Processing method of sulfur-free dried persimmons
Through closed-loop drying technology and gas treatment, the existing persimmon cake processing methods are complicated, high cost and poor taste, and sulfur-free persimmon cakes with soft texture and long shelf life are prepared, and the original taste is maintained after freezing and storage.
Patent Information
- Application Number
- CN202411909346.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-24
- Publication Date
- 2025-03-25
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
The existing persimmon cake processing methods are cumbersome, with high cost, short shelf life, and the drying process leads to poor taste.
The closed-loop drying technology is adopted to prepare a soft sulfur-free persimmon cake through three stages of temperature and humidity control, combined with nitrogen, ethylene and carbon dioxide gas treatment, and gas treatment is combined with pre-treatment, drying and post-treatment.
The persimmon cake has a soft texture and a delicate texture, extends the shelf life, and maintains the original taste after freezing and storage.
Smart Images
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Abstract
Description
[Technical field]
[0001] The present invention relates to the technical field of food processing, and in particular to a method for processing sulfur-free dried persimmons. [Background technology]
[0002] Persimmon, known as "woody grain and hardcore crop", has an economic lifespan of up to a hundred years. It is said that "one year of planting will bring a hundred years of income". It is an important economic fruit tree. Persimmon has high nutritional value. It is rich in carotene, vitamins, glucose, fructose, calcium, potassium and other minerals. It can stop bleeding and cool blood, clear away heat and dryness, moisten the lungs and resolve phlegm, moisten the intestines and promote bowel movements, detoxify alcohol, promote blood circulation and reduce inflammation, and protect the cardiovascular and cerebrovascular systems. In 2006, the World Health Organization listed persimmon as the eighth best fruit in the world.
[0003] As the persimmon planting area in my country continues to expand, the persimmon yield has gradually increased, but persimmons have a high water content and are not easy to store. Therefore, people often process persimmons into persimmon cakes. The persimmon cakes obtained by the existing processing methods have the following problems: 1. The processing method is too complicated and the cost is high, which is not conducive to large-scale production; 2. In order to increase the shelf life of persimmon cakes, preservatives need to be added or low-temperature refrigeration is performed; 3. Due to the need to be dried, the taste of persimmon cakes is not good, mainly manifested in the texture not being soft enough. [Summary of the invention]
[0004] In view of this, the object of the present invention is to provide a method for processing sulfur-free persimmon cakes, and to obtain a soft and delicious persimmon cake through the method of the present application, which can still maintain the original taste after freezing.
[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:
[0006] A method for processing sulfur-free persimmon cakes, the method comprising pre-treatment, drying, post-treatment and storage, wherein the drying specifically comprises: placing the pre-treated persimmons in a drying room for closed-loop drying treatment, the treatment comprising three stages, as follows:
[0007] The first stage: control the temperature in the drying room to 38-42℃ and process for 8-10 hours;
[0008] The second stage: adjust the temperature in the drying room to 24-26℃, and control the humidity in the drying room to above 90%, and continue the treatment for 8-10 hours;
[0009] The third stage: adjust the temperature in the drying room to 38-42℃ and process for 20-35 hours to complete the drying process.
[0010] The drying room includes three charging ports and one exhaust port, wherein the three charging ports are connected to an ethylene gas storage tank, a nitrogen gas storage tank and a carbon dioxide gas storage tank, and the exhaust port is used to discharge gas.
[0011] In the present invention, further, the first stage of drying also includes filling nitrogen into the drying room and exhausting the air in the drying room; in the second stage, ethylene gas is filled into the drying room so that the ethylene gas content in the drying room is 5-10%; in the third stage, nitrogen is filled into the drying room again and the ethylene gas in the drying room is exhausted.
[0012] In the present invention, further, the pretreatment is: collecting fresh persimmons that are 90% mature, peeling them and soaking them in a treatment liquid for 10-20 minutes, taking them out and draining them for later use; wherein the treatment liquid is obtained by mixing potassium sorbate and sodium VC aqueous solution in a mass ratio of 2-3:5.
[0013] In the present invention, further, the post-treatment is: after the drying is completed, the heating is stopped, and carbon dioxide gas is filled into the drying room to account for 15-20% of the total gas content, and maintained for 24-36 hours.
[0014] In the present invention, further, the concentration of the sodium VC aqueous solution is 3-5%.
[0015] In the present invention, further, the storage is: putting the processed dried persimmon into a cold storage at -20°C for storage.
[0016] The present invention has at least the following beneficial effects:
[0017] 1. The preparation method of the present application is simple to operate, and the obtained persimmon cake has a soft and sticky taste and a long shelf life. In addition, the persimmon cake can still maintain its original taste after being frozen.
[0018] 2. In the preparation process of dried persimmon cakes of the present application, the raw materials are selected from 90% ripe persimmons and fully ripe persimmons... During the preparation, pre-treatment is first performed, and potassium sorbate and sodium VC aqueous solution are used for soaking treatment, and the soaking time is 10-20 minutes. During this soaking time, a small amount of treatment liquid can adhere to the surface of the persimmon fruit, so as to avoid oxidation of the persimmons in the later processing process, resulting in uneven color, and to avoid internal water loss during the drying process, resulting in poor taste; the persimmons after pre-treatment are placed in a drying room for three stages of drying treatment. In the first stage, the temperature is controlled to be 38-42°C for drying treatment, and nitrogen is filled into the drying room to exhaust the oxygen in the room. In this stage, the persimmons are pre-dried... Then the second stage of treatment is performed, the temperature of the drying room is adjusted to room temperature, and ethylene gas is filled, and the humidity in the drying room is controlled to be above 90%. During the process, the persimmons are cooked at room temperature, and their astringency can be preliminarily removed. In the first stage of drying, the persimmons are dried at room temperature. Post-humidification and steaming can accelerate the softening of persimmons and promote the softer flesh inside the persimmons. In addition, during the steaming process, the carbohydrates in the flesh of the persimmons can be converted into sugar to increase the sweetness. After steaming, the third stage of drying follows. The third stage is the same as the first stage. This stage reduces the moisture content of the persimmons. After steaming, the persimmons dried again are dry but not hard, and can be stored for a long time while ensuring a soft taste. The steaming is performed once between the two dryings of the present application, which can soften the persimmons and avoid hardness and poor taste of the finished products due to excessive drying. This stage is performed in a closed-loop drying room, which is easy to operate and hygienic. After drying, the persimmons are post-processed and filled with carbon dioxide gas for 24 hours, which can further remove the astringency and improve the taste of the persimmons. The finished persimmon cakes are stored in a cold storage at -20°C. Experiments have found that even if the finished persimmon cakes are stored at low temperatures through the drying method of the present application, the taste of the persimmon cakes will not be affected. [Specific implementation method]
[0019] The following embodiments may help those skilled in the art to more fully understand the present invention, but shall not limit the present invention in any way.
[0020] Embodiment 1:
[0021] This embodiment provides a method for processing sulfur-free dried persimmon:
[0022] The processing method comprises the following steps:
[0023] (1) Pretreatment: Collect fresh persimmons that are 90% ripe, peel them, and soak them in a treatment solution for 10 minutes, then take them out, drain them, and set them aside; wherein the treatment solution is prepared by mixing potassium sorbate and sodium VC aqueous solution in a mass ratio of 2:5; the concentration of the sodium VC aqueous solution is 3%;
[0024] (2) Drying: The pre-treated persimmons are placed in a drying room for closed-loop drying, which includes three stages: the first stage: the temperature in the drying room is controlled to 38° C. and the treatment is performed for 8 hours; the second stage: the temperature in the drying room is adjusted to 24° C., and the humidity in the drying room is controlled to be above 90%, and the treatment is continued for 8 hours; the third stage: the temperature in the drying room is adjusted to 38° C. and the treatment is performed for 20 hours to complete the drying process; the first stage of drying also includes filling nitrogen into the drying room and exhausting the air in the drying room; the second stage is filling ethylene gas into the drying room so that the ethylene gas content in the drying room is 5%; the third stage is filling nitrogen into the drying room again and exhausting the ethylene gas in the drying room;
[0025] (3) Post-treatment: After drying is completed, stop heating and fill the drying room with carbon dioxide gas to account for 15% of the total gas content for 24 hours;
[0026] (4) Storage: Store the processed dried persimmons in a cold storage at -20°C.
[0027] Embodiment 2:
[0028] This embodiment provides a method for processing sulfur-free dried persimmon:
[0029] The processing method comprises the following steps:
[0030] (1) Pretreatment: Collect fresh persimmons that are 90% ripe, peel them, and soak them in a treatment solution for 15 minutes, then take them out, drain them, and set them aside; wherein the treatment solution is prepared by mixing potassium sorbate and sodium VC aqueous solution in a mass ratio of 2:5; the concentration of the sodium VC aqueous solution is 4%;
[0031] (2) Drying: The pre-treated persimmons are placed in a drying room for closed-loop drying, which includes three stages: the first stage: the temperature in the drying room is controlled to 40°C and the treatment is carried out for 9 hours; the second stage: the temperature in the drying room is adjusted to 25°C, and the humidity in the drying room is controlled to be above 90%, and the treatment is continued for 9 hours; the third stage: the temperature in the drying room is adjusted to 40°C and the treatment is carried out for 28 hours to complete the drying process; the first stage of drying also includes filling nitrogen into the drying room and exhausting the air in the drying room; the second stage is filling ethylene gas into the drying room so that the ethylene gas content in the drying room is 7%; the third stage is filling nitrogen into the drying room again and exhausting the ethylene gas in the drying room;
[0032] (3) Post-treatment: After the drying is completed, stop heating and fill the drying room with carbon dioxide gas to 17% of the total gas content for 30 hours;
[0033] (4) Storage: Store the processed dried persimmons in a cold storage at -20°C.
[0034] Embodiment 3:
[0035] This embodiment provides a method for processing sulfur-free dried persimmon:
[0036] The processing method comprises the following steps:
[0037] (1) Pretreatment: Collect fresh persimmons that are 90% ripe, peel them, and soak them in a treatment solution for 20 minutes, then take them out, drain them, and set them aside; wherein the treatment solution is prepared by mixing potassium sorbate and sodium VC aqueous solution in a mass ratio of 3:5; the concentration of the sodium VC aqueous solution is 5%;
[0038] (2) Drying: The pre-treated persimmons are placed in a drying room for closed-loop drying, which includes three stages: the first stage: the temperature in the drying room is controlled to 42°C and the treatment is carried out for 10 hours; the second stage: the temperature in the drying room is adjusted to 26°C, and the humidity in the drying room is controlled to be above 90%, and the treatment is continued for 10 hours; the third stage: the temperature in the drying room is adjusted to 42°C and the treatment is carried out for 35 hours to complete the drying process; the first stage of drying also includes filling nitrogen into the drying room and exhausting the air in the drying room; the second stage is filling ethylene gas into the drying room so that the ethylene gas content in the drying room is 10%; the third stage is filling nitrogen into the drying room again and exhausting the ethylene gas in the drying room;
[0039] (3) Post-treatment: After drying is completed, stop heating and fill the drying room with carbon dioxide gas to account for 20% of the total gas content for 36 hours;
[0040] (4) Storage: Store the processed dried persimmons in a cold storage at -20°C.
[0041] In order to illustrate the practical value of the processing method of the present application, the applicant conducted the following experiments:
[0042] First, set up the following comparison groups:
[0043] Comparative group 1: The drying method is: firstly carry out the second stage, then carry out the first stage and the third stage in sequence, except that the other methods are the same as those of Example 2;
[0044] Comparative group 2: During the second stage of the drying process, ethylene gas was not introduced into the drying room. Other methods were the same as those in Example 2.
[0045] Comparative group 3: During the drying process, the ethylene gas content charged in the second stage was 50%, and other methods were the same as those in Example 2;
[0046] Comparative group 4: During the drying process, the humidity in the second stage was 70%, and other methods were the same as those in Example 2;
[0047] Comparative group 5: pre-treatment using only potassium sorbate soaking in an amount equal to the treatment solution, and other methods are the same as those in Example 2;
[0048] Comparative group 6: commercially available persimmon cakes, purchased from Gongcheng, Guilin.
[0049] Comparing the finished product quality of the persimmons prepared by the above-mentioned comparative groups 1-6 and the persimmons prepared by Examples 1-3 of the present application, the sensory evaluation standards are shown in Table 1:
[0050] Table 1 Sensory evaluation standards
[0051]
[0052] Invite 20 people to conduct sensory evaluation on the above dried persimmons. All 20 people tasted the dried persimmons of the above comparative groups 1-6 and embodiments 1-3, and scored them according to the evaluation criteria in Table 2, and then took the average value. The results are shown in Table 2:
[0053] Table 2 Comparison of sensory evaluation results of each group
[0054]
[0055]
[0056] According to the results in Table 2, the persimmon cakes prepared by the present application have excellent qualities, soft texture and delicate taste. More importantly, the persimmon cakes obtained by the method of the present application will not affect the taste even after frozen storage, and can adapt to a variety of storage methods, thereby extending the storage time.
[0057] The above description is a detailed description of the preferred feasible embodiments of the present invention, but the embodiments are not intended to limit the scope of the patent application of the present invention. All equivalent changes or modified changes completed under the technical spirit suggested by the present invention should fall within the patent scope covered by the present invention.
Claims
1. A method for processing sulfur-free dried persimmon, characterized in that: The method includes pre-treatment, drying, post-treatment and storage, wherein the drying specifically includes: placing the pre-treated persimmons in a drying room for closed-loop drying treatment, and the treatment includes three stages, as follows: The first stage: control the temperature in the drying room to 38-42℃ and process for 8-10 hours; The second stage: adjust the temperature in the drying room to 24-26℃, and control the humidity in the drying room to above 90%, and continue the treatment for 8-10 hours; The third stage: adjust the temperature in the drying room to 38-42℃ and process for 20-35 hours to complete the drying process.
2. The method according to claim 1, characterized in that: The first stage of the drying also includes filling nitrogen into the drying room and exhausting the air in the drying room; the second stage is to fill ethylene gas into the drying room so that the ethylene gas content in the drying room is 5-10%; the third stage is to fill nitrogen into the drying room again and exhaust the ethylene gas in the drying room.
3. The method according to claim 1, characterized in that The pretreatment comprises: collecting fresh persimmons that are 90% ripe, peeling them, and soaking them in a treatment solution for 10-20 minutes, taking them out and draining them for later use; wherein the treatment solution is obtained by mixing potassium sorbate and sodium VC aqueous solution in a mass ratio of 2-3:
5.
4. The method according to claim 1, characterized in that: The post-treatment is as follows: after the drying is completed, the heating is stopped, and carbon dioxide gas is filled into the drying room until it accounts for 15-20% of the total gas content, and maintained for 24-36 hours.
5. The method according to claim 3, characterized in that: The concentration of the sodium VC aqueous solution is 3-5%.
6. The method according to claim 1, characterized in that The storage is as follows: the processed dried persimmons are placed in a cold storage at -20°C for storage.