Amomum tsao-ko drying method using box type hot air dryer

Abstract

The invention discloses a method for drying amomum tsao-ko by using a box type hot air dryer, and relates to the technical field of food processing. The drying method specifically comprises the following steps: (1) performing fixation: performing fixation on fresh amomum tsao-ko with water vapor to obtain to-be-dried amomum tsao-ko; (2) drying: conveying the to-be-dried amomum tsao-ko obtained in the step (1) into a box type hot air dryer, and performing staged gradient drying to obtain dried amomum tsao-ko with the water content of 12-13%; and (3) cooling the dried amomum tsao-ko obtained in the step (2), and packaging and storing the amomum tsao-ko. By adopting the technical scheme to dry the amomum tsao-ko, the method has the characteristics of economy, high efficiency, environmental protection and quality improvement, and has the advantages that the drying time can be obviously shortened, the processing cost can be reduced, the product quality can be improved, and the loss of internal nutritional ingredients can be avoided.

Description

Technical Field

[0001] The invention relates to the technical field of food processing, and in particular to a method for drying tsaoko using a box-type hot air drying machine. Background Art

[0002] Amomum tsaoko Crevost et Lemaire is a perennial evergreen herbaceous plant of the genus Amomum in the family Zingiberaceae. The whole plant has a spicy taste, and its fruit contains volatile oils with a specific spicy smell. It is often used as a spice in meat cooking. At the same time, Amomum tsaoko is also a plant with both medicinal and edible properties. As a traditional Chinese medicinal material, Amomum tsaoko is pungent and warm in nature, and enters the spleen and stomach meridians. It has the effects of drying dampness and warming the middle, stopping malaria and removing phlegm, and can be used for internal obstruction of cold and dampness, abdominal distension and pain, fullness and vomiting, malaria fever, and plague fever. The country produces 15,000 to 20,000 tons of Amomum tsaoko every year, accounting for about 80% of the global production of Amomum tsaoko. Nujiang Lisu Autonomous Prefecture in Yunnan Province is the largest producer of Amomum tsaoko in China.

[0003] Drying and processing of cardamom is an important part of cardamom production, which is directly related to the quality of cardamom. After the ripe fresh cardamom is picked, it is dried and made into dried cardamom for easy storage and circulation. This is the most common form of cardamom product. There are two common traditional drying methods for cardamom: smoke drying and air drying. Air drying is subject to site and climate factors, and the yield is very small. Smoke drying is to use the heat and smoke generated by the combustion of combustibles such as firewood, coal, and biomass pellet fuel to directly smoke the cardamom, and the product is smoked cardamom. During the drying process, smoke will adhere to the surface of the cardamom, causing the cardamom to be charred and have a pungent smoky smell. At the same time, smoking will cause the cardamom to be attached to substances that are harmful to human health, such as benzopyrene and sulfide. Traditional drying methods require a lot of manpower, time and fuel, with low processing efficiency and high processing costs. The processing method is also accompanied by ecological destruction and environmental pollution. The temperature is often judged by experience, the product quality is unstable, the appearance is poor, and there are food safety risks. It is urgently needed to be improved and developed.

[0004] In recent years, with consumers' increasing concern about food safety, and under the background of continuous promotion of government policies and increasing investment in science and technology, healthier tobacco-free fruit is gradually replacing traditional smoked grass fruit. At present, the new grass fruit drying equipment introduced by the science and technology department that can produce tobacco-free fruit, which is affordable, practical and has large-scale promotion, is mainly box-type hot air drying equipment with biomass pellet fuel, air energy heat pump or electric heating as heat source. During the production process of box-type hot air drying equipment, the grass fruit does not come into contact with smoke, and the products are all tobacco-free fruit. If there is a better baking process, the product quality and economic benefits will be significantly improved compared with the traditional smoking and fire baking method. However, due to the smaller distribution and total amount of grass fruit in the world compared with other bulk agricultural products, the box-type hot air drying equipment on the market is currently mainly designed for drying bulk products such as tobacco leaves, fruits and vegetables, and Chinese medicinal materials. The drying process of grass fruit is quite different from these products, and no manufacturer or enterprise has yet explored the optimal box-type hot air drying method specifically for grass fruit. Therefore, at this stage, companies that currently use box-type hot air drying equipment to dry cardamom still have a lot of room for improvement in product quality and economic benefits.

[0005] It can be seen that although the box-type hot air drying equipment is more advanced than the traditional drying method, there is a lack of the optimal drying method specifically for cardamom. Researching and determining the best process for cardamom processing with box-type hot air drying equipment is of great significance to improving the level of the entire cardamom processing industry and ensuring public food safety. Summary of the invention

[0006] In view of the above-mentioned defects of the prior art, the present invention proposes a method for drying cardamom using a box-type hot air drying machine to solve the problems raised by the above-mentioned background technology. The purpose of this technical solution is to use the most suitable drying process parameters for cardamom drying in the box-type hot air drying equipment that is widely used in cardamom drying, and introduce the withering process to solve the problems of long cardamom drying time, high processing cost, low efficiency, and poor quality after drying, so as to achieve economic, efficient, environmentally friendly and quality improvement of cardamom processing.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] A method for drying tsaoko using a box-type hot air dryer specifically comprises the following steps:

[0009] (1) Fixing: The cleaned fresh tsaoko is treated with steam to fix the tsaoko until it is dried;

[0010] (2) Drying: conveying the to-be-dried tsaoko obtained in step (1) into a box-type hot air drying machine for gradient drying in stages to obtain dried tsaoko with a moisture content of 12-13%;

[0011] The staged gradient drying is as follows:

[0012] In 0-10h, the drying temperature is controlled between 45-55℃, the total dehumidification time is 5-7h, and the humidity in the dryer is gradually reduced from 85% to 60%;

[0013] During 11-20h, the drying temperature is controlled between 55-65℃, the total dehumidification time is 5-7h, and the humidity in the dryer is gradually reduced from 60% to 30%;

[0014] At 21-26.2h, the drying temperature is controlled between 65-75℃, the total dehumidification time is 2-4h, and the humidity in the dryer is gradually reduced from 30% to 10%;

[0015] (3) Cooling: The dried tsaoko obtained in step (2) is cooled and then packaged and stored.

[0016] Preferably, the temperature of the water vapor in step (1) is 110-120°C.

[0017] Preferably, the temperature of the water vapor is 115°C.

[0018] Preferably, the time for the fixing treatment in step (1) is 5-15 minutes.

[0019] Preferably, the time for the fixing treatment is 10 minutes.

[0020] Preferably, the step (2) of step-by-step gradient drying is:

[0021] During the period of 0-10h, the drying temperature was controlled between 50℃, the total dehumidification time was 6h, and the humidity in the dryer was gradually reduced from 85% to 60%;

[0022] During 11-20h, the drying temperature was controlled at 60℃, the total dehumidification time was 6h, and the humidity in the dryer was gradually reduced from 60% to 30%;

[0023] At 21-25.1h, the drying temperature was controlled between 70°C, the total dehumidification time was 3h, and the humidity in the dryer was gradually reduced from 30% to 10%.

[0024] Preferably, the cooling treatment in step (3) is to start a circulating fan to cool the Amomum villosum to 28-30°C.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) There is a waxy layer on the surface of fresh tsaoko, which makes it difficult for water to evaporate when the tsaoko is baked. The fresh tsaoko can be blanched in a short time with high-temperature steam, which can destroy the waxy layer and accelerate the drying of the fresh fruit, thereby saving fuel and working hours. The present application is conducive to retaining the volatile oil components in the tsaoko by selecting a moderate blanching temperature of 115°C and a blanching time of 10 minutes, while ensuring that the enzyme activity in the tsaoko is passivated, preventing the tsaoko from continuing to ferment, and maintaining the color and aroma of the tsaoko.

[0027] (2) The present invention uses staged gradient drying: 0-10h, the temperature is controlled at 45-55°C, and the total dehumidification time should be controlled at 5-7h; 11-20h, the temperature is controlled at 55-65°C, and the total dehumidification time should be controlled at 5-7h. 21-26.2, the temperature is controlled at 65-75°C, and the total dehumidification time should be controlled at 2-4h. Reasonable control of the temperature and dehumidification time parameters during the drying process results in the obtained dried grass fruit being brown-red in color, with plump fruit grains, strong aroma, and excellent quality, which facilitates the precipitation of volatile oils in the subsequent cooking or medicinal use of the grass fruit. The volatile oil (essential oil) content of the grass fruit obtained by the drying method of Examples 1-3 is all above 3.0%, and the drying time of Example 3 is only 25.1h.

[0028] (3) The technical solution of the present application is simple to operate, saves fuel and labor costs (the processing cost of each kilogram of hay fruit is only 0.94 yuan), has a short baking time, is energy-saving and environmentally friendly, has a low processing cost, and does not add other chemical solvents during the processing. The obtained hay fruit is of good quality and is pure, natural and pollution-free. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of cleaning the grass fruit;

[0030] Figure 2 Schematic diagram of killing grass fruit;

[0031] Figure 3 This is a schematic diagram of drying cardamom. DETAILED DESCRIPTION

[0032] The technical solution of the present invention is further described in detail below in conjunction with specific implementation methods.

[0033] Example 1

[0034] A method for drying tsaoko using a box-type hot air dryer specifically comprises the following steps:

[0035] (1) Fixing: Clean the fresh tsaoko and use steam at a temperature of 110°C to fix the tsaoko for 5 minutes, and then dry the tsaoko;

[0036] (2) Drying: conveying the to-be-dried tsaoko obtained in step (1) into a box-type hot air drying machine for stepwise gradient drying to obtain dried tsaoko with a moisture content of 12%;

[0037] The staged gradient drying is as follows:

[0038] During 0-10h, the drying temperature was controlled at 45℃, the total dehumidification time was 7h, and the humidity in the dryer dropped to 60%;

[0039] At 11-20h, the drying temperature was controlled at 55℃, the total dehumidification time was 7h, and the humidity in the dryer dropped to 30%;

[0040] At 21-24.9h, the drying temperature was controlled at 65°C, the total dehumidification time was 4h, and the humidity in the dryer dropped to 10%;

[0041] (3) Cooling: Start the circulating fan to cool the dried tsaoko obtained in step (2), and pack and store the tsaoko after the temperature is cooled to 28°C.

[0042] Example 2

[0043] A method for drying tsaoko using a box-type hot air dryer specifically comprises the following steps:

[0044] (1) Fixing: The cleaned fresh tsaoko is fixed with steam at a temperature of 120°C for 15 minutes to obtain dry tsaoko;

[0045] (2) Drying: conveying the to-be-dried tsaoko obtained in step (1) into a box-type hot air drying machine for gradient drying in stages to obtain dried tsaoko with a moisture content of 13%;

[0046] The staged gradient drying is as follows:

[0047] During 0-10h, the drying temperature was controlled at 55°C, the total dehumidification time was 5h, and the humidity in the dryer dropped to 60%;

[0048] At 11-20h, the drying temperature was controlled at 65℃, the total dehumidification time was 5h, and the humidity in the dryer dropped to 30%;

[0049] At 21-26.2h, the drying temperature was controlled at 75°C, the total dehumidification time was 2h, and the humidity in the dryer dropped to 10%;

[0050] (3) Cooling: The dried tsaoko obtained in step (2) is cooled by starting a circulating fan, and the tsaoko is packaged and stored after the temperature is reduced to 30°C.

[0051] Example 3

[0052] A method for drying tsaoko using a box-type hot air dryer specifically comprises the following steps:

[0053] (1) Fixing: Clean the fresh tsaoko and use steam at a temperature of 115°C to fix the tsaoko for 10 minutes, and then dry the tsaoko;

[0054] (2) Drying: conveying the to-be-dried tsaoko obtained in step (1) into a box-type hot air drying machine for gradient drying in stages to obtain dried tsaoko with a moisture content of 13%;

[0055] The staged gradient drying is as follows:

[0056] In 0-10h, the drying temperature is controlled at 50℃, the total dehumidification time is 6h, and the humidity in the dryer is reduced to 60%;

[0057] At 11-20h, the drying temperature was controlled at 60℃, the total dehumidification time was 6h, and the humidity in the dryer dropped to 30%;

[0058] At 21-25.1h, the drying temperature was controlled at 70℃, the total dehumidification time was 3h, and the humidity in the dryer dropped to 10%;

[0059] (3) Cooling: Start the circulating fan to cool the dried tsaoko obtained in step (2) to 29°C.

[0060] Comparative Examples 1-12

[0061] The difference between Comparative Examples 1-12 and Example 3 is that the phased gradient drying parameters are different, and the other components and steps remain unchanged.

[0062]

[0063]

[0064] Comparative Examples 13-18

[0065] The difference between Comparative Examples 13-18 and Example 3 is that the fixing time is different, and the other ingredients and steps remain unchanged.

[0066] Process solution Fresh fruit (kg) Fixing time (min) Fixing temperature (℃) Drying time (h) Comparative Example 13 3500 0 115 29.4 Comparative Example 14 3500 5 115 28.3 Comparative Example 15 3500 15 115 24.6 Comparative Example 16 3500 20 115 24.4 Comparative Example 17 3500 25 115 24.3 Comparative Example 18 3500 30 115 24.3

[0067] Comparative Examples 19-25

[0068] The difference between Comparative Examples 19-25 and Example 3 is that the fixing temperature is different, and the other components and steps remain unchanged.

[0069] Process solution Fresh fruit (kg) Fixing time (min) Fixing temperature (℃) Drying time (h) Comparative Example 19 3500 10 25 29.4 Comparative Example 20 3500 10 100 28.5 Comparative Example 21 3500 10 105 27.4 Comparative Example 22 3500 10 110 26.2 Comparative Example 23 3500 10 120 24.9 Comparative Example 24 3500 10 125 24.6 Comparative Example 25 3500 10 130 24.5

[0070] Comparative Example 26

[0071] The method of Example 1 in the application number 201810473941.5 and the invention name is a method for drying cardamom is used to dry the cardamom.

[0072] A method for processing and drying tsaoko, comprising the following steps:

[0073] Step 1: Select the grass fruits without mildew, rot or mechanical damage and store them at a low temperature of 4°C;

[0074] Step 2: Remove the stems of the stored tsaoko, wash them with clean water, and let them dry naturally to remove the remaining moisture on the surface;

[0075] Step 3: Use a vacuum steam pulsation blanching device to blanch and inactivate enzymes on the cleaned tsaoko, and the enzyme inactivation parameters are set as follows: the pressure variation range of the blanching tank is set to 0.005Mpa, the steam temperature is 106°C, the blanching time is 1 minute, the vacuum time is 1 minute, and 3 blanching cycles are performed;

[0076] Step 4: Dry the blanched cardamom using a variable temperature and humidity drying device based on temperature and humidity monitoring, wherein the drying wind speed is 6 m / s, the drying temperature of the first drying section is 95°C, and when the wet basis moisture content of the cardamom drops to 61%, it enters the second drying section; the drying temperature of the second drying section is 85°C, and when the wet basis moisture content of the cardamom drops to about 47%, the cardamom is taken out for slow revival for 30 minutes, and then the third drying section is carried out; the drying temperature of the third drying section is 75°C, and when the wet basis moisture content of the cardamom drops to about 36%, it enters the fourth drying section; the drying temperature of the fourth drying section is 55°C, and when the wet basis moisture content of the cardamom drops to about 14%, the drying is stopped.

[0077] Step 5: The dried Amomum villosum is packaged in a vacuum or nitrogen-filled manner and stored away from light in an environment with a relative humidity of no more than 20%.

[0078] Comparative Example 27

[0079] The method of Example 1 in the application number 201810414668.9 and the invention name is a method for drying the cardamom by combining heat pump, microwave and infrared for interval drying is used to dry the cardamom.

[0080] A method for drying tsaoko using a heat pump, microwave and infrared combined interval method, comprising the following specific steps:

[0081] (1) Spread the fresh tsaoko evenly and send it to the high-pressure washing system to clean the surface stains, and then send it to the heat pump drying system for drying and preheating until there is no moisture on the surface of the tsaoko. The hot air temperature of the heat pump drying system is 70°C and the hot air flow rate is 3000m 3 / h, the thickness of fresh grass fruit evenly spread is 15mm, and the width is 1m;

[0082] (2) The obtained Amomum villosum in step (1) is transferred to a microwave-infrared interval drying system for microwave-infrared alternating drying for 15 minutes to obtain dried Amomum villosum, and the microwave-infrared interval drying system is subjected to centrifugal dehumidification; wherein the microwave power is 9 kW, the infrared power is 3 kW, and the air volume of the centrifugal dehumidification is 3000 m 3 / h, and the cycle of microwave-infrared alternating drying is 2min.

[0083] Experimental Example 1 Drying Equipment Selection

[0084] The comparison results of different grass fruit drying equipment are shown in Table 1-3:

[0085] Table 1 Comparison of parameters and processing capacity of different grass fruit drying equipment

[0086]

[0087]

[0088] Conclusion: The traditional smoking and fire roasting processing methods have problems such as environmental pollution and ecological damage. The box-type hot air dryer is more environmentally friendly and has little impact on the ecological environment.

[0089] Table 2 Comparison of 6 different kinds of grass fruit drying equipment

[0090]

[0091] Note: The ex-factory price of biomass pellet fuel is about 1.1 (yuan / kg), and the electricity price is calculated based on the agricultural production electricity consumption of Nujiang Prefecture in November of 0.38 (yuan / kWh);

[0092] in conclusion:

[0093] (1) The processing cost of 1 kg of hay fruit processed by a box-type hot air dryer is 1.35 yuan, which is lower than the processing cost of traditional smoking and fire roasting, and the economic benefits are higher than those of traditional processing methods.

[0094] (2) Compared with the hot air drying mesh belt production line, the box-type hot air dryer has similar processing costs, and the processed dried fruits are of the same quality, all of which are smokeless fruits. Although the drying method has the lowest cost, it is subject to weather and site factors, and the production capacity is extremely small. In addition, the aroma of the dried grass fruit processed by drying is relatively light, and it is easy to mold and infest insects. In comprehensive comparison, the use of box-type hot air dryers has greater competitiveness and economic benefits compared with other current processing methods.

[0095] Table 3 Comparison of equipment investment costs

[0096]

[0097] Conclusion: The investment cost of 10 box-type hot air dryers is about 400,000 yuan, and the investment cost of 1 hot air drying mesh belt production line is about 3 million yuan. The former takes 29.4 hours to process 40.0 tons of cardamom, and the latter takes 24 hours. Theoretically, when there are 11 box-type hot air dryers, the production capacity of the box-type hot air drying unit will be greater than that of 1 hot air drying mesh belt production line. At this time, the former only needs to invest 440,000 yuan, which is only 14.7% of the latter. It can be seen that under the same processing capacity, the use of box-type hot air dryers can greatly reduce the equipment investment cost.

[0098] Experimental Example 2 Effect of different drying parameters on cost, volatile oil content and quality evaluation

[0099] According to the method of comparative example 1-12, 3500 kg of fresh grass fruit is dried, and the total processing fee = fuel + electricity fee + labor fee, and the processing cost = (processing cost of embodiment 3 * total processing fee of other preparation methods) / total processing fee of embodiment 3. As shown in Table 4:

[0100] Table 4 Cost and appearance evaluation

[0101]

[0102]

[0103]

[0104] As can be seen from Table 4, in comprehensive comparison, the fuel consumption during the drying process of Comparative Examples 4 to 6 is the lowest, the processing cost is the lowest, and the processed dried grass fruit is brown-red, uniform in color, full in fruit grains, and good in appearance; the aroma is sufficient and the fragrance is pure, especially Comparative Example 5. Compared with other drying methods, its comprehensive evaluation of dried fruit quality is the best. Considering the two most important aspects of processing cost and dried fruit quality, the drying method of Comparative Example 5 is the optimal grass fruit baking process, and the processed dried grass fruit has the highest volatile oil content and great medicinal value. Controlling the total drying time and staged drying temperature parameters is very important for the extraction of grass fruit volatile oil. If the total drying time and staged drying temperature are too high or too low, it is easy to cause volatile oil volatilization, and the volatile oil content remaining in the grass fruit is low. According to different baking stages, temperature and humidity control are carried out separately. The temperature for 0-10h is 45-55℃, and the total dehumidification time should be 5-7h; the temperature for 11-20h is 55-65℃, and the total dehumidification time should be 5-7h. 21- The drying temperature is 65-75℃ and the total dehumidification time should be 2-4h.

[0105] Example 3 Effects of different fixing times on the volatile oil content and quality evaluation of Amomum villosum

[0106] Dried Amomum villosum was prepared according to the methods of Examples 1 to 3 and Comparative Examples 13 to 18, and the content of volatile oil in Amomum villosum was determined according to the volatile oil determination method 2204 of the fourth volume of the 2015 edition of the Chinese Pharmacopoeia. The standard requirement is that the content of volatile oil in Amomum villosum should not be less than 1.4% (ml / g). The content of volatile oil in Amomum villosum is shown in Table 5:

[0107] Table 5 Volatile oil content and quality evaluation of Amomum villosum at different fixing times

[0108]

[0109]

[0110] As can be seen from Table 5, the volatile oil content of the tsaoko obtained by the drying method of Examples 1-3 is all above 3.0% and the comprehensive evaluation is excellent, especially Example 3 is evaluated the best, which shows that different fixation times affect the volatile oil content of tsaoko. It can be seen from the comparison between Example 3 and Comparative Example 13 that if the tsaoko is not fixed, the drying time will be extended. It can be seen from the comparison between Example 3 and Comparative Example 14 that the low fixation temperature of tsaoko will extend the drying time. It can be seen from the comparison between Example 3 and Comparative Examples 15-18 that the too high fixation temperature will reduce the essential oil content in the dried fruit. It shows that although the addition of the fixation step can generally destroy the wax layer on the surface of the tsaoko, accelerate the drying of the fresh fruit, and achieve the effect of saving fuel and working hours (saving 4.5h of drying time), and can make the color of the dried tsaoko consistent, it is also easy to cause the loss of volatile oil of tsaoko. However, the technical solution selects a suitable fixation temperature, which can not only significantly shorten the drying time, but also will not cause the volatilization of volatile oil of tsaoko, which is conducive to retaining the active ingredients of tsaoko to the greatest extent. If the withering time of the grass fruit exceeds 15 minutes, the effect of shortening the drying time is not significant, and it will seriously affect the quality and essential oil content of the dried grass fruit.

[0111] Example 4 Effect of different fixing temperatures on the volatile oil content and quality evaluation of Amomum villosum

[0112] Dried Amomum villosum was prepared according to the method of Example 3 and Comparative Examples 19-27, and the content of essential oil (volatile oil) in Amomum villosum was shown in Table 6 as determined according to the volatile oil determination method in General Rules 2204 of Part IV of the 2015 edition of the Chinese Pharmacopoeia. The standard requirement is that the content of essential oil (volatile oil) in Amomum villosum should not be less than 1.4% (ml / g).

[0113] Table 6 Volatile oil content and quality evaluation of Amomum villosum at different fixing times

[0114]

[0115]

[0116] It can be seen from Table 6 that the volatile oil content of the cardamom obtained by the drying method of Example 3 reaches 3.2% and the comprehensive evaluation is the best. It can be seen that different withering temperatures affect the quality of cardamom. Comparison of Example 3 with Comparative Examples 19-21 shows that although the withering temperature is low, it does not affect the essential oil content of the dried fruit, it will prolong the drying time. Comparison of Example 3 with Comparative Examples 26 and 27 shows that the drying temperature of the first drying stage in Comparative Example 26 is 95°C. At higher temperatures, the volatile oil of the cardamom will be partially lost due to heat. The dried cardamom obtained by this technical solution has a higher volatile oil content than the dried cardamom obtained by the prior art, which helps to improve the economic value of the dried cardamom.

[0117] Example 5 Optimal Process

[0118] 3500 kg of fresh tsaoko are withered at a withering temperature of 115° C. for 10 minutes to obtain tsaoko to be dried, and then the tsaoko to be dried is transported into a box-type hot air dryer for staged gradient drying to obtain dry tsaoko with a moisture content of 13%;

[0119] The staged gradient drying process is as follows:

[0120] In 0-10h, the drying temperature is controlled at 50℃, the total dehumidification time is 6h, and the humidity in the dryer is reduced to 60%;

[0121] At 11-20h, the drying temperature was controlled at 60℃, the total dehumidification time was 6h, and the humidity in the dryer dropped to 30%;

[0122] At 21-25.1h, the drying temperature was controlled at 70℃, the total dehumidification time was 3h, and the humidity in the dryer dropped to 10%;

[0123] The circulating fan is started to cool the obtained dried tsaoko to 29°C.

[0124] The processing cost and quality of Amomum villosum under the optimal process conditions are shown in Table 7:

[0125] Table 7 Optimal process parameters

[0126]

[0127]

[0128] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for drying tsaoko using a box-type hot air dryer, characterized in that: The specific steps include: (1) Fixing: The cleaned fresh tsaoko is treated with steam to fix the tsaoko until it is dried; (2) Drying: conveying the to-be-dried tsaoko obtained in step (1) into a box-type hot air drying machine for gradient drying in stages to obtain dried tsaoko with a moisture content of 12-13%; The staged gradient drying is as follows: In 0-10h, the drying temperature is controlled between 45-55℃, the total dehumidification time is 5-7h, and the humidity in the dryer is gradually reduced from 85% to 60%; During 11-20h, the drying temperature is controlled between 55-65℃, the total dehumidification time is 5-7h, and the humidity in the dryer is gradually reduced from 60% to 30%; At 21-26.2h, the drying temperature is controlled between 65-75℃, the total dehumidification time is 2-4h, and the humidity in the dryer is gradually reduced from 30% to 10%; (3) Cooling: The dried tsaoko obtained in step (2) is cooled and then packaged and stored.

2. The method for drying tsaoko using a box-type hot air dryer according to claim 1, characterized in that: The temperature of the water vapor in step (1) is 110-120°C.

3. The method for drying tsaoko using a box-type hot air dryer according to claim 2, characterized in that: The temperature of the water vapor is 115°C.

4. The method for drying tsaoko using a box-type hot air dryer according to claim 1, characterized in that: The time for the fixing treatment in step (1) is 5-15 minutes.

5. The method for drying tsaoko using a box-type hot air dryer according to claim 4, characterized in that: The time of the fixing treatment is 10 minutes.

6. The method for drying tsaoko using a box-type hot air dryer according to claim 1, characterized in that: The step (2) of step-by-step gradient drying is as follows: During the period of 0-10h, the drying temperature was controlled between 50℃, the total dehumidification time was 6h, and the humidity in the dryer was gradually reduced from 85% to 60%; During 11-20h, the drying temperature was controlled at 60℃, the total dehumidification time was 6h, and the humidity in the dryer was gradually reduced from 60% to 30%; At 21-25.1h, the drying temperature was controlled between 70°C, the total dehumidification time was 3h, and the humidity in the dryer was gradually reduced from 30% to 10%.

7. The method for drying tsaoko using a box-type hot air dryer according to claim 1, characterized in that: The cooling treatment in step (3) is to start the circulating fan to cool the Amomum villosum to 28-30°C.

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