Extraction method for improving stability of orange peel pigment and application

Abstract

The invention belongs to the field of plant extraction, and particularly relates to an extraction method for improving the stability of orange peel pigment and application of the extraction method. And performing plasma treatment. According to the method, the orange peel pigment is subjected to short-time plasma treatment, so that the stability of the orange peel pigment under different illumination, temperature and acid-base conditions is improved on the premise of ensuring that the color development performance is not influenced, and the orange peel pigment is better suitable for processing, storage and transportation in the fields of foods and medicines.

Description

Technical Field

[0001] The invention belongs to the field of plant extraction, and particularly relates to an extraction method for improving the stability of orange peel pigment and an application thereof. Background Art

[0002] Synthetic pigments are harmful to the human body as food additives. Natural pigments, such as orange peel pigment, are highly regarded by people because of their excellent safety, certain antibacterial, anti-inflammatory and antiviral effects. Orange peel pigment can be added to food or medicine.

[0003] The methods for extracting orange peel pigment mainly include ethanol extraction, microwave extraction, ultrasonic extraction, enzyme extraction, etc. The orange peel pigment extracted by the existing extraction methods usually encounters the challenge of pigment stability. During food processing, storage and transportation, orange peel pigment is easily affected by external factors such as light, temperature, acidity and alkalinity, and fades, changes color or does not show color.

[0004] In the prior art, in order to improve the stability of orange peel pigment, microencapsulated orange peel pigment is prepared to achieve the purpose of improving stability. However, the preparation of microencapsulated orange peel pigment requires additional core materials and wall materials. The preparation process is complicated and will introduce additional ingredients, limiting the scope of application.

[0005] Therefore, it is necessary to provide an extraction method for improving the stability of orange peel pigment, by performing some simple treatment on the orange peel pigment to ensure that the color rendering performance is not affected, and to improve its stability under different light, temperature, acid and alkaline conditions. Summary of the invention

[0006] The purpose of the invention is to provide an extraction method and application for improving the stability of orange peel pigment.

[0007] In order to achieve the above objectives, the technical solution adopted by the present invention is as follows: A method for extracting orange peel pigment to improve its stability comprises the following steps: 1) Orange peel pigment extraction: Wash the citrus peel and dry it; crush it into citrus peel powder; extract the citrus peel powder with 90%-98% ethanol solution for 1-2 times, and place it in a microwave with a power of 180-230W for 1-2 minutes during the extraction; filter the extract to obtain a yellow liquid, and concentrate it under reduced pressure at 50-58°C to 11-14% of the volume of the original yellow liquid, and dry it to obtain citrus peel pigment powder; 2) Plasma treatment: The orange peel pigment powder is treated by cold plasma, the carrier gas is nitrogen or air, the power is 20-50W, the treatment time is 5-30s, the nitrogen or air flow rate is 40-60mL / min, and the orange peel pigment after cold plasma treatment is obtained.

[0008] The power and time of plasma treatment are crucial to the stability of orange peel pigment. Plasma treatment with lower plasma treatment power and shorter plasma treatment time can help to better improve the light stability, thermal stability and acid-base stability of orange peel pigment. Experiments have found that high plasma treatment power or longer plasma treatment time is not conducive to light stability, thermal stability and acid-base stability.

[0009] In a preferred embodiment, in step 2), orange peel pigment having a thickness of ≤0.5 mm is evenly spread on a glass dish and subjected to cold plasma treatment.

[0010] Furthermore, in step 2), the carrier gas is nitrogen.

[0011] In a preferred embodiment, in step 2), the processing time is 10 to 20 seconds.

[0012] Furthermore, in step 1), during each extraction, the mass volume ratio of orange peel powder to 90% to 98% ethanol solution is 1 g: 3 to 5 mL.

[0013] The present invention also discloses an extraction method for improving the stability of orange peel pigment, comprising the following steps: 1) Extract orange peel pigment to obtain orange peel pigment powder; 2) Plasma treatment: The orange peel pigment powder is treated by cold plasma, the carrier gas is nitrogen or air, the power is 20-50W, the treatment time is 5-30s, the nitrogen or air flow rate is 40-60mL / min, and the orange peel pigment after cold plasma treatment is obtained.

[0014] In a preferred embodiment, step 1) is specifically as follows: washing the citrus peel and drying it; crushing it into citrus peel powder; extracting the citrus peel powder with 95% to 98% ethanol solution for 1 to 2 times, and placing it in a microwave with a power of 180 to 230 W for 1 to 2 minutes during the extraction; filtering the extract to obtain a yellow liquid, concentrating it under reduced pressure at 50 to 58° C. to 11-14% of the volume of the original yellow liquid, and drying it to obtain citrus peel pigment powder.

[0015] Furthermore, in step 2), orange peel pigment with a thickness of ≤0.5 mm is evenly spread on a glass dish and subjected to cold plasma treatment.

[0016] Another object of the present invention is to provide orange peel pigment obtained by the aforementioned extraction method.

[0017] Another object of the present invention is to disclose the application of the aforementioned extraction method in improving the light stability, thermal stability or acid-base stability of orange peel pigment.

[0018] The present invention is beneficial in that: By using microwaves during extraction, the number of extractions can be reduced, the soaking time can be shortened, and the extraction efficiency can be improved.

[0019] Plasma treatment using lower plasma treatment power and shorter plasma treatment time can help to better improve the light stability, thermal stability and acid-base stability of orange peel pigment.

[0020] The thickness of orange peel pigment is ≤0.5mm, which is to make the plasma treatment more uniform and sufficient.

[0021] The invention performs short-time plasma treatment on orange peel pigment to ensure that the color development performance is not affected, thereby improving the stability of the orange peel pigment under different light, temperature, acid and alkalinity conditions, so that the orange peel pigment is better suitable for processing, storage and transportation in the fields of food and medicine. DETAILED DESCRIPTION

[0022] The present invention is described in detail below with reference to specific embodiments.

[0023] Embodiment 1

[0024] 1) Orange peel pigment extraction: Wash the citrus peel and dry it; crush it into citrus peel powder; extract the citrus peel powder with 95% ethanol solution twice (15 minutes each time), and the mass volume ratio of citrus peel powder to 95% ethanol solution is 1g:4mL each time; place the mixture of citrus peel powder and 95% ethanol solution in a microwave with a power of 200W for 1 minute each time; combine the extracts; filter the extracts to obtain a yellow liquid; concentrate under reduced pressure at 55°C to 12% of the volume of the original yellow liquid, and dry to obtain citrus peel pigment powder; 2) Plasma treatment: The orange peel pigment powder was treated by cold plasma (using cold plasma equipment), with nitrogen as carrier gas, power of 30W, treatment time of 20s, nitrogen or air flow rate of 50mL / min, to obtain orange peel pigment after cold plasma treatment. The orange peel pigment with a thickness of ≤0.5mm was evenly spread on a glass dish for cold plasma treatment.

[0025] Embodiment 2

[0026] 1) Orange peel pigment extraction: Wash the citrus peel and dry it; crush it into citrus peel powder; extract the citrus peel powder once with 95% ethanol solution (immerse for 20 minutes), and the mass volume ratio of citrus peel powder to 95% ethanol solution is 1g:5mL; during the extraction, place the mixture of citrus peel powder and 95% ethanol solution in a microwave with a power of 230W for 2 minutes; filter the extract to obtain a yellow liquid; concentrate it under reduced pressure at 50°C to 14% of the volume of the original yellow liquid, and dry it to obtain citrus peel pigment powder; 2) Plasma treatment: The orange peel pigment powder was treated by cold plasma (using cold plasma equipment), with nitrogen as carrier gas, power of 50W, treatment time of 15s, nitrogen or air flow rate of 60mL / min, to obtain orange peel pigment after cold plasma treatment. The orange peel pigment with a thickness of ≤0.5mm was evenly spread on a glass dish for cold plasma treatment.

[0027] Embodiment 3

[0028] 1) Orange peel pigment extraction: Wash the citrus peel and dry it; crush it into citrus peel powder; extract the citrus peel powder with 95% ethanol solution twice (15 minutes each time), and the mass volume ratio of citrus peel powder to 95% ethanol solution is 1g:3mL in each extraction; place the mixture of citrus peel powder and 95% ethanol solution in a microwave with a power of 180W for 2 minutes in each extraction; combine the extracts; filter the extracts to obtain a yellow liquid; concentrate under reduced pressure at 55°C to 11% of the volume of the original yellow liquid, and dry to obtain citrus peel pigment powder; 2) Plasma treatment: The orange peel pigment powder was treated by cold plasma (using cold plasma equipment), with nitrogen as carrier gas, power of 20W, treatment time of 30s, nitrogen or air flow rate of 40mL / min, to obtain orange peel pigment after cold plasma treatment. The orange peel pigment with a thickness of ≤0.5mm was evenly spread on a glass dish for cold plasma treatment.

[0029] Comparative Example 1 Orange peel pigment extraction: Wash the citrus peel and dry it; crush it into citrus peel powder; extract the citrus peel powder with 95% ethanol solution twice (15 minutes each time), and the mass volume ratio of citrus peel powder to 95% ethanol solution is 1g:4mL each time; place the mixture of citrus peel powder and 95% ethanol solution in a microwave with a power of 200W for 1 minute each time; combine the extracts; filter the extracts to obtain a yellow liquid; concentrate under reduced pressure at 55°C to 12% of the volume of the original yellow liquid, and dry to obtain citrus peel pigment powder.

[0030] Comparative Example 2 1) Orange peel pigment extraction: Wash the citrus peel and dry it; crush it into citrus peel powder; extract the citrus peel powder with 95% ethanol solution twice (15 minutes each time), and the mass volume ratio of citrus peel powder to 95% ethanol solution is 1g:4mL each time; place the mixture of citrus peel powder and 95% ethanol solution in a microwave with a power of 200W for 1 minute each time; combine the extracts; filter the extracts to obtain a yellow liquid; concentrate under reduced pressure at 55°C to 12% of the volume of the original yellow liquid, and dry to obtain citrus peel pigment powder; 2) Plasma treatment: The orange peel pigment powder was treated by cold plasma (using cold plasma equipment), with nitrogen as carrier gas, power of 300W, treatment time of 20s, nitrogen or air flow rate of 50mL / min, to obtain orange peel pigment after cold plasma treatment. The orange peel pigment with a thickness of ≤0.5mm was evenly spread on a glass dish for cold plasma treatment.

[0031] Comparative Example 3 1) Orange peel pigment extraction: Wash the citrus peel and dry it; crush it into citrus peel powder; extract the citrus peel powder with 95% ethanol solution twice (15 minutes each time), and the mass volume ratio of citrus peel powder to 95% ethanol solution is 1g:4mL each time; place the mixture of citrus peel powder and 95% ethanol solution in a microwave with a power of 200W for 1 minute each time; combine the extracts; filter the extracts to obtain a yellow liquid; concentrate under reduced pressure at 55°C to 12% of the volume of the original yellow liquid, and dry to obtain citrus peel pigment powder; 2) Plasma treatment: The orange peel pigment powder was treated by cold plasma (using cold plasma equipment), with nitrogen as carrier gas, power of 30W, treatment time of 5min, nitrogen or air flow rate of 50mL / min, to obtain orange peel pigment after cold plasma treatment. The orange peel pigment with a thickness of ≤0.5mm was evenly spread on a glass dish for cold plasma treatment.

[0032] Application Example 1 Light Stability For the orange peel pigment obtained in Examples 1-3 and Comparative Examples 1-3, 1 g / L orange peel pigment solutions were prepared respectively, and the absorbance at 436 nm was measured every 3 days under the condition of a light intensity of 40000 Lux, and the light stability of the orange peel pigment obtained in Examples 1-3 and Comparative Examples 1-3 was compared and analyzed. The results are shown in Table 1 below.

[0033] Table 1 Absorbance values ​​of the orange peel pigments of Examples 1-3 and Comparative Examples 1-3 after being prepared into solutions

[0034] First, plasma treatment itself can slightly increase the absorbance of orange peel pigment when it is prepared into solution. When the orange peel pigment obtained from Examples 1-3 and Comparative Examples 1-3 is prepared into 1 g / L orange peel pigment solution, there is no obvious difference in color between the Examples and Comparative Examples.

[0035] In Comparative Example 1, since only the orange peel pigment was extracted without any additional treatment, the absorbance of the prepared orange peel pigment solution decreased significantly over time, indicating that the orange peel pigment was destroyed.

[0036] Comparative Examples 2 and 3 used higher plasma treatment powers or longer plasma treatment times. As time went on, the absorbance of the prepared orange peel pigment solution also decreased, proving that the use of lower plasma treatment powers and shorter plasma treatment times in the present invention is more beneficial to light stability.

[0037] In Example 1-3, after the orange peel pigment is extracted, plasma treatment is performed using a lower plasma treatment power and a shorter plasma treatment time. As time goes by, the absorbance of the prepared orange peel pigment solution is basically maintained without showing a significant decrease.

[0038] Application Example 2 Thermal Stability For the orange peel pigment obtained in Examples 1-3 and Comparative Examples 1-3, 1 g / L orange peel pigment solutions were prepared respectively, and the absorbance values ​​at 436 nm were measured after 1 hour at temperatures of 30° C., 60° C., and 90° C., respectively, to compare and analyze the thermal stability of the orange peel pigment obtained in Examples 1-3 and Comparative Examples 1-3. The results are shown in Table 2 below.

[0039] Table 2 Thermal stability of orange peel pigments obtained from Examples 1-3 and Comparative Examples 1-3

[0040] In Comparative Example 1, since only orange peel pigment was extracted without additional treatment, the absorbance of the prepared orange peel pigment solution decreased during high temperature treatment (especially 90° C.).

[0041] Comparative Examples 2 and 3 used higher plasma treatment power or longer plasma treatment time. During high-temperature treatment, the absorbance of the prepared orange peel pigment solution also decreased, which proves that the use of lower plasma treatment power and shorter plasma treatment time in the present invention is more beneficial to thermal stability.

[0042] After the orange peel pigment is extracted, Example 1-3 uses a lower plasma treatment power and a shorter plasma treatment time for plasma treatment. During high-temperature treatment, the absorbance of the prepared orange peel pigment solution also decreases, but the decrease is lower than that of Comparative Examples 1-3.

[0043] Application Example 3 Acid-base stability For the orange peel pigment obtained in Examples 1-3 and Comparative Examples 1-3, 1 g / L orange peel pigment solutions were prepared respectively, and the absorbance at 436 nm was measured after 1 hour at pH 1 and 11 respectively, and the acid-base stability of the orange peel pigment obtained in Examples 1-3 and Comparative Examples 1-3 was compared and analyzed. As shown in Table 3 below:

[0044] It can be seen that the acid-base stability of Examples 1-3 is better than that of Comparative Example 1. The absorbance value of Comparative Example 1 increases (the color becomes darker) under strong alkaline conditions, and the absorbance value decreases significantly under strong acidic conditions, while the stability of Examples 1-3 is better than that of Comparative Example 1 under strong acid or strong base.

[0045] The above embodiments are only used to illustrate the technical solutions of the present invention. Those skilled in the art should understand that the above embodiments do not limit the present invention in any form, and any technical solutions obtained by equivalent replacement or equivalent transformation shall fall within the protection scope of the present invention.

Claims

1. A method for extracting orange peel pigment to improve its stability, characterized in that: The steps include: 1) Orange peel pigment extraction: Wash the citrus peel and dry it; crush it into citrus peel powder; extract the citrus peel powder with 90%-98% ethanol solution for 1-2 times, and place it in a microwave with a power of 180-230W for 1-2 minutes during the extraction; filter the extract to obtain a yellow liquid, and concentrate it under reduced pressure at 50-58°C to 11-14% of the volume of the original yellow liquid, and dry it to obtain citrus peel pigment powder; 2) Plasma treatment: The orange peel pigment powder is treated by cold plasma, the carrier gas is nitrogen or air, the power is 20-50W, the treatment time is 5-30s, the nitrogen or air flow rate is 40-60mL / min, and the orange peel pigment after cold plasma treatment is obtained.

2. A method for extracting orange peel pigment to improve its stability according to claim 1, characterized in that: In step 2), orange peel pigment with a thickness of ≤0.5 mm is evenly spread on a glass dish and subjected to cold plasma treatment.

3. A method for extracting orange peel pigment to improve its stability according to claim 1, characterized in that: In step 2), the carrier gas is nitrogen.

4. A method for extracting orange peel pigment to improve its stability according to claim 1, characterized in that: In step 2), the processing time is 10~20s.

5. A method for extracting orange peel pigment to improve its stability according to claim 1, characterized in that: In step 1), during each extraction, the mass volume ratio of orange peel powder to 95%-98% ethanol solution is 1 g: 3-5 mL.

6. A method for extracting orange peel pigment to improve its stability, characterized in that: The steps include: 1) Extract orange peel pigment to obtain orange peel pigment powder; 2) Plasma treatment: The orange peel pigment powder is treated by cold plasma, the carrier gas is nitrogen or air, the power is 20-50W, the treatment time is 5-30s, the nitrogen or air flow rate is 40-60mL / min, and the orange peel pigment after cold plasma treatment is obtained.

7. A method for extracting orange peel pigment to improve its stability according to claim 6, characterized in that: Step 1) is specifically as follows: washing the citrus peel and drying it; crushing it into citrus peel powder; extracting the citrus peel powder with a 90%-98% ethanol solution for 1-2 times, and placing it in a microwave with a power of 180-230 W for 1-2 minutes during the extraction; filtering the extract to obtain a yellow liquid, concentrating it under reduced pressure at 50-58° C. to 11-14% of the volume of the original yellow liquid, and drying it to obtain the citrus peel pigment powder.

8. A method for extracting orange peel pigment to improve its stability according to claim 6, characterized in that: In step 2), orange peel pigment with a thickness of ≤0.5 mm is evenly spread on a glass dish and subjected to cold plasma treatment.

9. Orange peel pigment obtained by the extraction method described in any one of claims 1 to 8.

10. Use of the extraction method according to any one of claims 1 to 8 in improving the light stability, thermal stability or acid-base stability of orange peel pigment.

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