Preparation method of citrus essential oil as well as product and application of citrus essential oil

Abstract

The invention relates to a preparation method of citrus essential oil and a product and application thereof, the preparation method comprises the following steps: (1) mixing a citrus peel raw material with enzyme and water, and performing enzymolysis treatment to obtain an enzymolysis treatment solution; (2) performing high-voltage pulse electric field treatment on the enzymolysis treatment liquid to obtain solid-liquid mixed liquid; and (3) carrying out steam distillation on the solid-liquid mixed solution, collecting distillate, and separating an oil phase to obtain the citrus essential oil. The citrus essential oil is prepared by utilizing an enzymolysis-high-pressure pulse-steam distillation combined extraction method, the extraction process is low in condition, no organic reagent is introduced, the extraction process is green and environment-friendly, the loss of volatile active ingredients of the essential oil is less, and two treatments of enzymolysis and high-pressure pulse are added before steam distillation treatment, so that the yield of the essential oil can be increased; moreover, the tyrosinase inhibitory activity and the anti-free radical activity of the essential oil are also obviously improved, and the two pre-treatments promote each other and have a synergistic effect in the aspect of the effects.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of plant essential oil extraction, and relates to a preparation method of citrus essential oil, a product and application thereof, in particular to a preparation method of high-yield and high-activity citrus essential oil, a product and application thereof. BACKGROUND

[0002] With the continuous improvement of people's living standards, consumers have higher and higher requirements for daily beauty and skin care products, and natural plant essential oil skin care products are favored by more and more consumers, and more and more skin care products play skin care effects by adding plant essential oils.

[0003] Citrus essential oil is a volatile oil extracted from the peels of citrus fruits, rich in active ingredients such as limonene, linalool and citral, and has the effects of soothing mood, antibacterial, antioxidant and the like, and is widely used in mood regulation, skin care and household cleaning and the like.

[0004] As a food spice, the traditional preparation method of citrus essential oil is to directly squeeze citrus peels as raw materials, but the yield of essential oil is not high. In order to improve the yield, lime water is often used to treat citrus peels, so that the oil yield of citrus peels in the squeezing process is improved, which is called lime water immersion and squeezing method. However, due to the saponification reaction of oil cells in the alkaline lime water, and the browning reaction of citrus peels in the alkaline condition, the oil fragrance is obviously reduced, the color is obviously changed, and the biological activity is also changed. There are also processes of extracting citrus peels with organic solvents, but there are solvent residues, the safety is not high, and the biological activity of the prepared essential oil is not good.

[0005] Therefore, it is very meaningful to develop a new preparation process of citrus essential oil with high yield and good biological activity. SUMMARY

[0006] In view of the deficiencies of the prior art, the purpose of the present application is to provide a preparation method of citrus essential oil, a product and application thereof, in particular to provide a preparation method of high-yield and high-activity citrus essential oil, a product and application thereof.

[0007] In order to achieve the purpose of the present application, the following technical solutions are adopted:

[0008] In the first aspect, the present application provides a preparation method of citrus essential oil, which comprises the following steps:

[0009] (1) mixing citrus peel raw materials with enzymes and water, and then performing enzymatic treatment to obtain an enzymatic treatment liquid;

[0010] (2) performing high-pressure pulse electric field treatment on the enzymatic treatment liquid to obtain a solid-liquid mixture;

[0011] (3) The solid-liquid mixture is subjected to water vapor distillation, the distillate is collected, and the oil phase is separated to obtain the citrus essential oil.

[0012] The application uses the combined extraction method of enzymolysis-high pressure pulse-water vapor distillation to prepare the citrus essential oil, the condition is low temperature in the extraction process, no organic reagent is introduced, it is green and environmental protection, the loss of volatile active ingredients of the essential oil is less, the enzymolysis and high pressure pulse are added before the water vapor distillation treatment, the yield of the essential oil can be improved, and the tyrosinase inhibition activity and the anti-free radical activity of the essential oil are also obviously improved, the two pretreatments promote each other and have synergistic effect in the above functions.

[0013] Preferably, the enzyme includes any one or a combination of at least two of cellulase, pectinase, hemicellulase or tannase.

[0014] Preferably, the enzyme includes a combination of cellulase, pectinase, hemicellulase and tannase.

[0015] In the application, the combination of cellulase, pectinase, hemicellulase and tannase is used for enzymolysis treatment, compared with other combined enzymes or single enzyme treatment, the yield of the essential oil and the tyrosinase inhibition activity and the anti-free radical activity of the essential oil can be improved.

[0016] Preferably, the mass ratio of the cellulase, the pectinase, the hemicellulase and the tannase is (1-3):(1-3):(1-3):(1-3), wherein the specific point value in (1-3) can be selected as 1, 1.2, 1.3, 1.4, 1.5, 1.7, 1.8, 2, 2.2, 2.4, 2.6, 2.8, 3 and the like, and other point values not listed in the range can be selected, which will not be described one by one here.

[0017] Preferably, the addition amount of the enzyme is 1-10% of the citrus peel raw material, for example, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10% and the like, and other point values not listed in the range can be selected, which will not be described one by one here. Preferably, 2-4%.

[0018] In the application, the total addition amount of the enzyme relative to the raw material also affects the extraction rate and activity of the essential oil to some extent, wherein 1-10% is a better range, and 2-4% is a more optimal range.

[0019] Preferably, the ratio of citrus peel raw material to water is 1:(2-10) g / mL, for example, 1:2 g / mL, 1:3 g / mL, 1:4 g / mL, 1:5 g / mL, 1:6 g / mL, 1:7 g / mL, 1:8 g / mL, 1:9 g / mL, 1:10 g / mL, etc. Other values ​​not listed within this range are also acceptable and will not be elaborated here. A ratio of 1:(3-5) g / mL is preferred.

[0020] In this invention, the ratio of citrus peel raw material to water also affects the extraction rate of essential oil to a certain extent. Among them, 1:(2-10) g / mL is a range with better effect, and 1:(3-5) g / mL is a range with even better effect.

[0021] Preferably, the enzymatic hydrolysis is performed at 40-60℃ (e.g., 40℃, 42℃, 44℃, 45℃, 47℃, 50℃, 52℃, 55℃, 60℃, etc.) for 40-80 min (e.g., 40 min, 50 min, 60 min, 70 min, 80 min, etc.). Other values ​​not listed above within the above range are also acceptable and will not be elaborated further here.

[0022] Preferably, the field strength of the high-voltage pulse electric field treatment is 30-50 kV / m, such as 30 kV / m, 35 kV / m, 40 kV / m, 45 kV / m, 50 kV / m, etc. Other unlisted values ​​within this range can be selected, and will not be elaborated here.

[0023] In this invention, the field strength of the high-voltage pulsed electric field treatment is selected within the range of 30-50 kV / m because the yield of essential oils obtained under this parameter is higher and the activity is better.

[0024] Preferably, the number of electric shocks in the high-voltage pulse electric field treatment is 60-140 times, such as 60, 70, 80, 90, 100, 110, 120, 130, 140 times, etc. Other unlisted values ​​within this range can be selected, and will not be elaborated here.

[0025] Preferably, the steam distillation time is 1-3.5 h, such as 1 h, 1.5 h, 2 h, 2.5 h, 3 h, 3.5 h, etc. Other unlisted values ​​within this range can be selected, and will not be elaborated here.

[0026] In this invention, the steam distillation time is selected within the range of 1-3.5 h because under this parameter, the yield of essential oil is higher and the activity is better.

[0027] Preferably, the process of separating the oil phase includes: allowing the distillate to stand and separate into layers, taking the upper oil phase, dehydrating and drying it with anhydrous sodium sulfate, filtering it, and obtaining citrus essential oil.

[0028] In a second aspect, the present invention provides citrus essential oil prepared according to the preparation method described in the first aspect.

[0029] Thirdly, the present invention provides the use of citrus essential oil according to the second aspect in the preparation of tyrosinase inhibitors.

[0030] Fourthly, the present invention provides the use of citrus essential oil according to the second aspect in the preparation of free radical scavengers.

[0031] Fifthly, the present invention provides the use of the citrus essential oil according to the second aspect in the preparation of products having whitening and / or antioxidant effects.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] This invention utilizes a combined extraction method of enzymatic hydrolysis-high pressure pulse-steam distillation to prepare citrus essential oil. The extraction process is carried out at low temperatures, without the introduction of any organic reagents, making it environmentally friendly and minimizing the loss of volatile active ingredients in the essential oil. The addition of both enzymatic hydrolysis and high pressure pulse treatments before steam distillation improves the essential oil yield and significantly enhances the tyrosinase inhibitory activity and free radical scavenging activity of the essential oil. The two pretreatments promote and synergistically enhance the aforementioned effects. Detailed Implementation

[0034] To further illustrate the technical means and effects of the present invention, the following describes the technical solution of the present invention in conjunction with preferred embodiments of the present invention. However, the present invention is not limited to the scope of the embodiments.

[0035] The cellulase used in the following descriptions is a product purchased from Yuanye brand S10041; pectinase is a product purchased from Yuanye brand S10007; hemicellulase is a product purchased from Yuanye brand S10044; tanninase is a product purchased from Yuanye brand S10207; β-glucanase is a product purchased from Yuanye brand S23089; and xylanase is a product purchased from Yuanye brand S23566.

[0036] Example 1

[0037] This embodiment provides a citrus essential oil, the preparation method of which is as follows:

[0038] (1) After washing and cutting the citrus peel into pieces, mix it with enzyme and water, and carry out enzymatic hydrolysis at 50℃ for 60 min. The enzyme is a complex enzyme of cellulase, pectinase, hemicellulase and tanninase in a mass ratio of 1:1:1:1, and the amount added is 3% of the citrus peel. The material-liquid ratio of citrus peel raw material to water is 1:4 g / mL to obtain the enzymatic hydrolysis solution.

[0039] (2) The enzymatic hydrolysis solution was subjected to a high-voltage pulsed electric field with a field strength of 40 kV / m and 100 electric shocks to obtain a solid-liquid mixture.

[0040] (3) The solid-liquid mixture was steam distilled for 2 h, the distillate was collected, the distillate was allowed to stand and separate into layers, the upper oil phase was taken, dehydrated and dried with anhydrous sodium sulfate, and filtered to obtain citrus essential oil.

[0041] Example 2

[0042] This embodiment provides a citrus essential oil, the preparation method of which is as follows:

[0043] (1) After washing and cutting the citrus peel into pieces, mix it with enzyme and water, and perform enzymatic hydrolysis at 55℃ for 50 min. The enzyme is a complex enzyme of cellulase, pectinase, hemicellulase and tanninase in a mass ratio of 1:1:2:2, and the amount added is 4% of the citrus peel. The material-liquid ratio of citrus peel raw material to water is 1:5 g / mL to obtain the enzymatic hydrolysis solution.

[0044] (2) The enzymatic hydrolysis solution was subjected to a high-voltage pulsed electric field treatment with an electric field strength of 50 kV / m and 80 electric shocks to obtain a solid-liquid mixture.

[0045] (3) The solid-liquid mixture was steam distilled for 2.5 h, the distillate was collected, the distillate was allowed to stand and separate into layers, the upper oil phase was taken, dehydrated and dried with anhydrous sodium sulfate, and filtered to obtain citrus essential oil.

[0046] Example 3

[0047] This embodiment provides a citrus essential oil, the preparation method of which is as follows:

[0048] (1) After washing and cutting the citrus peel into pieces, mix it with enzyme and water, and carry out enzymatic hydrolysis at 45℃ for 70 min. The enzyme is a complex enzyme of cellulase, pectinase, hemicellulase and tanninase in a mass ratio of 2:2:1:1, and the amount added is 2% of the citrus peel. The material-liquid ratio of citrus peel raw material to water is 1:3 g / mL to obtain the enzymatic hydrolysis solution.

[0049] (2) The enzymatic hydrolysis solution was subjected to a high-voltage pulsed electric field treatment with an electric field strength of 30 kV / m and 120 electric shocks to obtain a solid-liquid mixture.

[0050] (3) The solid-liquid mixture was steam distilled for 1.5 h, the distillate was collected, the distillate was allowed to stand and separate into layers, the upper oil phase was taken, dehydrated and dried with anhydrous sodium sulfate, and filtered to obtain citrus essential oil.

[0051] Example 4

[0052] This embodiment provides a citrus essential oil, the preparation method of which differs from that of Example 1 only in that: the amount of enzyme added in step (1) is 1% of the citrus peel, and other conditions remain unchanged.

[0053] Example 5

[0054] This embodiment provides a citrus essential oil, the preparation method of which differs from that of Example 1 only in that: the amount of enzyme added in step (1) is 6% of the citrus peel, and other conditions remain unchanged.

[0055] Example 6

[0056] This embodiment provides a citrus essential oil, the preparation method of which differs from that of Example 1 only in that: in step (1), the ratio of citrus peel raw material to water is 1:2 g / mL, and other conditions remain unchanged.

[0057] Example 7

[0058] This embodiment provides a citrus essential oil, the preparation method of which differs from that of Example 1 only in that: in step (1), the ratio of citrus peel raw material to water is 1:6 g / mL, and other conditions remain unchanged.

[0059] Example 8

[0060] This embodiment provides a citrus essential oil, the preparation method of which differs from that of Example 1 only in that: in step (2), the field strength is 55 kv / m, and other conditions remain unchanged.

[0061] Example 9

[0062] This embodiment provides a citrus essential oil, the preparation method of which differs from that of Example 1 only in that: in step (2), the field strength is 25 kv / m, and other conditions remain unchanged.

[0063] Example 10

[0064] This embodiment provides a citrus essential oil, the preparation method of which differs from that of Example 1 only in that: in step (3), steam distillation is carried out for 4 hours, while other conditions remain unchanged.

[0065] Example 11

[0066] This embodiment provides a citrus essential oil, the preparation method of which differs from that of Example 1 only in that: in step (1), the enzyme is a complex enzyme of pectinase, hemicellulase and tanninase in a mass ratio of 1:1:1, and other conditions remain unchanged.

[0067] Example 12

[0068] This embodiment provides a citrus essential oil, the preparation method of which differs from that of Example 1 only in that: in step (1), the enzyme is a complex enzyme of cellulase, hemicellulase and tanninase in a mass ratio of 1:1:1, and other conditions remain unchanged.

[0069] Example 13

[0070] This embodiment provides a citrus essential oil, the preparation method of which differs from that of Example 1 only in that: in step (1), the enzyme is a complex enzyme of cellulase, pectinase and tanninase in a mass ratio of 1:1:1, and other conditions remain unchanged.

[0071] Example 14

[0072] This embodiment provides a citrus essential oil, the preparation method of which differs from that of Example 1 only in that: in step (1), the enzyme is a complex enzyme of cellulase, pectinase and hemicellulase in a mass ratio of 1:1:1, and other conditions remain unchanged.

[0073] Example 15

[0074] This embodiment provides a citrus essential oil, the preparation method of which differs from that of Example 1 only in that: in step (1), the enzyme is a complex enzyme of cellulase, pectinase, β-glucanase and xylanase in a mass ratio of 1:1:1:1, and other conditions remain unchanged.

[0075] Comparative Example 1

[0076] This comparative example provides a citrus essential oil, the preparation method of which differs from that of Example 1 only in the absence of enzymatic hydrolysis, as detailed below:

[0077] (1) After washing and cutting the citrus peel into pieces, mix it with water. The ratio of citrus peel raw material to water is 1:4 g / mL. Then, subject it to high-voltage pulse electric field treatment with a field strength of 50 kv / m and 120 electric shocks to obtain a solid-liquid mixture.

[0078] (2) The solid-liquid mixture was steam distilled for 2 h, the distillate was collected, the distillate was allowed to stand and separate into layers, the upper oil phase was taken, dehydrated and dried with anhydrous sodium sulfate, and filtered to obtain citrus essential oil.

[0079] Comparative Example 2

[0080] This comparative example provides a citrus essential oil, the preparation method of which differs from that of Example 1 only in the absence of high-voltage pulsed electric field treatment, as detailed below:

[0081] (1) After washing and cutting the citrus peel into pieces, mix it with enzyme and water, and carry out enzymatic hydrolysis at 50℃ for 90 min. The enzyme is a complex enzyme of cellulase, pectinase, hemicellulase and tanninase in a mass ratio of 1:1:1:1, and the amount added is 3% of the citrus peel. The material-liquid ratio of citrus peel raw material to water is 1:4 g / mL to obtain the enzymatic hydrolysis solution.

[0082] (2) The enzymatic hydrolysis solution was steam distilled for 2 h, the distillate was collected, the distillate was allowed to stand and separate into layers, the upper oil phase was taken, dehydrated and dried with anhydrous sodium sulfate, and filtered to obtain citrus essential oil.

[0083] Comparative Example 3

[0084] This comparative example provides a citrus essential oil, the preparation method of which is as follows:

[0085] After washing and cutting the citrus peel into pieces, it was mixed with water at a ratio of 1:4 g / mL. The mixture was then steam distilled for 3 hours. The distillate was collected and allowed to stand to separate into layers. The upper oil phase was taken, dehydrated and dried with anhydrous sodium sulfate, and then filtered to obtain citrus essential oil.

[0086] Test Example 1

[0087] Essential oil extraction rate calculation:

[0088] The extraction rates of citrus essential oils obtained in Examples 1-15 and Comparative Examples 1-3 were calculated using the formula: (mass of essential oil product / mass of citrus peel raw material) × 100%. The results are shown in Table 1.

[0089] Test Example 2

[0090] Tyrosinase activity inhibition experiment:

[0091] The tyrosinase activity inhibition of the citrus essential oils prepared in Examples 1-15 and Comparative Examples 1-3 was detected by adding liquid according to Table 2.

[0092] Table 2

[0093]

[0094] The specific procedure was as follows: phosphate buffer, essential oil sample solutions of different concentration gradients, and tyrosinase solution were added sequentially to a 96-well plate, followed by the addition of the substrate L-tyrosine. Timing was started immediately. The absorbance at 475 nm was measured after 20 min of reaction at 25℃. During the measurement, a corresponding negative control was used as a reference. The inhibition rate of the test solution on tyrosinase was calculated using the formula: Tyrosinase inhibition rate (%) = (1-(B0-B1) / (A0-A1))×100. The half-maximal inhibitory concentration (IC50) was obtained based on the concentration-enzyme inhibition rate curve. The results are shown in Table 1.

[0095] Test Example 3

[0096] DPPH free radical scavenging rate experiment:

[0097] The DPPH free radical scavenging activity of the citrus essential oils prepared in Examples 1-15 and Comparative Examples 1-3 was tested by adding liquid according to Table 3.

[0098] Table 3

[0099]

[0100] The specific procedure was as follows: Anhydrous ethanol, essential oil sample solutions of different concentration gradients, and finally DPPH solution were added sequentially to a 96-well plate, and timing was started immediately. The absorbance at 517 nm was measured after reacting at 25℃ for 30 min. During the measurement, the corresponding negative control was used as a reference. The DPPH scavenging rate of the test solution was calculated according to the formula: DPPH scavenging rate (%) = (1-(A1-A2) / A0)×100, and the half-maximal inhibitory concentration (IC50) was obtained based on the concentration-DPPH scavenging rate curve. The results are shown in Table 1.

[0101] The results are shown in Table 1.

[0102] Table 1

[0103]

[0104]

[0105] As shown in Table 1, compared with Comparative Examples 1-3, the combined extraction method of enzymatic hydrolysis-high pressure pulse-steam distillation used in Examples 1-15 to prepare citrus essential oil can improve the essential oil yield, tyrosinase inhibitory activity, and free radical scavenging activity. A comparison between Example 1 and Comparative Examples 1-2 shows that the two pretreatments, enzymatic hydrolysis and high pressure pulse, mutually promote and synergistically enhance the above-mentioned effects.

[0106] The applicant declares that the technical solution of this invention is illustrated by the above embodiments, but this invention is not limited to the above embodiments, that is, it does not mean that this invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of raw materials for the products of this invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of this invention.

[0107] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0108] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

Claims

1. A method for preparing a citrus essential oil, characterized by, The preparation method comprises the following steps: (1) mixing citrus peel raw material with enzymes and water, and then performing enzymatic hydrolysis treatment to obtain an enzymatic hydrolysis treatment liquid; (2) performing high-voltage pulsed electric field treatment on the enzymatic hydrolysis treatment liquid to obtain a solid-liquid mixture; (3) performing water vapor distillation on the solid-liquid mixture, collecting a distillate, separating an oil phase, and obtaining citrus essential oil.

2. The production method according to claim 1, characterized by, The enzymes comprise any one or a combination of at least two of cellulase, pectinase, hemicellulase, or tannase; Preferably, the enzymes comprise a combination of cellulase, pectinase, hemicellulase, and tannase; Preferably, the mass ratio of the cellulase, pectinase, hemicellulase, and tannase is (1-3):(1-3):(1-3):(1-3).

3. The production method according to claim 1 or 2, characterized by, The addition amount of the enzymes is 1-10%, preferably 2-4%, of the citrus peel raw material; Preferably, the solid-liquid ratio of the citrus peel raw material to water is 1:(2-10) g / mL, preferably 1:(3-5) g / mL; Preferably, the enzymatic hydrolysis treatment is performed at 40-60°C for 40-80 min.

4. The production method according to any one of claims 1 to 3, characterized by, The field strength of the high-voltage pulsed electric field treatment is 30-50 kv / m; Preferably, the high-voltage pulsed electric field treatment is performed 60-140 times.

5. The production method according to any one of claims 1 to 4, characterized by, The time of the water vapor distillation is 1-3.5 h.

6. The production method according to any one of claims 1 to 5, characterized by, The operation of separating the oil phase comprises: allowing the distillate to stand and separate into layers, taking the upper oil phase, dehydrating and drying the oil phase with anhydrous sodium sulfate, and filtering to obtain the citrus essential oil.

7. Citrus essential oil prepared by the preparation method according to any one of claims 1-6.

8. Application of the citrus essential oil according to claim 7 in the preparation of a tyrosinase inhibitor.

9. Application of the citrus essential oil according to claim 7 in the preparation of a free radical scavenger.

10. Application of the citrus essential oil according to claim 7 in the preparation of a product with whitening and / or antioxidant efficacy.

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