Method for extracting and analyzing palmitic acid in pepper essential oil

Abstract

The invention discloses a method for extracting and analyzing palmitic acid in pepper essential oil, and belongs to the technical field of food detection.The method comprises the steps that S1, processed black pepper particles and processed white pepper particles are obtained, the prepared black pepper particles and the prepared white pepper particles are smashed respectively, and black pepper powder and white pepper powder are obtained; s2, water and steam are added into the black pepper powder and the white pepper powder for distillation, after distillation is completed, an essential oil layer is taken, and white pepper essential oil and black pepper essential oil are obtained; and S3, respectively adding a petroleum ether extracting solution into the essential oil for extraction, adding a potassium hydroxide and methanol mixed solution for methyl esterification, adding ultrapure water, centrifuging, taking supernatant, filtering, diluting the filtered sample with chromatographic-grade normal hexane, and detecting the content of palmitic acid by using a gas chromatograph-mass spectrometer. According to the method disclosed by the embodiment of the invention, the composition of special effective substances of the pepper essential oil is determined by researching a pepper essential oil palmitic acid component detection technical method, and an important basic technical support is provided for research, development and application of pepper high-quality products in China.

Description

Technical Field

[0001] The invention relates to the technical field of food detection, in particular to a method for extracting palmitic acid from pepper essential oil and an analysis method thereof. Background Art

[0002] Pepper is a perennial evergreen vine of the genus Piper in the family Piperaceae. It is one of the most important tropical spices in the world and has a cultivation history of more than 2,000 years. Pepper has a very high application value. It often appears in the form of seasoning in the food field and has antibacterial and anti-inflammatory effects in the medical field. Pepper essential oil is an aromatic oil extracted from the fruit, roots, leaves, stems, flowers, etc. of pepper, also known as pepper volatile oil. Pepper essential oil contains a lot of aroma substances, which has the effects of purifying the skin and relieving skin fatigue. It is usually produced into cosmetics such as pepper essential oil soap and pepper essential oil. Pepper fruit contains a variety of chemical components, among which piperine and pepper essential oil are the most significant. Piperine is mainly studied for its medical value, while the smell of pepper is mainly reflected through volatile essential oils. Studying the chemical composition of pepper essential oil and clarifying the main substances are the main ways to study the aroma of pepper.

[0003] Palmitic acid is an important fatty acid, belonging to the primary saturated fatty acid. Palmitic acid can provide energy supply. Palmitic acid contains a variety of natural antioxidants, which can play an antioxidant and skin protection role. There is no suitable analytical method for the palmitic acid content in pepper essential oil in the prior art.

[0004] Due to the different processing methods of white pepper and black pepper, the chemical composition and characteristics of pepper essential oil are different. Using white pepper and black pepper as materials, the palmitic acid content of their fruit essential oil components was analyzed. By studying the technical methods for detecting the palmitic acid component of pepper essential oil, the special effective substance composition of pepper essential oil was clarified, providing important basic technical support for the research and development and application of high-quality pepper products in my country. Summary of the invention

[0005] The invention aims to provide a method for extracting palmitic acid from pepper essential oil and an analysis method thereof, so that the method can use pepper powder as a raw material and measure the palmitic acid content in the extracted pepper essential oil.

[0006] The technical solution adopted by the present invention to solve the technical problem is:

[0007] Provided is a method for extracting palmitic acid in pepper essential oil and analyzing the same, comprising the following steps:

[0008] S1: obtaining processed black peppercorns and white peppercorns, and crushing the prepared black peppercorns and white peppercorns in a grinder to obtain black pepper powder and white pepper powder;

[0009] S2: adding water to black pepper powder and white pepper powder respectively, wherein the mass ratio of pepper powder to water is 1:10-15, and steam distilling for 4-6 hours. After the distillation is completed, taking the essential oil layer to obtain white pepper essential oil and black pepper essential oil;

[0010] S3: adding petroleum ether extract to white pepper essential oil and black pepper essential oil respectively for extraction, adding potassium hydroxide methanol mixed solution for methyl esterification, adding ultrapure water, centrifuging and filtering the supernatant, diluting the filtered sample 40 times with chromatographic grade n-hexane, and detecting the palmitic acid content by gas chromatography-mass spectrometry.

[0011] Further, in S1, the crushed pepper powder is passed through a 40-mesh sieve.

[0012] Furthermore, in S2, during the extraction of the essential oil, the steam distillation is carried out in a state of maintaining a slight boiling temperature at 100°C.

[0013] Further, in S3, the essential oil is diluted 5 times with petroleum ether extract.

[0014] Furthermore, in S3, the concentration of the potassium hydroxide-methanol mixed solution is 0.4 mol / L.

[0015] Furthermore, in S3, the methyl esterification time is 1 to 1.5 hours.

[0016] Furthermore, in S3, the centrifugation condition is 8000 r / min for 10 min.

[0017] Further, in S3, the supernatant is filtered through a 0.22 μm filter membrane.

[0018] Furthermore, in S3, when the palmitic acid content was detected by gas chromatography-mass spectrometry, the split ratio of the pepper essential oil sample was 10:1 when it was tested on the machine, and the sample was diluted more than 200 times;

[0019] During the test, the initial temperature was 50°C, which was increased to 200°C at a rate of 5°C / min, and then to 230°C at a rate of 2°C / min;

[0020] The chromatographic column model used is DB-225ms, 30m×250μm×0.25μm.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The palmitic acid extraction and analysis method in pepper essential oil exemplified in the present invention are also applicable to the extraction and content analysis of palmitic acid in black pepper and white pepper. The method first extracts the essential oil by steam distillation, then extracts the palmitic acid of the sample, and then the extracted sample is tested on a machine, a standard sample is selected for comparative spectrum analysis, the palmitic acid content in the extracted pepper essential oil is obtained by calculation, and finally the difference in palmitic acid content in white pepper essential oil and black pepper essential oil is obtained. The process is simple and the operation steps are relatively few, and the special effective substance composition of pepper essential oil is clarified, providing important basic technical support for the research and development and application of high-quality pepper products in my country. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0024] Figure 1 This is the chromatogram of the white pepper essential oil sample after methyl esterification;

[0025] Figure 2 This is the internal standard control chromatogram of white pepper essential oil;

[0026] Figure 3 This is the chromatogram of the black pepper essential oil sample after methyl esterification;

[0027] Figure 4 This is the internal standard control chromatogram of black pepper essential oil;

[0028] Figure 5 Overlapping chromatograms of white pepper essential oil and black pepper essential oil samples after methyl esterification. DETAILED DESCRIPTION

[0029] The present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention. It is also necessary to explain that, for ease of description, only the parts related to the invention are shown in the accompanying drawings.

[0030] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0031] The present embodiment provides a method for extracting palmitic acid from pepper essential oil and analyzing the same. Samples are collected from the pepper germplasm resource garden of Xinglong Tropical Botanical Garden in Wanning City, Hainan Province. Mature fresh pepper fruits are collected. The collected fresh pepper fruits are soaked in running water for peeling and then dried in the sun to produce white pepper. Black pepper is produced by directly drying in the sun without peeling.

[0032] Embodiment 1:

[0033] First, obtain processed white pepper grains, and grind the prepared white pepper grains in a grinder through a 40-mesh sieve to obtain white pepper powder.

[0034] Secondly, weigh 40g of white pepper powder, add 500ml of water into a 1000ml round-bottom flask, perform steam distillation at 100°C for 5h, add a small amount of explosion-proof glass beads during distillation, and after the distillation is completed, take the essential oil layer to obtain white pepper essential oil.

[0035] Finally, 0.17 g of white pepper essential oil was taken, 1 mL of petroleum ether (boiling range 60-90 ° C) was added, and it was diluted 5 times here, 0.5 mL of 0.4 mol / L potassium hydroxide methanol mixed solution was added for methyl esterification, 1 mL of ultrapure water was added, and the centrifuge was centrifuged at 8000 r / min for 10 min. The supernatant was taken and filtered through a 0.22 μm filter membrane. The filtered sample was diluted 40 times with chromatographic grade n-hexane, and the palmitic acid content was detected by gas chromatography-mass spectrometry.

[0036] In view of the current situation that the existing technology is indeed suitable for the analysis method of palmitic acid content in pepper essential oil, the present invention detects the content of palmitic acid methyl ester (also known as hexadecanoic acid methyl ester) by gas chromatography-mass spectrometry, thereby calculating the palmitic acid content. When the palmitic acid content is detected by gas chromatography-mass spectrometry, the split ratio of the white pepper essential oil sample is 10:1 when it is tested on the machine, and the sample is diluted more than 200 times. The initial temperature during the test is 50°C, and the temperature is increased to 200°C at a rate of 5°C / min, and then increased to 230°C at a rate of 2°C / min. The chromatographic column model used is DB-225ms, 30m×250μm×0.25μm.

[0037] Example 1 The results show that the palmitic acid content in white pepper essential oil is 226.386 μg / g.

[0038] Embodiment 2:

[0039] First, obtain processed black peppercorns, and grind the prepared black peppercorns in a grinder and pass them through a 40-mesh sieve to obtain black pepper powder.

[0040] Secondly, weigh 40g of black pepper powder, add 500ml of water into a 1000ml round-bottom flask, perform steam distillation at 100°C for 5h, add a small amount of explosion-proof glass beads during distillation, and after the distillation is completed, take the essential oil layer to obtain black pepper essential oil.

[0041] Finally, 0.21 g of black pepper essential oil was taken, 1 mL of petroleum ether (boiling range 60-90 ° C) was added, and it was diluted 5 times here, 0.5 mL of 0.4 mol / L potassium hydroxide methanol mixed solution was added for methyl esterification, 1 mL of ultrapure water was added, and the centrifuge was centrifuged at 8000 r / min for 10 min. The supernatant was taken and filtered through a 0.22 μm filter membrane. The filtered sample was diluted 40 times with chromatographic grade n-hexane, and the palmitic acid content was detected by gas chromatography-mass spectrometry.

[0042] When the palmitic acid content was detected by gas-mass spectrometry, the split ratio of the black pepper essential oil sample was 10:1, and the sample was diluted more than 200 times. The initial temperature was 50°C, and the temperature was increased to 200°C at a rate of 5°C / min, and then to 230°C at a rate of 2°C / min. The chromatographic column model used was DB-225ms, 30m×250μm×0.25μm.

[0043] Example 2 The results show that the palmitic acid content in black pepper essential oil is 143.362 ug / g.

[0044] It can be seen from Example 1 and Example 2 that the palmitic acid content in white pepper essential oil and black pepper essential oil is different to a certain extent. In the two essential oils selected by the present invention, the palmitic acid content in white pepper essential oil is higher than that in black pepper essential oil. The research of this method provides basic theoretical data for the application of essential oils in industries such as cosmetics.

[0045] Those skilled in the art should understand that the scope of the invention involved in this application is not limited to the technical solutions formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A method for extracting palmitic acid in pepper essential oil and an analysis method thereof, characterized in that: The following steps are involved: S1: obtaining processed black peppercorns and white peppercorns, and crushing the prepared black peppercorns and white peppercorns in a grinder to obtain black pepper powder and white pepper powder; S2: adding water to black pepper powder and white pepper powder respectively, wherein the mass ratio of pepper powder to water is 1:10-15, and steam distilling for 4-6 hours. After the distillation is completed, taking the essential oil layer to obtain white pepper essential oil and black pepper essential oil; S3: adding petroleum ether extract to white pepper essential oil and black pepper essential oil respectively for extraction, adding potassium hydroxide methanol mixed solution for methyl esterification, adding ultrapure water, centrifuging and filtering the supernatant, diluting the filtered sample 40 times with chromatographic grade n-hexane, and detecting the palmitic acid content by gas chromatography-mass spectrometry.

2. The palmitic acid extraction and analysis method of pepper essential oil according to claim 1, characterized in that: In S1, the crushed pepper powder is passed through a 40-mesh sieve.

3. The palmitic acid extraction and analysis method of pepper essential oil according to claim 1, characterized in that: In S2, during the extraction of the essential oil, the steam distillation was carried out in a state of maintaining a slight boil at 100°C.

4. The palmitic acid extraction and analysis method of pepper essential oil according to claim 1, characterized in that: In S3, the volume ratio of essential oil to petroleum ether extract is 1:

5.

5. The palmitic acid extraction and analysis method of pepper essential oil according to claim 1, characterized in that: In S3, the concentration of the potassium hydroxide-methanol mixed solution is 0.4 mol / L.

6. The palmitic acid extraction and analysis method of pepper essential oil according to claim 1, characterized in that: In S3, the methyl esterification time is 1 to 1.5 hours.

7. The palmitic acid extraction and analysis method of pepper essential oil according to claim 1, characterized in that: In S3, the centrifugation condition is 8000 r / min for 10 min.

8. The palmitic acid extraction and analysis method of pepper essential oil according to claim 1, characterized in that: In S3, the supernatant was filtered through a 0.22 μm filter membrane.

9. The palmitic acid extraction and analysis method of pepper essential oil according to claim 1, characterized in that: In S3, when the palmitic acid content was detected by gas chromatography-mass spectrometry, the split ratio of the pepper essential oil sample was 10:1, and the sample was diluted more than 200 times; During the test, the initial temperature was 50°C, which was increased to 200°C at a rate of 5°C / min, and then to 230°C at a rate of 2°C / min; The chromatographic column model used is DB-225ms, 30m×250μm×0.25μm.

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