A method for processing dried orange peel and optimizing dried orange peel aging

Abstract

The application belongs to the field of food processing, and discloses a dried orange peel and a method for optimizing dried orange peel aging, which comprises the following steps: Step 1: preparing a portuguese williams yeast solution; inoculating the portuguese williams yeast into a culture medium and culturing to obtain the portuguese williams yeast solution; Step 2: inoculating the portuguese williams yeast solution into dried orange peel and culturing for 40-60 days; and Step 3: performing steaming and drying operation on the product obtained in Step 2 for at least 3 times. The application improves the conversion efficiency of active substances in dried orange peel by the cooperation of specific yeast fermentation and steaming and drying process, and shortens the process of the traditional process. Meanwhile, the application also provides dried orange peel prepared based on the method.

Description

Technical Field

[0001] This invention relates to the field of food processing, specifically to a type of dried tangerine peel and a method for optimizing the aging process of dried tangerine peel. Background Technology

[0002] Dried tangerine peel, or Chenpi, is the dried, mature peel of the citrus fruit (Citrus reticulata Blanco) and its cultivated varieties, belonging to the Rutaceae family. It contains various bioactive substances, such as flavonoids, and possesses properties that regulate qi and strengthen the spleen, dry dampness and resolve phlegm, and have anti-inflammatory and antioxidant effects. The harvesting of citrus fruits generates a large amount of byproducts, such as peels and seeds, leading to resource waste and environmental pollution. With the increasing planting area and yield of citrus fruits year by year, this problem has become increasingly prominent and has attracted widespread attention.

[0003] Aging is a crucial process in the production of dried tangerine peel, significantly impacting its final quality. The most common existing method is traditional natural sun-drying; the longer the aging process, the better the quality and the higher the price. However, traditional natural aging methods have several drawbacks, such as being time-consuming, hindering mass production, being difficult to control, and prone to mold growth due to environmental factors. Therefore, it is urgently needed to develop a method that accelerates the aging process while simultaneously enhancing its effectiveness.

[0004] In the prior art, CN 116570011 A discloses a four-lobed tangerine peel and its drying process, which describes a tangerine peel processing method. Specifically, the tangerine peel to be aged undergoes pretreatment, sun-drying to remove moisture, and then nine rounds of steaming and sun-drying to obtain the tangerine peel, with a total steaming time of 180-270 minutes. This method only adds steaming and sun-drying to the traditional method to shorten the aging time, but the nine-round steaming and sun-drying process is cumbersome, unsuitable for mass production, and does not improve the aging effect or yield higher quality tangerine peel.

[0005] Therefore, the technical problem to be solved in this case is: how to shorten the number of steaming and drying cycles. Summary of the Invention

[0006] The technical problem to be solved by this invention is to overcome the shortcomings of the prior art and provide a method for optimizing the aging of dried tangerine peel. By combining specific yeast fermentation and steaming-drying processes, the conversion efficiency of active substances in dried tangerine peel is improved, and the process flow of traditional methods is shortened.

[0007] Meanwhile, the present invention also discloses the dried tangerine peel prepared based on this method.

[0008] To achieve this objective, the present invention employs the following technical solution:

[0009] A method for optimizing the aging of dried tangerine peel includes the following steps:

[0010] Step 1: Prepare Portuguese Corydalis yeast culture; Inoculate Portuguese Corydalis yeast into a culture medium and culture it to obtain Portuguese Corydalis yeast culture.

[0011] Step 2: Inoculate the Portuguese yeast culture into the new peel of dried tangerine peel and ferment for 40-60 days;

[0012] Step 3: Perform the steaming and drying operation on the product obtained in Step 2 at least 3 times;

[0013] The steaming and drying operation includes steaming and drying.

[0014] In this invention, by adopting a process of fermentation followed by steaming and drying, the aging effect of dried tangerine peel can be significantly improved;

[0015] Some studies in this invention have found that even fermentation alone can improve the aging effect of dried tangerine peel; other studies in this invention have found that steaming and sun-drying can also improve the aging effect, but multiple steaming and sun-drying operations are required, which makes it difficult to scale up industrial production.

[0016] We believe that the process of fermentation followed by steaming and drying pre-converts the active ingredients such as hesperidin and lemon balm glycosides in the new peel of tangerine peel, and decomposes some of the active ingredients into flavonoid aglycones and phenolic substances.

[0017] By comparing samples that were fermented without steaming and dried, and samples that were steamed and dried without fermentation, we were surprised to find that the content of flavonoids and phenolic substances in samples that were both fermented and steamed and dried was significantly increased, and their antioxidant activity was significantly enhanced.

[0018] Preferably, the preservation number of the Portuguese Clavispora is GDMCC No: 61036, the depositary institution is Guangdong Provincial Center for Microbial Culture Collection, the depositary address is 5th Floor, Experimental Building, No. 100 Xianlie Middle Road, Yuexiu District, Guangzhou City, Guangdong Province, the deposit date is May 27, 2020, and the Latin name of the strain is Clavispora lusitaniae CP-1.

[0019] Preferably, in step 1, the culture medium is malt extract culture medium; the culture conditions are: culture temperature of 10-40℃ and culture time of 12-24h.

[0020] Preferably, in step 2, 10-30g of *Corydalis lucida* yeast solution is inoculated per 100g of fresh tangerine peel; the viable cell content of the *Corydalis lucida* yeast solution is 1.0 × 10⁻⁶. 4 ~9.0×10 9 cfu / ml.

[0021] Preferably, the culture temperature in step 2 is 0–50°C, and the culture humidity is 30–90%.

[0022] More preferably, step 2 is performed by alternating between high-temperature, high-humidity culture and low-temperature, low-humidity culture;

[0023] The culture temperature for the high-temperature and high-humidity culture is 25–50°C; the culture humidity is 60–90%.

[0024] The culture temperature for the low-temperature and low-humidity culture is 0–25°C; the culture humidity is 30–60%.

[0025] In further research of this invention, we discovered that alternating fermentation methods are more effective in activating the transformation of active substances into flavonoids and phenolic compounds. This is likely because high temperature and humidity increase the moisture content and water activity of the tangerine peel, which is beneficial for microbial transformation of active ingredients and accelerates the chemical reaction rate. Low temperature and low humidity slow down the reaction rate and effectively prevent mold growth. Repeated high and low humidity environments cause frequent changes in the internal moisture of the tangerine peel, further intensifying the chemical reaction.

[0026] Preferably, the duration of a single high-temperature and high-humidity culture is 4 to 6 days; the duration of a single low-temperature and low-humidity culture is 4 to 6 days.

[0027] Preferably, the steaming operation in step 3 is performed at a temperature of 80–100°C for 30–60 minutes; the sun-drying operation is performed under natural sunlight for 12–48 hours.

[0028] In addition, a type of dried tangerine peel is disclosed, which is prepared using any of the methods described above.

[0029] The beneficial effects of this invention are:

[0030] This invention utilizes yeast to ferment the new peel of dried tangerine peel, and through specific steaming and sun-drying processes, enhances the conversion of active substances in the tangerine peel and shortens the number of steaming and sun-drying cycles in traditional aging processes. Detailed Implementation

[0031] In the description of this invention, it should be noted that unless specific conditions are specified in the examples, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0032] Product Information:

[0033] The strain used in Example 1 has the accession number GDMCC No: 61036, the depository is Guangdong Provincial Center for Microbial Culture Collection, the depository address is 5th Floor, Experimental Building, No. 100 Xianlie Middle Road, Yuexiu District, Guangzhou City, Guangdong Province, the deposit date is May 27, 2020, and the Latin name of the strain is Clavispora lusitaniae CP-1.

[0034] The strain used in Comparative Example 1 has the accession number GDMCC No: 63249, is deposited at the Guangdong Provincial Center for Microbial Culture Collection, located at 5th Floor, Experimental Building, No. 100 Xianlie Middle Road, Yuexiu District, Guangzhou, Guangdong Province, on March 10, 2023, and has the Latin name Pichia kudriavzevii SJ36.

[0035] The strain used in Comparative Example 2 has the accession number GDMCC No: 60317, the depository is Guangdong Provincial Center for Microbial Culture Collection, the depository address is 5th Floor, Experimental Building, No. 100 Xianlie Middle Road, Yuexiu District, Guangzhou, Guangdong Province, the deposit date is January 24, 2018, and the Latin name of the strain is Lactobacillus furmentum L3.

[0036] Part One

[0037] This section mainly examines the relationship between fermentation and steaming / drying. The specific experimental methods are as follows:

[0038] Example 1

[0039] Step 1: Processing tea branches and fruit peels;

[0040] Wash fresh tangerine peels, air dry them, and peel them (using a two- or three-cut method). Place the peels in a cool, ventilated place to air dry for 4-5 hours. After air drying, turn the peels inside out and sun dry them naturally to further evaporate the moisture. Once dried (moisture content around 13wt%), you will have tangerine peel (new peel) ready for use.

[0041] The results of the tests on the new peel of dried tangerine peel are shown in Table 1.

[0042] Step 2: Preparation of Portuguese Corynebacterium tumefaciens culture;

[0043] Prepare 600 mL of malt extract liquid culture medium (Guangdong Huankai Microbial Technology Co., Ltd., model: 021120). Dispense 200 mL of the medium into three 250 mL Erlenmeyer flasks. Autoclave at 115℃ for 20 min, cool to room temperature, inoculate with *Corynebacterium paeonii* colonies, and incubate at 37℃ and 200 rpm for 16 h. Aliquot into 50 mL centrifuge tubes and centrifuge at 5000 rpm for 10 min. Discard the supernatant, resuspend the bacterial pellet in 10 mL of sterile water in each tube, combine the bacterial suspensions, and add sterile water to a final volume of 150 mL. This yields 4.0 × 10⁻⁶ *Corynebacterium paeonii* bacterial suspension suitable for inoculating dried tangerine peel. 7 ~9.0×10 8 cfu / ml.

[0044] Step 3: Preparation of dried tangerine peel samples inoculated with Portuguese Corynebacterium.

[0045] The dried tangerine peel was inoculated with Portuguese yeast using a precision spraying device.

[0046] (1) Equipment sterilization method: spray with 75% alcohol for 10 minutes, spray with sterile water for 15 minutes, wipe clean, and then sterilize with ultraviolet lamp for 30 minutes.

[0047] (2) Sterilization of dried tangerine peel: Weigh 300g of fresh dried tangerine peel, spread it in the drawer, sterilize it with ultraviolet light for 30 minutes, turn it over and continue sterilization for 30 minutes.

[0048] (3) Inoculation method: The sterilized tangerine peel was sprayed with 30g of Portuguese Corynebacterium tumefaciens liquid using a precision spraying device.

[0049] (4) Fermentation culture: The inoculated new peel of tangerine peel was placed in an artificial incubator, and 150 mL of Portuguese yeast solution was sprayed on both sides of the new peel. The low temperature and low humidity (20℃, 52.5%) and high temperature and high humidity (30℃, 82.5%) were alternately run for 5 days each. At the 0d, 10d, 20d, 30d, 40d, 50d and 60d of the culture time, an appropriate amount of sample was taken and stored in a -20℃ refrigerator for testing.

[0050] The relevant test results are shown in Table 1;

[0051] Step 4: Take the 50-day dried tangerine peel sample obtained in Step 3, steam it (100℃, 40 min), and sun-dry it naturally for 24 h to further evaporate the moisture. After drying (moisture content of about 13wt%), steam it again and repeat the steaming and sun-drying process 3 times.

[0052] Step 5: Index determination; the results are shown in Table 1.

[0053] All embodiments and comparative examples of this invention use the same batch of fresh tangerine peel.

[0054] Comparative Example 1

[0055] Step 1: Processing tea branches and fruit peels;

[0056] Wash fresh tangerine peels, air dry them, and peel them (using a two- or three-cut method). Place the peels in a cool, ventilated place to air dry for 4-5 hours. After air drying, turn the peels inside out and sun dry them naturally to further evaporate the moisture. Once dried (moisture content around 13wt%), you will have tangerine peel (new peel) ready for use.

[0057] Step 2: Preparation of dried tangerine peel samples.

[0058] The dried tangerine peel was sprayed with sterile water using a precision spraying device.

[0059] (1) Equipment sterilization method: spray with 75% alcohol for 10 minutes, spray with sterile water for 15 minutes, wipe clean, and then sterilize with ultraviolet lamp for 30 minutes.

[0060] (2) Sterilization of dried tangerine peel: Weigh 300g of fresh dried tangerine peel, spread it in the drawer, sterilize it with ultraviolet light for 30 minutes, turn it over and continue sterilization for 30 minutes.

[0061] (3) Place the sterilized new peel of tangerine peel in an artificial incubator and spray 150 mL of sterile water on both sides of the new peel. Set up low temperature and low humidity (20℃, 52.5%) and high temperature and high humidity (30℃, 82.5%) alternating for 5 days each. Take appropriate samples at 0d, 10d, 20d, 30d, 40d, 50d and 60d respectively and store them in a -20℃ refrigerator for testing.

[0062] Step 3: Take the 50-day dried tangerine peel sample obtained in Step 2, steam it (100℃, 40 min), and sun-dry it naturally for 24 h to further evaporate the moisture. After drying (moisture content of about 13wt%), steam it again. Repeat the steaming and sun-drying process 3 times.

[0063] Step 4: Index determination; the determination results are shown in Table 1.

[0064] Indicator testing methods:

[0065] (1) Extraction of dried tangerine peel samples

[0066] Take the dried tangerine peel sample and methanol (100% by volume) at a ratio of 0.1g:4mL, vortex for 30s, extract at 60℃, and sonicate for 30min. Repeat this step twice, and combine the supernatants to obtain the flavonoid extract.

[0067] (2) Determination of total flavonoids

[0068] Take 6 mL of appropriately diluted flavonoid extract and 1 mL of 5% NaNO2 solution, shake well, let stand for 5 min, add 1 mL of 10% Al(NO3)3 solution, shake well, let stand for 6 min, add 4 mL of 1 mol / L NaOH solution, shake well, place in a 45℃ water bath for 10 min, remove and cool, centrifuge at 6000 r / min for 5 min, take the supernatant and measure the absorbance at 510 nm. The total flavonoid content is expressed as rutin equivalents (mg RE / g).

[0069] (3) Determination of total phenol content

[0070] Take 1 ml of appropriately diluted flavonoid extract, add 2 mL of Folin-Ciocalteu reagent, shake to mix, then add 2 ml of 5% sodium carbonate solution, incubate in the dark for 1 h, and measure the absorbance at 760 nm. The results are expressed as gallic acid equivalents (mgGAE / g).

[0071] (4) Antioxidant capacity determination

[0072] DPPH method: Take 50 μL of diluted sample, add 150 μL of DPPH solution (0.2 mmol / L), mix well, and react in the dark at room temperature for 20 min. Measure the absorbance at 517 nm using a microplate reader. Using Trolox as a standard, determine the DPPH free radical scavenging rate of different mass concentrations of Trolox and plot a standard curve. The experiment also included a reagent blank group (anhydrous ethanol), a control group (using an equal volume of methanol instead of the sample), and a sample blank group (using an equal volume of anhydrous ethanol instead of the DPPH solution). The DPPH free radical scavenging ability of the sample is expressed as Trolox equivalents. The DPPH scavenging rate is calculated using the following formula.

[0073] Clearance rate / % = [(A1-A0)-(Ai-Aj) / (A1-A0)]×100

[0074] In the formula: A1 is the absorbance of the control group; A0 is the absorbance of the reagent blank group; Ai is the absorbance of the sample group; Aj is the absorbance of the sample blank group.

[0075] ABTS Method: Mix 50 mL of 7 mmol / L ABTS solution and 0.88 mL of 140 mmol / L potassium persulfate solution, and let stand overnight at room temperature in the dark to prepare ABTS stock solution. Before use, dilute with anhydrous ethanol to an absorbance of 0.7 ± 0.02 at 734 nm. Take 10 μL of the appropriately diluted sample, add 200 μL of ABTS solution, vortex for 30 s, and react for 6 min at room temperature in the dark. Measure the absorbance at 734 nm using a microplate reader. Using Trolox as a standard, determine the scavenging rate of ABTS cations by different mass concentrations of Trolox, and plot a standard curve. The experiment also included a reagent blank group, a control group, and a sample blank group. Results are expressed as Trolox equivalents (mg TE / kg). The scavenging rate is calculated according to the following formula:

[0076] Clearance rate / % = [(A1-A0)-(Ai-Aj) / (A1-A0)]×100

[0077] In the formula: A1 is the absorbance of the control group; A0 is the absorbance of the reagent blank group; Ai is the absorbance of the sample group; Aj is the absorbance of the sample blank group.

[0078] FRAP method: Take 1 mL of diluted flavonoid extract, add 0.2 mL of 0.2 mol / L PBS (pH 6.6) solution and 1.5 mL of 0.3% potassium ferricyanide solution, mix well, incubate at 50℃ for 20 min, remove and cool rapidly, add 1 mL of 10% trichloroacetic acid, mix well, centrifuge at 3000 r / min for 10 min, take 2 mL of supernatant, add 0.5 mL of 0.3% ferric chloride solution, mix well, then add 3 mL of pure water, shake well, and measure the absorbance at a wavelength of 700 nm. Using Trolox as a standard, determine the reducing power of Trolox to iron ions at different concentrations, and plot a standard curve. Results are expressed as Trolox equivalents (mg TE / kg).

[0079] The relevant test results can be found in Table 1.

[0080] Table 1. Content of active substances and antioxidant activity in tangerine peel under different fermentation days and steaming / drying times.

[0081]

[0082]

[0083] Conclusion Analysis:

[0084] 1. In Example 1, after the dried tangerine peel was inoculated with *Corynebacterium tumefaciens*, the content of its active substances increased with the increase of fermentation days. Comparing Sample 1 (Step 3-60d) with Sample 1 (Step 1), the active substance content reached its highest value at 50 days of fermentation. Compared with fresh dried tangerine peel, the total phenolic content increased by 21%, the total flavonoids by 16%, the DPPH value by 18%, the ABTS value by 11%, and the FRAP value by 9%.

[0085] After natural aging, the amount of some active substances in the new peel of tangerine peel also increased slightly. Comparing the sample Comparative Example 1 - Step 3 - 60 days with Comparative Example 1 - Step 1, the total phenol content increased by 4%, the total flavonoids increased by 5%, the FRAP value increased by 3%, the DPPH value increased by 2%, and the ABTS value increased by 1%.

[0086] The above analysis shows that pre-fermentation of dried tangerine peel is beneficial to the enhancement of active ingredients.

[0087] 2. After fermentation, Example 1 underwent three rounds of steaming and drying. As can be seen from the data in Table 1, compared with the data after 60 days of fermentation, the total phenol content increased by 46%, the total flavonoids increased by 44%, the DPPH value increased by 31%, the ABTS value increased by 21%, and the FRAP value increased by 15%.

[0088] Comparative Example 1 underwent three rounds of steaming and sun-drying after natural aging. As shown in Table 1, compared with the data from natural aging for 60 days, the total phenol content increased by 21%, the total flavonoids increased by 37%, the DPPH value increased by 26%, the ABTS value increased by 16%, and the FRAP value increased by 7%.

[0089] The above analysis shows that steaming and sun-drying after fermentation can effectively improve the efficiency of active ingredient conversion.

[0090] Based on data from previous steaming and drying processes, we can clearly see that fermentation can significantly reduce the number of times this tedious process is performed, thus having great economic value.

[0091] More specifically, the use of Portuguese Corynebacterium tumefaciens to ferment and then steam-dry the new tangerine peel allows for a significant increase in the amount of active substances in the tangerine peel in a short period of time through the synergistic effect of fermentation and steaming, thus shortening the traditional steaming process.

[0092] Part Two

[0093] This section mainly studies the relationship between fermentation by different microbial strains. The specific experimental methods are as follows:

[0094] Comparative Example 2

[0095] For specific experimental steps, please refer to Example 1. The difference is that the strain used in step 2 is Pichia pastoris.

[0096] Comparative Example 3

[0097] The specific experimental steps are the same as in Example 1, except that the strain used in step 2 is *Lactobacillus fermentum*. Relevant test results can be found in Table 2.

[0098] Table 2. Content of active substances and antioxidant activity in dried tangerine peel after fermentation with different strains.

[0099]

[0100]

[0101] Conclusion Analysis:

[0102] Comparing Comparative Example 2 - Step 3 - 50d with Comparative Example 2 - Step 1, it was found that fermentation with Pichia pastoris for 60d resulted in a 15% increase in total phenolic content, a 6% increase in total flavonoids, an 11% increase in DPPH value, a 9% increase in ABTS value, and a 5% increase in FRAP value compared to fresh tangerine peel.

[0103] Comparing Comparative Example 2 - Step 5 - 3 with Comparative Example 2 - Step 1, it was found that after 60 days of fermentation, and three more steaming and drying processes, the total phenol content increased by 33%, the total flavonoids increased by 34%, the DPPH value increased by 18%, the ABTS value increased by 9%, and the FRAP value increased by 10% compared to 60 days of fermentation.

[0104] Comparing Comparative Example 3-Step 3-50d with Comparative Example 3-Step 1, it was found that fermentation with Lactobacillus fermentum for 60d resulted in a 5% increase in total phenolic content, a -0.3% increase in total flavonoids, a 6% increase in DPPH value, a 5% increase in ABTS value, and a 4% increase in FRAP value compared to fresh tangerine peel.

[0105] Comparing Comparative Example 3-Step 5-3 with Comparative Example 3-Step 1, it was found that after 60 days of fermentation, and three more steaming and drying processes, the total phenol content increased by 25%, the total flavonoid content increased by 25%, the DPPH value increased by 22%, the ABTS value increased by 6%, and the FRAP value increased by 8% compared to 60 days of fermentation.

[0106] Comparison of the data from Example 1 with Comparative Examples 2 and 3 shows that the increase rate of active substances in the new peel of dried tangerine peel when fermented with Pichia pastoris or Lactobacillus fermentum is much lower than that when fermented with Corynebacterium tumefaciens, indicating that Corynebacterium tumefaciens used in this invention is irreplaceable.

[0107] Meanwhile, comparing the data from Comparative Examples 1, 2, and 3, it was found that the overall efficiency of fermenting and steaming the new tangerine peel using Pichia pastoris was superior to that of the natural aging method. The overall efficiency of fermenting and steaming the new tangerine peel using Lactobacillus fermentum showed no significant difference compared to the natural aging method, further demonstrating the crucial importance of selecting the Corynebacterium lucida from this invention.

[0108] Part Three

[0109] This section mainly explores the effect of the number of steaming and sun-drying cycles. The specific experimental methods are as follows:

[0110] Comparative Example 4

[0111] For specific experimental steps, refer to Comparative Example 1, except that the number of steaming and drying times in step 4 is 9.

[0112] When the number of steaming and sun-drying cycles was increased to 9, compared with the control group's 3-time steaming and sun-drying scheme, the total phenol content increased by 10.2 mg / GAE g, the total flavonoids increased by 3.5 mg / GAE g, the DPPH value increased by 3.1 mg / GAE g, the ABTS value increased by 4.4 mg / GAE g, and the FRAP value increased by 4 mg / GAE g.

[0113] Comparative Example 5

[0114] For specific experimental steps, please refer to Example 1. The difference is that the number of steaming and drying cycles in step 4 is 9.

[0115] When the number of steaming and sun-drying cycles was increased to 9, compared with the control group's 3-time steaming and sun-drying scheme, the total phenol content increased by 2.9 mg / GAE g, the total flavonoids increased by 1.7 mg / GAE g, the DPPH value increased by 1.4 mg / GAE g, the ABTS value increased by 1.6 mg / GAE g, and the FRAP value increased by 1.4 mg / GAE g.

[0116] As can be seen from the above examples, increasing the number of steaming and drying cycles based on Example 1, and then performing even more steaming and drying cycles, has no practical significance.

[0117] As can be seen from Comparative Example 4, increasing the number of steaming and sun-drying cycles based on Comparative Example 1, and then performing even more steaming and sun-drying cycles, can increase the content of effective ingredients to a certain extent.

[0118] The experimental data above shows that by fermenting with appropriate strains and steaming and drying three times, tangerine peel with a high content of effective ingredients can be obtained.

[0119] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for aging dried tangerine peel, characterized in that, Includes the following steps: Step 1: Prepare Portuguese yeast culture; Portuguese Corynebacterium was inoculated into a culture medium and cultured to obtain Portuguese Corynebacterium liquid; Step 2: Inoculate the Portuguese yeast culture into the new peel of dried tangerine peel and ferment for 40-60 days; Step 3: Perform the steaming and drying operation on the product obtained in Step 2 at least 3 times; The steaming and drying operation includes steaming and drying. The steaming operation temperature in step 3 is 80~100℃; the time is 30~60min. The sun-drying process is carried out under natural sunlight, and the sun-drying time is 12-48 hours. Step 2 is carried out by alternating between high-temperature and high-humidity culture and low-temperature and low-humidity culture. The high-temperature and high-humidity culture is conducted at a temperature of 25-50°C and a humidity of 60-90%. The low-temperature, low-humidity culture is conducted at a temperature of 0–25°C and a humidity of 30–60%. The duration of a single high-temperature, high-humidity culture is 4-6 days; the duration of a single low-temperature, low-humidity culture is 4-6 days. The preservation number of the Portuguese saccharomyces is GDMCC No: 61036, and the Latin name of the strain is Clavisporalusitaniae CP-1; In step 1, the culture medium is malt extract medium; the culture conditions are: culture temperature of 10~40℃, and culture time of 12~24h; in step 2, 10~30g of *Corydalis lucida* liquid is inoculated per 100g of fresh tangerine peel; the viable cell content of the *Corydalis lucida* liquid is 1.0×10⁻⁶. 4 ~9.0×10 9 cfu / ml.

2. A type of dried tangerine peel, characterized in that, It is prepared by the method described in claim 1.

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