ascorbic acid eutectic

Abstract

An ascorbic acid eutectic is composed of ascorbic acid and a polyol bonded to ascorbic acid by intermolecular forces. The polyol is selected from diols with a total carbon number of 4 to 10, sorbitol monolaurate, sorbitol monopalmitate, sorbitol monostearate, or polyoxyethylene sorbitan monolaurate. Based on a total ascorbic acid eutectic content of 100 mol%, the ascorbic acid content is 20 mol% or more but less than 100 mol%. Through the intermolecular bonding of the polyol to ascorbic acid, the degradation rate of the ascorbic acid eutectic in aqueous solution or at different pH environments is lower than that of ascorbic acid, indicating that it is less susceptible to oxidative degradation due to environmental influences. Therefore, its stability is superior to that of ascorbic acid, and its antioxidant capacity is comparable to that of ascorbic acid and superior to previous ascorbic acid derivatives.

Description

Technical Field

[0001] This invention relates to an ascorbic acid derivative, and more particularly to an ascorbic acid eutectic. Prior Technology

[0002] Ascorbic acid (AA) is an excellent antioxidant and is used in fields such as cosmetics and skincare products. However, in environments containing light, heat, oxygen, alkalis, or heavy metals, ascorbic acid easily decomposes and loses its activity. Therefore, ascorbic acid has poor chemical stability, making it difficult to store for long periods and thus limiting its applications.

[0003] To address the stability issue of ascorbic acid, current research focuses on using modifiers to covalently bind with ascorbic acid, forming stable ascorbic acid derivatives such as sodium ascorbyl phosphate (SAP), magnesium ascorbyl phosphate (MAP), ascorbyl glucoside (AA-2G), ascorbyl palmitate (AA-6P), or 3-O-ethyl ascorbic acid (EAA).

[0004] Although these modifiers can effectively improve the stability of ascorbic acid, the free radical scavenging rate of these ascorbic acid derivatives is significantly lower than that of ascorbic acid, and therefore, these ascorbic acid derivatives have poor antioxidant capacity. Summary of the Invention

[0005] Therefore, the object of the present invention is to provide an ascorbic acid eutectic with better stability and good antioxidant capacity.

[0006] Therefore, the ascorbic acid eutectic of the present invention is formed by dissolving ascorbic acid and a polyol in a solvent and then removing the solvent. It is composed of ascorbic acid and a polyol bonded to the ascorbic acid by intermolecular forces. The polyol is selected from diols with a total carbon number of 4 to 10, sorbitol monolaurate, sorbitol monopalmitate, sorbitol monostearate, or polyoxyethylene sorbitan monolaurate. The ascorbic acid content is 20 mol% or more and less than 100 mol% based on a total ascorbic acid eutectic of 100 mol%.

[0007] The advantages of this invention are as follows: Through intermolecular forces, a polyol is eutecticly bonded to ascorbic acid. This ascorbic acid eutectic exhibits superior stability compared to ascorbic acid itself, and its antioxidant capacity is comparable to, and superior to, that of previously mentioned ascorbic acid derivatives. Specifically, the ascorbic acid in the eutectic of this invention shows a low degradation rate in aqueous solutions or at different pH levels, indicating that the eutectic is not easily oxidized and degraded by environmental factors, thus possessing excellent stability. Simple Explanation of the Diagram

[0008] Other features and effects of the present invention will be clearly presented in the embodiments with reference to the drawings, wherein: Figure 1 is a nuclear magnetic resonance spectrum illustrating the structure of the ascorbic acid eutectic of Example 1 of the present invention; Figure 2 is a nuclear magnetic resonance spectrum illustrating the structure of the ascorbic acid eutectic of Example 2 of the present invention; Figure 3 is a nuclear magnetic resonance spectrum illustrating the structure of the ascorbic acid eutectic of Example 3 of the present invention; Figure 4 is a nuclear magnetic resonance spectrum illustrating the structure of the ascorbic acid eutectic of Example 4 of the present invention; Figure 5 is a nuclear magnetic resonance spectrum illustrating the structure of the ascorbic acid eutectic of Example 5 of the present invention; Figure 6 is a nuclear magnetic resonance spectrum illustrating the structure of the ascorbic acid eutectic of Example 6 of the present invention; Figure 7 is a nuclear magnetic resonance spectrum illustrating the structure of the ascorbic acid eutectic of Example 7 of the present invention; Figure 8 is a nuclear magnetic resonance spectrum illustrating the structure of the ascorbic acid eutectic of Example 8 of the present invention; Figure 9 is a nuclear magnetic resonance spectrum illustrating the structure of the ascorbic acid eutectic of Example 9 of the present invention; Figure 10 is a nuclear magnetic resonance spectrum illustrating the structure of the ascorbic acid eutectic of Example 10 of the present invention; Figure 11 is a nuclear magnetic resonance spectrum illustrating the structure of the ascorbic acid eutectic of Example 11 of the present invention; Figure 12 is an nuclear magnetic resonance spectrum illustrating the structure of the ascorbic acid eutectic of Example 12 of the present invention; and Figure 13 is a nuclear magnetic resonance spectrum illustrating the structure of L-ascorbic acid. Implementation

[0009] The ascorbic acid eutectic of the present invention is formed by dissolving ascorbic acid and a polyol in a solvent and then removing the solvent. It is composed of ascorbic acid and a polyol bonded to the ascorbic acid by intermolecular forces. The polyol is selected from diols with a total carbon number of 4 to 10, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, or polyoxyethylene sorbitan monolaurate. The ascorbic acid content is 20 mol% or more and less than 100 mol% based on a total ascorbic acid eutectic content of 100 mol%.

[0010] In some embodiments of the present invention, the intermolecular forces are hydrogen bonds and / or van der Waals forces.

[0011] The diol having a total carbon number of 4 to 10 is, for example, but not limited to, butanediol, pentanediol, hexanediol, heptanediol, octanediol, or decanediol. The butanediol is, for example, but not limited to, 1,3-butanediol. The octanediol is, for example, but not limited to, 1,2-octanediol. The hexanediol is, for example, but not limited to, 1,2-hexanediol or 1,6-hexanediol. The decanediol is, for example, but not limited to, 1,10-decanediol. In some embodiments of the invention, the diol having a total carbon number of 4 to 10 is a diol having a total carbon number of 4 to 8. In some embodiments of the invention, the diol having a total carbon number of 4 to 10 is a diol having a total carbon number of 5 to 8. In some embodiments of the invention, the diol having a total carbon number of 4 to 10 is hexanediol or octanediol.

[0012] The polyoxyethylene sorbitan monolaurate is, for example, but not limited to, Tween 20.

[0013] In some embodiments of the present invention, the molar ratio of ascorbic acid to polyol is 1:1 to 1:3. In some embodiments of the present invention, the molar ratio of ascorbic acid to polyol is 1:1 to 1:2. In some embodiments of the present invention, the ascorbic acid content is 25 mol% to 50 mol% based on a total ascorbic acid eutectic of 100 mol%. The solvent is, for example, ethanol.

[0014] The present invention will be further described with reference to the following embodiments, but it should be understood that the embodiments are for illustrative purposes only and should not be construed as limiting the implementation of the present invention.

[0015] Example 1

[0016] 1.0 mmol of sorbitol monolaurate was mixed with 10 mL of ethanol to form a first mixture. Then, 1.0 mmol of ascorbic acid was added to this first mixture, and the mixture was subjected to ultrasonic vibration for 3 minutes in a 45°C water bath to form a second mixture. Next, the second mixture was concentrated under reduced pressure in a 45°C water bath. Then, a vacuum pump was used to evacuate the mixture, ensuring no ethanol residue remained, to obtain a solid ascorbic acid eutectic.

[0017] Examples 2 to 15

[0018] Examples 2 to 15 were performed using the same steps as Example 1, with the main difference being the change in the type and amount of polyol (see Table 1). In Example 2, the polyol was sorbitol monopalmitate, and a solid ascorbic acid eutectic was obtained. In Example 3, the polyol was sorbitol monostearate, and a solid ascorbic acid eutectic was obtained. In Examples 4 to 6, the polyol was 1,3-butanediol, and an ascorbic acid eutectic was obtained, with the eutectic being predominantly solid and occasionally liquid. In Examples 7 to 9, the polyol was 1,2-hexanediol, and an ascorbic acid eutectic was obtained, with the eutectic being predominantly solid and occasionally liquid. In Examples 10 to 12, the polyol was 1,2-octanediol, and an ascorbic acid eutectic was obtained, with the eutectic being predominantly solid and occasionally liquid. In Example 13, the polyol was polyoxyethylene (20) sorbitan monolaurate (tween 20), yielding an ascorbic acid eutectic, which was predominantly liquid with some solid states. In Example 14, the polyol was 1,10-decanediol, yielding an ascorbic acid eutectic, which was predominantly solid with some liquid states. In Example 15, the polyol was 1,6-hexanediol, yielding an ascorbic acid eutectic, which was predominantly solid with some liquid states.

[0019] Table 1 ascorbic acid eutectic Ascorbic acid dosage (g, mmol / L) polyol dosage (grams, mmole) The molar ratio of ascorbic acid to polyol in ascorbic acid eutectic Ascorbic acid content (mol%) in ascorbic acid eutectic Melting point (°C) "—": Cannot be measured Example 1 0.176, 1.0 0.347, 1.0 1:1 50 135.8~137.3 2 0.176, 1.0 0.403, 1.0 1:1 50 145.8~153 3 0.176,1.0 0.431,1.0 1:1 50 147.6~150.1 4 0.176,1.0 0.090,1.0 1:1 50 — 5 0.176,1.0 0.180,2.0 1:2 33.3 — 6 0.176,1.0 0.271,3.0 1:3 25 — 7 0.176,1.0 0.118,1.0 1:1 50 — 8 0.176,1.0 0.236,2.0 1:2 33.3 — 9 0.176,1.0 0.355,3.0 1:3 25 — 10 0.176,1.0 0.146,1.0 1:1 50 — 11 0.176,1.0 0.292, 2.0 1:2 33.3 — 12 0.176, 1.0 0.439, 3.0 1:3 25 — 13 0.176, 1.0 1.227, 1.0 1:1 50 — 14 0.176, 1.0 0.174, 1.0 1:1 50 — 15 0.176, 1.0 0.118, 1.0 1:1 50 — L-Ascorbic Acid -- -- -- -- 189~192.5

[0020] Figures 1 to 13 show the spectra obtained by mixing the ascorbic acid eutectics of Examples 1 to 12 and L-ascorbic acid with dimethyl sulfoxide-d6 (DMSO-d6), respectively, and then measuring them using a nuclear magnetic resonance spectrometer (manufacturer: JEOL Ltd.; model: ECZ400S) at a hydrogen nuclear resonance frequency of 400 MHz. Figures 1 to 12 show the structures of the ascorbic acid eutectics of Examples 1 to 12. As can be seen from Figures 1 to 12, these ascorbic acid eutectics not only have the characteristic peaks of L-ascorbic acid but also the characteristic peaks of polyols. Therefore, it can be concluded that the L-ascorbic acid and polyols in these ascorbic acid eutectics are not covalently bonded.

[0021] Evaluation Project

[0022] Stability Measurement: The ascorbic acid eutectics from Examples 1 to 12 were mixed with deionized water to form several mixtures, wherein the concentration of ascorbic acid in these mixtures was 15 ppm. These mixtures were analyzed using a UV-Vis spectrometer (Thermo Fisher Scientific; Model: Thermo Scientific GENESYS 150) to obtain graphs. The absorption intensity of the characteristic peak at 265 nm in these graphs was defined as A0. The mixtures were then placed in an environment at 28°C for 10 to 580 minutes, and samples were taken periodically to obtain test samples. These test samples were then analyzed using the same UV-Vis spectrometer to obtain graphs, and the absorption intensity of the characteristic peak at 265 nm in these graphs was defined as A1. The degradation rate was then calculated using [(A0-A1) / A0] x 100%. These results are presented in Tables 2 and 3.

[0023] Degradation half-life measurement in aqueous solution: The stability measurement time was plotted on the x-axis and the obtained degradation rate on the y-axis. A linear regression was performed on the degradation rate and time to obtain a curve of a linear equation in two variables. Then, a degradation rate of 50% was substituted into this linear equation to obtain the degradation half-life. These results are presented in Table 4.

[0024] DPPH free radical scavenging assay: 0.0394 g of 2,2-diphenyl-1-picrylhydrazine (DPPH) powder was mixed with methanol in a container to form a deep purple first mixture. The container holding the first mixture was wrapped with aluminum foil. The concentration of DPPH in the first mixture was 10 mM. Then, 1 mL of the first mixture was diluted with methanol to 10 mL to obtain a second mixture, in which the concentration of DPPH was 1 mM. The second mixture was shaken and mixed with L-ascorbic acid (purchased from Sigma-Aldrich®), sodium ascorbate phosphate (Choneye Pure Chemicals®), magnesium ascorbate phosphate (Choneye Pure Chemicals®), the ascorbic acid eutectic of Example 7, and the ascorbic acid eutectic of Example 10, respectively, and allowed to stand at room temperature for 30 minutes in the dark to form several test samples. In these test samples, the concentrations of L-ascorbic acid, sodium ascorbate phosphate, magnesium ascorbate phosphate, the ascorbic acid eutectic of Example 7, and the ascorbic acid eutectic of Example 10 were 40 μg / mL. The samples were analyzed using an enzyme immunoassay analyzer (ELISA reader; Biochrom; EZ Read 2000) and a spectrometer [Thermo Fisher Scientific; model: Spectrolinker™ UV Crosslinkers XL-1000; with 8-Watt UV C (254nm)], and the absorbance value (A1) of the characteristic peak at a wavelength of 517nm was obtained. The second mixture was analyzed using the same enzyme immunoassay analyzer and spectrometer, and the absorbance value (A0) of the characteristic peak at a wavelength of 517nm was obtained. The DPPH radical scavenging rate (in %) was calculated using [(A0-A1) / A0] x 100%. These results are presented in Table 5.

[0025] ABTS Free Radical Scavenging Assay: An aqueous solution of ABTS [containing water and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid, ABTS), wherein the concentration of ABTS in the aqueous solution is 7 mM] and an ammonium persulfate solution (containing deionized water and ammonium persulfate, wherein the concentration of ammonium persulfate in the ammonium persulfate solution is 245 mM) were mixed at a volume ratio of 1:100 to obtain a first mixture. This first mixture was reacted at room temperature in the dark for 16 hours to form a second mixture containing ABTS+ free radicals. The second mixture was diluted with ultrapure water to an absorbance of 0.70 ± 0.02 at a wavelength of 734 nm to obtain a third mixture. This third mixture was then reacted with L-ascorbic acid, sodium ascorbate phosphate (Choneye Pure Chemicals®), and magnesium ascorbate phosphate (Choneye Pure Chemicals®), respectively. Chemicals®), the ascorbic acid eutectic of Example 7 and the ascorbic acid eutectic of Example 10 were shaken and mixed, and then allowed to stand at room temperature for 10 minutes in the dark to form several test samples. In these test samples, the concentrations of L-ascorbic acid, sodium ascorbate phosphate, magnesium ascorbate phosphate, the ascorbic acid eutectic of Example 7 and the ascorbic acid eutectic of Example 10 were 0.4 w / v%. The assay was performed using an enzyme immunoassay analyzer (ELISA reader; Biochrom; EZ Read 2000) and a spectrometer [Thermo Fisher Scientific; model: Spectrolinker™ UV Crosslinkers XL-1000; with 8-Watt UV]. The absorbance of the samples was analyzed using [C(254nm)], and the absorbance value of the characteristic peak at 734nm (A1) was obtained. The third mixture was analyzed using the enzyme immunoassay analyzer and the spectrometer, and the absorbance value of the characteristic peak at 734nm (A0) was obtained. The ABTS+ free radical scavenging rate (unit: %) was calculated using [(A0-A1) / A0] x 100%. These results are presented in Table 5.

[0026] Solubility analysis: 5 mg of the ascorbic acid eutectic from Examples 1 to 12 was mixed with 1 mL of a solvent, wherein the solvent was water, ethanol, ethyl acetate, glycerol, n-hexane, diethyl ether, or acetone. The mixture was stirred at 28°C for 10 minutes, then allowed to stand for 10 minutes, and observed visually. Complete dissolution was indicated as O, while partial dissolution or complete insolution was indicated as X. These results are presented in Table 6.

[0027] Stability measurement under different pH conditions: L-ascorbic acid, the ascorbic acid eutectic of Example 7, and the ascorbic acid eutectic of Example 10 were respectively mixed with buffer solutions to obtain several mixtures, wherein the concentration of L-ascorbic acid and the ascorbic acid eutectic of Example 7 in these mixtures was 16 mg / L. The buffer solutions were buffer solutions with pH 3.5, pH 5, pH 7, and pH 8, and were prepared from deionized water, disodium hydrogen phosphate, and citric acid. The mixture was analyzed using a UV-Vis spectrometer (Thermo Fisher Scientific; model: Thermo Scientific GENESYS 150), and the resulting graphs were used. The absorption intensity of the characteristic peak at 265 nm in these graphs was defined as A0. The mixture was then placed in an environment at 28°C for 10 to 480 minutes, with samples taken periodically to obtain test samples. These test samples were then analyzed using the same UV-Vis spectrometer, and the resulting graphs were used. The absorption intensity of the characteristic peak at 265 nm in these graphs was defined as A1. The degradation rate was then calculated using [(A0-A1) / A0] x 100%. These results are presented in Table 7.

[0028] Table 2 Degradation rate (%) "--": Not measured Example 1 2 3 4 5 6 Time (minutes) 0 0.00 0.00 0.00 0.00 0.00 0.00 10 7.22 1.60 3.60 0.19 2.44 4.63 20 15.45 4.51 4.47 0.39 6.42 10.00 30 23.87 9.52 9.82 0.87 11.51 15.51 40 32.50 16.73 16.25 1.74 15.34 21.52 50 41.93 25.15 23.25 2.61 22.45 27.90 60 49.35 33.97 30.16 7.85 28.70 34.29 70 56.47 42.18 40.25 10.56 34.90 40.80 80 -- 49.60 46.96 14.14 41.02 47.05 90 -- 55.81 53.19 18.78 46.15 52.94 100 -- -- -- 23.32 51.90 -- 110 -- -- -- 29.13 -- -- 120 -- -- -- 36.96 -- -- 130 -- -- -- 40.73 -- -- 140 -- -- -- 46.82 -- -- 150 -- -- -- 53.59 -- --

[0029] Table 3 Degradation rate (%) "--": Not measured Implementation Examples 7 8 9 10 11 12 Time (minutes) 0 0.00 0.00 0.00 0.00 0.00 0.00 10 0.88 0.47 6.04 -1.26 -0.35 1.51 20 1.86 1.23 13.86 1.47 2.22 10.20 30 3.04 2.55 23.45 2.10 4.79 15.63 40 4.32 5.00 30.47 2.73 7.35 21.07 50 5.79 9.54 38.14 3.29 9.85 26.59 60 7.26 16.24 45.27 3.99 12.41 32.25 70 8.64 23.89 53.36 4.69 14.98 37.39 80 10.40 31.72 -- 5.38 17.48 42.37 90 12.07 39.47 -- 6.01 19.90 47.13 100 13.94 46.74 -- 6.71 22.26 51.66 110 15.70 53.25 -- 7.41 24.62 -- 120 17.66 -- -- 7.97 26.98 -- 130 19.53 -- -- 8.67 29.20 -- 140 21.39 -- -- 9.51 31.41 -- 150 23.36 -- -- 10.35 33.70 -- 160 25.42 -- -- 11.26 35.78 -- 170 27.67 -- -- 12.03 37.86 -- 180 29.93 -- -- 13.71 42.09 -- 190 32.38 -- -- 16.01 48.20 -- 200 34.84 -- -- 16.78 50.14 -- 210 37.19 -- -- 17.76 -- -- 220 39.55 -- -- 18.67 -- -- 230 41.90 -- -- 19.51 -- -- 240 44.16 -- -- 20.35 -- -- 250 46.52 -- -- 21.26 -- -- 260 48.77 -- -- 22.10 -- -- 270 50.93 -- -- 23.01 -- -- 280 -- -- -- 22.71 -- -- 290 -- -- -- 24.97 -- -- 300 -- -- -- 25.94 -- -- 310 -- -- -- 26.85 -- -- 320 -- -- -- 27.76 -- -- 330 -- -- -- 28.67 -- -- 340 -- -- -- 29.51 -- -- 350 -- -- -- 30.42 -- -- 360 -- -- -- 31.47 -- -- 370 -- -- -- 32.31 -- -- 380 -- -- -- 33.22 -- -- 390 -- -- -- 33.85 -- -- 400 -- -- -- 35.52 -- -- 410 -- -- -- 36.29 -- -- 420 -- -- -- 37.34 -- -- 430 -- -- -- 38.18 -- -- 440 -- -- -- 39.02 -- -- 450 -- -- -- 39.86 -- -- 460 -- -- -- 40.63 -- -- 470 -- -- -- 41.40 -- -- 480 -- -- -- 42.31 -- -- 490 -- -- -- 43.08 -- -- 500 -- -- -- 43.71 -- -- 510 -- -- -- 44.55 -- -- 520 -- -- -- 45.31 -- -- 530 -- -- -- 46.08 -- -- 540 -- -- -- 45.64 -- -- 550 -- -- -- 47.76 -- -- 560 -- -- -- 48.67 -- -- 570 -- -- -- 49.44 -- -- 580 -- -- -- 50.49 -- --

[0030] Table 4 Degradation half-life (T [, 1 / 2 , ], min) L-Ascorbic Acid 50 Example 1 61 Example 2 84 Example 3 89 Example 4 161 Example 5 97 Example 6 86 Example 7 283 Example 8 114 Example 9 62 Example 10 576 Example 11 210 Example 12 94

[0031] As can be seen from the experimental data in Table 4, the degradation half-life of the ascorbic acid eutectic of the present invention is longer than that of L-ascorbic acid, which indicates that the ascorbic acid eutectic of the present invention is superior to L-ascorbic acid in terms of stability.

[0032] Table 5 L-Ascorbic Acid Sodium ascorbate phosphate Magnesium ascorbate phosphate Example 7 10 DPPH free radical scavenging rate (%) 98.17 16.00 20.56 93.87 95.90 ABTS free radical scavenging rate (%) 95.83 22.30 39.14 87.61 86.86

[0033] As can be seen from the experimental results in Table 5, the antioxidant capacity of the ascorbic acid eutectic of the present invention is quite similar to that of L-ascorbic acid and superior to the ascorbic acid derivatives mentioned in the prior art, such as sodium ascorbate phosphate and magnesium ascorbate phosphate.

[0034] Table 6 Example water ethanol Ethyl acetate glycerin n-Hexane Diethyl ether acetone 1 X The X The X X The 2 X The X X X X The 3 X The X X X X The 4 The The X The X X The 5 The The X The X X The 6 The The X The X X The 7 The The X The X X The 8 The The X The X X The 9 O O X O X X O 10 O O X O X X O 11 O O X O X X O 12 O O X O X X O

[0035] Table 7 Degradation rate (%) Example 7 10 Buffer solution with pH 3.5 0 minutes 0 0 30 minutes 1.63 2.14 60 minutes 2.72 3.5 90 minutes 3.63 4.86 120 minutes 4.9 6.42 150 minutes 5.99 7.78 180 minutes 6.9 10.12 210 minutes 7.99 10.51 240 minutes 9.07 11.87 270 minutes 10.16 13.23 300 minutes 11.07 14.4 330 minutes 11.98 15.56 360 minutes 13.07 16.93 390 minutes 13.97 18.09 420 minutes 15.06 19.46 450 minutes 15.97 20.62 480 minutes 16.88 21.79 Buffer solution with pH 5 0 minutes 0 0 30 minutes 7.2 1.61 60 minutes 13.05 3.14 90 minutes 18.58 4.83 120 minutes 23.68 6.53 150 minutes 27.95 8.14 180 minutes 32.05 9.75 210 minutes 35.82 11.28 240 minutes 39.33 12.81 270 minutes 42.43 14.26 300 minutes 45.44 15.71 330 minutes 48.28 17.16 360 minutes 51.05 18.61 390 minutes 55.31 19.98 420 minutes 60.33 21.35 450 minutes 65.27 22.64 480 minutes 70.54 24.09 Buffer solution with pH 7 0 minutes 0 0 30 minutes 4.14 4.82 60 minutes 7.44 8.89 90 minutes 10.58 12.38 120 minutes 13.57 16.69 150 minutes 16.1 20.02 180 minutes 18.71 23.34 210 minutes 21.09 26.58 240 minutes 23.39 29.49 270 minutes 25.46 32.14 300 minutes 27.53 34.8 330 minutes 29.6 37.54 360 minutes 31.52 40.03 390 minutes 33.44 42.44 420 minutes 35.2 44.68 450 minutes 36.96 46.84 480 minutes 38.8 49.25 Buffer solution with pH 8 0 minutes 0 0 30 minutes 5.37 4.8 60 minutes 10.29 9.45 90 minutes 15.29 14.33 120 minutes 19.49 18.9 150 minutes 23.16 22.5 180 minutes 26.84 26.18 210 minutes 30.29 29.62 240 minutes 33.46 32.99 270 minutes 36.4 35.95 300 minutes 39.34 38.83 330 minutes 42.21 41.79 360 minutes 44.93 44.52 390 minutes 47.57 47.16 420 minutes 50.07 49.64 450 minutes 53.01 52.04 480 minutes 55.37 54.68

[0036] As shown in Table 7, under the same time conditions, the ascorbic acid eutectic of Example 7 exhibited a low degradation rate under acidic conditions (pH 3.5) and a high degradation rate under alkaline conditions. Therefore, the ascorbic acid eutectic of Example 7 is more suitable for use in acidic and neutral environments with a pH of 3.5. Under the same time conditions, the ascorbic acid eutectic of Example 10 exhibited a low degradation rate under acidic conditions and a high degradation rate under alkaline conditions. Therefore, the ascorbic acid eutectic of Example 10 is more suitable for use in acidic and neutral environments.

[0037] In summary, this invention utilizes polyols to bind with ascorbic acid through intermolecular forces. This ascorbic acid eutectic exhibits superior stability compared to ascorbic acid itself, and its antioxidant capacity is comparable to, and superior to, that of previously mentioned ascorbic acid derivatives. Specifically, the ascorbic acid eutectic of this invention demonstrates good stability in aqueous solutions or at different pH levels, indicating that it is not easily oxidized or degraded by environmental factors, thus effectively achieving the objectives of this invention.

[0038] However, the above description is merely an embodiment of the present invention and should not be construed as limiting the scope of the present invention. Any simple equivalent changes and modifications made in accordance with the scope of the patent application and the contents of the patent specification of the present invention shall still fall within the scope of the patent of the present invention.

Claims

1. An ascorbic acid eutectic, formed by dissolving ascorbic acid and a polyol in ethanol and then removing the ethanol, comprising ascorbic acid and a polyol bonded to the ascorbic acid by intermolecular forces, wherein the polyol is selected from octanediol, sorbitol monolaurate, sorbitol monopalmitate, sorbitol monostearate, or polyoxyethylene sorbitan monolaurate, wherein... Based on a total amount of 100 mol% of the ascorbic acid eutectic, the content of ascorbic acid is 25 mol% to 50 mol%.

2. The ascorbic acid eutectic as described in claim 1, wherein, The intermolecular forces are hydrogen bonds, van der Waals forces, or a combination thereof.

3. The ascorbic acid eutectic as described in claim 1, wherein, The molar ratio of ascorbic acid to polyol is 1:1 to 1:2.

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