Preparation method of tilia miqueliana absolute oil

Abstract

The invention relates to the technical field of tilia flower absolute oil preparation, in particular to a tilia miqueliana absolute oil preparation method which comprises the following steps: (1) picking flowers; (2) flower optimization and drying; (3) primary ethanol soaking; (4) secondary ethanol soaking; (5) vacuum concentration; (6) wax removal and refining; according to the tilia miqueliana absolute oil manufacturing method, compared with the prior art, the oil yield and the oil yield are greatly improved, and the method is mainly achieved through the unique three-section type variable-temperature baking process adopted by the method and cooperation of all the steps.

Description

Technical Field

[0001] The invention relates to the technical field of making linden flower absolute oil, in particular to a method for making Nanjing linden flower absolute oil. Background Art

[0002] Nanjing Tilia (Tiliamiqueliana Maxim.) is a tree of the Tiliaceae family. Its flowers are not only beautiful in shape, but also emit a pleasant aroma. Nanjing Tilia flowers contain a variety of bioactive ingredients, such as flavonoids and terpenes. Both Nanjing Tilia flowers and bark can be used as medicine. Its infusion has the effects of sedation, sweating, antispasmodic and antipyretic. The stem bark contains tannins, fats, waxes and pectin, etc., which are mainly used to treat symptoms such as initial fatigue and fatigue, chronic cough, etc. In particular, the absolute oil extracted from Nanjing Tilia flowers is expected to show great application potential in high-end perfumes, skin care products and natural medicines due to its unique aroma and biological activity.

[0003] Supercritical carbon dioxide extraction is commonly used at home and abroad to extract the oil of Nanjing linden flowers. In a supercritical state, supercritical carbon dioxide is brought into contact with the substance to be separated, so that it can selectively extract components with different polarity, boiling point and molecular weight. However, supercritical carbon dioxide extraction has high requirements on environmental conditions, the operation is relatively cumbersome and the extraction cost is high; linden flowers are small and the consumption is high.

[0004] The method of the invention can obtain relatively high-yield linden flower absolute oil in a simple and low-cost manner. Summary of the invention

[0005] Aiming at the problems existing in the prior art, the present invention provides a method for preparing Nanjing linden flower absolute oil.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A method for preparing Nanjing linden flower absolute oil comprises the following steps:

[0008] (1) Flower picking: Flower picking is carried out from mid-to-late May to early June every year;

[0009] (2) High-quality flowers: Select flowers with good color and full shape from the collected flowers, and remove defective flowers; improve the quality of subsequent extracted raw materials and ensure the quality of oil-infused products;

[0010] Flower baking: Wash the selected flowers, drain the water, and then use a three-stage variable temperature baking process to bake the flowers to obtain baked flowers;

[0011] (3) Initial ethanol soaking: Take 100-120 g of roasted flowers, crush them, add 1000-1100 ml of 70% ethanol solution, and soak them in a vacuum environment for 10-12 hours;

[0012] During the soaking period, the mixture was stirred every 1 hour for 2 minutes. After the soaking, the mixture was filtered to collect the initial soaking liquid.

[0013] The stirring speed is 150r / min each time;

[0014] (4) Secondary ethanol soaking: Add 700-750 ml of 80% ethanol solution to the flower residue after the initial soaking and immersion, and soak in a water bath for 9-10 hours. During the soaking process, stir once every hour for 2 minutes each time at a stirring speed of 200 r / min. Then filter and collect the secondary soaking liquid;

[0015] Combining the primary soaking solution and the secondary soaking solution to obtain a combined soaking solution;

[0016] (5) Concentration under reduced pressure: The collected combined soaking liquid is subjected to reduced pressure distillation, and the ethanol is volatilized in a water bath at 40° C. to obtain a preliminarily concentrated extract;

[0017] (6) Waxing and refining:

[0018] Wax removal: dissolve the initially concentrated extract with anhydrous ethanol, then cool it to precipitate the wax and other impurities, remove the precipitate by filtering, and obtain a refined filtrate;

[0019] Secondary vacuum distillation: The refined filtrate is subjected to vacuum distillation again in a 40°C water bath to completely remove the ethanol and finally obtain high-purity linden flower absolute oil.

[0020] As a further technical solution: the three-stage variable temperature baking process in step (2) includes a first stage of temperature rising baking, a second stage of temperature falling baking, and a third stage of temperature rising baking.

[0021] As a further technical solution: the first stage of temperature rise and baking: after the selected Nanjing linden flowers are placed in the oven, the temperature is gradually raised from room temperature to 48-50°C at a rate of 2°C every 5 minutes, and maintained at 48-50°C for 2-2.5 hours. The slow temperature rise in this stage can avoid damage to the flowers due to sudden temperature changes. At the same time, the temperature of 48-50°C can cause some of the water in the flowers to begin to evaporate, laying the foundation for the subsequent drying process.

[0022] As a further technical solution: The second stage of cooling and baking: after the first stage of heating and baking, the temperature is reduced to 40-42°C at a rate of 1°C every 5 minutes, and maintained at 40-42°C for 1-1.5 hours. Appropriate cooling can prevent the effective ingredients in the flowers from being excessively destroyed due to excessive temperature. 40-42°C can not only continue to dry the flowers, but also better retain their nutrients and aroma substances.

[0023] As a further technical solution: the third stage of temperature rise baking: after the second stage of temperature drop baking, the temperature is raised to 44-46°C at a rate of 1°C every 5 minutes, and maintained at 44-46°C for 3-4 hours. The final stage of temperature rise can further dry the flowers, ensuring that the appropriate degree of dryness is achieved, which is convenient for subsequent soaking and extraction operations. At the same time, the temperature of 44-46°C will not have a negative impact on the quality of the flowers.

[0024] As a further technical solution: the vacuum degree of the vacuum environment in step (3) is 0.1-0.2 Pa; the immersion temperature is 30-35°C.

[0025] As a further technical solution: in step (4), the water bath environment temperature is 40-42°C.

[0026] As a further technical solution: in step (6), the ratio of the initially concentrated extract to anhydrous ethanol is 1:5-6.

[0027] As a further technical solution: the cooling in step (6) is cooling to 0-3°C and keeping warm for 6 hours, so as to promote the full precipitation of wax and impurities, effectively improve the purity of linden flower absolute oil and enhance product quality.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The method for producing the Nanjing Tilia flower absolute oil of the present invention has greatly improved the oil output and oil yield rate compared with the prior art, which is mainly achieved by the unique three-stage variable temperature baking process adopted by the present invention and the coordinated cooperation between the various steps.

[0030] In the traditional method of extracting pure oil from linden flowers, the temperature is often too high or rises too fast during the baking process, and the temperature is kept constant throughout the baking process, which easily destroys or volatilizes the effective components of the oil in the flowers, resulting in a decrease in the oil content and affecting the subsequent oil extraction efficiency. The three-stage variable temperature baking process of the present invention is carried out in stages and in a targeted manner according to the characteristics of Nanjing linden flowers, which can retain the oil components in the flowers to the greatest extent and make them easier to extract, greatly improving the oil yield.

[0031] In the first stage of heating and baking, the slow heating method is crucial, which avoids damage to the flowers due to sudden temperature changes. As the temperature gradually rises, part of the water in the flowers begins to evaporate, and the cell structure gradually becomes loose, creating favorable conditions for the subsequent ethanol solution to enter the cells to dissolve the oil. At the same time, within this temperature range, the oil components will not be lost due to excessive volatilization, ensuring the effective retention of the oil in the flowers; in the second stage of cooling and baking, appropriate cooling is to prevent excessive damage to the effective ingredients in the flowers due to excessive temperature. At this relatively mild temperature, the flowers can continue to dry, and the oil components are further stabilized. More importantly, at this time, the cell structure of the flowers has been adjusted to become more conducive to the penetration of ethanol. Ethanol can enter the cells more smoothly and fully contact with the oil, thereby improving the dissolution efficiency of the oil; in the third stage of heating and baking, the heating at this stage can further dry the flowers to a suitable degree of dryness. In this process, the oil components in the flowers are more concentrated, which is convenient for subsequent soaking and extraction operations. Moreover, this temperature range will not have a negative impact on the quality of the flowers, ensuring the quality of the final pure oil.

[0032] In summary, the method for producing Nanjing Tilia flower absolute oil of the present invention significantly improves the oil output and oil yield through a three-stage variable temperature baking process and an optimized combination of each step, while also ensuring a higher quality of the absolute oil.

[0033] Instruction Manual

[0034] Figure 1 It is a bar graph of the oil yield of each group of the embodiments of the present invention and the comparative examples. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] The following are specific embodiments:

[0037] Example 1

[0038] The method for preparing Nanjing linden flower absolute oil comprises the following steps:

[0039] (1) Picking flowers

[0040] Nanjing linden flowers are collected from mid-to-late May to early June every year.

[0041] (2) Flower quality and flower baking

[0042] Select the flowers with good color and full shape from the collected flowers, and remove the defective flowers. Wash the selected flowers, drain the water, and then use the three-stage variable temperature baking process to bake the flowers to obtain baked flowers. The three-stage variable temperature baking process is as follows:

[0043] The first stage of temperature rise and baking: After the selected Nanjing linden flowers are placed in the oven, the temperature is gradually raised from room temperature to 48°C at a rate of 2°C every 5 minutes, and maintained at 48°C for 2 hours.

[0044] The second stage of baking: the temperature was lowered to 40°C at a rate of 1°C every 5 minutes and maintained at 40°C for 1 hour.

[0045] The third stage of temperature-raising baking: the temperature was raised to 44°C at a rate of 1°C every 5 minutes, and maintained at 44°C for 3 hours.

[0046] (3) Initial ethanol soaking

[0047] Take 100g of roasted flowers and crush them, add 1000ml of 70% ethanol solution, and soak them in a vacuum environment with a vacuum degree of 0.1Pa and a temperature of 30℃ for 10 hours. During the soaking period, stir once every hour at a speed of 150r / min, and each stirring time is 2min. After the soaking is completed, filter and collect the initial soaking liquid.

[0048] (4) Secondary ethanol immersion

[0049] Add 700 ml of 80% ethanol solution to the flower residue after the initial soaking and filtration, and soak in a 40°C water bath for 9 hours. During the soaking process, stir once every hour at a speed of 200 r / min, and each stirring time is 2 minutes. Then filter and collect the secondary soaking liquid. Combine the initial soaking liquid and the secondary soaking liquid to obtain a combined soaking liquid.

[0050] (5) Vacuum concentration

[0051] The collected combined soaking liquid is subjected to reduced pressure distillation, and the ethanol is volatilized in a water bath at 40° C. to obtain a preliminarily concentrated extract.

[0052] (6) Waxing and refining

[0053] Wax removal: Dissolve the initially concentrated extract with anhydrous ethanol at a solid-liquid ratio of 1:5, then cool to 0°C and keep warm for 6 hours to allow the wax and other impurities to precipitate. Remove the precipitate by filtering to obtain a refined filtrate.

[0054] Secondary vacuum distillation: The refined filtrate is subjected to vacuum distillation again in a 40°C water bath to completely remove the ethanol and finally obtain high-purity linden flower absolute oil.

[0055] Example 2

[0056] The method for preparing Nanjing linden flower absolute oil comprises the following steps:

[0057] (1) Picking flowers

[0058] Nanjing linden flowers are collected from mid-to-late May to early June every year.

[0059] (2) Flower quality and flower baking

[0060] Select the flowers with good color and full shape from the collected flowers, and remove the defective flowers. Wash the selected flowers, drain the water, and then use the three-stage variable temperature baking process to bake the flowers to obtain baked flowers. The three-stage variable temperature baking process is as follows:

[0061] The first stage of temperature rise and baking: After the selected Nanjing linden flowers are placed in the oven, the temperature is gradually raised from room temperature to 49°C at a rate of 2°C every 5 minutes, and maintained at 49°C for 2.2 hours.

[0062] The second stage of cooling and baking: the temperature was lowered to 41°C at a rate of 1°C every 5 minutes and maintained at 41°C for 1.2 hours.

[0063] The third stage of temperature-raising baking: the temperature was raised to 45°C at a rate of 1°C every 5 minutes, and maintained at 45°C for 3.2 hours.

[0064] (3) Initial ethanol soaking

[0065] Take 105g of roasted flowers and crush them, add 1020ml of 70% ethanol solution, and soak them for 10.5 hours in a vacuum environment with a vacuum degree of 0.12Pa and a temperature of 32°C. During the soaking period, stir once every hour at a speed of 150r / min, and each stirring time is 2min. After the soaking is completed, filter and collect the initial soaking liquid.

[0066] (4) Secondary ethanol immersion

[0067] Add 720 ml of 80% ethanol solution to the flower residue after the initial soaking and filtration, and soak in a 41°C water bath for 9.2 hours. During the soaking process, stir once every hour at a speed of 200 r / min, and each stirring time is 2 minutes. Then filter and collect the secondary soaking liquid. Combine the initial soaking liquid and the secondary soaking liquid to obtain a combined soaking liquid.

[0068] (5) Vacuum concentration

[0069] The collected combined soaking liquid is subjected to reduced pressure distillation, and the ethanol is volatilized in a water bath at 40° C. to obtain a preliminarily concentrated extract.

[0070] (6) Waxing and refining

[0071] Wax removal: Dissolve the initially concentrated extract with anhydrous ethanol at a solid-liquid ratio of 1:5.2, then cool to 1°C and keep warm for 6 hours to precipitate the wax and other impurities. Remove the precipitate by filtering to obtain a refined filtrate.

[0072] Secondary vacuum distillation: The refined filtrate is subjected to vacuum distillation again in a 40°C water bath to completely remove the ethanol and finally obtain high-purity linden flower absolute oil.

[0073] Example 3

[0074] The method for preparing Nanjing linden flower absolute oil comprises the following steps:

[0075] (1) Picking flowers

[0076] Nanjing linden flowers are collected from mid-to-late May to early June every year.

[0077] (2) Flower quality and flower baking

[0078] Select the flowers with good color and full shape from the collected flowers, and remove the defective flowers. Wash the selected flowers, drain the water, and then use the three-stage variable temperature baking process to bake the flowers to obtain baked flowers. The three-stage variable temperature baking process is as follows:

[0079] The first stage of temperature rise and baking: After the selected Nanjing linden flowers are placed in the oven, the temperature is gradually raised from room temperature to 49°C at a rate of 2°C every 5 minutes, and maintained at 49°C for 2.4 hours.

[0080] The second stage of cooling and baking: the temperature was lowered to 42°C at a rate of 1°C every 5 minutes and maintained at 42°C for 1.4 hours.

[0081] The third stage of temperature-raising baking: the temperature was raised to 45°C at a rate of 1°C every 5 minutes, and maintained at 45°C for 3.8 hours.

[0082] (3) Initial ethanol soaking

[0083] Take 115g of roasted flowers and crush them, add 1080ml of 70% ethanol solution, and soak them for 11.5 hours in a vacuum environment with a vacuum degree of 0.18Pa and a temperature of 34°C. During the soaking period, stir once every hour at a speed of 150r / min, and each stirring time is 2min. After the soaking is completed, filter and collect the initial soaking liquid.

[0084] (4) Secondary ethanol immersion

[0085] Add 740 ml of 80% ethanol solution to the flower residue after the initial soaking and filtration, and soak in a water bath at 41°C for 9.8 hours. During the soaking process, stir once every hour at a speed of 200 r / min, and each stirring time is 2 minutes. Then filter and collect the secondary soaking liquid. Combine the initial soaking liquid and the secondary soaking liquid to obtain a combined soaking liquid.

[0086] (5) Vacuum concentration

[0087] The collected combined soaking liquid is subjected to reduced pressure distillation, and the ethanol is volatilized in a water bath at 40° C. to obtain a preliminarily concentrated extract.

[0088] (6) Waxing and refining

[0089] Wax removal: Dissolve the initially concentrated extract with anhydrous ethanol at a solid-liquid ratio of 1:5.8, then cool to 2°C and keep warm for 6 hours to precipitate the wax and other impurities. Remove the precipitate by filtering to obtain a refined filtrate.

[0090] Secondary vacuum distillation: The refined filtrate is subjected to vacuum distillation again in a 40°C water bath to completely remove the ethanol and finally obtain high-purity linden flower absolute oil.

[0091] Example 4

[0092] The method for preparing Nanjing linden flower absolute oil comprises the following steps:

[0093] (1) Picking flowers

[0094] Nanjing linden flowers are collected from mid-to-late May to early June every year.

[0095] (2) Flower quality and flower baking

[0096] Select the flowers with good color and full shape from the collected flowers, and remove the defective flowers. Wash the selected flowers, drain the water, and then use the three-stage variable temperature baking process to bake the flowers to obtain baked flowers. The three-stage variable temperature baking process is as follows:

[0097] The first stage of temperature rise and baking: After the selected Nanjing linden flowers are placed in the oven, the temperature is gradually raised from room temperature to 50°C at a rate of 2°C every 5 minutes, and maintained at 50°C for 2.5 hours.

[0098] The second stage of cooling and baking: the temperature was lowered to 42°C at a rate of 1°C every 5 minutes and maintained at 42°C for 1.5 hours.

[0099] The third stage of temperature rise baking: the temperature was raised to 46°C at a rate of 1°C every 5 minutes and maintained at 46°C for 4 hours.

[0100] (3) Initial ethanol soaking

[0101] Take 120g of roasted flowers and crush them, add 1100ml of 70% ethanol solution, and soak them in a vacuum environment with a vacuum degree of 0.2Pa and a temperature of 35℃ for 12 hours. During the soaking period, stir once every hour at a speed of 150r / min, and each stirring time is 2min. After the soaking is completed, filter and collect the initial soaking liquid.

[0102] (4) Secondary ethanol immersion

[0103] Add 750 ml of 80% ethanol solution to the flower residue after the initial soaking and filtration, and soak it in a water bath at 42°C for 10 hours. During the soaking process, stir once every hour at a speed of 200 r / min, and each stirring time is 2 minutes. Then filter and collect the secondary soaking liquid. Combine the initial soaking liquid and the secondary soaking liquid to obtain a combined soaking liquid.

[0104] (5) Vacuum concentration

[0105] The collected combined soaking liquid is subjected to reduced pressure distillation, and the ethanol is volatilized in a water bath at 40° C. to obtain a preliminarily concentrated extract.

[0106] (6) Waxing and refining

[0107] Wax removal: Dissolve the initially concentrated extract with anhydrous ethanol at a solid-liquid ratio of 1:6, then cool to 3°C and keep warm for 6 hours to allow the wax and other impurities to precipitate. Remove the precipitate by filtering to obtain a refined filtrate.

[0108] Secondary vacuum distillation: The refined filtrate is subjected to vacuum distillation again in a 40°C water bath to completely remove the ethanol and finally obtain high-purity linden flower absolute oil.

[0109] Comparative Example 1

[0110] Based on Example 1, only the first stage of baking is performed, and the total time remains unchanged.

[0111] Comparative Example 2

[0112] Based on Example 1, only the third stage of baking is performed, and the total time remains unchanged.

[0113] Comparative Example 3

[0114] Based on Example 1, only the first and second baking stages are performed, and the original third baking time is evenly distributed to the first and second baking stages, and the total time remains unchanged.

[0115] test:

[0116] Oil production test:

[0117] According to the methods of the examples and comparative examples, Nanjing Tilia flower absolute oil was prepared, and each example and comparative example were tested 5 times in parallel. In each experiment, 500±0.1g of Nanjing Tilia flower was accurately weighed, and according to the corresponding example and comparative example methods, Tilia flower absolute oil was finally obtained. The mass of the absolute oil was accurately weighed with an electronic balance, and the average value of the 5 experimental results was taken as the oil yield of the example and comparative example;

[0118] Table 1

[0119]

[0120]

[0121] It can be seen from Table 1 that the method of the present invention can obtain a higher yield of Tilia flower absolute oil.

[0122] Oil yield test

[0123] The calculation formula for the oil yield in this test is:

[0124] Oil yield (%) = (oil yield mass ÷ raw material mass) × 100%;

[0125] Table 2

[0126] Oil yield% Example 1 0.712 Example 2 0.686 Example 3 0.732 Example 4 0.702 Comparative Example 1 0.534 Comparative Example 2 0.482 Comparative Example 3 0.596

[0127] It can be seen from Table 2 that the method of the present invention can greatly improve the oil yield of Nanjing Tilia flowers.

[0128] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all details in detail, nor do they limit the invention to only the specific embodiments described. Obviously, many modifications and changes can be made according to the content of this specification.

Claims

1. A method for preparing Nanjing linden flower absolute oil, characterized in that: The following steps are involved: (1) Flower picking: Flower picking is carried out from mid-to-late May to early June every year; (2) High-quality flowers: Select flowers with good color and full shape from the collected flowers, and remove defective flowers; Flower baking: Wash the selected flowers, drain the water, and then use a three-stage variable temperature baking process to bake the flowers to obtain baked flowers; (3) Initial ethanol soaking: Take 100-120g of roasted flowers, crush them, add 1000-1100ml of 70% ethanol solution, and soak them in a vacuum environment for 10-12 hours; During the soaking period, the mixture was stirred every 1 hour for 2 minutes. After the soaking, the mixture was filtered to collect the initial soaking liquid. The stirring speed is 150r / min each time; (4) Secondary ethanol soaking: Add 700-750 ml of 80% ethanol solution to the flower residue after the initial soaking and filtration, and soak it in a water bath for 9-10 hours. During the soaking process, stir once every hour for 2 minutes each time at a stirring speed of 200 r / min. Then filter and collect the secondary soaking liquid; Combining the primary soaking solution and the secondary soaking solution to obtain a combined soaking solution; (5) Concentration under reduced pressure: The collected combined soaking liquid is subjected to reduced pressure distillation, and the ethanol is evaporated in a water bath at 40°C to obtain a preliminarily concentrated extract; (6) Waxing and refining: Wax removal: dissolve the initially concentrated extract with anhydrous ethanol, then cool it to precipitate the wax and other impurities, remove the precipitate by filtering, and obtain a refined filtrate; Secondary vacuum distillation: The refined filtrate is subjected to vacuum distillation again in a 40°C water bath to completely remove the ethanol and finally obtain high-purity linden flower absolute oil.

2. The method for preparing Nanjing Tilia flower absolute according to claim 1, characterized in that: The three-stage variable temperature baking process in step (2) includes a first stage of temperature rising baking, a second stage of temperature falling baking, and a third stage of temperature rising baking.

3. The method for producing Nanjing Tilia flower absolute according to claim 2, characterized in that: for: The first stage of heating and baking: After the selected Nanjing linden flowers are placed in the oven, the temperature is gradually increased from room temperature to 48-50°C at a rate of 2°C every 5 minutes, and maintained at 48-50°C for 2-2.5 hours.

4. The method for preparing Nanjing Tilia flower absolute according to claim 2, characterized in that: The second stage of temperature reduction baking: after the first stage of temperature increase baking, the temperature is reduced to 40-42° C. at a rate of 1° C. every 5 minutes, and maintained at 40-42° C. for 1-1.5 hours.

5. The method for producing Nanjing Tilia flower absolute according to claim 2, characterized in that: The third stage of temperature rise baking: after the second stage of temperature drop baking, the temperature is raised to 44-46°C at a rate of 1°C every 5 minutes, and maintained at 44-46°C for 3-4 hours.

6. The method for preparing Nanjing Tilia flower absolute according to claim 1, characterized in that: The vacuum degree of the vacuum environment in step (3) is 0.1-0.2 Pa; and the immersion temperature is 30-35°C.

7. The method for preparing Nanjing Tilia flower absolute according to claim 1, characterized in that: In step (4), the water bath environment temperature is 40-42°C.

8. The method for producing Nanjing Tilia flower absolute according to claim 1, characterized in that: In step (6), the ratio of the initially concentrated extract to anhydrous ethanol is 1:5-6.

9. The method for preparing Nanjing Tilia flower absolute according to claim 1, characterized in that: The cooling in step (6) is cooling to 0-3°C and keeping warm for 6 hours.

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