Flavor-improved vinegar-soaked radish, preparation method thereof and application of lemongrass essential oil

Abstract

The invention provides flavor-improved vinegar-soaked radishes, a preparation method of the flavor-improved vinegar-soaked radishes and application of lemongrass essential oil, and relates to the technical field of food. The preparation method comprises the following steps: (1) preparing lemongrass essential oil: mixing lemongrass with saline water, soaking, distilling, and collecting the essential oil part to obtain the lemongrass essential oil; (2) preparing the vinegar-soaked radishes: mixing the radishes with vinegar, sugar and salt, soaking, and sterilizing to obtain the vinegar-soaked radishes; and (3) preparing the vinegar-soaked radishes with the improved flavor: mixing the lemongrass essential oil in the step (1) with the vinegar-soaked radishes in the step (2) according to the addition amount of 0.05-0.2% to obtain the vinegar-soaked radishes with the improved flavor. According to the method disclosed by the invention, volatile compound components of the vinegar-soaked radishes are remarkably changed, and the flavor is remarkably improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of food, and specifically relates to a flavor-improved pickled radish in vinegar, a preparation method thereof, and the application of lemongrass essential oil. Background Art

[0002] Pickled vegetables refer to vegetable products processed by pickling or marinating, and pickled radish in vinegar is exactly pickled with vinegar and other seasonings and belongs to one kind of pickled vegetables. Radish is rich in vitamins, minerals, crude fiber, etc., which helps to eliminate greasiness, promote digestion, enhance appetite, and regulate the spleen and stomach. Pickled radish in vinegar has a unique flavor, being moderately sweet and salty, crispy, tender, fragrant, and with a crispy taste.

[0003] Chinese invention patent CN115956663A discloses a microbial fermentation process for pickled vegetables, including the following steps: (1) preparing a fermentation broth; (2) sterilizing raw materials; (3) adding auxiliary materials, which include components in parts by weight: 4-7 parts of Sichuan pepper, 5-8 parts of pickled peppers, 7-9 parts of yellow ginger, 4-6 parts of garlic, 2-3 parts of lemongrass, 3-5 parts of perilla juice, and 2-3 parts of honeysuckle; (4) microbial fermentation; this invention prepares pickled vegetables through a microbial fermentation process, not only retaining the nutritional value of the raw materials of pickled vegetables, increasing the nutritional components of pickled vegetables during the microbial fermentation process, enhancing the flavor and crispy taste, making the fragrance strong and lasting, and also being able to inhibit the generation of nitrite and harmful microorganisms. Although this technical solution ensures the color and shelf life of pickled vegetables by adding auxiliary materials, the flavor of the obtained pickled vegetables is poor and there is no fresh fragrance.

[0004] Pickled radish in vinegar has a special fragrance, and the flavors of pickled radish in vinegar prepared by different preparation methods are different. Tian Kun studied the process of pickled crispy radish peel (Tian Kun. Research on the Process of Pickled Crispy Radish Peel [D]. Hunan Agricultural University, 2019.), and studied the influence of the addition amounts of different auxiliary materials and preparation process parameters on the sensory quality score of pickled crispy radish peel. Currently, the evaluation of food flavor generally includes sensory evaluation and instrumental evaluation, and there are relatively large subjective and artificial factors in sensory evaluation, and the scoring results are not accurate.

[0005] In view of this, it is necessary to provide a different process for improving the flavor of pickled radish in vinegar, detect the volatile components and their contents in pickled radish in vinegar, and evaluate the flavor improvement and the content of odor components of pickled radish in vinegar with objective technical effects, so that the fresh fruity fragrance and sweetness of pickled radish in vinegar are stronger and the taste is richer. Summary of the Invention

[0006] In view of the problems existing in the prior art, the present invention provides a flavor-improved pickled radish with vinegar, its preparation method and the application of citronella essential oil. The citronella is prepared into citronella essential oil, and the citronella essential oil is added to the pickled radish with vinegar according to a specific ratio to improve the flavor. The volatile compound components in the obtained pickled radish with vinegar improved by citronella flavor change significantly, and the flavor is significantly improved.

[0007] In the present invention, the pickled radish with vinegar is treated with citronella essential oil, and then the volatile components and their contents in the pickled radish with vinegar are detected. The contents of acetic acid and nonanal in the pickled radish with vinegar decrease significantly, while the contents of components such as citronellal, β-ocimene M, and β-ocimene D with fresh fruity fragrance and sweetness increase significantly.

[0008] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0009] First, the present invention provides a preparation method for a flavor-improved pickled radish with vinegar, including the steps:

[0010] (1) Preparation of citronella essential oil: Citronella is mixed with brine, soaked and then distilled, and the essential oil part is collected to obtain citronella essential oil;

[0011] (2) Preparation of pickled radish with vinegar: Radish is mixed and impregnated with vinegar, sugar and salt, and sterilized to obtain pickled radish with vinegar;

[0012] (3) Preparation of flavor-improved pickled radish with vinegar: The citronella essential oil in step (1) is mixed with the pickled radish with vinegar in step (2) at an addition amount of 0.05%-0.2% to obtain the flavor-improved pickled radish with vinegar.

[0013] Preferably, in step (1), the brine is an aqueous NaCl solution with a mass concentration of 5%-20%.

[0014] More preferably, the mass concentration of the aqueous NaCl solution is 8.4%.

[0015] Preferably, in step (1), the citronella needs to be crushed and sieved through a 10-50 mesh sieve before being mixed with the brine; more preferably, it is sieved through a 20-30 mesh sieve.

[0016] Preferably, in step (1), the solid-liquid ratio of the citronella to the brine is 1:15-30 g / mL.

[0017] More preferably, in step (1), the solid-liquid ratio of the citronella to the brine is 1:22 g / mL.

[0018] Preferably, in step (1), the soaking time is 0.5-2 h, and the soaking temperature is 10-30 °C.

[0019] Further preferably, in step (1), the soaking time is 1 h and the soaking temperature is 20 °C.

[0020] Preferably, in step (1), the distillation time is 3 - 8 h and the distillation temperature is 80 - 100 °C.

[0021] Further preferably, in step (1), the distillation time is 5 h and the distillation temperature is 95 °C.

[0022] Preferably, in step (1), there is still water in the essential oil part and the water needs to be removed. The water removal method is: adding anhydrous Na 2 SO 4 to remove the water.

[0023] Further preferably, the addition amount of anhydrous Na 2 SO 4 is 10% of the weight of the essential oil.

[0024] Preferably, in step (2), the vinegar used is the vinegar commonly used in the art, and the types are not limited to red vinegar, white vinegar, rice vinegar, aromatic vinegar, and fruit vinegar.

[0025] Preferably, in step (2), the mass concentration of the vinegar is 15% - 25%.

[0026] Further preferably, the mass concentration of the vinegar is 20%.

[0027] Preferably, in step (2), the mass ratio of the vinegar, sugar, and salt is 15 - 25:6 - 10:0.5 - 1.5 to prepare an impregnating solution; in the impregnating solution, the mass concentration of the vinegar is 15% - 25%, the mass concentration of the sugar is 6% - 10%, the mass concentration of the salt is 0.5 - 1.5%, and the balance is water.

[0028] Further preferably, the mass ratio of the vinegar, sugar, and salt is 20:7.5:1; in the impregnating solution, the mass concentration of the vinegar is 20%, the mass concentration of the sugar is 7.5%, the mass concentration of the salt is 1%, and the balance is water.

[0029] Preferably, in step (2), during the impregnation process, ensure that the radish is completely immersed in the impregnating solution; impregnate at room temperature for 36 - 60 h.

[0030] Further preferably, the impregnation time is 48 h.

[0031] Preferably, in step (2), a preservative needs to be added after impregnation.

[0032] Preferably, in step (2), the sterilization is pasteurization.

[0033] Preferably, in step (3), the addition amount is the mass ratio of the lemongrass essential oil in step (1) to the pickled radish in vinegar in step (2).

[0034] More preferably, in step (3), the addition amount is 0.1% - 0.15%; even more preferably, in step (3), the addition amount is 0.1%.

[0035] Preferably, in step (3), the mixing treatment is specifically: after stirring evenly, vacuum sealing, and placing in the dark at room temperature for 14 - 35 days.

[0036] More preferably, the number of days of placement is 28 days.

[0037] Then, the present invention provides pickled radish in vinegar with improved flavor prepared by the above preparation method.

[0038] Finally, the present invention provides the application of lemongrass essential oil in the preparation of pickled radish in vinegar with improved flavor.

[0039] Preferably, the preparation method of the lemongrass essential oil includes the steps of: mixing lemongrass with brine, soaking and then distilling, collecting the essential oil part to obtain lemongrass essential oil.

[0040] More preferably, the brine is an aqueous NaCl solution with a mass concentration of 5% - 20%; even more preferably, the mass concentration of the aqueous NaCl solution is 8.4%.

[0041] More preferably, before mixing with the brine, the lemongrass needs to be crushed and passed through a 10 - 50 mesh sieve; even more preferably, it is passed through a 20 - 30 mesh sieve.

[0042] More preferably, the solid - liquid ratio of the lemongrass to the brine is 1:15 - 30 g / mL; even more preferably, the solid - liquid ratio of the lemongrass to the brine is 1:22 g / mL.

[0043] More preferably, the soaking time is 0.5 - 2 h and the soaking temperature is 10 - 30 °C; even more preferably, the soaking time is 1 h and the soaking temperature is 20 °C.

[0044] More preferably, the distillation time is 3 - 8 h and the distillation temperature is 80 - 100 °C; even more preferably, the distillation time is 5 h and the distillation temperature is 95 °C.

[0045] More preferably, there is still water in the essential oil part, and water needs to be removed from it. The water removal method is: adding anhydrous Na 2 SO 4 to remove the water; anhydrous Na 2 SO 4The addition amount is 10% of the weight of the essential oil.

[0046] In the present invention, a large number of flavor compounds are produced during the fermentation process of pickled radish in vinegar:

[0047] (1) Aldehyde compounds are mainly formed by the oxidative degradation of polyunsaturated fatty acids under the action of microorganisms and enzymes. They are important aroma compounds in food, and some compounds will exhibit pleasant odors such as grassy, malty, fruity, and cheesy odors.

[0048] (2) Ester substances are mainly formed by the esterification reaction of acids and alcohols during the fermentation process. Most ester compounds have fruity flavors.

[0049] (3) Ketone compounds are produced by the oxidation or degradation of unsaturated fatty acids, the degradation of amino acids, or the oxidation of microorganisms. Some ketone substances can also have pleasant flavors such as fruity and milky flavors.

[0050] (4) Alcohol compounds are mainly produced by the oxidation of fats, the metabolism of amino acids and carbohydrates, and are usually considered as precursor substances for many biochemical reactions in fermentation products.

[0051] (5) Acid substances are mainly acetic acid. Acetic acid can reduce the pH value of pickled vegetables during the fermentation process, increase the sour taste, and improve the flavor of pickled radish. However, as the fermentation time prolongs, the acidity of pickled radish increases too much, resulting in a pungent sour taste, which is not suitable for consumption. Therefore, in the actual production process, acidity is the monitoring index for controlling the whole fermentation reaction. When the acidity reaches a certain value, the reaction needs to be stopped to maintain the palatability and flavor of the product.

[0052] Compared with the prior art, the present invention has the following beneficial effects:

[0053] 1. The present invention uses lemongrass essential oil to improve the flavor of pickled radish in vinegar. The lemongrass essential oil is added at a ratio of 0.05 - 0.2% of the mass of pickled radish in vinegar. The content of volatile components in the pickled radish in vinegar treated with lemongrass essential oil changes significantly. The content of substances with bad odors such as acetic acid, nonanal D, and nonanal M decreases, and the fragrance contribution value decreases; the content of chemical substances with high-quality sweet and fragrant odors such as limonene, 4-heptanone, phenethyl acetate M, β-ocimene M, and β-ocimene D increases, and the fragrance contribution value increases.

[0054] 2. The pickled radish in vinegar with improved flavor by lemongrass essential oil in the present invention has an increased lemon flavor, sweet flavor, orange flavor, citrus fruit flavor, and fresh woody flavor, and significantly reduced bad odors such as pungent flavor and oily flavor. The preparation method of the present invention has a significant effect on improving the flavor of pickled radish in vinegar. Detailed implementation manners

[0055] The following non-limiting examples can enable those of ordinary skill in the art to more comprehensively understand the present invention, but do not limit the present invention in any way. The following content is only an exemplary illustration of the scope claimed by the present invention. Those skilled in the art can make various changes and modifications to the present invention based on the disclosed content, and such changes and modifications should also fall within the scope claimed by the present invention.

[0056] When the examples give a numerical range, it should be understood that unless otherwise specified in the present invention, both endpoints of each numerical range and any value between the two endpoints can be selected. Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0057] The present invention will be further described below by way of specific examples. All kinds of chemical reagents used in the examples of the present invention are obtained through conventional commercial channels unless otherwise specified.

[0058] Example 1

[0059] A preparation method of a flavor-improved pickled radish in vinegar is as follows:

[0060] (1) Lemongrass is pulverized and sieved through a 20-mesh sieve. The lemongrass powder is mixed with an 8.4% (by mass) NaCl aqueous solution at a solid-liquid ratio of 1:22 g / mL, soaked at 20 °C for 1 h, and then distilled at 95 °C for 5 h. The essential oil part is collected, and 10% (by weight) of anhydrous Na 2 SO 4 is added to remove moisture, obtaining lemongrass essential oil;

[0061] (2) Preparation of pickled radish in vinegar: The radish is evenly sliced and fully mixed and stirred with the impregnating solution, impregnated at room temperature for 48 h, and then potassium sorbate is added, and pasteurization is carried out to kill microorganisms; in the impregnating solution, the mass concentration of red vinegar is 20%, the mass concentration of sugar is 7.5%, the mass concentration of salt is 1%, and the balance is water;

[0062] (3) Preparation of flavor-improved pickled radish in vinegar: The lemongrass essential oil obtained in step (1) is stirred evenly with the pickled radish in vinegar obtained in step (2) at an addition amount of 0.1%, vacuum-sealed, and placed at room temperature in the dark for 28 days to obtain the flavor-improved pickled radish in vinegar.

[0063] Example 2

[0064] Different from Example 1, in step (3), the lemongrass essential oil is stirred evenly with the pickled radish in vinegar obtained in step (2) at an addition amount of 0.05%, vacuum-sealed, and placed at room temperature in the dark for 28 days to obtain the flavor-improved pickled radish in vinegar. The rest are the same as those in Example 1.

[0065] Example 3

[0066] Different from Example 1, in step (3), lemongrass essential oil was added at an amount of 0.2% and evenly stirred with the pickled radish in vinegar in step (2), then vacuum sealed and placed at room temperature away from light for 28 days to obtain pickled radish with improved flavor. The rest was the same as in Example 1.

[0067] Comparative Example 1

[0068] Different from Example 1, lemongrass essential oil was not added, and only the pickled radish in vinegar was prepared: the radish was evenly sliced and fully mixed and stirred with the pickling solution, pickled at room temperature for 48 h, then potassium sorbate was added, and pasteurized to kill microorganisms to obtain pickled radish in vinegar; in the pickling solution, the mass concentration of red vinegar was 20%, the mass concentration of sugar was 7.5%, the mass concentration of salt was 1%, and the balance was water.

[0069] Comparative Example 2

[0070] Different from Example 1, lemongrass essential oil was replaced with: dried ginger essential oil, angelica dahurica essential oil, galangal essential oil, star anise essential oil, Chinese prickly ash essential oil, white cardamom essential oil respectively; 6 groups of pickled radish in vinegar treated with different essential oils were obtained.

[0071] The preparation method of each essential oil was the same as that of the lemongrass essential oil in Example 1.

[0072] Comparative Example 3

[0073] Different from Example 1, step (1) for the preparation of lemongrass essential oil was not carried out.

[0074] In this comparative example, the lemongrass raw material in Example 1 was directly added to the pickled radish in vinegar and evenly stirred with the pickled radish in vinegar. Specifically:

[0075] (1) Preparation of pickled radish in vinegar: the same as in Example 1;

[0076] (2) Preparation of pickled radish in vinegar with improved flavor: the lemongrass raw material (the mass of this lemongrass was the same as that of the lemongrass in Example 1) was evenly stirred with the pickled radish in vinegar, vacuum sealed, and placed at room temperature away from light for 28 days to obtain pickled radish in vinegar with improved flavor.

[0077] Test 1 Detection of Volatile Compounds

[0078] Test method: GC-IMS was used to detect the volatile compounds of the pickled radish in vinegar with improved flavor that was not sealed, sealed for 14 days, and sealed for 28 days respectively. The content (%) results of each volatile compound are shown in Table 1, Table 2 and Table 3 respectively.

[0079] Comparative Example 1 was the group without essential oil treatment; Example 1 was the group treated with lemongrass essential oil.

[0080] Table 1

[0081]

[0082] Table 2

[0083]

[0084] Table 3

[0085]

[0086]

[0087] In Table 1, Table 2 and Table 3, M: monomer; D: dimer.

[0088] It can be seen from Table 1, Table 2 and Table 3 that there are 48 volatile compounds in the pickled radish with lemongrass essential oil added, and the contents of each volatile compound have changed significantly. The 48 volatile compounds belong to ketones, acids, esters, alcohols, aldehydes, alkenes and ethers respectively. Among them, there are 9 kinds of ketone compounds, 4 kinds of acid compounds, 10 kinds of ester compounds, 7 kinds of alcohol compounds, 11 kinds of aldehyde compounds, 6 kinds of alkene compounds and 1 kind of ether compound.

[0089] After adding lemongrass essential oil, the content of the target component acetic acid suddenly decreased, but during the subsequent reaction process, acetic acid showed an increasing trend. From 0 to 14 days, the content of acetic acid increased from 16.04% to 20.75%, and then the increasing trend slowed down. By the 28th day, the content of acetic acid reached 21.64%. During this process, other volatile compounds in the pickled radish all changed to varying degrees.

[0090] Detection of aroma contribution value in Experiment 2

[0091] Test method: Analyze the flavor contribution of 48 volatile compounds in Tables 1 - 3.

[0092] Headspace treatment conditions: Take 2.0 g of the sample and put it into a 20 mL headspace vial, add 10 μL of 2-methyl-3-heptanone (concentration 10 μg / mL), incubate at 50 °C for 15 minutes, and then inject 500 μL. Each sample is repeated in 3 groups.

[0093] Chromatographic conditions: MXT-WAX capillary column (15 m × 0.53 mm, 1.0 μm), carrier gas is high-purity nitrogen (purity ≥ 99.999%), carrier gas flow rate: 0 - 2 minutes, 2.0 mL / min; 2 - 8 minutes, 2 - 10.0 mL / min; 8 - 18 minutes, 10 - 100.0 mL / min; 18 - 38 minutes, 100.0 mL / min.

[0094] GC-IMS detection conditions: The drift tube length is 53 mm, the electric field strength is set at 500 V / cm, the temperature is 45 °C, the flow rate is 150 mL / min, and the ion source is a tritium source (3H).

[0095] The results of aroma descriptions and aroma contribution values (ROAV) are shown in Tables 4 and 5. T in Tables 4 and 5 is the olfactory threshold: the concentration of a substance that causes the minimum stimulus for human olfactory perception.

[0096] Table 4

[0097]

[0098] Table 5

[0099]

[0100] The citronella essential oil with an addition amount of 0.05% has a weak inhibitory effect on acetic acid. Overall, within 28 days of treatment, there is no over-acidification. Compounds with fruity aromas such as phenethyl acetate M, 4-heptanone, β-ocimene M, and β-ocimene D can still be produced, ensuring that the pickled radish has a fruity aroma. Due to the decrease in the addition amount, the inhibitory effect on nonanal M compounds in the system also weakens, but it can still inhibit the generation of oily flavor to a certain extent. Finally, the pickled radish can exhibit a certain fruity taste; if the addition amount is further reduced, there will be no fruity taste.

[0101] The citronella essential oil with an addition amount of 0.2% has a strong inhibitory effect on acetic acid. Within 28 days of treatment, it ensures a low acetic acid content. Compounds with fruity aromas such as phenethyl acetate M, 4-heptanone, β-ocimene M, and β-ocimene D can be produced, and the yield has a certain increase, making the fruity aroma of the pickled radish more obvious. At the same time, the inhibitory effect on nonanal M compounds in the system is also prominent, inhibiting the generation of oily flavor. However, due to the excessive addition amount, the contents of limonene and citronellal in the pickled radish are relatively high in the end, making the pickled radish exhibit a certain lemongrass flavor; if the addition amount is further increased, the pickled radish will present a strong lemongrass flavor, covering up the fruity aroma.

[0102] The ROAV value is a method for evaluating the contribution of volatile compounds to the overall odor. It determines the relative contribution of each compound to the overall odor by comparing the odor intensity of each volatile compound with its concentration in the sample. The larger the ROAV value, the greater the contribution of the compound to the overall flavor. Substances with ROAV ≥ 1 are the key flavor compounds in the sample. There are mainly 10 kinds of flavor substances with ROAV values greater than 1 in the flavor-improved pickled radish system of the present invention, and these compounds play a major role in the flavor of the pickled radish.

[0103] The present invention changes the flavor of pickled radishes by adding lemongrass essential oil. In the initial stage of addition, the pickled radishes as a whole present the smell of lemongrass. As the reaction time increases, the content of citronellal (the main flavor substance of lemongrass) gradually decreases to 2.60%, which is lower than the citronellal content of 3.34% in the untreated group, and finally eliminates the peculiar smell brought by the addition of lemongrass essential oil. At the same time, the research finds that the contents of compounds such as acetic acid, benzoic acid, nonanal, and 2,3-butanedione, which have a negative impact on the aroma such as bitter almond and strong oily smell, are significantly reduced, while the contents of compounds such as limonene, 4-heptanone, phenethyl acetate, and β-ocimene, which have a positive adjustment effect on the aroma, are significantly increased. Therefore, the taste of the pickled radishes treated with lemongrass essential oil is significantly improved.

[0104] Experiment 3 Sensory Evaluation

[0105] Refer to the sensory evaluation model established by Demi et al. (DEMI N, et al, Journal of Food Processing and Preservation, 2006.). Select 10 evaluators (5 males and 5 females) with a background in sensory evaluation to score the color, smell, taste, and crispness of the samples (vinegar-pickled radishes) fermented for 28 days.

[0106] The scoring criteria for sensory indexes are as shown in Table 6 below. The final score is the sum of the scoring values of the 4 indexes (full score 100 points). All samples are provided at room temperature of 20°C and evaluated in random order.

[0107] Table 6

[0108]

[0109]

[0110] The evaluators made sensory descriptions of the flavors of the vinegar-pickled radishes with different treatments, and the description results are shown in Table 7.

[0111] Table 7

[0112]

[0113] The evaluators made sensory scores of the vinegar-pickled radishes with different treatments, and the scoring results are shown in Table 8.

[0114] Table 8

[0115]

[0116]

[0117] As can be seen from Table 7 and Table 8, for the pickled radishes treated with different essential oils of plants, the groups treated with star anise essential oil, Chinese prickly ash essential oil, and lemongrass essential oil have the most intense aroma. However, due to the strong flavors of star anise and Chinese prickly ash themselves, the pickled radishes treated with them respectively show obvious star anise flavor and spicy flavor, changing the original sweet and sour flavor of the radishes and causing a relatively strong flavor competition phenomenon. The group treated with lemongrass essential oil presents an obvious fruit aroma. Without changing the original sweet and sour flavor of the radishes, it adds a fruit aroma and enhances the richness of the flavor. The groups treated with lemongrass essential oil and amomum kravanh pierre ex gagnep essential oil show good color protection performance.

[0118] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than limiting the protection scope of the present invention. Any simple modification or equivalent replacement of the technical solution of the present invention by those of ordinary skill in the art does not depart from the essence and scope of the technical solution of the present invention.

Claims

1. A method for preparing pickled radish with improved flavor, characterized in that: Includes steps: (1) Preparation of citronella essential oil: citronella is mixed with salt water, soaked and then distilled, and the essential oil portion is collected to obtain citronella essential oil; (2) Preparation of pickled radish in vinegar: immersing radish in a mixture of vinegar, sugar and salt, sterilizing the mixture, and obtaining pickled radish in vinegar; (3) Preparation of flavor-improved pickled radish in vinegar: 0.05%-0.2% of the citronella essential oil from step (1) is added to the pickled radish from step (2) to obtain flavor-improved pickled radish in vinegar.

2. The preparation method according to claim 1, characterized in that: In step (1), the brine is a NaCl aqueous solution with a mass concentration of 5%-20%; In step (1), the lemongrass needs to be crushed and passed through a 10-50 mesh sieve before being mixed with the salt water.

3. The preparation method according to claim 1, characterized in that: In step (1), the solid-to-liquid ratio of the lemongrass to the brine is 1:15-30 g / mL.

4. The preparation method according to claim 1, characterized in that: In step (1), the soaking time is 0.5-2h, and the soaking temperature is 10-30°C; In step (1), the distillation time is 3-8 hours and the distillation temperature is 80-100°C.

5. The preparation method according to claim 1, characterized in that: In step (2), the mass concentration of the vinegar is 15%-25%.

6. The preparation method according to claim 1, characterized in that: In step (2), the mass ratio of the vinegar, sugar and salt is 15-25:6-10:0.5-1.5 to prepare an impregnation liquid.

7. The preparation method according to claim 1, characterized in that: In step (2), during the soaking process, ensure that the radish is completely immersed in the soaking liquid; soak at room temperature for 36-60 hours; and the sterilization is pasteurization.

8. The preparation method according to claim 1, characterized in that: In step (3), the added amount is 0.1%-0.15%; In step (3), the mixing treatment is specifically as follows: after stirring evenly, vacuum sealing, and placing in a dark place at room temperature for 14-35 days.

9. Pickled radish with improved flavor prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the citronella essential oil obtained by the preparation method according to any one of claims 1 to 8 in preparing pickled radish with improved flavor.

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