Method for removing pesticide residues from ginger oleoresin

Abstract

The present application provides a kind of method for removing pesticide residue in ginger oleoresin, the method comprises the following steps: (1) with fatty acid as entrainer, organic phosphorus pesticide and ginger essential oil in ginger oleoresin raw material are separated by supercritical carbon dioxide extraction method;Wherein, extraction pressure is 10-18MPa, extraction temperature is 35-70 DEG C;(2) with ginger essential oil as entrainer, the material remaining in supercritical carbon dioxide extraction device in step (1) is extracted, and pesticide-free ginger oleoresin is separated;Wherein, extraction pressure is 18-40MPa, extraction temperature is 35-70 DEG C.The present application process is simple, low in cost, can be effectively applied to large-scale production, solve the problem that pesticide residue in ginger oleoresin product is overproof, gingerol content and pesticide residue can be completely separated, and clean, safe ginger extract product is prepared.

Description

Technical Field

[0001] This invention relates to the field of natural product separation and extraction technology, and in particular to a method for removing pesticide residues from ginger oleoresin. Background Technology

[0002] Ginger is the fresh rhizome of a perennial herbaceous plant belonging to the ginger family and the ginger genus. Ginger is widely used as a medicine due to its medicinal properties, including expectorant, cough-suppressant, heat-clearing, detoxifying, lung-warming, and cold-dispelling effects. It is also consumed as a spice and vegetable. Currently, there are two main types of ginger in the domestic market: one is the small yellow ginger from Yunnan and Guizhou provinces, which prefers warm and humid environments, begins to sprout above 16℃, has an optimal growth temperature of 20-25℃ for seedlings, and 25-28℃ for stem and leaf growth, and is not resistant to low temperatures and frost; the other is the large ginger from Shandong province, which is large, thin-skinned, has few fibers, fine flesh, a strong spicy flavor, is rich in nutrients, and is resistant to storage. The main flavor compounds in ginger are ginger oleoresin products, and the aroma compounds include ginger essential oil.

[0003] The main extraction methods for ginger oleoresin currently include steam distillation, solvent extraction, ultrasonic extraction, supercritical carbon dioxide extraction, and pressing. Solvent extraction has the lowest production cost, approximately 1500 yuan per ton of raw material, and yields ideal amounts of ginger essential oil and gingerol, making it very suitable for large-scale ginger raw material processing and industrial production. Supercritical carbon dioxide extraction, due to its high equipment cost, limited processing capacity, and raw material processing cost of approximately 7000-10000 yuan per ton, is suitable only for processing high-value-added raw materials.

[0004] To maximize ginger yield, farmers need to fumigate the planting area with chloropicrin before planting to prevent ginger seed from being infected with ginger blight. During planting, frequent pesticide spraying is required to control pests and prevent damage. Furthermore, pesticide spraying is necessary during harvesting and storage to prevent pests and rot. This frequent use of pesticides before and after planting leads to excessive pesticide residues in dried ginger. Pesticide residues in ginger are difficult to remove, especially when using solvent extraction methods. The resulting ginger oleoresin product has a very complex composition, including gingerol, volatile oils, diphenylheptane, and harmful impurities. In particular, pesticide residues far exceed EU standards, with the main types including organophosphorus and organochlorine pesticides. Pesticide residues are a major factor limiting the application of ginger oleoresin.

[0005] Currently, domestic technologies related to pesticide residue removal include those using supercritical carbon dioxide extraction, such as CN110037130A and CN113730959A, which use butane and pepper oil as entrainers to remove pesticide residues from tea and pepper oleoresins, respectively. However, the aforementioned patents do not report how to separate the product from the pesticide residues. Therefore, based on market needs, there is an urgent need to study the development of a process for removing pesticide residues from ginger oleoresins. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a method for removing pesticide residues from ginger oleoresin, reducing the pesticide residue level to less than 15 ppm.

[0007] This invention provides a method for removing pesticide residues from ginger oleoresin, comprising the following steps:

[0008] (1) Using fatty acids as entrainers, supercritical carbon dioxide extraction was used to separate organophosphorus pesticides and ginger essential oil from ginger oleoresin raw materials.

[0009] The extraction pressure is 10-18 MPa, and the extraction temperature is 35-70℃.

[0010] (2) Using ginger essential oil as an entrainer, the remaining material in the supercritical carbon dioxide extraction device in step (1) is extracted and separated to obtain ginger oleoresin without pesticide residue.

[0011] The extraction pressure is 18-40 MPa and the extraction temperature is 35-70℃.

[0012] This invention has found that using fatty acids as an entrainer can achieve better solubility for pesticide residues, improving the removal efficiency of pesticide residues in ginger oleoresin. Then, through separation, pesticide residues and the entrainer can be separated simultaneously to prepare pesticide residue-free ginger essential oil products. Furthermore, using ginger essential oil as an entrainer can improve the extraction efficiency of gingerol content. Through subsequent separation, gingerol and ginger essential oil are separated to produce ginger oleoresin that meets pesticide residue requirements, leaving behind organochlorine pesticide residues and ginger oleoresin impurities in the extraction vessel. In addition to the selection of the entrainer, the extraction pressure and temperature are also crucial. The extraction pressure in steps (1) and (2) is not the same; it is 18 MPa. It is necessary to ensure that the extraction pressure in step (2) is greater than that in step (1). The preferred extraction pressure in step (2) is 27-40 MPa.

[0013] The method for removing pesticide residues from ginger oleoresin according to the present invention uses caprylic / capric triglyceride as the fatty acid. The effect is better when caprylic / capric triglyceride is selected as the fatty acid.

[0014] According to the method for removing pesticide residues from ginger oleoresin provided by the present invention, the amount of entrainer added in step (1) is 5%-60% of the weight of ginger oleoresin raw material.

[0015] Furthermore, in step (1), the pressure in the separation tank is 5-10 MPa, and the temperature in the separation tank is 30-50℃. The pressure and temperature during separation also have a significant impact on the separation effect. This invention has found that when the separation pressure and temperature are controlled within the above range, the separation effect is better.

[0016] Furthermore, the carbon dioxide flow rate during extraction in step (1) is 5-15 L / h.

[0017] More preferably, the extraction temperature in step (1) is 45-60℃ and the extraction time is 0.5-3h.

[0018] According to the method for removing pesticide residues from ginger oleoresin provided by the present invention, the amount of entrainer added in step (2) is 0.1-2 times the weight of ginger oleoresin raw material.

[0019] Furthermore, in step (2), the pressure of the separator is 5-10 MPa and the temperature of the separator is 30-50℃.

[0020] Furthermore, the carbon dioxide flow rate during extraction in step (2) is 5-10 L / h.

[0021] More preferably, the extraction temperature in step (2) is 45-60℃ and the extraction time is 2-6h.

[0022] In some preferred embodiments of the present invention, the method for removing pesticide residues from ginger oleoresin includes the following steps:

[0023] (1) Using caprylic / capric triglyceride as an entrainer, ginger oleoresin raw material was extracted and separated by supercritical carbon dioxide extraction device. Oily substances containing organophosphorus pesticides and ginger essential oil were obtained in the separation tank.

[0024] The entrainer is added at 5%-60% of the weight of ginger oleoresin raw material; the extraction pressure is 10-18 MPa, the extraction temperature is 45-60℃, and the extraction time is 0.5-3 h; the carbon dioxide flow rate during extraction is 5-15 L / h; the separation pressure is 5-10 MPa, and the separation temperature is 30-50℃.

[0025] (2) Using ginger essential oil as an entrainer, the remaining material in the supercritical carbon dioxide extraction device in step (1) is extracted to separate ginger oleoresin and ginger essential oil products without pesticide residues. The remaining organochlorine pesticide residues and impurities in the extraction vessel are removed.

[0026] The amount of entrainer added is 0.1-2 times the weight of ginger oleoresin raw material; the extraction pressure is 18-40 MPa, the extraction temperature is 45-60℃, and the extraction time is 2-6 h; the carbon dioxide flow rate during extraction is 5-10 L / h; the separation pressure is 5-10 MPa, and the separation temperature is 30-50℃.

[0027] Furthermore, both steps (1) and (2) employ a two-stage separation vessel for separation. The method for removing pesticide residues from ginger oleoresin includes the following steps:

[0028] (1) Using caprylic / capric triglyceride as an entrainer, ginger oleoresin raw material was extracted using a supercritical carbon dioxide extraction device. The extraction pressure was 10-18 MPa, the extraction temperature was 45-60℃, and the extraction time was 0.5-3 h. The carbon dioxide flow rate during extraction was 5-15 L / h. The amount of entrainer added was 5%-60% of the weight of ginger oleoresin raw material.

[0029] The extract then enters separation vessel one, where the pressure is 5-10 MPa and the temperature is 30-50℃, to collect pesticide residues (mainly organophosphorus pesticide residues). It then enters separation vessel two, where the pressure is 5-10 MPa and the temperature is 30-50℃, to collect ginger essential oil without pesticide residues.

[0030] (2) Using ginger essential oil as an entrainer, the remaining material in the supercritical carbon dioxide extraction device in step (1) is extracted. The extraction pressure is 18-40 MPa (greater than the extraction pressure in step (1)), the extraction temperature is 45-60℃, and the extraction time is 2-6 h. The carbon dioxide flow rate during extraction is 5-10 L / h. The amount of entrainer added is 0.1-2 times the weight of ginger oleoresin raw material.

[0031] The extract then enters separation vessel three, where the pressure is 5-10 MPa and the temperature is 30-50℃. Ginger oleoresin with pesticide residues meeting the requirements (<15 ppm) is collected. It then enters separation vessel four, where the pressure is 5-10 MPa and the temperature is 30-50℃. Ginger essential oil without pesticide residues is collected. The remaining extract vessel contains organochlorine pesticide residues and impurities.

[0032] More preferably, the pressure of separation vessel three is higher than that of separation vessel four, and the pressure of separation vessel four is controlled at 5-6 MPa.

[0033] The pesticide residue in the ginger oleoresin raw material described in this invention is 15.1-500 ppm, and the pesticide types include one or more of organophosphorus pesticides and organochlorine pesticides. Examples of organophosphorus pesticides include thiamethoxam, imidacloprid, thiamethoxam, and thiamethoxam, while examples of organochlorine pesticides include bifenthrin and cypermethrin.

[0034] This invention also provides a method for preparing ginger oleoresin, comprising obtaining crude ginger oleoresin by solvent extraction, and then removing pesticide residues from the crude ginger oleoresin using the above method. Compared with directly preparing ginger oleoresin from ginger using supercritical carbon dioxide extraction, this method has the advantages of low cost, suitability for large-scale industrial production, and the ability to obtain ginger oleoresin with higher purity, which can be utilized at a higher value.

[0035] This invention provides a method for removing pesticide residues from ginger oleoresin, solving the problem of excessive pesticide residues in ginger oleoresin products. The process of this invention is simple to operate, low in cost, and can be effectively applied to large-scale production. It can completely separate gingerol content and pesticide residues to prepare clean and safe ginger extract products. Attached Figure Description

[0036] Figure 1 This is a process flow diagram of the method for removing pesticide residues from ginger oleoresin provided in Embodiment 1 of the present invention. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0038] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, the materials and reagents used in the following examples are commercially available or prepared according to conventional methods in the art.

[0039] The raw material used in the following examples is ginger oleoresin with excessive pesticide residues extracted by solvent extraction. The pesticide residue content is 132.93 ppm, including pesticides such as cypermethrin, bifenthrin, thiamethoxam, thiamethoxam, and thiamethoxam.

[0040] It should be noted that, unless otherwise specified, the pesticide residue yields in the following examples are all calculated based on a pesticide residue level of 132.93 ppm. For example, in Example 1, "the pesticide residue yield is 64.15%" means that the pesticide residue in the first separation vessel is 132.93 ppm * 64.15% = 85.27 ppm.

[0041] Example 1

[0042] This embodiment provides a method for removing pesticide residues from ginger oleoresin, and its process flow diagram is shown below. Figure 1 As shown, the specific steps are as follows:

[0043] 400g of ginger oleoresin raw material was weighed and put into a supercritical carbon dioxide extraction vessel. Supercritical carbon dioxide was introduced into the supercritical extraction vessel, the extraction pressure was raised to 16MPa, the extraction vessel temperature was 55℃, the extraction time was 2h, the flow rate was 9L / h, and the weight of the entrainer caprylic / capric glyceride was 120g. The extract entered the first separation vessel, and the pressure of the separation vessel was controlled at 8.8MPa and the temperature at 43℃. Pesticide residues were collected, and the yield of pesticide residues was 64.15%. The pressure of the second separation vessel was 5.5MPa and the temperature was 35℃. Ginger essential oil without pesticide residues was collected.

[0044] The extraction vessel pressure was further increased to 27 MPa, the extraction vessel temperature was maintained at 50℃, the extraction time was 2 hours, and the flow rate was 6 L / h. 40 g of pesticide-free ginger essential oil was used as an entrainer. The extract entered separation vessel three, where the pressure was controlled at 8.8 MPa and the temperature at 43℃. Low-pesticide-residue ginger oleoresin was collected, with a pesticide residue level of 3.18 ppm. Separation vessel four was then subjected to a pressure of 5.5 MPa and a temperature of 35℃, where pesticide-free ginger essential oil was collected. Organochlorine pesticide residues and impurities were collected in the extraction vessel. Separation vessel one and the final extraction vessel contained virtually no gingerol, while the ginger oleoresin obtained in separation vessel three had a high gingerol content.

[0045] Example 2

[0046] This embodiment provides a method for removing pesticide residues from ginger oleoresin, specifically including:

[0047] 400g of ginger oleoresin raw material was weighed and put into a supercritical carbon dioxide extraction vessel. Supercritical carbon dioxide was introduced into the supercritical extraction vessel, the extraction pressure was raised to 11MPa, the extraction vessel temperature was 55℃, the extraction time was 2h, the flow rate was 9L / h, and the weight of the entrainer caprylic / capric glyceride was 120g. The extract entered the first separation vessel, and the pressure of the separation vessel was controlled at 8.8MPa and the temperature at 43℃. Pesticide residues were collected, and the yield of pesticide residues was 61.28%. The pressure of the second separation vessel was 5.5MPa and the temperature was 35℃. Ginger essential oil without pesticide residues was collected.

[0048] The pressure in the extraction vessel was further increased to 27 MPa, the temperature was 50°C, the extraction time was 2 hours, the flow rate was 6 L / h, and 40 g of pesticide-free ginger essential oil was used as an entrainer. The extract entered the separation vessel, where the pressure was 8.8 MPa and the temperature was 43°C. Low-pesticide-residue ginger oleoresin was collected, with a pesticide residue of 3.64 ppm. The pressure in the fourth separation vessel was 5.5 MPa and the temperature was 35°C, where pesticide-free ginger essential oil was collected. Organochlorine pesticide residues and impurities were collected in the extraction vessel.

[0049] Example 3

[0050] This embodiment provides a method for removing pesticide residues from ginger oleoresin, specifically including:

[0051] 400g of ginger oleoresin raw material was weighed and put into a supercritical carbon dioxide extraction vessel. Supercritical carbon dioxide was introduced into the supercritical extraction vessel, the extraction pressure was raised to 16MPa, the extraction vessel temperature was 55℃, the extraction time was 2h, the flow rate was 9L / h, and the weight of the entrainer caprylic / capric glyceride was 20g. The extract entered the first separation vessel, and the pressure of the separation vessel was controlled at 8.8MPa and the temperature at 43℃. Pesticide residues were collected, and the yield of pesticide residues was 59.29%. The pressure of the second separation vessel was 5.5MPa and the temperature was 35℃. Ginger essential oil without pesticide residues was collected.

[0052] The pressure in the extraction vessel was further increased to 27 MPa, the temperature was 50°C, the extraction time was 2 hours, the flow rate was 6 L / h, and 40 g of pesticide-free ginger essential oil was used as an entrainer. The extract entered the separation vessel, where the pressure was 8.8 MPa and the temperature was 43°C. Low-pesticide-residue ginger oleoresin was collected, with a pesticide residue of 5.53 ppm. The pressure in the fourth separation vessel was 5.5 MPa and the temperature was 35°C, where pesticide-free ginger essential oil was collected. Organochlorine pesticide residues and impurities were collected in the extraction vessel.

[0053] Example 4

[0054] This embodiment provides a method for removing pesticide residues from ginger oleoresin, specifically including:

[0055] 400g of ginger oleoresin raw material was weighed and put into a supercritical carbon dioxide extraction vessel. Supercritical carbon dioxide was introduced into the supercritical extraction vessel, the extraction pressure was raised to 16MPa, the extraction vessel temperature was 55℃, the extraction time was 2h, the flow rate was 9L / h, and the weight of the entrainer caprylic / capric glyceride was 220g. The extract entered the first separation vessel, and the pressure of the separation vessel was controlled at 8.8MPa and the temperature at 43℃. Pesticide residues were collected, and the yield of pesticide residues was 63.64%. The pressure of the second separation vessel was 5.5MPa and the temperature was 35℃. Ginger essential oil without pesticide residues was collected.

[0056] The pressure in the extraction vessel was increased to 27 MPa, the temperature was set at 50°C, the extraction time was 2 hours, and the flow rate was 6 L / h. 40 g of pesticide-free ginger essential oil was used as an entrainer. The extract entered the separation vessel. The pressure in the third separation vessel was 8.8 MPa, the temperature was 43°C, and ginger oleoresin with low pesticide residue was collected. The pesticide residue was 1.58 ppm. The pressure in the fourth separation vessel was 5.5 MPa, the temperature was 35°C, and pesticide-free ginger essential oil was collected. Organochlorine pesticide residues and impurities were collected in the extraction vessel.

[0057] Example 5

[0058] This embodiment provides a method for removing pesticide residues from ginger oleoresin, specifically including:

[0059] 400g of ginger oleoresin raw material was weighed and put into a supercritical carbon dioxide extraction vessel. Supercritical carbon dioxide was introduced into the supercritical extraction vessel, the extraction pressure was raised to 16MPa, the extraction vessel temperature was 55℃, the extraction time was 2h, the flow rate was 9L / h, and the weight of the entrainer caprylic / capric glyceride was 120g. The extract entered the first separation vessel, and the pressure of the separation vessel was controlled at 8.3MPa and the temperature at 43℃. Pesticide residues were collected, and the yield of pesticide residues was 65.67%. The pressure of the second separation vessel was 5.5MPa and the temperature was 35℃. Ginger essential oil without pesticide residues was collected.

[0060] The pressure in the extraction vessel was further increased to 27 MPa, the temperature was 50°C, the extraction time was 2 hours, the flow rate was 6 L / h, and 40 g of pesticide-free ginger essential oil was used as an entrainer. The extract entered the separation vessel, where the pressure was 8.8 MPa and the temperature was 43°C. Low-pesticide-residue ginger oleoresin was collected, with a pesticide residue of 2.90 ppm. The pressure in the fourth separation vessel was 5.5 MPa and the temperature was 35°C, where pesticide-free ginger essential oil was collected. Organochlorine pesticide residues and impurities were collected in the extraction vessel.

[0061] Example 6

[0062] This embodiment provides a method for removing pesticide residues from ginger oleoresin, specifically including:

[0063] 400g of ginger oleoresin raw material was weighed and put into a supercritical carbon dioxide extraction vessel. Supercritical carbon dioxide was introduced into the supercritical extraction vessel, the extraction pressure was raised to 16MPa, the extraction vessel temperature was 55℃, the extraction time was 2h, the flow rate was 9L / h, and the weight of the entrainer caprylic / capric glyceride was 120g. The extract entered the first separation vessel, and the pressure of the separation vessel was controlled at 9.6MPa and the temperature at 43℃. Pesticide residues were collected, and the yield of pesticide residues was 58.63%. The pressure of the second separation vessel was 5.5MPa and the temperature was 35℃. Ginger essential oil without pesticide residues was collected.

[0064] The pressure in the extraction vessel was further increased to 27 MPa, the temperature was 50°C, the extraction time was 2 hours, the flow rate was 6 L / h, and 40 g of pesticide-free ginger essential oil was used as an entrainer. The extract entered the separation vessel, where the pressure was 7.5 MPa and the temperature was 43°C. Low-pesticide-residue ginger oleoresin was collected, with a pesticide residue of 3.57 ppm. The pressure in the fourth separation vessel was 6.0 MPa and the temperature was 35°C. Pesticide-free ginger essential oil was collected. Organochlorine pesticide residues and impurities were collected in the extraction vessel.

[0065] Example 7

[0066] This embodiment provides a method for removing pesticide residues from ginger oleoresin, specifically including:

[0067] 400g of ginger oleoresin raw material was weighed and put into a supercritical carbon dioxide extraction vessel. Supercritical carbon dioxide was introduced into the supercritical extraction vessel, the extraction pressure was raised to 16MPa, the extraction vessel temperature was 55℃, the extraction time was 2h, the flow rate was 9L / h, and the weight of the entrainer caprylic / capric glyceride was 120g. The extract entered the first separation vessel, and the pressure of the separation vessel was controlled at 8.8MPa and the temperature at 43℃. Pesticide residues were collected, and the pesticide residue recovery rate was 61.61%. The pressure of the second separation vessel was 5.5MPa and the temperature was 35℃. Ginger essential oil without pesticide residues was collected.

[0068] The extraction vessel pressure was further increased to 27 MPa, the extraction vessel temperature was 50℃, the extraction time was 2 hours, the flow rate was 6 L / h, and 600 g of pesticide-free ginger essential oil was used as an entrainer. The extract entered the third separation vessel, where the pressure was controlled at 8.8 MPa and the temperature at 43℃. Low pesticide residue ginger oleoresin was collected, with a pesticide residue content of 8.83 ppm. The fourth separation vessel pressure was 5.5 MPa and the temperature was 35℃, where pesticide-free ginger essential oil was collected. Organochlorine pesticide residues and impurities were collected in the extraction vessel, and the gingerol content in the extract was 1.59%.

[0069] Example 8

[0070] This embodiment provides a method for removing pesticide residues from ginger oleoresin, specifically including:

[0071] 400g of ginger oleoresin raw material was weighed and put into a supercritical carbon dioxide extraction vessel. Supercritical carbon dioxide was introduced into the supercritical extraction vessel, the extraction pressure was raised to 16MPa, the extraction vessel temperature was 55℃, the extraction time was 2h, the flow rate was 9L / h, and the weight of the entrainer caprylic / capric glyceride was 120g. The extract entered the first separation vessel, and the pressure of the separation vessel was controlled at 8.8MPa and the temperature at 43℃. Pesticide residues were collected, and the pesticide residue recovery rate was 62.19%. The pressure of the second separation vessel was 5.5MPa and the temperature was 35℃. Ginger essential oil without pesticide residues was collected.

[0072] The extraction vessel pressure was further increased to 37 MPa, the extraction vessel temperature was 50℃, the extraction time was 2 hours, the flow rate was 6 L / h, and 40 g of pesticide-free ginger essential oil was used as an entrainer. The extract entered the third separation vessel, and the pressure of the separation vessel was controlled at 8.8 MPa and the temperature at 43℃. Ginger oleoresin with low pesticide residue was collected, with a pesticide residue of 7.54 ppm. The pressure of the fourth separation vessel was 5.5 MPa and the temperature was 35℃. Pesticide-free ginger essential oil was collected. Organochlorine pesticide residues and impurities were collected in the extraction vessel.

[0073] Comparative Example 1

[0074] This comparative example provides a method for removing pesticide residues from ginger oleoresin. The specific method differs from Example 1 in that no entrainer, caprylic / capric triglyceride, is added during the pesticide residue extraction process. The yield of pesticide residues in separation vessel one is 11.25%; the pesticide residue rate in ginger essential oil in separation vessel two is 52.39%. It is evident that this comparative example does not effectively separate pesticide residues from ginger essential oil, with a large amount of pesticide residue remaining in the ginger essential oil.

[0075] Comparative Example 2

[0076] This comparative example provides a method for removing pesticide residues from ginger oleoresin. The specific method differs from that in Example 1 in that ginger essential oil is used as an entrainer during the pesticide residue extraction process, in accordance with CN112546665B. The pesticide residues are extracted and separated at 16 MPa, and the pesticide residues and ginger essential oil are completely mixed in the separation vessel.

[0077] Comparative Example 3

[0078] This comparative example provides a method for removing pesticide residues from ginger oleoresin. The specific method differs from that in Example 1 in that the extraction pressure during the pesticide residue extraction process is 9 MPa, the yield of pesticide residues in separation vessel one is 16.51%, and the pesticide-free ginger essential oil is collected in separation vessel two.

[0079] The pressure in the extraction vessel was increased to 27 MPa, the temperature was set at 50°C, the extraction time was 2 hours, the flow rate was 6 L / h, and pesticide-free ginger essential oil was used as an entrainer. The extract entered the separation vessel, where ginger oleoresin was collected. The yield of pesticide residues in the ginger oleoresin was 48.92%.

[0080] Comparative Example 4

[0081] This comparative example provides a method for removing pesticide residues from ginger oleoresin. The specific method differs from Example 1 in that the extraction pressure during pesticide residue extraction is 19 MPa, the yield of pesticide residues in separation vessel one is 65.16%, and the gingerol content yield is 12.35% (based on the total gingerol content in the input raw materials); separation vessel two collects ginger essential oil without pesticide residues. It is evident that in this comparative example, some gingerol remained in separation vessel one and was not well separated from the pesticide residues, while the gingerol content in the ginger oleoresin in separation vessel three was significantly reduced.

[0082] Comparative Example 5

[0083] This comparative example provides a method for removing pesticide residues from ginger oleoresin. The specific method differs from that in Example 1 in that the pressure of the first separation vessel is controlled at 4 MPa to collect pesticide residues, the pesticide residue recovery rate is 64.94%, and the ginger essential oil content in the first separation vessel is 21%; the remaining ginger essential oil without pesticide residues is collected in the second separation vessel.

[0084] Comparative Example 6

[0085] This comparative example provides a method for removing pesticide residues from ginger oleoresin. The specific method differs from that in Example 1 in that the pressure of the first separation vessel is controlled at 11 MPa to collect pesticide residues, and the pesticide residue recovery rate is 3.57%; the remaining ginger essential oil is collected in the second separation vessel, and the pesticide residue recovery rate is 59.16%.

[0086] Comparative Example 7

[0087] This comparative example provides a method for removing pesticide residues from ginger oleoresin. The specific method differs from Example 7 in that the extraction vessel pressure is further increased to 43 MPa. In the third separation vessel, ginger oleoresin is collected, with a pesticide residue level of 40.62 ppm. In the fourth separation vessel, ginger essential oil without pesticide residue is collected. It is evident that when the extraction pressure exceeds 40 MPa in the second step, pesticide residues are separated into the ginger oleoresin product.

[0088] Comparative Example 8

[0089] This comparative example provides a method for removing pesticide residues from ginger oleoresin. The specific method differs from Example 7 in that the extraction vessel pressure is further increased to 17 MPa. In the third separation vessel, ginger oleoresin with low pesticide residue is collected (1.68 ppm). In the fourth separation vessel, ginger essential oil without pesticide residue is collected. The extraction vessel collects organochlorine pesticide residues and impurities. The gingerol content in the extract is 25.91%. It is evident that the extraction pressure in the second step is below 18 MPa, resulting in incomplete extraction of gingerol from the extract and a lower product yield.

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for removing pesticide residues from ginger oleoresin, characterized in that, Includes the following steps: (1) Using fatty acids as entrainers, supercritical carbon dioxide extraction was used to separate organophosphorus pesticides and ginger essential oil from ginger oleoresin raw materials; The extraction pressure is 10-18 MPa, and the extraction temperature is 35-70℃. (2) Using ginger essential oil as an entrainer, the remaining material in the supercritical carbon dioxide extraction device in step (1) is extracted and separated to obtain ginger oleoresin without pesticide residue. The extraction pressure is 18-40 MPa, and the extraction temperature is 35-70℃. The fatty acid is caprylic / capric triglyceride.

2. The method for removing pesticide residues from ginger oleoresin according to claim 1, characterized in that, In step (1), the amount of entrainer added is 5%-60% of the weight of ginger oleoresin raw material.

3. The method for removing pesticide residues from ginger oleoresin according to claim 2, characterized in that, In step (1), the pressure of the separator is 5-10 MPa and the temperature of the separator is 30-50℃.

4. The method for removing pesticide residues from ginger oleoresin according to claim 3, characterized in that, In step (1), the carbon dioxide flow rate during extraction is 5-15 L / h.

5. The method for removing pesticide residues from ginger oleoresin according to claim 1, characterized in that, In step (2), the amount of entrainer added is 0.1-2 times the weight of ginger oleoresin raw material.

6. The method for removing pesticide residues from ginger oleoresin according to claim 5, characterized in that, In step (2), the pressure of the separator is 5-10 MPa and the temperature of the separator is 30-50℃.

7. The method for removing pesticide residues from ginger oleoresin according to claim 6, characterized in that, In step (2), the carbon dioxide flow rate during extraction is 5-10 L / h.

8. The method for removing pesticide residues from ginger oleoresin according to any one of claims 1-7, characterized in that, The residual pesticide content in the ginger oleoresin raw material is 15.1-500 ppm, and the pesticide types include one or more of organophosphorus pesticides and organochlorine pesticides.

9. A method for preparing ginger oleoresin, characterized in that, This includes obtaining crude ginger oleoresin by solvent extraction, and then removing pesticide residues from the crude ginger oleoresin using the method described in any one of claims 1-8.

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