A preparation method of high-transparency antioxidant crude oil

Abstract

The present invention provides a method for preparing a highly transparent antioxidant crude oil, and belongs to the technical field of refining of plant cold-pressed oil. The method comprises the following steps: (1) taking peony seed meal after oil pressing and placing it in a NaOH solution for stirring, and then deproteinizing and desugaring; taking 30-50wt% of the product obtained after drying and ashing under 400-500°C, the remaining part is directly powdered to obtain seed meal powder, adding a plasticizer and mixing evenly to obtain a filter filler; (2) the obtained filter layer filler and the middle filling layer are used in conjunction with a filter tank, and the plant seed oil after cold pressing is added for decolorization; (3) the refined oil after decolorization oil is subjected to conventional deacidification and deodorization steps to obtain refined crude oil; (4) finally dissolving an antioxidant in the refined crude oil to obtain a highly transparent antioxidant crude oil. The present invention not only prepares highly permeable crude oil, but also can use the peony seed meal after oil pressing to filter impurities in the cold-pressed oil, so as to achieve the purpose of decolorization, and make full use of the discarded peony seed meal.

Description

Technical Field

[0001] The invention relates to the technical field of refining plant cold-pressed oil, in particular to a method for preparing high-transparency antioxidant crude oil. Background Art

[0002] Peony is a perennial deciduous shrub of the genus Paeonia in the family Ranunculaceae. It is a traditional famous flower in my country and is widely distributed in Heze, Shandong, Luoyang, Henan, Baichuan, Hebei, Tongling, Anhui, Hanzhong, Shaanxi, Zhejiang, Sichuan, etc. Peony has always been highly valued in its medicinal research. Its root bark is also called moutan bark, which has the effects of clearing heat and cooling blood, promoting blood circulation and removing blood stasis.

[0003] Peony seeds are the seeds of peonies and are also a byproduct of peony bark production. The unsaturated fatty acid content of its seed oil is as high as 90%, and it is rich in linoleic acid and linolenic acid, which has the effects of lowering blood lipids and blood sugar. Since 2011, peony seed oil has become a new resource food in my country. The planting area of ​​oil-producing peonies has reached 2.3 million mu. At present, the annual output of oil-producing peony seeds is about 2.4×10 4 The annual processing capacity of peony seed oil is as high as 20,000 tons.

[0004] However, the most serious problem in oil processing and storage is that oils are prone to rancidity and have a short storage period. Most antioxidants are poorly oil-soluble and cannot effectively prevent oils from rancidity and extend their storage period. Therefore, finding new methods to extend the shelf life of oils and prevent them from rancidity has become a critical issue in oil processing.

[0005] Peony seed meal is the main byproduct after oil extraction from oil-producing peonies, accounting for about 60% of oil-producing peonies. Peony seed meal is rich in protein (28.67%) and cellulose (27.5%). However, the current development and utilization of peony seed meal has not received much attention, and a large amount of peony seed meal is discarded, causing serious waste and resource pollution, and low resource utilization. Therefore, it is necessary to develop a method for fully utilizing peony seed meal to solve the problem of existing resource waste. Summary of the invention

[0006] In view of the above problems existing in the prior art, the present invention provides a method for preparing a highly permeable and antioxidant crude oil. The present invention not only prepares highly permeable crude oil, but also can use the peony seed meal after oil pressing to filter impurities in the cold-pressed oil, thereby achieving the purpose of decolorization and making full use of the discarded peony seed meal.

[0007] The technical solution of the present invention is as follows:

[0008] A method for preparing a highly transparent antioxidant crude oil comprises the following steps:

[0009] (1) Preparing peony seed meal filter layer filler: taking peony seed meal after oil extraction, placing it in a NaOH solution for stirring, then performing acid precipitation to remove protein, and then adding alcohol to remove sugar;

[0010] The wet solid obtained after desugaring is dried, and 30-50 wt% of the dried product is ash-cured at 400-500° C., and then cooled and pulverized to obtain ash powder; the remaining part of the dried product is directly pulverized to obtain seed meal powder;

[0011] The ash powder, seed meal powder and plasticizer obtained in the above steps are mixed evenly to obtain a filter filler;

[0012] (2) Decolorization of refined oil: The filter layer filler and the intermediate filling layer obtained in step (1) are connected to the filter tank, and the cold-pressed plant seed oil is added, and the mixture is circulated at normal pressure for 1-5 min, and the pressure is increased to 0.1-0.5 MPa, and the mixture is circulated for 30-60 min, and the oil is recovered to obtain the decolorized refined oil;

[0013] (3) preparing highly transparent and antioxidant crude oil: subjecting the refined oil after the decolorized oil obtained in step (2) to conventional deacidification and deodorization steps to obtain refined crude oil;

[0014] (4) Finally, the antioxidant is dissolved in the refined crude oil to obtain the highly transparent antioxidant crude oil.

[0015] Preferably, the concentration of the NaOH solution in step (1) is 1-3wt%, the mass volume of the peony seed meal and the NaOH solution is 1g:5-10ml; the stirring temperature of the peony seed meal in the NaOH solution is 60-80°C, and the stirring time is 1-2h.

[0016] Preferably, the plasticizer in step (1) is dimethyl phthalate and / or diethyl phthalate; the mass of the plasticizer is 10-25% of the total of the ash powder, seed meal powder and the plasticizer.

[0017] Furthermore, the stirring temperature in the NaOH solution in step (1) is preferably 65-75°C.

[0018] Furthermore, the ashing time in step (1) is 60-90 minutes; and the ashing powder and seed meal powder are respectively sieved through a 100-150 mesh sieve.

[0019] Furthermore, the method for removing protein by acid precipitation in step (1) is: adjusting the pH of the system to 4-4.5 with hydrochloric acid and standing at 4°C for 2 hours.

[0020] Furthermore, the method of adding alcohol for desugaring in step (1) is: adjusting the concentration of the desugaring alcohol with 95wt% ethanol to 60-65wt% and standing at 2-4°C for 2h.

[0021] Preferably, the intermediate filling layer in step (2) is a conventional decolorizing material, including but not limited to diatomaceous earth and white clay.

[0022] Preferably, the mass ratio of the antioxidant to the refined crude oil in step (4) is 1-5 mg: 1 g.

[0023] Furthermore, the method for preparing the antioxidant in step (4) comprises the following steps:

[0024] S1. First, take one of dihydroquercetin or tetrahydrocurcumin, mix it with soybean lecithin in anhydrous ethanol, stir and react at 40-60° C. until the solution is clear, centrifuge, take the supernatant, evaporate the solvent, and obtain a light yellow powder for use;

[0025] S2, then dissolving chitosan and emulsifier in 1wt% acetic acid solution, mixing evenly, and letting stand overnight;

[0026] S3. Finally, the yellowish powder obtained in step S1 is dissolved in ethanol, and slowly added dropwise to the solution obtained in step S2 under uniform stirring, and stirred until it emits a blue opalescent light, and dried at 40-60° C. and crushed to obtain an antioxidant.

[0027] Preferably, in step S1, the concentration of the dihydroquercetin or tetrahydrocurcumin dissolved in anhydrous ethanol is 10-15 g / L; the mass ratio of the dihydroquercetin or tetrahydrocurcumin to soybean lecithin is 1:2-2.5.

[0028] Furthermore, the reaction temperature of step S1 is preferably 45-55°C.

[0029] Preferably, the emulsifier in step S2 is peony seed oil alone, or a mixture of peony seed oil and a lipophilic emulsifier; the lipophilic emulsifier includes at least one of Tween 80 and glyceryl stearate; when the emulsifier is a mixture, the mass ratio of peony seed oil to lipophilic emulsifier is 1-5:1.

[0030] Preferably, in step S2, the concentration of chitosan after being dissolved in acetic acid solution is 10-15 mg / ml; the concentration of emulsifier after being dissolved in acetic acid solution is 2-5 wt%.

[0031] Preferably, the concentration of the light yellow powder in step S3 after being dissolved in ethanol is 20-50 mg / ml; 5-15 ml of the solution obtained in step S2 is added dropwise to every 1 ml of the ethanol solution of the light yellow powder.

[0032] Furthermore, the uniform stirring speed in step S3 is preferably 150-200 rpm, the stirring time is 60-90 min, and the drying temperature is preferably 50-55°C.

[0033] The beneficial technical effects of the present invention are:

[0034] 1. In the prior art, seed meal is used as filler mainly to utilize its cellulose, while the present invention uses peony seed meal as filler mainly to make full use of the residue after oil extraction, in which the cellulose content is very low. The present invention makes full use of the residue left after cold pressing of peony seeds, effectively solving the problem of waste of peony seed meal and the environmental pollution caused by it.

[0035] 2. In the present invention, the seed meal is dissolved in alkali for 1-2 hours to remove the protein in the seed meal, and the alcohol is added to remove the polysaccharide in the seed meal, both of which are aimed at reducing impurities in the seed meal to prevent contamination of the raw materials during the filtration process. The powder after ashing is mixed with the seed meal powder after deproteinization and desugaring, and then the plasticizer is added to increase the pore size and surface area of ​​the filler.

[0036] 3. In the conventional decolorization process of the prior art, the decolorization materials such as clay need to be fully mixed with the oil and need to be removed by suction after stirring for a period of time. However, the present invention fixes the filler used for decolorization, eliminating the step of removing the decolorization material. Specifically, the present invention uses seed meal as a filtering matrix and fills the decolorization filler into the pipe part used for filtration. The fixation of the decolorization and deacidification filler can solve the problem of filler removal.

[0037] 4. In the prior art, when adding antioxidants to crude oil, oil-soluble antioxidants such as VE and VC are usually used, which have poor antioxidant activity and affect the properties of crude oil. However, the present invention utilizes the self-assembly nanoparticle technology of dihydroquercetin or tetrahydrocurcumin reacting with soybean lecithin to greatly increase the solubility of dihydroquercetin and other substances that are insoluble in oil in oil through self-assembly means, and exhibits excellent antioxidant activity. While solving the problems of antioxidant oil solubility and drug loading rate, no other contaminating impurities are added.

[0038] 5. The self-assembly technology of dihydroquercetin can make the self-assembled particles embedded therein reach the nanoscale. When applied to the cosmetic field, it can penetrate the surface layer of the skin and effectively release slowly in the deep layer of the skin to achieve precise antioxidant effects. At the same time, the present invention replaces the conventional emulsifier with peony oil (or a mixture of peony oil and a lipophilic emulsifier), further solving the problems of poor oil solubility and low drug loading rate of nanoparticles in the prior art. DETAILED DESCRIPTION

[0039] The present invention is described in detail below in conjunction with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. 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.

[0040] Embodiment 1:

[0041] (1) Preparation of peony seed oil filter filler: 10 g of peony seed meal after oil extraction was dissolved in 100 mL of 1 wt% NaOH solution, stirred at 65°C for 2 h, adjusted the pH to 4 with hydrochloric acid, and refrigerated at 4°C for 2 h to remove protein, adjusted the ethanol concentration to 60% with 95% ethanol, and refrigerated at 4°C for 2 h to remove sugar.

[0042] Dry, take 5g and incinerate at 500℃ for 60min, grind into powder after cooling, and grind the remaining part directly into powder after drying. Both of them are sieved through 100 mesh after grinding.

[0043] The incinerated seed meal, seed meal powder and 2.5 g of dimethyl phthalate were fully dissolved in 20 ml of deionized water and mixed evenly, and dried to obtain a filter filler.

[0044] (2) The filter layer filler and the middle filling layer diatomaceous earth obtained in step (1) are connected to a filter tank, 50 ml of cold-pressed peony seed oil is added, and the mixture is circulated at normal pressure for 5 min, the pressure is increased to 0.5 MPa, and the mixture is circulated for 60 min to recover the oil and obtain decolorized refined oil.

[0045] (3) The decolorized refined oil is heated to 55°C, 1000 ml of 9% NaOH solution is added, stirred for 20 min, heated to 80°C, 50 g of alumina is added, stirred for 20 min, allowed to stand for 10 h, the water layer and the oil layer are separated to obtain deacidified oil; the deacidified oil is heated to 180°C under 0.05 MPa and reacted in vacuum for 4 h. After completion, refined crude oil is obtained.

[0046] (4) Preparation of antioxidant: First, 1 g of dihydroquercetin was mixed with 2 g of soybean lecithin in 100 ml of anhydrous ethanol, and the mixture was stirred at 40° C. until the solution was clear. The mixture was centrifuged, the supernatant was collected, and the solvent was evaporated to obtain a slightly yellow powder for later use.

[0047] Then, 100 mg of chitosan and 0.5 g of peony seed oil were dissolved in 10 ml of 1% acetic acid solution, mixed evenly, and allowed to stand overnight to obtain a chitosan-acetic acid mixed solution.

[0048] Finally, 100 mg of the obtained light yellow powder was dissolved in 2 ml of ethanol, and slowly added dropwise into 10 ml of chitosan-acetic acid mixture under uniform stirring, and stirred at 200 rpm for 90 min until it emitted a light blue opalescent light. The powder was dried at 50°C and crushed to obtain an antioxidant.

[0049] (5) Take 1 mg of the antioxidant obtained in step (4) and dissolve it in 1 g of the crude oil obtained in step (3) to obtain a highly permeable antioxidant crude oil.

[0050] Embodiment 2:

[0051] (1) Preparation of peony seed oil filter filler: 10 g of peony seed meal after oil extraction was dissolved in 80 mL of 1 wt% NaOH solution, stirred at 80°C for 2 h, adjusted the pH to 4.5 with hydrochloric acid, refrigerated at 2°C overnight for deproteinization, adjusted the ethanol concentration to 63% with 95% ethanol, and refrigerated at 3°C ​​for 2 h for desugaring.

[0052] After drying, take 3g and incinerate at 400℃ for 90min, and grind into powder after cooling. The other part is dried and grind into powder, and the two powders are respectively passed through a 120-mesh sieve.

[0053] The incinerated seed meal and seed meal powder, 1.3 g of dimethyl phthalate and 1 g of diethyl phthalate were fully dissolved in 20 ml of deionized water, mixed evenly, and dried to obtain a filter filler.

[0054] (2) The filter layer filler and the middle filling layer carclazyte obtained in step (1) are connected with a filter tank, 50 ml of cold-pressed peony seed oil is added, and the mixture is circulated at normal pressure for 5 min, the pressure is increased to 0.3 MPa, and the mixture is circulated for 30 min to recover the grease and obtain refined grease after decolorization.

[0055] (3) After decolorization, the crude oil is heated to 55°C, 1000 ml of 9% NaOH solution is added, stirred for 20 min, heated to 80°C, 50 g of alumina is added, stirred for 20 min, allowed to stand for 10 h, the water layer and the oil layer are separated to obtain deacidified oil; the deacidified oil is heated to 180°C under 0.05 MPa and reacted in vacuum for 4 h. After completion, refined crude oil is obtained.

[0056] (4) Preparation of antioxidant: First, 1 g of dihydroquercetin was mixed with 2.3 g of soybean lecithin in 100 ml of anhydrous ethanol, and stirred at 45°C until the solution was clear. The mixture was centrifuged, the supernatant was collected, and the solvent was evaporated to obtain a slightly yellow powder for later use.

[0057] Then, 150 mg of chitosan, 0.25 g of peony seed oil and 0.25 g of Tween 80 were dissolved in 10 ml of 1% acetic acid solution, mixed evenly and allowed to stand overnight to obtain a chitosan-acetic acid mixed solution.

[0058] Finally, 40 mg of the obtained light yellow powder was dissolved in 2 ml of ethanol, and slowly added dropwise into 10 ml of chitosan-acetic acid mixture under uniform stirring, and stirred at 200 rpm for 90 min until it emitted a light blue opalescent light. The powder was dried at 40°C and crushed to obtain an antioxidant.

[0059] (5) Take 5 mg of the antioxidant obtained in step (4) and dissolve it in 1 g of the crude oil obtained in step (3) to obtain a highly transparent antioxidant crude oil.

[0060] Embodiment 3:

[0061] (1) Preparation of peony seed oil filter filler: 10 g of peony seed meal after oil extraction was dissolved in 90 mL of 1 wt% NaOH solution, stirred at 70°C for 1.5 h, adjusted the pH to 4 with hydrochloric acid, refrigerated at 3°C ​​for two hours to remove protein, adjusted the ethanol concentration to 65% with 95% ethanol, and refrigerated at 2°C for 2 hours to remove sugar.

[0062] Dry, take 4g and incinerate at 500℃ for 70min, cool and grind into powder. Dry the other part and grind into powder, and pass the two powders through 150 mesh sieve respectively.

[0063] The incinerated seed meal and seed meal powder, 1 g of dimethyl phthalate and 1.3 g of diethyl phthalate were fully dissolved in 20 ml of deionized water, mixed evenly, and dried to obtain a filter filler.

[0064] (2) The filter layer filler and the middle filling layer diatomaceous earth obtained in step (1) are connected to a filter tank, 50 ml of cold-pressed peony seed oil is added, and the mixture is circulated at normal pressure for 3 min, the pressure is increased to 0.4 MPa, and the mixture is circulated for 50 min to recover the oil and obtain refined oil after decolorization.

[0065] (3) After decolorization, the crude oil is heated to 55°C, 1000 ml of 9% NaOH solution is added, stirred for 20 min, heated to 80°C, 50 g of alumina is added, stirred for 20 min, allowed to stand for 10 h, the water layer and the oil layer are separated to obtain deacidified oil; the deacidified oil is heated to 180°C under 0.05 MPa and reacted in vacuum for 4 h. After completion, refined crude oil is obtained.

[0066] (4) Preparation of antioxidant: First, 1 g of tetrahydrocurcumin was mixed with 2.5 g of soybean lecithin in 100 ml of anhydrous ethanol, and stirred at 40° C. until the solution was clear. The mixture was centrifuged, the supernatant was collected, and the solvent was evaporated to obtain a slightly yellow powder for use.

[0067] Then, 100 mg chitosan, 0.3 g peony seed oil, 0.1 g Tween 80 and 0.1 g glycerol stearate were dissolved in 10 ml acetic acid solution with a concentration of 1%, mixed evenly and allowed to stand overnight to obtain a chitosan-acetic acid mixed solution.

[0068] Finally, 60 mg of the obtained light yellow powder was dissolved in 2 ml of ethanol, and slowly added dropwise into 10 ml of chitosan-acetic acid mixture under uniform stirring, and stirred at 200 rpm for 90 min until it emitted a light blue opalescent light. The powder was dried at 60°C and crushed to obtain an antioxidant.

[0069] (5) Take 3 mg of the antioxidant obtained in step (4) and dissolve it in 1 g of the crude oil obtained in step (3) to obtain a highly transparent antioxidant crude oil.

[0070] Comparative Example 1:

[0071] The emulsifier was replaced with Tween 80, and the other processing techniques were the same as those in Example 1.

[0072] Comparative Example 2:

[0073] The concentration of dihydroquercetin was adjusted to 5 g / L, and the other processing techniques were the same as those in Example 1.

[0074] Comparative Example 3:

[0075] The dihydroquercetin antioxidant was replaced by VE, and the other processing techniques were the same as those in Example 1.

[0076] Comparative Example 4:

[0077] The dihydroquercetin antioxidant was replaced by VC, and the other processing techniques were the same as those in Example 1.

[0078] Test example:

[0079] The antioxidant activity and stability of the high-transmittance antioxidant crude oil in the experimental group were determined by the following specific determination method and the results are shown in Table 1.

[0080] (1) DPPH clearance rate determination:

[0081] Mix different volumes of sample solution with 4 mL of 100 μM DPPH ethanol solution, react in the dark at 37°C for 30 minutes, and measure the absorbance at 517 nm. Ethanol is the negative control, and ascorbic acid is the positive control (the concentration of ascorbic acid at 100% clearance rate needs to be tested). The scavenging effect of DPPH free radicals is expressed as the clearance rate R, and the formula is as follows:

[0082] R=(A0-A1) / A0×100%

[0083] R: Clearance rate (%)

[0084] A0: absorbance of negative control;

[0085] A1: Absorbance of the sample.

[0086] DPPH ethanol solution preparation:

[0087] Weigh 19.7 mg DPPH and dissolve it in 100 mL anhydrous ethanol to make a 500 μM stock solution. Dilute it 5 times before use. Store in a dark place and refrigerate.

[0088] (2) Stability determination:

[0089] The sample solution was placed in a 60°C thermostat and observed for 2 weeks to determine its clarity and the presence of precipitation.

[0090] Table 1

[0091] DPPH free radical scavenging rate stability Example 1 88.34±0.96％ Clear, no precipitation Example 2 97.25±0.25％ Clear, no precipitation Example 3 94.17±1.12％ Clear, no precipitation Comparative Example 1 70.11±0.15％ Slightly turbid, no precipitation Comparative Example 2 56.18±0.19％ Clear, no precipitation Comparative Example 3 19.81±2.65％ Turbidity, stratification, no precipitation Comparative Example 4 40.30±0.48％ White precipitate is formed and the oil has a strong rancid smell.

[0092] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and implementation modes, and can be fully applicable to various fields suitable for the present invention. For those familiar with the art, for those of ordinary skill in the art, various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present invention. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to specific details.

Claims

1. A method for preparing a highly transparent antioxidant crude oil, characterized in that: The following steps are involved: (1) Preparation of peony seed meal filter filler: 10 g of peony seed meal after oil extraction was dissolved in 80 mL of 1 wt% NaOH solution, stirred at 80 °C for 2 h, adjusted the pH to 4.5 with hydrochloric acid, refrigerated at 2 °C for 2 h to remove protein, adjusted the sugar alcohol concentration to 63% with 95% ethanol, and refrigerated at 3 °C for 2 h to remove sugar; The wet solid obtained after desugaring was dried, and 3 g of the product obtained after drying was ashed at 400°C for 90 min, and then cooled and pulverized to obtain ashed powder; the remaining part of the product obtained after drying was directly pulverized to obtain seed meal powder; the ashed powder and seed meal powder were respectively sieved through a 120-mesh sieve; The incinerated seed meal and seed meal powder, 1.3 g of dimethyl phthalate, and 1 g of diethyl phthalate were fully dissolved in 20 ml of deionized water, mixed evenly, and dried to obtain a filter filler; (2) Decolorization of refined oil: The filter layer filler and the intermediate filling layer obtained in step (1) are connected to the filter tank, 50 mL of cold-pressed peony seed oil is added, and the mixture is circulated at normal pressure for 5 min. The pressure is increased to 0.3 MPa and circulated for 30 min. The oil is recovered to obtain decolorized refined oil. (3) Preparation of highly transparent antioxidant crude oil: the refined oil after decolorization obtained in step (2) is heated to 55°C, 1000 ml of 9% by mass NaOH solution is added, stirred for 20 min, heated to 80°C, 50 g of alumina is added, stirring is continued for 20 min, allowed to stand for 10 h, the water layer and the oil layer are separated to obtain deacidified oil; the deacidified oil is heated to 180°C under 0.05 Mpa and reacted in vacuum for 4 h to obtain refined crude oil; (4) Preparation of antioxidant: First, take 1 g of dihydroquercetin and 2.3 g of soybean lecithin and mix them in 100 ml of anhydrous ethanol. Stir and react at 45°C until the solution is clear. Centrifuge, take the supernatant, evaporate the solvent, and obtain a slightly yellow powder for use. Then, 150 mg chitosan, 0.25 g peony seed oil, and 0.25 g Tween 80 were dissolved in 10 ml acetic acid solution with a concentration of 1%, mixed evenly, and allowed to stand overnight to obtain a chitosan-acetic acid mixed solution; Finally, 40 mg of the obtained light yellow powder was dissolved in 2 ml of ethanol, and slowly added dropwise into 10 ml of chitosan-acetic acid mixture under uniform stirring, and stirred at 200 rpm for 90 min until it emitted a light blue opalescent light; dried at 40° C., and crushed to obtain an antioxidant; (5) Take 5 mg of the antioxidant obtained in step (4) and dissolve it in 1 g of the crude oil obtained in step (3) to obtain a highly permeable antioxidant crude oil.