Citron white cortex layer drying method

Abstract

The invention discloses a citron white cortex layer drying method, and belongs to the technical field of citron processing. The method comprises the steps of fruit selection, slicing and three times of drying: selecting ripe citron fruits from October to December, the white skin layer thickness of the citron fruits is more than 3cm, the citron fruits are free of plant diseases and insect pests and mechanical damage, and the surfaces of the citron fruits are wiped clean; the thickness of the slices is 0.5-1 cm, and the weight of the slices is 10-15 g; and placing the slices in a fruit drying machine with rated voltage of 220V, rated frequency of 50Hz and vertically integrated temperature adjustment of an inner cavity, and carrying out three drying treatments of drying at 55-65 DEG C for 1-2 hours, drying at 75-85 DEG C for 1-2 hours and drying at 55-65 DEG C until the weight is constant, so as to obtain the dried citron slice product. According to the method, the problems that traditional dried citron slices are insanitary, long in consumed time, easy to be influenced by weather and easy to deform in appearance are solved, the obtained dried slices are clean and sanitary, the appearance is relatively complete, the problem that the edges of the slices shrink is effectively solved, the consumed time is only about 5 h, and reference is provided for factory-like and standardized production of the dried citron slices.

Description

Technical Field

[0001] This invention relates to the field of citron processing technology, specifically to a method for drying the white bark layer of citron. Background Technology

[0002] citron( Citrus medica L. Citron is a plant that is both food and medicine. It has the functions of soothing the liver and regulating qi, relieving chest congestion, and resolving phlegm. Its main edible part is the white peel. Unlike citrus crops such as lemon and Buddha's hand, the white peel of citron has a low water content, no fruit juice sacs, and a harder texture and finer structure.

[0003] Currently, the traditional method for processing citron involves slicing the white bark into thin slices and then sun-drying them. However, this traditional method has significant drawbacks: the drying process is susceptible to dust and contaminants, resulting in unsanitary slices; it is dependent on weather conditions, making it impossible to operate on rainy days, and the process takes up to three days; and after drying, the slices have wrinkled edges, a dull color, and poor appearance. With the increasing demands of the citron processing industry, the traditional sun-drying method can no longer meet the requirements of hygienic, efficient, and standardized production. There is an urgent need for a drying method that is unaffected by weather, shorter in time, and can guarantee product quality. Summary of the Invention

[0004] The technical problem to be solved by this invention is to provide a method for drying the white bark of citron, which solves the problems of unsanitary conditions, long drying time, susceptibility to weather, and easy deformation of appearance of traditional sun-dried citron slices. The resulting dried slices are clean and hygienic with a relatively intact appearance, effectively improving the problem of wrinkled edges of the slices. The drying time is only about 5 hours, providing a reference for the industrialized and standardized production of dried citron slices.

[0005] This invention is implemented as follows: A method for drying the white bark of citron includes the following steps: (1) Selecting fruits: Select fresh citron fruits that mature from October to December, with a white skin layer of more than 3cm, free from pests, diseases and mechanical damage, and wipe the surface of the fruit clean for later use. (2) Slicing: Use a fruit slicer with adjustable slice thickness to slice the white citron peel into thin slices. The thickness of the slices is 0.5-1cm and the weight of a single slice is 10g-15g. (3) Drying: Place the sliced ​​citron white bark in a fruit dryer and dry it three times to constant weight; the first drying conditions are 55-65℃ for 1-2 hours, the second drying conditions are 75-85℃ for 1-2 hours, and the third drying conditions are 55-65℃ to constant weight. Furthermore, the citron mentioned is 'dog's head' citron.

[0006] Furthermore, the citron white peel layer mentioned in step (1) is the white spongy peel layer on the outer layer of the citron fruit.

[0007] Furthermore, the thickness of the sheet is 0.5 cm.

[0008] Furthermore, the fruit dryer described in step (3) has a rated voltage of 220V and a rated frequency of 50Hz, and the inner cavity has an integrated temperature control, which can simulate natural air drying; The fruit dryer's simulated natural air drying function is achieved through a built-in ventilation device with a ventilation speed of 0.5~1.2m / s and an internal temperature uniformity error of ≤±2℃. Furthermore, the specific temperatures and times for the three drying processes in step (3) are as follows: the first drying at 60℃ for 2 hours, the second drying at 80℃ for 2 hours, and the third drying at 60℃ for 1 hour until constant weight.

[0009] The present invention has the following advantages: 1. Clean and hygienic, avoiding dust and dirt contamination; 2. Drying cycle of about 5 hours, significantly improving production efficiency; 3. Unaffected by weather, allowing for continuous production around the clock; 4. Slices have a relatively intact appearance, with no obvious wrinkles, uniform color, and better marketability; This invention effectively improves the problem of slice edge wrinkling caused by constant temperature drying through three-stage alternating temperature drying, and has a better rehydration ratio, preserving the excellent quality of the citron white skin layer, providing reliable technical support for the industrialized and standardized production of dried citron slices. Attached Figure Description

[0010] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0011] Figure 1 These are comparative images of citron bark slices after different drying treatments. Detailed Implementation

[0012] The following will be combined with the appendix Figure 1 The technical solution of the present invention will be clearly and completely described in detail with specific embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments used, unless otherwise specified, are all commercially available conventional products. Example 1

[0013] A method for drying the white bark layer of citron includes the following steps: (1) Select fruit: Select fresh 'dog head' citron fruits that mature from October to December, with a white skin layer 3cm thick, free from pests and diseases and mechanical damage, and wipe the surface clean for later use; (2) Slicing: Use a fruit slicer with adjustable slice thickness to slice the white citron peel into thin slices with a thickness of 0.5cm and a weight of 10g~15g; (3) Drying: Place the sliced ​​citron white peel into a fruit dryer for drying. The rated voltage of the fruit dryer is 220V and the rated frequency is 50Hz. The inner cavity is temperature-controlled from top to bottom to simulate natural air drying. The specific drying times and temperatures for the three drying processes are as follows: First drying: 60℃ for 2 hours; Second drying: dry at 80℃ for 2 hours; The third drying process involves drying at 60°C for 1 hour until constant weight is achieved.

[0014] Comparative Example 1 (1) Select fruit: Select fresh 'dog head' citron fruits that mature from October to December, with a white skin layer 3cm thick, free from pests and diseases and mechanical damage, and wipe the surface clean for later use; (2) Slicing: Use a fruit slicer with adjustable slice thickness to slice the white citron peel into thin slices with a thickness of 0.5cm and a weight of 10g~15g; (3) Drying: Dry in the sun.

[0015] Comparative Example 2 (1) Select fruit: Select fresh 'dog head' citron fruits that mature from October to December, with a white skin layer 3cm thick, free from pests and diseases and mechanical damage, and wipe the surface clean for later use; (2) Slicing: Use a fruit slicer with adjustable slice thickness to slice the white citron peel into thin slices with a thickness of 0.5cm and a weight of 10g~15g; (3) Drying: Place the sliced ​​citron white bark in a fruit dryer and dry at 60°C for 7 hours until constant weight.

[0016] The specific appearance of the dried products from the above three sets of tests is as follows: Figure 1 As shown, Figure 1 These are comparative images of citron bark slices after different drying treatments. A is an undried citron bark slice, B is a slice treated with the method of this invention (Example 1), C is a slice treated with traditional sun drying (Comparative Example 1), and D is a slice treated with a single 60℃ constant temperature drying (Comparative Example 2).

[0017] Rehydration ratio: Immerse the dried slice (m1) in distilled water at approximately 30 °C for 30 min to fully absorb water. After removing it, blot the surface moisture with filter paper and accurately weigh it (m2). Calculate the weight ratio of the two: Refill ratio = m2 / m1; Drying ratio: The weight ratio of dried slices (m1) to undried slices (m3): Drying ratio = m1 / m3; Shrinkage rate: The smaller the shrinkage rate, the smaller the morphological change, and the closer it is to the original state of the fresh section: Shrinkage rate = (volume of section before shrinkage - volume of section after shrinkage) / volume of section before shrinkage × 100%; The results of various parameters of the dried products from the three groups of experiments are shown in Table 1 below. Table 1

[0018] from Figure 1 As can be seen from Table 1, compared with the traditional sun-drying method (Comparative Example 1), the method of the present invention (Example 1) is: clean and hygienic, avoiding dust and dirt contamination; the drying cycle time is shortened from 3 days to about 5 hours, and the efficiency is greatly improved; it is not affected by the weather and can be produced continuously around the clock. The slices are relatively intact, with no obvious wrinkles and uniform color, making them more marketable.

[0019] Compared with the single 60℃ constant temperature drying method (Comparative Example 2), the present invention effectively improves the problem of edge wrinkling of slices caused by constant temperature drying through three-stage temperature alternating drying, and has a better rehydration ratio, preserving the excellent quality of the citron white bark layer, providing reliable technical support for the industrialized and standardized production of dried citron slices.

[0020] While specific embodiments of the present invention have been described above, those skilled in the art should understand that the specific embodiments described are merely illustrative and not intended to limit the scope of the present invention. Equivalent modifications and variations made by those skilled in the art in accordance with the spirit of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for drying the white bark layer of citron, characterized in that: Includes the following steps: (1) Selecting fruits: Select fresh citron fruits that mature from October to December, with a white skin layer of more than 3cm, free from pests, diseases and mechanical damage, and wipe the surface of the fruit clean for later use. (2) Slicing: Cut the white bark of citron into thin slices, the thickness of which is 0.5-1cm and the weight of each slice is 10g-15g; (3) Drying: Place the sliced ​​citron white bark in a fruit dryer and dry it three times to constant weight; the first drying conditions are 55-65℃ for 1-2 hours, the second drying conditions are 75-85℃ for 1-2 hours, and the third drying conditions are 55-65℃ to constant weight.

2. The method for drying the white bark of citron according to claim 1, characterized in that: The citron mentioned is the 'dog's head' citron.

3. The method for drying the white bark of citron according to claim 1, characterized in that: The citron white skin layer mentioned in step (1) is the white spongy skin layer on the outer layer of the citron fruit.

4. The method for drying the white bark of citron according to claim 1, characterized in that: The thickness of the sheet is 0.5 cm.

5. The method for drying the white bark of citron according to claim 1, characterized in that: The fruit dryer described in step (3) has a rated voltage of 220V and a rated frequency of 50Hz. The inner cavity has integrated temperature control at the top and bottom, which can simulate natural air drying.

6. The method for drying the white bark of citron according to claim 1, characterized in that: The specific temperatures and times for the three drying steps in step (3) are as follows: first drying at 60℃ for 2 hours, second drying at 80℃ for 2 hours, and third drying at 60℃ for 1 hour until constant weight.

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