Pericarpium citri reticulatae and method for optimizing aging of pericarpium citri reticulatae

Abstract

The invention belongs to the field of food processing, and discloses pericarpium citri reticulatae and a method for optimizing pericarpium citri reticulatae aging, and the method comprises the following steps: step 1, preparing corynespora aspera liquid; the method comprises the following steps: inoculating a culture medium with corynespora aspera, and culturing to obtain a corynespora aspera solution; step 2, inoculating the corynespora aspera liquid into the new pericarpium citri reticulatae peel, and carrying out fermentation culture for 40-60 days; and step 3, steaming and drying the product obtained in the step 2 for at least three times. Through cooperation of specific yeast fermentation and steaming and drying processes, the conversion efficiency of active substances of the dried orange peel is improved, and the flow of a traditional process is shortened; meanwhile, the invention further provides the pericarpium citri reticulatae prepared on the basis of the method.

Description

Technical Field

[0001] The invention relates to the field of food processing, and in particular to tangerine peel and a method for optimizing tangerine peel aging. Background Art

[0002] Tangerine peel is the dried mature peel of the citrus plant (Citrus reticulata Blanco) and its cultivated varieties. It contains a variety of bioactive substances, such as flavonoids, which have the effects of regulating qi and strengthening the spleen, drying dampness and resolving phlegm, and anti-inflammatory and antioxidant effects. After citrus fruits are picked, a large number of by-products such as peels and seeds are produced, causing problems such as waste of resources and environmental pollution. With the annual increase in its planting area and output, this problem has become increasingly prominent and has attracted widespread attention.

[0003] Aging is an extremely important process in making tangerine peel from peel, which affects the quality of the final tangerine peel. The existing tangerine peel preparation method is a more common method of traditional natural airing. The longer the aging time, the better the quality of the tangerine peel obtained, and the higher the price. However, the traditional natural aging method has many disadvantages, such as taking too long, being unable to produce in large quantities, poor process control, and easily causing tangerine peel to mold due to factors such as the natural environment. In summary, it is extremely urgent to invent a method that can accelerate the aging of tangerine peel and improve the aging effect at the same time.

[0004] In the prior art, CN 116570011 A discloses a four-petal dried tangerine peel and its drying process, and discloses a dried tangerine peel process, wherein the dried tangerine peel to be aged is pretreated, exposed to the sun to kill water, and then steamed and dried nine times to obtain the dried tangerine peel, and the total steaming time is 180 min to 270 min. This method only adds steaming and drying treatment to the traditional method in order to shorten the aging time, but the nine-steaming and nine-drying process is cumbersome and not suitable for mass production, and it cannot improve the aging effect and obtain higher quality dried tangerine peel.

[0005] Therefore, the technical problem solved in this case is: how to shorten the steaming and drying times. Summary of the invention

[0006] The technical problem to be solved by the present invention is to overcome the deficiencies in the prior art and provide a method for optimizing tangerine peel aging. Through the cooperation of specific yeast fermentation and steaming and drying process, the conversion efficiency of tangerine peel active substances is improved and the process of traditional process is shortened.

[0007] At the same time, the invention also discloses tangerine peel prepared based on the method.

[0008] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0009] A method for optimizing tangerine peel aging, comprising the following steps:

[0010] Step 1: preparing a Portuguese coryneformis yeast liquid; inoculating Portuguese coryneformis yeast into a culture medium and culturing the culture medium to obtain a Portuguese coryneformis yeast liquid;

[0011] Step 2: inoculating the Portuguese coryneformis yeast solution into the new peel of tangerine peel, and fermenting and culturing for 40 to 60 days;

[0012] Step 3: steaming and drying the product obtained in step 2 for at least 3 times;

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

[0014] In the present invention, by adopting the operation of first fermentation and then steaming and drying, the aging effect of tangerine peel can be significantly improved;

[0015] In some studies of the present invention, it was found that even if only fermentation operation was used, it could still improve the aging effect of tangerine peel; in some other studies of the present invention, it was found that steaming and drying operation could also improve the aging effect, but multiple steaming and drying operations were required, which brought difficulties to industrial expansion of production.

[0016] We believe that after the operation of first fermentation and then steaming and drying, the active ingredients such as hesperidin and melissin in the new peel of tangerine peel are pre-converted, and some of the active ingredients are pre-decomposed into flavonoid aglycones and phenolic substances;

[0017] After comparing samples that were only fermented but not steamed and dried with samples that were only steamed and dried but not fermented, 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 the antioxidant activity was significantly enhanced.

[0018] Preferably, the deposit number of the Portuguese Clavispora yeast is GDMCC No: 61036, the depository is Guangdong Microbiological Culture Collection Center, the deposit address is 5th Floor, Compound 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 is 10-40° C., and the culture time is 12-24 hours.

[0020] Preferably, in step 2, 10 to 30 g of Portuguese coryneformis solution is inoculated per 100 g of new tangerine peel; the viable bacteria content of the Portuguese coryneformis solution is 1.0×10 4 ~9.0×10 9 cfu / ml.

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

[0022] Further preferably, the step 2 is performed by alternating high temperature and high humidity culture with low temperature and low humidity culture;

[0023] The culture temperature of the high temperature and high humidity culture is 25 to 50°C; the culture humidity is 60 to 90%;

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

[0025] In further research of the present invention, we found that when the alternating fermentation mode is adopted, the active substances can be more activated to the conversion of flavonoids and phenolic substances. The possible reason is that high temperature and high humidity can increase the moisture content of dried tangerine peel, increase the water activity, and help microorganisms to transform active ingredients, accelerate the chemical reaction rate of dried tangerine peel. Low temperature and low humidity slow down the reaction rate, and effectively prevent the dried tangerine peel from getting moldy. Repeated high humidity and low humidity environment make the internal moisture of dried tangerine peel change frequently, and accelerate the chemical reaction more violently.

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

[0027] Preferably, the steaming operation temperature of step 3 is 80-100° C. and the time is 30-60 min. The drying operation is natural sunlight drying, and the drying operation time is 12-48 h.

[0028] In addition, a tangerine peel is disclosed, which is prepared by any of the above methods.

[0029] The beneficial effects of the present invention are:

[0030] The invention utilizes yeast to ferment the new peel of tangerine peel, and improves the conversion of active substances in the tangerine peel through specific steaming and drying operation treatment, thereby shortening the steaming and drying times of the traditional aging process. DETAILED DESCRIPTION

[0031] In the description of the present invention, it should be noted that, if the specific conditions are not specified in the examples, the experiments were carried out according to conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used, if the manufacturer is not specified, are all conventional products that can be purchased commercially.

[0032] Product information:

[0033] The deposit number of the bacteria used in Example 1 is GDMCC No: 61036, the depository is Guangdong Microbiological Culture Collection Center, the deposit address is 5th Floor, Dayuan 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 preservation number of the bacteria used in Comparative Example 1 is GDMCC No: 63249, the preservation unit is Guangdong Microbial Culture Collection Center, the preservation address is 5th Floor, Compound Experimental Building, No. 100 Xianlie Middle Road, Yuexiu District, Guangzhou City, Guangdong Province, the preservation date is March 10, 2023, and the Latin name of the strain is Pichia kudriavzevii SJ36.

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

[0036] Part I

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

[0038] Example 1

[0039] Step 1: Processing tea branch peel;

[0040] Fresh tangerine peels are washed, dried, peeled (two or three cuts), and placed in a cool and ventilated place for shade drying for 4 to 5 hours. After shade drying, the peels are turned over and exposed to natural sunlight to further evaporate the water. After drying (the water content is about 13wt%), new tangerine peels are obtained for later use.

[0041] The new peel of dried tangerine peel was tested, and the test results can be seen in Table 1.

[0042] Step 2: Preparation of Portuguese Corynespora yeast solution;

[0043] Prepare 600mL malt extract liquid culture medium (Guangdong Huankai Microbiological Technology Co., Ltd., model: 021120), 200mL per bottle was divided into 3 250mL conical flasks, sterilized at 115℃ for 20min, cooled to room temperature, inoculated with Portuguese coryneform yeast colonies, placed in a shaker at 37℃ and 200r / min for 16h, divided into 50mL centrifuge tubes and centrifuged at 5000r / min for 10min, discard the supernatant, use 10mL sterile water to resuspend the bacterial precipitate in each tube, combine the bacterial solution, add sterile water to a final volume of 150mL, and obtain 4.0×10- ... 7 ~9.0×10 8 cfu / ml.

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

[0045] The tangerine peel was sprayed and inoculated with Portuguese coryneformis using the Guang tangerine peel precision spraying equipment.

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

[0047] (2) Sterilization of dried tangerine peel: Weigh 300 g of fresh dried tangerine peel, spread it in a drawer, sterilize it under ultraviolet light for 30 min, turn it over and continue sterilizing for 30 min.

[0048] (3) Inoculation method: Use the Guang Chenpi precision spraying equipment to spray and inoculate 30 g of Portuguese Corynosporum yeast solution on the sterilized tangerine peel.

[0049] (4) Fermentation culture: The inoculated new peel of dried tangerine peel was placed in an artificial incubator, and 150 mL of Portuguese coryneformis solution was sprayed on the front and back sides of the new peel of dried tangerine peel; low temperature and low humidity (20°C, 52.5%) and high temperature and high humidity (30°C, 82.5%) were set to operate alternately for 5 days each, and appropriate amounts of samples were taken at 0d, 10d, 20d, 30d, 40d, 50d, and 60d of incubation time, and stored in a -20°C refrigerator for testing.

[0050] The relevant test results can be seen in Table 1;

[0051] Step 4: take the 50d dried tangerine peel sample obtained in step 3, steam (100°C, 40min), expose to sunlight for 24h, further allow water to evaporate, steam again after drying (moisture content of about 13wt%), and repeatedly steam and sun-dry 3 times.

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

[0053] All embodiments and comparative examples of the present invention adopt the same batch of fresh tangerine peels.

[0054] Comparative Example 1

[0055] Step 1: Processing tea branch peel;

[0056] Fresh tangerine peels are washed, dried, peeled (two or three cuts), and placed in a cool and ventilated place for shade drying for 4 to 5 hours. After shade drying, the peels are turned over and exposed to natural sunlight to further evaporate the water. After drying (the water content is about 13wt%), new tangerine peels are obtained for later use.

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

[0058] Use Guang Chenpi precision spraying equipment to spray tangerine peel with sterile water.

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

[0060] (2) Sterilization of dried tangerine peel: Weigh 300 g of fresh dried tangerine peel, spread it in a drawer, sterilize it under ultraviolet light for 30 min, turn it over and continue sterilizing for 30 min.

[0061] (3) The sterilized tangerine peel was placed in an artificial incubator, and 150 mL of sterile water was sprayed on the front and back sides of the tangerine peel; low temperature and low humidity (20°C, 52.5%) and high temperature and high humidity (30°C, 82.5%) were set to run alternately for 5 days each, and appropriate amounts of samples were taken at 0 days, 10 days, 20 days, 30 days, 40 days, 50 days, and 60 days of incubation, and stored in a -20°C refrigerator for testing.

[0062] Step 3: Take the 50d dried tangerine peel sample obtained in step 2, steam (100°C, 40min), and expose to sunlight for 24h, further allow water to evaporate, and steam again after drying (moisture content of about 13wt%), and repeatedly steam and sun-dry for 3 times.

[0063] Step 4: Index determination; the determination results can be seen in Table 1.

[0064] Indicator testing method:

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

[0066] Take the tangerine peel sample and methanol (volume 100%) in a solid-liquid ratio of 0.1 g:4 mL, vortex for 30 seconds, extract at 60°C, and ultrasonicate for 30 minutes. 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% NaNO 2The solution was shaken and allowed to stand for 5 min before adding 1 mL of 10% Al(NO 3 ) 3 The solution was shaken and allowed to stand for 6 min, then 4 mL of 1 mol / L NaOH solution was added and shaken, placed in a 45°C water bath for 10 min, removed and cooled, centrifuged at 6000 r / min for 5 min, and the supernatant was taken to measure the absorbance at 510 nm. The total flavonoid content was expressed as rutin equivalent (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 and mix, then add 2 ml of 5% sodium carbonate solution, place in the dark for 1 hour, and measure the absorbance at 760 nm. The result is expressed as gallic acid equivalent (mgGAE / g).

[0071] (4) Antioxidant capacity determination

[0072] DPPH method: Take 50μL of diluted sample, add 150μL DPPH solution (0.2mmol / L), mix well and react in the dark at room temperature for 20min, use a microplate reader to measure the absorbance at a wavelength of 517nm, use Trolox as the standard, measure the scavenging rate of Trolox of different mass concentrations on DPPH free radicals, draw a standard curve, and set up 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 DPPH solution) at the same time. The scavenging ability of the sample on DPPH free radicals is expressed as Trolox equivalent. The DPPH scavenging rate is calculated as follows.

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

[0074] Wherein: 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 7mmol / L ABTS solution (50mL) and 140mmol / L potassium persulfate solution (0.88mL), and let stand overnight at room temperature in the dark to form an ABTS stock solution. Dilute with anhydrous ethanol before use to an absorbance of 0.7±0.02 at a wavelength of 734nm. Take 10μL of the appropriately diluted sample, add 200μL ABTS solution, vortex and oscillate for 30s, react for 6min in the dark at room temperature, and measure the absorbance at a wavelength of 734nm with an enzyme marker. Using Trolox as the standard, determine the clearance rate of Trolox of different mass concentrations for ABTS cations, draw a standard curve, and set up a reagent blank group, a control group, and a sample blank group at the same time. The results are expressed as Trolox equivalents (mg TE / kg). The clearance rate is calculated according to the following formula:

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

[0077] Wherein: 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 1mL of diluted flavonoid extract, add 0.2mL 0.2mol / L PBS (pH 6.6) solution and 1.5mL 0.3% potassium ferricyanide solution, mix well and incubate at 50℃ for 20min, take out and cool quickly and add 1mL 10% trichloroacetic acid, mix well and centrifuge at 3000r / min for 10min, take 2mL of supernatant and add 0.5mL 0.3% ferric chloride solution and mix well, then add 3mL pure water, shake well and measure the absorbance at a wavelength of 700nm. Take Trolox as the standard, measure the reducing power of Trolox on iron ions at different concentrations, and draw a standard curve. The results are expressed as Trolox equivalent (mg TE / kg).

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

[0080] Table 1 Contents of active substances and antioxidant activity in dried tangerine peels at different fermentation days and steaming times

[0081]

[0082]

[0083] Conclusion analysis:

[0084] 1. After the dried tangerine peel of embodiment 1 was inoculated with Portuguese corynosporum yeast, along with the increase of fermentation days, the content of its active substance also increased thereupon. Sample embodiment 1-step 3-60d compared with embodiment 1-step 1, when fermenting 50d, the active substance content reached the highest value, compared with dried tangerine peel new peel, total phenol content increased by 21%, total flavonoids increased by 16%, DPPH value increased by 18%, ABTS value increased by 11%, and FRAP value increased by 9%.

[0085] After natural aging of Example 1, the amount of some active substances in the new tangerine peel will also increase slightly. Comparison of sample Example 1-step 3-60d with Example 1-step 1 shows that compared with the new tangerine peel, the total phenol content is increased by 4%, the total flavonoids are increased by 5%, the FRAP value is increased by 3%, the DPPH value is increased by 2%, and the ABTS value is increased by 1%.

[0086] From the above analysis, it can be seen that the pre-fermentation of tangerine peel is beneficial to the improvement of active ingredients.

[0087] 2. After fermentation, Example 1 was steamed and dried for three times. The data in Table 1 show that, compared with the data of fermentation for 60 days, 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 was naturally aged and then steamed and dried for three times. The data in Table 1 show that compared with the data of 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] From the above analysis, it can be seen that steaming and drying after fermentation can effectively improve the efficiency of steaming and drying for the conversion of active ingredients.

[0090] Combined with the data from previous steaming and drying operations, we can clearly see that fermentation can significantly reduce the number of times this tedious operation of steaming and drying occurs, which has great economic value.

[0091] More specifically, Portuguese Corysporum yeast is used to ferment the new tangerine peel first and then steam and dry it. Through the synergistic effect of fermentation and steaming, the amount of active substances in the tangerine peel is greatly increased in a short period of time, which can shorten the process of traditional steaming and drying.

[0092] Part 2

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

[0094] Comparative Example 2

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

[0096] Comparative Example 3

[0097] The specific experimental steps refer to Example 1, except that the strain used in step 2 is Lactobacillus fermentum. The relevant test results can be seen in Table 2.

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

[0099]

[0100]

[0101] Conclusion analysis:

[0102] Comparison of sample comparative example 2-step 3-50d with comparative example 2-step 1 showed that, after 60d of fermentation with Pichia pastoris, the total phenol content increased by 15%, the total flavonoids increased by 6%, the DPPH value increased by 11%, the ABTS value increased by 9%, and the FRAP value increased by 5% compared with the new tangerine peel.

[0103] Comparison of sample comparative example 2-step 5-3 with comparative example 2-step 1 shows that, based on 60 days of fermentation, after three steaming and drying, compared with 60 days of fermentation, 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%.

[0104] Comparison of sample comparative example 3-step 3-50d with comparative example 3-step 1 showed that after fermentation for 60d using Lactobacillus fermentum, the total phenol content increased by 5%, the total flavonoids increased by -0.3%, the DPPH value increased by 6%, the ABTS value increased by 5%, and the FRAP value increased by 4% compared with the new tangerine peel.

[0105] Comparison of sample comparative example 3-step 5-3 with comparative example 3-step 1 shows that, based on 60 days of fermentation, after 3 steaming and drying, compared with 60 days of fermentation, the total phenol content increased by 25%, the total flavonoids increased by 25%, the DPPH value increased by 22%, the ABTS value increased by 6%, and the FRAP value increased by 8%.

[0106] By comparing the data of Example 1 with those of Comparative Examples 2 and 3, it can be concluded that the increase rate of the amount of active substances in the new peel of tangerine peel when fermented with Pichia pastoris or Lactobacillus fermentum is much lower than that when fermented with Portuguese spore yeast, indicating that the Portuguese spore yeast used in the present invention is irreplaceable.

[0107] At the same time, the data of Comparative Example 1, Comparative Example 2, and Comparative Example 3 are compared to obtain that the comprehensive efficiency of the efficiency of fermenting and steaming the new peel of tangerine peel by Pichia pastoris is better than the natural aging method. The comprehensive efficiency of the efficiency of fermenting and steaming the new peel of tangerine peel by Lactobacillus fermentum has no obvious difference in quality between the method and the natural aging method, which further illustrates that the screening of the Portuguese corynosporum yeast of the present invention is crucial.

[0108] Part 3

[0109] This part mainly explores the influence of steaming and drying times. The specific experimental methods are as follows:

[0110] Comparative Example 4

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

[0112] When the number of steaming and drying times increased to 9 times, compared with the scheme of steaming and drying 3 times in comparative example 1, 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] The specific experimental steps refer to Example 1, except that the number of steaming and drying in step 4 is 9 times.

[0115] When the number of steaming and drying times increased to 9 times, compared with the scheme of steaming and drying 3 times in comparative example 1, 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] It can be seen from the above cases that after increasing the number of steaming and drying times on the basis of Example 1, there is no practical significance in performing more steaming and drying times.

[0117] It can be seen from Comparative Example 4 that by increasing the number of steaming and drying times on the basis of Comparative Example 1 and then performing more steaming and drying times, the content of the effective ingredient can be increased to a certain extent.

[0118] From the above experimental data, it can be seen that through fermentation with suitable bacteria and three times of steaming and drying, tangerine peel with a high content of effective ingredients can be obtained.

[0119] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principles of the present invention shall be equivalent replacement methods and shall be included in the protection scope of the present invention.

Claims

1. A method for optimizing tangerine peel aging, characterized in that: The steps include: Step 1: preparing a Portuguese coryneformis yeast liquid; inoculating Portuguese coryneformis yeast into a culture medium and culturing the culture medium to obtain a Portuguese coryneformis yeast liquid; Step 2: inoculating the Portuguese coryneformis yeast solution into the new peel of tangerine peel, and fermenting and culturing for 40 to 60 days; Step 3: steaming and drying the product obtained in step 2 for at least 3 times; The steaming and drying operation includes a steaming operation and a drying operation.

2. The method for optimizing tangerine peel aging according to claim 1, wherein: The preservation number of the Portuguese Clavispora yeast is GDMCC No: 61036, the preservation unit is Guangdong Microbial Culture Collection Center, the preservation address is 5th Floor, Dayuan Experimental Building, No. 100 Xianlie Middle Road, Yuexiu District, Guangzhou City, Guangdong Province, the preservation date is May 27, 2020, and the Latin name of the strain is Clavispora lusitaniae CP-1.

3. The method for optimizing tangerine peel aging according to claim 1, wherein: In step 1, the culture medium is malt extract culture medium; the culture conditions are: the culture temperature is 10-40° C., and the culture time is 12-24 hours.

4. The method for optimizing tangerine peel aging according to claim 1, wherein: In step 2, 10 to 30 g of Portuguese corynac yeast solution is inoculated per 100 g of new tangerine peel; the viable bacteria content in the Portuguese corynac yeast solution is 1.0×10 4 ~9.0×10 9 cfu / ml.

5. The method for optimizing tangerine peel aging according to claim 1, wherein: The culture temperature in step 2 is 0-50° C.; the culture humidity is 30-90%.

6. The method for optimizing tangerine peel aging according to claim 5, wherein: Step 2 is performed by alternating high temperature and high humidity culture with low temperature and low humidity culture; The culture temperature of the high temperature and high humidity culture is 25 to 50° C. and the culture humidity is 60 to 90%; The culture temperature of the low-temperature and low-humidity culture is 0-25° C.; the culture humidity is 30-60%.

7. The method for optimizing tangerine peel aging according to claim 6, wherein: The time for a single high temperature and high humidity culture is 4 to 6 days; the time for a single low temperature and low humidity culture is 4 to 6 days.

8. The method for optimizing tangerine peel aging according to claim 1, wherein: The steaming operation temperature of step 3 is 80-100° C. and the time is 30-60 minutes.

9. The method for optimizing tangerine peel aging according to claim 1, wherein: The drying operation is natural sunlight drying, and the drying time is 12 to 48 hours.

10. A dried orange peel, characterized in that: The method is prepared by any one of claims 1 to 9.

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