A method for ultrasonic extraction of curcumin from turmeric using porous crystalline nanomaterials combined with solvents

Abstract

This invention discloses a method for ultrasonic extraction of curcumin from turmeric using porous crystalline nanomaterials combined with solvent. The specific process involves: crushing and sieving dried turmeric, adding it to a solvent at a specific material-to-liquid ratio, adding a certain amount of porous crystalline nanomaterials, and then ultrasonically extracting the curcumin-containing extract. This invention utilizes porous crystalline nanomaterials such as graphene oxide, fullerol, and MOF materials to assist in extraction, resulting in a process that uses less organic solvent, has a faster extraction speed, a higher extraction rate, significantly reduced costs, and obvious economic value.

Description

Technical Field

[0001] This invention belongs to the field of natural compound extraction technology, specifically relating to a method for ultrasonic extraction of curcumin using porous crystalline nanomaterials combined with solvent. Background Technology

[0002] Porous crystalline nanomaterials refer to nanoscale (at least one dimension smaller than 100 nm) materials with a porous structure and high specific surface area and high porosity. Common types include carbon-based nanomaterials and metal-organic frameworks (MOFs). Carbon-based materials refer to carbon materials with at least one dimension of dispersed phase smaller than 100 nm, including graphene oxide and fullerols. They possess characteristics such as high specific surface area, high thermal conductivity, high electrical conductivity, high stability, high chemical inertness, and low density. For example, graphene oxide (GO), as an important oxide of graphene, has a considerably high specific surface area and abundant hydroxyl and epoxy functional groups, showing broad application prospects in composite materials, catalysis, and biomedicine. Metal-organic frameworks, on the other hand, refer to crystalline porous materials with a periodic network structure formed by the self-assembly of transition metal ions and organic ligands. They possess advantages such as high porosity, low density, large specific surface area, regular channels, tunable pore size, and diverse and customizable topologies.

[0003] Curcumin is a natural polyphenolic compound extracted from plants of the genus Curcuma in the ginger family (Zingiberaceae). The content of curcumin compounds is relatively high in the rhizomes of turmeric. Numerous studies have shown that curcumin compounds have significant health-promoting effects, including antiviral, anti-inflammatory, antioxidant, antibacterial, antitumor, and lipid-lowering properties. Due to its excellent anticancer, anti-inflammatory, and antibacterial properties, it is widely used in the pharmaceutical industry and, as a coloring agent, is considered a valuable natural food pigment, having long been widely used in seasonings and food additives both domestically and internationally.

[0004] Curcumin, with a diketone structure, is an orange-yellow crystalline powder, insoluble in water and ether. Its extraction and separation methods have long been a focus of research. Numerous studies have been conducted both domestically and internationally on the extraction of curcuminoids from turmeric, including solvent extraction, percolation, acid-base extraction, supercritical fluid extraction, enzymatic methods, sodium salicylate extraction, and ultrasonic methods. Solvent extraction, however, is time-consuming and results in significant losses; acid-base extraction may lead to curcumin decomposition. In recent years, ultrasonic and enzymatic extraction methods have begun to be applied to curcumin extraction. For example, CN106866397A describes a method where turmeric is sequentially subjected to ethanol immersion and concentration, petroleum ether extraction and concentration, sodium hydroxide aqueous solution dissolution, and ethyl acetate extraction and concentration to obtain a primary turmeric extract. This primary extract is then dissolved in ethanol and further separated using a specially modified attapulgite in conjunction with ultrasound for highly matched adsorption and separation. While this method can yield a mixture of demethoxycurcumin and didemethoxycurcumin, as well as high-purity curcumin, the overall process is complex, utilizing various organic solvents and a specially prepared attapulgite. CN113387785A discloses a method for extracting curcumin from turmeric using a combination of enzymatic extraction and continuous flow ultrasound-assisted extraction, which improves the yield and purity of the curcumin extract. However, the enzyme extraction method requires stringent enzyme activity and sophisticated equipment. Another method involves supercritical CO2 extraction, which is convenient and leaves no toxic residues. However, supercritical fluid extraction requires significant equipment investment, making large-scale production difficult. Given the numerous factors affecting extraction rate and the considerable differences in the type and state of raw materials, it is crucial to explore an extraction method that achieves high extraction rate, fast extraction speed, low organic solvent consumption, and minimal impact on the activity of curcumin-like compounds. Summary of the Invention

[0005] To address the shortcomings of existing curcumin extraction processes, this invention provides a method for extracting curcumin from turmeric using porous crystalline nanomaterials combined with solvent ultrasonic leaching. This method can significantly improve the extraction efficiency of curcumin, and the porous crystalline nanomaterial-assisted solvent extraction method is also an economical and green new method for extracting curcumin.

[0006] This invention provides a method for ultrasonic extraction of curcumin from turmeric using porous crystalline nanomaterials combined with a solvent, comprising the following steps:

[0007] After crushing and sieving the dried turmeric, it was added to the solvent at a material-to-liquid ratio of 1:10 to 1:20 g / L. Then, porous crystalline nanomaterials were added to the solvent at a mass ratio of 0.5 to 2 mg / g to turmeric. The mixture was then ultrasonically extracted and filtered to obtain an extract containing curcumin.

[0008] The method wherein the solvent is an aqueous solution of methanol or ethanol.

[0009] The method wherein the solvent contains 60% to 80% by volume of methanol or ethanol.

[0010] The method wherein the ultrasonic power is 100-150W.

[0011] The method wherein the ultrasonic immersion temperature is 50–70°C.

[0012] The method wherein the ultrasonic immersion time is 1.5 to 2.5 hours.

[0013] The porous crystalline nanomaterial described in the method is one or a combination of graphene oxide, fullerol, and MOF materials.

[0014] The method described herein, wherein the crushing and sieving is performed through a sieve of 24 to 80 mesh.

[0015] Compared with the prior art, the beneficial effects of the present invention include:

[0016] 1. The process of this invention is simple and easy to operate. The solvent used in the process is simple and readily available, and there are no toxic or harmful residues. Compared with other existing methods for extracting curcumin using ultrasound, the nanomaterial-assisted solvent ultrasound extraction process of this invention has a higher extraction rate of curcumin.

[0017] 2. This invention reduces the production cost of curcumin in industrial production. The reduction in extraction temperature and solvent concentration also means a safer environment in industrial production, which is in line with the modern society's green, clean and environmentally friendly production concept. Attached Figure Description

[0018] Figure 1 This is a comparison chart showing the yield of curcumin extracted by Examples 1-4 and the comparative example of the present invention relative to other existing methods;

[0019] Figure 2 This is a comparison chart showing the cost required to extract curcumin in Examples 1 and 2 of the present invention, Comparative Examples 1 and 2, and methods disclosed in existing journal articles. Detailed Implementation

[0020] To enhance understanding of the present invention, the following detailed description is provided with reference to embodiments. These embodiments are for illustrative purposes only and do not constitute a limitation on the scope of protection of the present invention. Modifications or improvements made based on the present invention that are obvious to those skilled in the art are within the scope of protection claimed by the present invention.

[0021] Example 1

[0022] After crushing dried turmeric, it was passed through a 24-mesh sieve and added to a 60% volume ratio ethanol solvent at a material-to-liquid ratio of 1:10 g / L. Then, graphene oxide was added to the solvent at a mass ratio of 1 mg / g to turmeric. After soaking for 1.5 h at 50℃ and 100 W ultrasonic power, the extract containing curcumin was obtained by filtration.

[0023] The absorbance of the extract in this embodiment was measured at 424 nm using a UV spectrophotometer, and the curcumin yield was calculated to be 6.50%.

[0024] Example 2

[0025] After crushing dried turmeric, it was passed through a 50-mesh sieve and added to a 65% volume ratio methanol solvent at a material-to-liquid ratio of 1:15 g / L. Then, graphene oxide was added to the solvent at a mass ratio of 1.5 mg / g to turmeric. After soaking for 2 hours at 55℃ and 120 W ultrasonic power, the extract containing curcumin was obtained by filtration.

[0026] The absorbance of the extract in this embodiment was measured at 424 nm using a UV spectrophotometer, and the curcumin yield was calculated to be 6.62%.

[0027] Example 3

[0028] After crushing the dried turmeric, it was passed through a 65-mesh sieve and added to a 70% volume ratio ethanol solvent at a material-to-liquid ratio of 1:15 g / L. Fullerol was then added to the solvent at a mass ratio of 1.5 mg / g to turmeric. The extract was then soaked at 60°C and 130 W of ultrasonic power for 2 hours and then filtered to obtain an extract containing curcumin.

[0029] The absorbance of the extract in this embodiment was measured at 424 nm using a UV spectrophotometer, and the curcumin yield was calculated to be 6.67%.

[0030] Example 4

[0031] After crushing the dried turmeric, it was passed through an 80-mesh sieve and added to an 80% volume ratio of ethanol solvent at a material-to-liquid ratio of 1:20 g / L. Fullerol was then added to the solvent at a mass ratio of 2 mg / g to turmeric. The extract was then soaked at 65°C and 140 W of ultrasonic power for 2.5 h and filtered to obtain an extract containing curcumin.

[0032] The absorbance of the extract in this embodiment was measured at 424 nm using a UV spectrophotometer, and the curcumin yield was calculated to be 6.69%.

[0033] Example 5

[0034] After crushing dried turmeric, it was passed through an 80-mesh sieve and added to an 80% volume ratio methanol solvent at a material-to-liquid ratio of 1:15 g / L. Then, MOF material ZIF-8 was added to the solvent at a mass ratio of 1.5 mg / g to turmeric. After soaking for 2 hours at 60℃ and 140 W ultrasonic power, the extract containing curcumin was obtained by filtration.

[0035] The absorbance of the extract in this embodiment was measured at 424 nm using a UV spectrophotometer, and the curcumin yield was calculated to be 6.67%.

[0036] Example 6

[0037] After crushing dried turmeric, it was passed through a 50-mesh sieve and added to a 60% volume ratio methanol solvent at a material-to-liquid ratio of 1:15 g / L. Then, MOF material ZIF-8 was added to the solvent at a mass ratio of 0.5 mg / g to turmeric. After soaking for 2 hours at 70℃ and 120 W ultrasonic power, the extract containing curcumin was obtained by filtration.

[0038] The absorbance of the extract in this embodiment was measured at 424 nm using a UV spectrophotometer, and the curcumin yield was calculated to be 6.38%.

[0039] Example 7: Comparison of the extraction effects of curcumin by the method of this application, comparative examples, and existing methods.

[0040] 1. Experimental setup

[0041] (1) Experimental method: The method described in Examples 1-4;

[0042] (2) Comparative Example 1

[0043] Dried turmeric was crushed and passed through a 50-mesh sieve. It was then added to a 70% (v / v) ethanol solvent at a material-to-liquid ratio of 1:10 g / L, without adding any porous crystalline nanomaterials. The extract was then steeped at 60℃ and ultrasonically at 150W for 2 hours, followed by filtration to obtain a curcumin-containing extract. The absorbance of the extract was measured at 424 nm using a UV spectrophotometer, and the curcumin yield was calculated to be 6.10%.

[0044] Comparative Example 2

[0045] Dried turmeric was crushed and passed through a 50-mesh sieve. It was then added to a 70% (v / v) methanol solvent at a material-to-liquid ratio of 1:15 g / L, without adding any nanomaterials. The extract was then steeped at 60°C and 120 W ultrasonically for 2.5 hours, followed by filtration to obtain an extract containing curcumin. The absorbance of this comparative example extract was measured at 424 nm using a UV spectrophotometer, and the curcumin yield was calculated to be 6.27%.

[0046] (3) Prior art methods: The following prior art methods for extracting curcumin are used as comparative methods:

[0047] Existing patent 1: CN113387785A;

[0048] Existing patent 2: CN106866397A;

[0049] Existing literature: "Optimization of ultrasonic-assisted extraction of curcumin compounds and kinetic analysis using response surface methodology" published by Sun Pengyao et al. in 2016.

[0050] 2. Comparison of extraction results

[0051] Using curcumin yield as the evaluation index, the effects of Examples 1-4 of this application, comparative examples, existing patents, and literature methods on curcumin extraction from turmeric were compared. The results are as follows: Figure 1 As shown.

[0052] It can be seen that under the process conditions of temperature 50-70℃, solvent volume fraction 60-80%, material-liquid ratio 1:10-1:20 g / L, ultrasonic power 100-150W, and extraction time 1.5-2.5h, in Comparative Examples 1 and 2, without the addition of porous crystalline nanomaterials, the curcumin content after ultrasonic-assisted extraction with ethanol or methanol was 6.10% and 6.27%, respectively.

[0053] Comparing the results of each group: In Example 1, the curcumin yield was 6.50% after ultrasound-assisted ethanol extraction with 1 mg / g graphene oxide. In Example 2, the curcumin yield was 6.62% after ultrasound-assisted methanol extraction with 1.5 mg / g graphene oxide. In Example 3, the curcumin yield was 6.67% after ultrasound-assisted ethanol extraction with 1.5 mg / g fullerol. In Example 4, the curcumin yield was 6.69% after ultrasound-assisted ethanol extraction with 2 mg / g fullerol. In Example 5, the curcumin yield was 6.67% after ultrasound-assisted methanol extraction with 1.5 mg / g MOF material ZIF-8. In Example 6, the curcumin yield was 6.38% after ultrasound-assisted ethanol extraction with 0.5 mg / g MOF material ZIF-8.

[0054] The curcumin yields in existing patents and literature are as follows:

[0055] Existing patent 1 (CN113387785A): Fresh turmeric is washed, cut into slices, dried, pulverized, and sieved to obtain fine turmeric powder. 1000ml of pure water is added and stirred evenly. The mixture is then placed in a water bath at 65℃ for 50 minutes to obtain turmeric slurry. A complex enzyme (1.0% cellulase, 1.0% hemicellulase, 0.5% pectinase, and 1.0% amylase) is added to the turmeric slurry, and the pH of the enzymatic hydrolysis system is adjusted to 4.2. Enzymatic hydrolysis is performed for 4 hours, enzyme activity is inactivated, and the mixture is cooled and filtered to obtain enzymatically hydrolyzed turmeric powder. The enzymatically hydrolyzed turmeric powder is subjected to continuous flow ultrasonic extraction for 70 minutes. The extracted liquid is pumped out every 5 minutes using a peristaltic pump. The extracted liquid is recycled twice. The filtrate is filtered, concentrated, homogenized, and spray-dried. The highest curcumin yield is 5.12%.

[0056] Existing patent 2 (CN106866397A): Dried turmeric is added to ethanol (75% aqueous solution, volume concentration) (solid-liquid ratio 1g:9mL), and extracted at 55℃ for 50min, while simultaneously subjected to 45Hz ultrasound. The turmeric extract is used to prepare a paste, which is then extracted with ethanol and ethyl acetate. The paste is then added to ethanol (75% aqueous solution, volume concentration 1g:9mL), modified attapulgite is added, and the pH is adjusted to 6-7 (20wt% dilute hydrochloric acid). The mixture is then ultrasonically vibrated at 38Hz for 35min to obtain an adsorbent solution. The adsorbent solution is then subjected to… The mixture was filtered, and then concentrated and dried to obtain a mixture of demethoxycurcumin and bisdemethoxycurcumin. The filter residue was added to ethanol (75% aqueous solution, volume concentration) (material-to-liquid ratio of 1g:9mL), ultrasonically vibrated at 60Hz for 25min, and then filtered. The filter residue was recovered and dried for recycling as modified attapulgite. The filtrate was concentrated and dried to obtain curcumin. The total extraction rate of the three curcumin compounds (demethoxycurcumin, bisdemethoxycurcumin, and curcumin) was 4.71%, and the curcumin yield was 3.76%.

[0057] Existing literature ("Optimization of Ultrasonic-Assisted Extraction of Curcumin Compounds and Kinetic Analysis using Response Surface Methodology"): The optimal process is an ethanol concentration of 80.4%, a solid-liquid ratio of 1:21.9 g / mL, an extraction temperature of 41℃, and a curcumin yield of 4.430%.

[0058] Therefore, even without the addition of porous crystalline nanomaterials, the curcumin yield obtained by ultrasonic extraction according to the process method of this application is significantly higher than that of existing ultrasonic extraction and other extraction methods. The addition of nanomaterials further significantly improves the extraction efficiency of curcumin, especially since existing patent 2 uses modified attapulgite as an ultrasonic-assisted extraction agent, but the curcumin extraction rate is significantly lower than that of the embodiments of this invention.

[0059] 3. Cost comparison

[0060] Using comprehensive cost as the evaluation index, the extraction costs of Example 1, Comparative Example 1, Example 2, Comparative Example 2 of this application and the method disclosed in "Optimization of Ultrasonic-Assisted Extraction of Curcumin Compounds and Kinetic Analysis by Response Surface Methodology" published by Sun Pengyao et al. in 2016 were compared.

[0061] Calculation method:

[0062] Reagents, materials, and electricity costs are all calculated at industrial prices: electricity is 1.025 yuan per kilowatt-hour, ethanol is 20 yuan per liter, graphene oxide is 1750 yuan per kilogram, and methanol is 67.6 yuan per liter.

[0063] Electricity cost = (δ1 + δ2) α = [(t1'P l )+(t2.v2)].α (1)

[0064] In the formula, δ1 and δ2 are the electrical energy consumed by the ultrasonic machine during heating and operation (kW·h), t1 is the time required for the ultrasonic machine to heat to the specified temperature (h), t2 is the ultrasonic extraction time (h), P1 and P2 are the heating power (0.55kW) and ultrasonic power (0.15kW), and α is the electricity cost.

[0065]

[0066] (Note: 1 kW / h = 3.6 × 10⁻⁶) 6 J)

[0067] In the formula, W is the work done by heat (J), Q is the heat (J), and C is the specific heat capacity (60% ethanol: 3.22 × 10⁻⁶). 3 J / (kg·℃), 70% ethanol: 3.03×10 3 J / (kg·℃)), M is the solvent mass (Example 1 (0.088 kg), Comparative Example 1 (0.086 kg), ΔT1: the difference between the extraction temperature and the solvent temperature before heating (25℃).

[0068]

[0069] Cost of graphene oxide = m·m0·γ·10 -6 (4)

[0070] In the formula, τ is the volume fraction of ethanol (%), β is the volume of solvent (L), m is the price per unit volume of ethanol (per L), m is the mass of dried turmeric powder (g), m0 is the concentration of graphene oxide (mg / g), and γ is the price per unit mass of graphene oxide (per mg).

[0071] Total cost = Electricity cost + Solvent cost + Graphene oxide cost (5)

[0072] Example 2, Comparative Example 2, and existing literature methods also calculate the corresponding electricity and solvent costs using the formulas described above.

[0073] The estimated costs of Example 1, Comparative Example 1, Example 2, Comparative Example 2, and existing literature were compared. In the extraction process, the total cost of the method in Example 1 (171,009.6 yuan / ton) was reduced by approximately 26,000 yuan per ton of turmeric powder used, compared to Comparative Example 1 (145,010 yuan / ton); and the total cost of the method in Example 2 (692,755 yuan / ton) was reduced by approximately 55,822 yuan per ton of turmeric powder used, compared to Comparative Example 2 (748,577 yuan / ton).

[0074] According to statistics, my country's annual production of dried turmeric is approximately 9,000 tons. Based on this usage, the annual costs of the methods in Example 1, Comparative Example 1, Example 2, and Comparative Example 2 were compared. The total annual cost for the method in Example 1 was 1,305,090,000 yuan, for Comparative Example 1 it was 1,539,080,000 yuan, for Example 2 it was 6,234,795,000 yuan, and for Comparative Example 2 it was 6,737,193,000 yuan. Figure 2 As shown. That is, if the process of Example 1 is applied to the industrial production of curcumin, the annual cost is RMB 1,305.09 million, which can generate an additional profit of approximately RMB 234 million compared with the process of Comparative Example 1 (annual cost of RMB 1,539.08 million).

[0075] The above calculation results show that, compared with Comparative Example 1, the method in Example 1 of this invention uses less ethanol, has a shorter extraction time, reduces extraction costs, and achieves a higher yield. Compared with existing literature, the method in Example 1 of this invention reduces the volume fraction of ethanol, uses less solvent, reduces extraction costs, and achieves a higher yield. Compared with Comparative Example 2, the method in Example 2 of this invention uses less methanol, has a shorter extraction time, lower extraction costs, and achieves a higher yield. Although it increases the cost of nanomaterials such as graphene oxide, ultrasound-assisted ethanol extraction with graphene oxide can still significantly reduce the overall production cost of curcumin for industrial production.

[0076] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art will understand that modifications can 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 ultrasonic extraction of curcumin from turmeric using porous crystalline nanomaterials combined with a solvent, characterized in that... The process includes the following steps: after crushing dried turmeric, it is sieved and added to a solvent at a material-to-liquid ratio of 1:10 to 1:20 g / L. Then, porous crystalline nanomaterials are added to the solvent at a mass ratio of 0.5 to 2 mg / g to turmeric. The mixture is then ultrasonically extracted and filtered to obtain an extract containing curcumin. The porous crystalline nanomaterials include one or more of graphene oxide and MOF materials, wherein the MOF material is ZIF-8.

2. The method of claim 1, wherein the solvent is an aqueous solution of methanol or ethanol.

3. The method of claim 2, wherein the solvent contains 60% to 80% by volume of methanol or ethanol.

4. The method as described in claim 1, wherein the ultrasonic power is 100~150W.

5. The method of claim 1, wherein the ultrasonic immersion temperature is 50~70°C.

6. The method of claim 1, wherein the ultrasonic immersion time is 1.5 to 2.5 hours.

7. The method of claim 1, wherein the crushing and sieving is performed through a 24-80 mesh sieve.

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