noted that the above embodiments are only used to illustrate the technical solution of polycyclic aromatic hydrocarbons content of the present invention and are not intended to be limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for processing fragrant tea seed oil, characterized in that: include: Raw material pretreatment: Select high-quality tea seeds, dry and shell them to obtain tea seed kernels and tea seed shells; Obtaining tea seed kernel powder: crushing the tea seed kernel to obtain tea seed kernel powder; Obtaining Camellia oleifera freeze-dried powder and Camellia oleifera ethanol aqueous solution extract; wherein obtaining the Camellia oleifera ethanol aqueous solution extract comprises: soaking the Camellia oleifera freeze-dried powder in an ethanol aqueous solution with a volume fraction of 40% to 50% at a solid-liquid ratio of 1:30 g / mL to 1:40 g / mL, soaking for 12 to 24 hours, filtering out solid residues, and refrigerating the extract for standby use; Mixing formula 1: The tea seed kernel powder, the tea seed shell, and the Camellia oleifera freeze-dried powder are mixed evenly according to the mass percentages of 88% to 90%, 9% to 11%, and 1% to 3%, respectively, to obtain a mixture I; First flaking: flaking the mixture I until the surface is uniform and oil-free, and the flaking material A is obtained with a thickness of 0.4-0.6 mm; After the material embryo A is steamed and fried for the first time, it is pressed for the first time to obtain the first pressed oil; First sedimentation and filtration: the first pressed oil is allowed to settle, and filtered to obtain tea seed oil I; Mixing formula II: mixing the tea seed kernel powder and the tea seed shell, and then evenly spraying the extract, the spraying amount being 1-5% of the total mass of the tea seed kernel powder and the tea seed shell, to obtain mixture II; Second flaking: flaking the mixture II until the surface is uniform and oil-free, and the flaking material B is 0.3-0.5 mm thin; After the material embryo B is steamed and fried for the second time, it is pressed for the second time to obtain the second pressed oil; Second sedimentation and filtration: the second pressed oil is allowed to settle, and filtered to obtain tea seed oil II; Blending in proportion: mixing the tea seed oil I and the tea seed oil II in proportion to obtain a strong-flavored tea seed oil.

2. The method for processing rich-flavor tea seed oil according to claim 1, characterized in that: The method for obtaining the Camellia oleifera freeze-dried powder comprises: freeze-drying the Camellia oleifera, grinding the Camellia oleifera into powder, obtaining the Camellia oleifera freeze-dried powder, and sealing and refrigerating the powder for later use.

3. The method for processing rich-flavor tea seed oil according to claim 1, characterized in that: The drying conditions are: The drying temperature of the dryer is 55°C~65°C, the drying time is 18~20 hours, and the air humidity in the dryer is maintained at 20%~40% to obtain tea seeds with a moisture content of 9%~13%.

4. The method for processing rich-flavor tea seed oil according to claim 1, characterized in that: The mesh number of the tea seed kernel powder is 10-20 meshes.

5. The method for processing rich-flavor tea seed oil according to claim 1, characterized in that: In the second mixing formula, the mass percentages of the tea seed kernel powder and the tea seed shell are 88% to 92% and 8% to 12% respectively.

6. The method for processing rich-flavor tea seed oil according to claim 1, characterized in that: The temperature of the first steaming and frying is 130° C. to 150° C., and the steaming and frying time is 30 to 50 minutes.

7. The method for processing rich-flavor tea seed oil according to claim 1, characterized in that: The pressure of the first pressing is 7-9 MPa.

8. The method for processing rich-flavor tea seed oil according to claim 1, characterized in that: The temperature of the second steaming and frying is 120° C. to 140° C., and the steaming and frying time is 40 to 60 minutes.

9. The method for processing rich-flavor tea seed oil according to claim 1, characterized in that: The pressure of the second pressing is 8-10 MPa.

10. The method for processing rich-flavor tea seed oil according to claim 1, characterized in that: The blending is carried out in proportion, wherein the mass proportion of the camellia oil I is 20% to 80%.

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