A high-quality citronellal composition

Abstract

The present invention provides a high-quality citronellal composition, which satisfies at least one of the following conditions: 1) in the citronellal composition, the citronellal content is 97wt% or more, preferably 98wt%-99wt%; 2) in the citronellal composition, the L-isopulegol content is 0.001wt%-0.05wt%, preferably 0.01wt%-0.05wt%, and the D-isopulegol content is 0.001wt%-0.05wt%, preferably 0.01wt%-0.05wt%; 3) in the citronellal composition, the citronellal acid content is ≤0.5wt%, preferably ≤0.4wt%. The present invention improves the aroma performance of the product by regulating the content of key components in the product.

Description

Technical Field

[0001] The invention belongs to the field of perfume chemicals, and in particular relates to a high-quality citronellal composition and a production method. Background Art

[0002] Citronellal, molecular formula is C 10 H 18 O, whose scientific name is 3,7-dimethyl-6-octenal, also known as andrographolaldehyde, is a colorless to light yellow liquid. It is a very important fragrance and is used in the field of daily chemical or food flavors, especially in mosquito repellent products.

[0003] Patent CN118164838B discloses a method for preparing citronellal. After the raw material citral is pretreated, citronellal is prepared by an asymmetric hydrogenation reaction under the action of an iron-based catalyst. In a preferred embodiment, the reaction conversion rate is greater than 99%, the selectivity is greater than 99%, and the ee value is greater than 90%. However, the composition and application performance of the citronellal product are not explored.

[0004] Patent CN107250091B discloses a method for synthesizing optically active carbonyl compounds, in which citral is asymmetrically hydrogenated to produce citronellal under the action of rhodium and a chiral bidentate diphosphine ligand. The results also only focus on reaction properties such as conversion rate and selectivity, and no relevant research is conducted on product composition and application performance.

[0005] At present, the citronellal products on the market are all mixtures of multiple substances. Some commercially available products even contain more than ten types of components. In addition, there are very obvious differences in the composition and odor of the citronellal products launched by various manufacturers. Such differences create great uncertainty for the quality of downstream products. Summary of the invention

[0006] The present invention aims to provide a high-quality citronellal composition product, wherein the citronellal composition product has better aroma performance.

[0007] The inventors have conducted relevant explorations on the composition and smell of citronellal products and found that the aroma quality of citronellal can be improved by controlling the types and contents of components in citronellal products.

[0008] In order to achieve the above-mentioned object of the invention, the present invention adopts the following scheme:

[0009] A high-quality citronellal composition satisfies at least one of the following conditions:

[0010] 1) In the citronellal composition, the citronellal content is 97 wt% or more, preferably 98 wt%-99 wt%;

[0011] 2) In the citronellal composition, the content of L-isopulegol is 0.001wt%-0.05wt%, preferably 0.01wt%-0.05wt%, and the content of D-isopulegol is 0.001wt%-0.05wt%, preferably 0.01wt%-0.05wt%;

[0012] 3) In the citronellal composition, the content of citronellal acid is ≤0.5wt%, preferably ≤0.4wt%.

[0013] As a preferred embodiment, the citronellal composition meets the above three conditions.

[0014] By controlling the contents of L-isopulegol and D-isopulegol, the aroma performance of the citronellal composition is harmonized, so that the overall aroma of the citronellal composition is improved and has a more excellent aroma performance.

[0015] The invention also relates to a method for preparing the citronellal composition.

[0016] The citronellal composition of the present invention can be obtained by artificial blending, or by subjecting crude citronellal to a aging treatment;

[0017] The crude citronellal of the present invention can be naturally extracted or artificially synthesized. The artificial synthesis mainly refers to the preparation through the citral hydrogenation process;

[0018] In some specific embodiments, in the crude citronellal, the citronellal content is 90 wt%-97 wt%, the L-isopulegol content is ≤1 wt%, the D-isopulegol content is ≤1 wt%, and the citronellal acid content is ≤2 wt%.

[0019] The aging treatment method of the present invention can be one or more of the common chemical process methods such as vacuum distillation, vacuum rectification, reactive distillation, etc., preferably reactive distillation;

[0020] In some specific embodiments, the reactive distillation conditions should meet the following range requirements:

[0021] The theoretical plate number of the distillation tower is 30-80, the bottom temperature is 70-110℃, and the top pressure is 0.2-1.5KPaA;

[0022] In some specific embodiments, the reactive distillation requires the participation of a catalyst, and the catalyst is preferably one or more of Fe, Ni, and Mo. The Fe may be derived from one or more of elemental iron, iron alloy, ferric chloride, ferrous acetate, ferric phosphate, and ferric oxide. The nickel may be derived from one or more of nickel iodide, nickel acetylacetonate, nickel powder, nickel alloy, nickel oxide, and nickel chloride. The molybdenum may be derived from one or more of molybdenum powder, molybdenum acetylacetonate, molybdenum phosphide, molybdenum trichloride, molybdenum sulfide, and molybdenum alloy.

[0023] In some specific embodiments, the amount of the catalyst is 5-1000 ppm, preferably 10-500 ppm, where the amount of the catalyst refers to the mass content of the metal element in the crude citronellal.

[0024] The beneficial effects of the present invention are:

[0025] 1) The aging process can significantly reduce the content of citronellal impurities, thereby eliminating the acidic taste of the citronellal composition to a certain extent and improving the storage stability of the product;

[0026] 2) By adjusting the content of L-isopulegol and D-isopulegol, the aroma of the citronellal composition is harmonized, the overall aroma of the citronellal composition is enhanced, and the thorny feeling brought by citronellal itself is weakened, the softness of the composition is improved, which is conducive to improving the tolerance of people with sensitive skin to citronellal products, thereby improving the user experience. DETAILED DESCRIPTION

[0027] The present invention will be further described in detail below in conjunction with embodiments, but the scope of the present invention is not limited to these embodiments.

[0028] Main raw materials

[0029] Anhydrous ferric chloride, purity ≥99.9wt%, Aladdin Reagent Co., Ltd.

[0030] Ferrous acetate, purity ≥95wt%, Aladdin Reagent Co., Ltd.

[0031] Nickel iodide, purity ≥99wt%, Aladdin Reagent Co., Ltd.

[0032] Nickel acetylacetonate, purity ≥95wt%, Aladdin Reagent Co., Ltd.

[0033] Molybdenum trichloride, purity ≥95wt%, Aladdin Reagent Co., Ltd.

[0034] Composition analysis method

[0035] Analysis method of citronellal content and citronellal acid content:

[0036] The chromatographic column model was HP-INNOWAX (column length 30 m, column inner diameter 0.25 mm, liquid film thickness 0.25 μm), the vaporization chamber temperature was 220 °C, the detector temperature was 250 °C, the split ratio was 50:1, and the column box temperature program was 80 °C for 2 min, then increased to 150 °C at a rate of 10 °C / min, and then increased to 240 °C at a rate of 15 °C / min, and maintained at 240 °C for 10 min;

[0037] Analysis method of L-isopulegol and D-isopulegol content:

[0038] The chromatographic column model is BETA-DEX-225 (column length 30m, column inner diameter 0.25mm, liquid film thickness 0.25μm), the vaporization chamber temperature is 220℃, the detector temperature is 300℃, the split ratio is 100:1, and the column box temperature program is 85℃ constant temperature for 55min, then heated to 130℃ at a rate of 20℃ / min, and maintained at 130℃ for 15min.

[0039] Storage stability test method

[0040] Take 10 mL of sample and place it in a 20 mL silk-mouth bottle. After sealing, place it in a 50°C constant temperature box. After 60 days, take out the test sample to determine the citronellal content and calculate the deterioration rate.

[0041] Aroma evaluation method

[0042] A professional fragrance evaluation team evaluated the samples based on three dimensions: purity of smell, softness, and slight acidic flavors. The full score is 10 for each dimension, and the higher the score, the better the performance.

[0043] Crude Citronellal:

[0044] Citronellal was synthesized according to the method described in Example 3 of patent CN110961154B, and the resulting reaction solution had the following composition:

[0045]

[0046] Example 1

[0047] Select a distillation tower with a theoretical plate number of 50, add 1 kg of crude citronellal into a 2L three-necked flask in the bottom of the tower, then add 700 mg of anhydrous ferric chloride, turn on the power of the equipment for reactive distillation, set the bottom reboiler temperature to 110°C, the top condensation temperature to 10°C, and the top pressure to 1.5 KPaA.

[0048] The distillate was collected from the top of the tower for composition and aroma analysis and storage stability testing.

[0049] Example 2

[0050] Select a distillation tower with a theoretical plate number of 30, add 1 kg of crude citronellal into a 2L three-necked flask in the bottom of the tower, then add 50 mg of anhydrous ferric chloride and 10 mg of molybdenum trichloride, turn on the power of the equipment for reactive distillation, set the bottom reboiler temperature to 100°C, the top condensation temperature to 10°C, and the top pressure to 0.6 KPaA.

[0051] The distillate was collected from the top of the tower for composition and aroma analysis and storage stability testing.

[0052] Example 3

[0053] Select a distillation tower with a theoretical plate number of 80, add 1 kg of crude citronellal into a 2L three-necked flask in the bottom of the tower, then add 1800 mg of ferrous acetate and 2000 mg of nickel iodide, turn on the power of the equipment for reactive distillation, set the bottom reboiler temperature to 70°C, the top condensation temperature to 10°C, and the top pressure to 0.2 KPaA.

[0054] The distillate was collected from the top of the tower for composition and aroma analysis and storage stability testing.

[0055] Comparative Example 1

[0056] Select a distillation tower with a theoretical plate number of 20, add 1 kg of crude citronellal into a 2L three-necked flask in the bottom of the tower, then add 100 mg of nickel acetylacetonate and 100 mg of molybdenum trichloride, turn on the power of the equipment for reactive distillation, set the bottom reboiler temperature to 100 °C, the top condensation temperature to 10 °C, and the top pressure to 0.6 KPaA.

[0057] The distillate was collected from the top of the tower for composition and aroma analysis and storage stability testing.

[0058] Comparative Example 2

[0059] Select a distillation tower with a theoretical plate number of 50, add 1 kg of crude citronellal into a 2L three-necked flask in the bottom of the tower, then add 1600 mg of ferrous acetate and 1600 mg of molybdenum trichloride, turn on the power of the equipment for reactive distillation, set the bottom reboiler temperature to 100°C, the top condensation temperature to 10°C, and the top pressure to 0.6 KPaA.

[0060] The distillate was collected from the top of the tower for composition and aroma analysis and storage stability testing.

[0061] Comparative Example 3

[0062] Select a distillation tower with a theoretical plate number of 70, add 1 kg of crude citronellal into a 2L three-necked flask in the bottom of the tower, then add 5 mg of ferrous acetate and 5 mg of nickel iodide, turn on the power of the equipment for reactive distillation, set the bottom reboiler temperature to 70°C, the top condensation temperature to 10°C, and the top pressure to 0.2 KPaA.

[0063] The distillate was collected from the top of the tower for composition and aroma analysis and storage stability testing.

[0064] The evaluation results are as follows:

[0065] Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Citronellal / wt% 98.80 98.82 98.49 98.39 98.44 98.759 L isopulegol / wt% 0.02 0.03 0.03 0.05 0.12 0.0005 D isopulegol / wt% 0.04 0.01 0.04 0.04 0.13 0.0005 Citronellal acid / wt% 0.11 0.05 0.33 0.70 0.10 0.23 Other components / wt% 1.03 1.09 1.11 0.82 1.21 1.01 Purity of smell 9 8 8 7 5 8 Softness 7 6 8 8 8 5 Slight acidic taste 8 9 7 5 8 8 Deterioration rate / % 0.36 0.12 0.51 1.02 0.27 0.42

[0066] It is easy to understand that the above embodiments are only examples for clear explanation and do not mean that the present invention is limited thereto. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from this are still within the protection scope of the present invention.

Claims

1. A citronellal composition, satisfying at least one of the following conditions: 1) In the citronellal composition, the citronellal content is 97 wt% or more, preferably 98 wt%-99 wt%; 2) In the citronellal composition, the content of L-isopulegol is 0.001wt%-0.05wt%, preferably 0.01wt%-0.05wt%, and the content of D-isopulegol is 0.001wt%-0.05wt%, preferably 0.01wt%-0.05wt%; 3) In the citronellal composition, the content of citronellal acid is ≤0.5wt%, preferably ≤0.4wt%.

2. The method for preparing the citronellal composition according to claim 1, wherein the crude citronellal is obtained by subjecting the crude citronellal to a aging treatment.

3. The method according to claim 2, wherein: The crude citronellal has a citronellal content of 90 wt%-97 wt%, an L-isopulegol content of ≤1 wt%, a D-isopulegol content of ≤1 wt%, and a citronellal acid content of ≤2 wt%.

4. The method according to claim 2 or 3, wherein: The aging treatment is carried out by a method selected from vacuum distillation, vacuum rectification, and reactive distillation, preferably reactive distillation.

5. The method according to claim 4, wherein: The reactive distillation conditions are as follows: The theoretical plate number of the distillation tower is 30-80, the bottom temperature is 70-110°C, and the top pressure is 0.2-1.5KPaA.

6. The method according to claim 4 or 5, wherein: The reactive distillation involves the participation of a catalyst, and the catalyst is preferably one or more selected from Fe, Ni, and Mo.

7. The method according to claim 6, wherein: The Fe is derived from one or more of elemental iron, iron alloy, ferric chloride, ferrous acetate, ferric phosphate, and ferric oxide.

8. The method according to claim 6, wherein: The Ni is derived from one or more of nickel iodide, nickel acetylacetonate, nickel powder, nickel alloy, nickel oxide and nickel chloride.

9. The method according to claim 6, wherein: The Mo is derived from one or more of molybdenum powder, molybdenum acetylacetonate, molybdenum phosphide, molybdenum trichloride, molybdenum sulfide, and molybdenum alloy.

10. The method according to any one of claims 6 to 9, wherein: The catalyst dosage is 5-1000 ppm, preferably 10-500 ppm, and the catalyst dosage is the mass content of the metal element in the crude citronellal.

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