Process for preparing colorless camellia oil by silica gel chromatography

Abstract

The invention relates to the field of camellia oil high-valued processing technology and application, in particular to a technology for preparing colorless camellia oil through silica gel chromatography. The method is characterized in that different silica gel adsorbents and activated carbon are pre-treated and then construct a chromatographic column according to a specific combination, so that the aim of preparing the colorless camellia oil for cosmetics from cold-pressed camellia oil, degummed and deacidified camellia oil, refined camellia oil or edible camellia oil in one step at normal temperature is fulfilled. The method effectively avoids the technical defects of high temperature and repeated physical adsorption decolorization in the traditional process, and has the advantages of safe and environment-friendly raw materials, simple process flow, obviously reduced energy consumption and high preparation efficiency; the pigment components are removed by adsorption chromatography, the quality of the cosmetic-grade colorless camellia oil is achieved, a novel preparation path of the colorless camellia oil is opened up, and a technical support can be provided for high-quality development of the camellia oil industry.

Description

Technical Field

[0001] The invention relates to a high-value processing technology for camellia oil and its application field, in particular to a process for preparing colorless camellia oil by silica gel chromatography. Background Art

[0002] Camellia oil, a natural woody plant oil extracted from the seeds of the camellia oleifera tree, is a unique edible oil in my country. Its exceptional nutritional value has earned it the reputation of being the "Olive Oil of the East." Camellia oil is rich in approximately 80% monounsaturated fatty acids, with oleic acid at 68%-87% and linoleic acid at 3.8%-14%. This monounsaturated fatty acid content is significantly higher than most vegetable oils, and its quality is comparable to that of olive oil. Camellia oil is also rich in trace bioactive ingredients such as tocopherol, squalene, phytosterols, and tea polyphenols, endowing it with multiple benefits, including antioxidant, antibacterial, anti-inflammatory, lipid-lowering, and beauty-enhancing properties. These properties have broad potential applications not only as a high-end edible oil but also in cosmetics, medical, and other fields.

[0003] In order to meet the stringent requirements of cosmetic and medical oils for high purity, low impurities and high safety, raw camellia oil, after initial processing into refined camellia oil or commercial camellia oil, still needs to undergo deep bleaching treatment to achieve a clear and transparent state in order to meet relevant application requirements. Existing methods for preparing colorless camellia oil are as follows: Chinese invention patent publication No. CN112831371A discloses a method for preparing high-quality colorless camellia oil, but this method requires three repeated adsorption and decolorization steps under heating and a certain vacuum, which consumes a lot of energy and materials, and has low production efficiency; Chinese invention patent publication No. CN107746745A discloses a method for preparing woody plant-based colorless oil at low temperature, but this method uses petroleum ether to dilute the oil, which easily causes solvent residue in subsequent processing; Chinese invention patent publication No. CN106635412B discloses a method for processing and separating oil, but this method uses short-range molecular distillation to separate pigment components to prepare colorless camellia oil. High temperature may destroy heat-sensitive active ingredients in the camellia oil, such as vitamin E, and the conditions are harsh, energy consumption is high, and the steps are numerous, resulting in low production efficiency.

[0004] At present, the production of colorless camellia oil at home and abroad is still in its infancy. Therefore, the present invention aims to provide a simple process for preparing colorless camellia oil for cosmetics, broaden the application field of camellia oil, improve the economic benefits brought by camellia oil, and provide new ideas for the high-quality development of camellia oil. Summary of the Invention

[0005] The present invention aims to provide a process for preparing colorless camellia oil by silica gel chromatography. The method can solve the problems of complex procedures, harsh production conditions, high energy consumption, and residual solvents in the oil in the current preparation process. Colorless camellia oil for cosmetics can be quickly prepared without changing the camellia oil refining and processing production line.

[0006] The technical solution adopted by the present invention to solve the above-mentioned problems is: The process for preparing colorless camellia oil by silica gel chromatography is characterized by comprising the following steps: Step (1), filler pretreatment: soak the sulfonic acid silica gel adsorbent in ultrapure water, methanol and n-hexane with a volume equivalent to 3 to 8 times the mass of the sulfonic acid silica gel adsorbent, respectively, for 3 to 24 hours and then dry to constant weight to obtain sulfonic acid silica gel adsorbent A; Step (2), filling the chromatography column: filling the sulfonic acid silica gel adsorbent A, activated carbon or amino silica gel adsorbent obtained in step (1) into the chromatography column in the order of sulfonic acid silica gel adsorbent A-amino silica gel adsorbent-activated carbon or sulfonic acid silica gel adsorbent A-activated carbon and a certain oil-to-weight ratio, and compacting to obtain a chromatography column; Step (3), decolorization of camellia oil: at room temperature, pour the raw camellia oil into the chromatography column obtained in step (2), filter and collect the effluent to obtain colorless camellia oil.

[0007] In this invention, ultrapure water immersion is primarily used to remove residual acidic substances from the adsorbent, preventing an increase in the acid value of the camellia oil after decolorization. The sulfonic acid silica gel adsorbent specifically adsorbs weakly cationic pigments in camellia oil, while the amino silica gel adsorbent specifically adsorbs polar and weakly anionic pigments. Activated carbon exhibits physical, chemical, and ion exchange adsorption capabilities for pigments in camellia oil. Chromatographic columns packed according to this scheme achieve superior decolorization and peroxide value reduction compared to single adsorbents or other adsorbent combinations.

[0008] According to the above scheme, the average particle size of the sulfonic acid silica gel adsorbent is 40~300 μm; the average particle size of the amino silica gel adsorbent is 40~300 μm; and the average particle size of the activated carbon is 20~200 mesh.

[0009] According to the above scheme, in step (1), the sulfonic acid silica gel adsorbent is a benzenesulfonic acid silica gel adsorbent or a propanesulfonic acid silica gel adsorbent.

[0010] According to the above scheme, in step (2), the amino silica gel adsorbent is an aminoethyl silica gel adsorbent, an aminopropyl silica gel adsorbent or an aminobutyl silica gel adsorbent.

[0011] According to the above scheme, in step (2), when the filler is sulfonic acid silica gel adsorbent A-amino silica gel adsorbent-activated carbon, the filling amount of sulfonic acid silica gel adsorbent A is 0.1%~10% of the oil weight, the filling amount of amino silica gel adsorbent is 0.1%~10% of the oil weight, and the filling amount of activated carbon is 0.1%~10% of the oil weight.

[0012] According to the above scheme, in step (2), when the filler is sulfonic acid silica gel adsorbent A-activated carbon, the filling amount of sulfonic acid silica gel adsorbent A is 0.1%~10% of the oil weight, and the filling amount of activated carbon is 0.1%~10% of the oil weight.

[0013] According to the above scheme, in step (3), the raw material camellia oil is one or more of cold-pressed camellia oil, degummed and deacidified camellia oil, refined camellia oil or edible camellia oil.

[0014] Compared with the prior art, the present invention has the following beneficial effects: (1) The operating temperature of the present invention is low, which effectively solves the problem of high temperature destruction of beneficial components of camellia oil in traditional methods and has low energy consumption; no solvent is used to dissolve oil, avoiding the safety problem of solvent residue; it is used for the direct preparation of refined camellia oil or commercial camellia oil to first-grade colorless camellia oil, and can be achieved without changing the existing camellia oil refining production line, with simple operation, high production efficiency, and easy production; the chromatography column has a large adsorption capacity, and the amount of adsorbent used is greatly reduced compared to traditional adsorbents such as white clay and attapulgite, which significantly reduces the amount of solid waste generated, has little environmental pollution, and meets the requirements of green production.

[0015] (2) The present invention can effectively solve the problem of poor decolorization effect of traditional camellia oil. The product color reaches the standard of first-class white oil, which can meet the standards of medical and cosmetic oils. At the same time, its physical and chemical index parameters such as acid value and peroxide value meet the standards of camellia oil used as raw material for cosmetics. The product of the present invention is of high quality, opens up a preparation path for colorless camellia oil, and provides technical support for the high-quality development of the camellia oil industry. DETAILED DESCRIPTION

[0016] The present invention is further explained below with reference to specific embodiments.

[0017] Example 1

[0018] Take 1 kg of cold-pressed camellia oil, and weigh 5% of the oil weight of benzenesulfonic acid silica gel adsorbent (55-75 μm), 5% of aminopropyl silica gel adsorbent (55-75 μm) and 5% of activated carbon (20-50 mesh), respectively. The benzenesulfonic acid silica gel adsorbent is soaked in ultrapure water (7 times the volume of the filler mass), 3 times the volume of methanol and 3 times the volume of n-hexane for 24 h, 6 h and 24 h, respectively, and dried to constant weight to obtain benzenesulfonic acid adsorbent A. Then, the chromatography column is filled in the order of benzenesulfonic acid silica gel adsorbent A layer-aminopropyl silica gel adsorbent layer-activated carbon layer. The cold-pressed camellia oil is passed into the chromatography column, and the filtrate is collected to obtain colorless camellia oil.

[0019] Example 2

[0020] Take 1 kg of degummed and deacidified camellia oil, weigh 6% benzenesulfonic acid silica gel adsorbent (55~75μm), 5% aminopropyl silica gel adsorbent (45~65μm) and 8% activated carbon (20~50 mesh) respectively, soak the benzenesulfonic acid silica gel adsorbent and propanesulfonic acid silica gel adsorbent with 6 times the volume of ultrapure water, 3 times the volume of methanol and 3 times the volume of n-hexane equivalent to the filler mass for 6h, 3h and 3h respectively, and dry to constant weight to obtain benzenesulfonic acid silica gel adsorbent A, then fill the chromatography column in the order of benzenesulfonic acid silica gel adsorbent A layer-aminopropyl silica gel adsorbent A layer-activated carbon layer, pass the refined camellia oil into the chromatography column, and collect the filtrate to obtain colorless camellia oil.

[0021] Example 3

[0022] Take 1 kg of commercially available refined camellia oil, and weigh 4% propanesulfonic acid silica gel adsorbent (45-65 μm) and 5% activated carbon (20-50 mesh) by weight of the oil respectively. Soak the propanesulfonic acid silica gel adsorbent with 4 times the volume of ultrapure water, 4 times the volume of methanol, and 4 times the volume of n-hexane equivalent to the mass of the filler for 8 h, 3 h, and 3 h, respectively, and dry to constant weight to obtain propanesulfonic acid silica gel adsorbent A. Then, fill the chromatography column in the order of propanesulfonic acid silica gel adsorbent A layer-activated carbon layer, pass the commercially available refined camellia oil into the chromatography column, and collect the filtrate to obtain colorless camellia oil.

[0023] Example 4

[0024] Take 1 kg of refined camellia oil, weigh 5% benzenesulfonic acid silica gel adsorbent (55-75 μm) and 5% activated carbon (20-50 mesh) by weight of the oil, soak the benzenesulfonic acid silica gel adsorbent with 5 times the volume of ultrapure water, 3 times the volume of methanol, and 3 times the volume of n-hexane equivalent to the filler mass for 5 h, 3 h, and 3 h, respectively, and dry to constant weight to obtain benzenesulfonic acid silica gel adsorbent A. Then, fill the chromatography column in the order of benzenesulfonic acid silica gel adsorbent A layer-activated carbon layer, pass the refined camellia oil into the chromatography column, and collect the filtrate to obtain colorless camellia oil.

[0025] Example 5

[0026] Take 1 kg of refined camellia oil, and weigh 3% propanesulfonic acid silica gel adsorbent (45-65 μm), 3% aminopropyl silica gel adsorbent (55-75 μm) and 5% activated carbon (20-50 mesh) respectively. The propanesulfonic acid silica gel adsorbent is soaked with 3 volumes of ultrapure water, 3 volumes of methanol and 3 volumes of n-hexane equivalent to the mass of the filler for 6 h, 4 h and 3 h, respectively, and dried to constant weight to obtain propanesulfonic acid silica gel adsorbent A. Then, a chromatography column is filled with propanesulfonic acid silica gel adsorbent A layer - aminopropyl silica gel adsorbent layer - activated carbon layer in the order of layer. The refined camellia oil is passed into the chromatography column, and the filtrate is collected to obtain colorless camellia oil.

[0027] The colorless camellia oil obtained in the above five examples and the related indicators of the raw material camellia oil are shown in Table 1. The decolorization rate is calculated as follows: Decolorization rate Y (%) = (Y 原山茶油 -Y 无色山茶油 ) / Y 原山茶油 ; Decolorization rate R(%)=(R 原山茶油 -R 无色山茶油 ) / R 原山茶油 ; Peroxide value reduction rate (%) = (peroxide value of raw camellia oil - peroxide value of colorless camellia oil) / peroxide value of raw camellia oil.

[0028] Table 1 Quality index detection of the product and raw material camellia oil in the embodiment

[0029] The determination of oil color shall refer to GB / T22460-2008; the determination of acid value shall refer to GB229-2016; the determination of peroxide value shall refer to GB227-2023.

[0030] As shown in Examples 1-5 in Table 1, the color of the colorless camellia oil obtained after treatment with silica gel chromatography was reduced to red 0.1 and yellow less than or equal to 0.3, the acid value was reduced or remained unchanged, and the peroxide value was 60.7% to 84.6% lower than the peroxide value reduction rate of the raw camellia oil. All indicators met or exceeded the standards for camellia oil used in cosmetics.

[0031] We compared the effects of different adsorbents, filler pretreatment methods and adsorbent loading sequences on the decolorization of camellia oil.

[0032] Comparative Example 1

[0033] Take 1kg of degummed and deacidified tea oil (same as Example 2), and weigh 10% of the oil weight of polyamide silica gel adsorbent, Florisil, C18 silica gel adsorbent, glycol silica gel adsorbent, quaternary ammonium silica gel adsorbent, cyano silica gel adsorbent, aluminum oxide, benzenesulfonic acid silica gel adsorbent, propanesulfonic acid silica gel adsorbent, aminopropyl silica gel adsorbent, activated carbon, C18 silica gel adsorbent-activated carbon combination (1:1), Florisil-activated carbon combination (1:1), benzenesulfonic acid silica gel adsorbent-Florisil, and 10% of the oil weight of the mixed solvent. The adsorbents were loaded onto chromatography columns, and degummed and deacidified camellia oil was passed through the columns. The camellia oil was then collected and filtered. The results are shown in Table 2.

[0034] Table 2 Comparison of decolorization effects of various adsorbents

[0035] It can be seen from Table 2 that activated carbon, benzenesulfonic acid silica gel adsorbent, and propanesulfonic acid silica gel adsorbent can remove yellow pigment to a large extent when used alone; activated carbon, benzenesulfonic acid silica gel adsorbent, propanesulfonic acid silica gel adsorbent, and aminopropyl silica gel adsorbent can remove red pigment to a certain extent when used alone; the decolorization effect of other adsorbents is not obvious when used alone.

[0036] It can be found from Table 2 that the decolorization rate of the mixed adsorption of the two adsorbents is better than that of using them alone; among the two adsorbent combinations, propanesulfonic acid silica gel adsorbent-activated carbon (1:1) is better than other mixed adsorbents, with decolorization rates Y and R of 98.4% and 75%, respectively.

[0037] It can be found from Table 2 that among the three adsorbent combinations, the decolorization rate R of benzenesulfonic acid silica gel adsorbent-aminopropyl silica gel adsorbent-activated carbon (1:1:1) is better than that of other mixed adsorbents, and the decolorization rates Y and R are 98.9% and 83.3%, respectively.

[0038] We also investigated the effect of the loading order of benzenesulfonic acid-based silica gel adsorbent and activated carbon on the decolorization rate. The results are shown in Table 3.

[0039] Table 3 Effect of filling order on tea oil decolorization rate

[0040] From Table 3, it can be found that the decolorization rate of first filling activated carbon is significantly improved compared with that of first filling benzenesulfonic acid-based silica gel adsorbent.

[0041] Comparative Example 2

[0042] Different from Example 2, five parts of oil weight were weighed, 6% benzenesulfonic acid silica gel adsorbent, 5% aminopropyl silica gel adsorbent and 8% activated carbon were used to explore the effect of different solvent combinations on the acid value and peroxide value of tea oil.

[0043] The benzenesulfonic acid-based silica gel adsorbent in one portion was soaked in ultrapure water only for 12 hours, one portion was soaked in methanol and n-hexane for 6 hours respectively, one portion was soaked in water and methanol for 6 hours respectively, one portion was soaked in water and n-hexane for 6 hours respectively, and the last portion was soaked in a 1:1 mixture of petroleum ether and ethyl acetate for 12 hours. The remaining parameters and operations were the same as in Example 2. Camellia oil was collected and filtered. The results are shown in Table 4.

[0044] Table 4 Effects of different pretreatment methods on acid value and peroxide value

[0045] It can be found from Table 4 that under the same total soaking time, the acid value remains basically unchanged when pretreatment is carried out by water soaking; the acid value is significantly increased when pretreatment is carried out by soaking only in organic solvents (methanol, n-hexane, petroleum ether, ethyl acetate); the effect of reducing the peroxide value by soaking in water, methanol, and n-hexane is the best.

[0046] Comparative Example 3

[0047] Unlike Example 2, two adsorbents were weighed: one containing a benzenesulfonic acid silica gel adsorbent with a particle size of 300-400 μm, an aminopropyl silica gel adsorbent with a particle size of 300-400 μm, and an activated carbon particle size of 5-10 mesh. This adsorbent set was numbered 1; the other containing a benzenesulfonic acid silica gel adsorbent with a particle size of 0.4-0.5 mm, an aminopropyl silica gel adsorbent with a particle size of 0.4-0.5 mm, and an activated carbon particle size of 10-20 mesh. This adsorbent set was numbered 2. Other parameters and procedures were the same as in Example 2. The results are shown in Table 5.

[0048] Table 5 Effects of different adsorbent particle sizes on various indicators of tea oil

[0049] Table 5 shows that the adsorbent particle size affects the decolorization effect and quality indicators of tea oil. The larger the adsorbent particle size, the worse the decolorization effect and the peroxide value reduction rate gradually decreases.

[0050] Therefore, Tables 1 to 5 demonstrate that, if the conditions specified in the present invention are changed, the colorless camellia oil obtained thereby is inferior to or not superior to the colorless camellia oil obtained after treatment with the silica gel chromatography method of the present invention in terms of color or quality indicators.

Claims

1. A process for preparing colorless camellia oil by silica gel chromatography, characterized in that The steps include: Step (1), filler pretreatment: soak the sulfonic acid silica gel adsorbent in ultrapure water, methanol and n-hexane with a volume equivalent to 3 to 8 times the mass of the sulfonic acid silica gel adsorbent, respectively, for 3 to 24 hours and then dry to constant weight to obtain sulfonic acid silica gel adsorbent A; Step (2), filling the chromatography column: filling the sulfonic acid silica gel adsorbent A, activated carbon or amino silica gel adsorbent obtained in step (1) into the chromatography column in the order of sulfonic acid silica gel adsorbent A-amino silica gel adsorbent-activated carbon or sulfonic acid silica gel adsorbent A-activated carbon and a certain oil-to-weight ratio, and compacting to obtain a chromatography column; Step (3), decolorization of camellia oil: at room temperature, pour the raw camellia oil into the chromatography column obtained in step (2), filter and collect the effluent to obtain colorless camellia oil.

2. The process for preparing colorless camellia oil by silica gel chromatography according to claim 1, characterized in that: The average particle size of the sulfonic acid silica gel adsorbent is 40-300 μm; the average particle size of the amino silica gel adsorbent is 40-300 μm; and the average particle size of the activated carbon is 20-200 meshes.

3. The process for preparing colorless camellia oil by silica gel chromatography according to claim 1, characterized in that: In step (1), the sulfonic acid silica gel adsorbent is a benzenesulfonic acid silica gel adsorbent or a propanesulfonic acid silica gel adsorbent.

4. The process for preparing colorless camellia oil by silica gel chromatography according to claim 1, characterized in that: In step (2), the amino silica gel adsorbent is aminoethyl silica gel adsorbent, aminopropyl silica gel adsorbent or aminobutyl silica gel adsorbent.

5. The process for preparing colorless camellia oil by silica gel chromatography according to claim 1, characterized in that: In step (2), when the filler is sulfonic acid silica gel adsorbent A-amino silica gel adsorbent-activated carbon, the filling amount of sulfonic acid silica gel adsorbent A is 0.1% to 10% of the oil weight, the filling amount of amino silica gel adsorbent is 0.1% to 10% of the oil weight, and the filling amount of activated carbon is 0.1% to 10% of the oil weight.

6. The process for preparing colorless camellia oil by silica gel chromatography according to claim 1, characterized in that: In step (2), when the filler is sulfonic acid silica gel adsorbent A-activated carbon, the filling amount of sulfonic acid silica gel adsorbent A is 0.1% to 10% of the oil weight, and the filling amount of activated carbon is 0.1% to 10% of the oil weight.

7. The process for preparing colorless camellia oil by silica gel chromatography according to claim 1, characterized in that: In step (3), the raw camellia oil is one or more of cold-pressed camellia oil, degummed and deacidified camellia oil, refined camellia oil or edible camellia oil.

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