Preparation method and application of gradient fiber
By constructing a parallel circuit to independently adjust the nozzle voltage or current, precise control of the gradient fiber in the electrospinning process is achieved, solving the problems of complex equipment and poor stability in the existing technology, and realizing the large-scale production of gradient fibers and their application in fruit preservation.
Patent Information
- Application Number
- CN202510689335.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-27
- Publication Date
- 2025-09-16
AI Technical Summary
The existing electrospinning process is mainly used to prepare fibers of a single diameter, which limits the versatility and performance optimization of the material. The traditional gradient fiber preparation technology has complex equipment, difficult process precise control, and poor production stability, which limits the large-scale application of gradient fibers.
By constructing a parallel circuit, connecting multiple nozzles, and independently adjusting the voltage or current of each nozzle, precise control of the gradient fiber can be achieved, and a controllable gradient change can be formed during the electrospinning process using a zein solution.
The method realizes the preparation of gradient fibers with simple equipment, continuously adjustable gradient and good repeatability, which is suitable for large-scale stable production and expands the application range of gradient fibers, especially in the field of fruit preservation.
Smart Images
Figure CN120649164A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of biomaterial preparation, and in particular relates to a preparation method of gradient fibers and applications thereof. Background Art
[0002] Electrospinning is a technology that uses high-voltage electrostatic fields to stretch and produce nano- or micron-sized fibers. It has the advantages of simple process, controllable fiber diameter, and a wide range of applications. It is widely used in filter materials, tissue engineering, sensors, energy storage, and other fields. However, existing electrospinning processes are mainly used to produce fibers with a single diameter, which limits the versatility and performance optimization of the material. To further improve material performance and achieve a wider range of applications, it is urgent to develop innovative methods for preparing controllable gradient fibers.
[0003] Gradient fibers are fiber structures with gradients in diameter, morphology, or composition. Existing gradient fiber preparation techniques primarily include phase separation, template generation, and vapor deposition. However, these methods suffer from complex equipment, difficulty in precise process control, and poor production stability, limiting their large-scale application.
[0004] Therefore, it is of great significance to develop a simple, controllable and stable method for preparing gradient fibers. Summary of the Invention
[0005] The present invention aims to provide a method for electrospinning gradient fibers based on a simple parallel circuit. By constructing a parallel circuit, connecting multiple nozzles, and independently adjusting the voltage or current of each nozzle, precise control of the gradient fibers can be achieved. This method can be electrically regulated to form a controllable gradient in the fibers. Compared to traditional methods, this solution has simple equipment, continuously adjustable gradients, and good repeatability. It is suitable for large-scale, stable production of gradient fiber materials and has broad application prospects.
[0006] To achieve the above object, the technical solution of the present invention is as follows:
[0007] In a first aspect, the present invention provides a method for preparing a gradient fiber, the method comprising the following steps:
[0008] (1) preparing an electrospinning solution: adding zein to an 80% acetic acid aqueous solution and stirring in a constant temperature heated magnetic stirrer until the zein is completely dissolved, thereby obtaining an electrospinning solution;
[0009] (2) Preparation of an electrospinning parallel circuit: connecting the injection needles to the parallel circuits respectively, then connecting the injection needles filled with electrospinning liquid in parallel, and connecting a sliding resistor in series in one of the circuits to obtain an electrospinning parallel circuit;
[0010] (3) Preparation of gradient fibers: electrospinning is performed using the electrospinning solution obtained in step (1) and the electrospinning parallel circuit obtained in step (2) to obtain gradient fibers.
[0011] Preferably, the heating temperature of the constant temperature heating magnetic stirrer is 60-100°C.
[0012] Preferably, the stirring time of the constant temperature heating magnetic stirrer is 1-5 hours.
[0013] Preferably, the resistance of the sliding rheostat is adjusted to 1 / 5-5 / 5 of the injection needle.
[0014] In the present invention, sliding rheostats are connected in parallel to perform voltage division, and the resistance of the sliding rheostats is adjusted to make the resistance 1 / 5 to 5 / 5 of the injection needle tube.
[0015] In the present invention, electrospinning uses a 10 mL syringe as a solution reservoir; a 21G stainless steel needle is used as the needle of the injection syringe; the solution flow is controlled by a microinjection pump; and a paper towel plate is used to receive the gradient fiber.
[0016] Preferably, the electrospinning process parameters are: propulsion rate of 0.5-3 mL / h, voltage of 10-20 kV, distance from the needle tip of the injection needle to the receiving device of 8-16 cm, and electrospinning time of 0.5-2 h.
[0017] Preferably, the receiving device is a tissue flat plate.
[0018] In a second aspect, a gradient fiber is provided, wherein the gradient fiber is prepared by the preparation method of the present invention.
[0019] In a third aspect, a packaging material for preserving fruits is provided, wherein the packaging material is prepared from the gradient fiber of the present invention.
[0020] In a fourth aspect, there is provided use of the gradient fiber and / or packaging material of the present invention in fruit preservation.
[0021] In a fifth aspect, the present invention provides the use of the gradient fiber and / or packaging material described in the present invention in the adsorption of endogenous ethylene in fruits and the extension of the shelf life of fruits.
[0022] Compared with the prior art, the technical solution provided by the present invention has at least the following beneficial effects or advantages:
[0023] The present invention realizes that multiple nozzles independently regulate the electric field intensity and accurately control the gradient change of the fiber by constructing a parallel circuit. The method of the present invention has simple equipment, continuously adjustable gradient, high repeatability, avoids the problems of fiber mutation and unevenness in traditional methods, and improves production stability. It is particularly suitable for the field of fruit preservation, can realize large-scale production, and expand the application range of gradient fibers. Specifically, (1) the present invention uses a simple parallel circuit to simplify the complex control system and reduce manufacturing costs. (2) The present invention independently adjusts the voltage or current of each nozzle by constructing a parallel circuit to control the gradient change of fiber characteristics such as diameter and shape (morphology) in different areas, thereby achieving stable and precise gradient change. (3) The present invention mainly avoids the stability problem caused by solution changes through physical field regulation, is not easily affected by environmental changes, makes the gradient fiber more controllable, suitable for large-scale production, and has higher repeatability. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 This is a diagram of the electrospinning device of the present invention.
[0025] Figure 2 Schematic diagram of the structure of the electrospinning device of the present invention; 10-injection needle; 20-parallel circuit; 30-sliding rheostat.
[0026] Figure 3 This is a diagram of the electrospinning process of the present invention.
[0027] Figure 4 This is a digital photo of the gradient fiber obtained in Example 1 of the present invention.
[0028] Figure 5 This is a scanning electron microscope image of the gradient fiber obtained in Example 1 of the present invention.
[0029] Figure 6 This is a scanning electron microscope image of the gradient fiber obtained in Example 2 of the present invention. DETAILED DESCRIPTION
[0030] The technical solutions of the present invention are described below with reference to the following examples. However, the present invention is not limited to the following examples. The experimental methods and detection methods described in each example are conventional methods unless otherwise specified; the reagents and materials described are commercially available unless otherwise specified.
[0031] In the examples of the present invention, zein was purchased from Shanghai Yuanye Biotechnology Co., Ltd. with a batch number / item number of S12025-500g.
[0032] Example 1
[0033] This embodiment provides a method for preparing gradient fibers, the method comprising the following steps:
[0034] (1) Preparation of electrospinning solution: 20 mL of 80% acetic acid was measured with a graduated cylinder and added to a 100 mL beaker. 5 g of zein powder was weighed with an electronic analytical balance and added to the beaker containing acetic acid. A magnetic rotor was added. The beaker was placed in a constant temperature heated magnetic stirrer and heated and stirred in an 80°C water bath for 1 h. After the zein was completely dissolved in the acetic acid, the beaker was removed and allowed to cool at room temperature to obtain electrospinning solution Z@A-1. Another beaker was charged with equal amounts of the above acetic acid and zein, a magnetic rotor was added, and the beaker was placed in a constant temperature heated magnetic stirrer and heated and stirred in an 80°C water bath for 2 h. After the zein was completely dissolved in the acetic acid, the beaker was removed and allowed to cool at room temperature to obtain electrospinning solution Z@A-2.
[0035] (2) Preparation of electrospinning parallel circuit:
[0036] 5 mL of each Z@A-1 and Z@A-2 solution was added to a 10 mL syringe. The syringe was then mounted on a microinjection pump. The electrostatic spraying process parameters were set as follows: propulsion rate of 0.5 mL / h, voltage of 12 kV, distance from the syringe needle to the receiving device of 12 cm, and electrospinning time of 0.5 h.
[0037] Connect the syringe to the circuit. Connect the syringes equipped with Z@A-1 and Z@A-2 in parallel, and connect a sliding rheostat in series in the Z@A-2 branch. Adjust the resistance of the sliding rheostat so that its resistance is 1 / 5 of the syringe's.
[0038] (3) Preparation of gradient fibers: Start the electrospinning experiment to obtain gradient fibers. Figure 1 , the schematic diagram of the electrospinning device is shown in Figure 2 , the electrospinning process diagram is shown in Figure 3 ,Depend on Figure 3 It can be seen that Z@A-1 forms fine fibers, while Z@A-2, due to its high viscosity and rapid solvent evaporation, produces coarser fibers, constructing a three-dimensional gradient fiber structure (GIF). The formation of this structure is mainly due to the following reasons: 1) The low viscosity of Z@A-1 easily forms fine and uniform fibers, while the high viscosity of Z@A-2 produces coarser fibers; 2) Z@A-2 has a low solvent content and a higher viscosity. After the surface solidifies quickly, it cannot completely encapsulate the internal electrospinning liquid, causing the fibers to bend and accumulate. 3) The series resistance at the Z@A-2 needle reduces the voltage, insufficient fiber stretching, and leads to loose fiber stacking.
[0039] Digital photos of gradient fibers are shown in Figure 4 , the scanning electron microscope images of gradient fibers are shown in Figure 5 .Depend on Figure 4 It can be seen that GIF is extremely light and can be stably held by the tentacles of Setaria viridis without any deformation of the tentacles. Figure 5The gradient fibers exhibited a bimodal diameter, with an average diameter of 0.17 ± 0.51 μm for thin fibers and 1.95 ± 0.65 μm for thick fibers. This is because, during electrospinning, high-viscosity solutions, due to their high molecular chain concentration and strong interaction, form coarse jets, resulting in insufficient stretching and ultimately producing thicker fibers. Low-viscosity solutions, on the other hand, have fewer molecular chains and are more easily stretched, resulting in a thinner jet. Furthermore, rapid solvent evaporation contributes to the formation of finer fibers.
[0040] Example 2
[0041] This embodiment provides a method for preparing gradient fibers, the method comprising the following steps:
[0042] (1) Preparation of electrospinning solution: 20 mL of 80% acetic acid was measured with a graduated cylinder and added to a 100 mL beaker. 5 g of zein powder was weighed with an electronic analytical balance and added to the beaker containing acetic acid. A magnetic rotor was added. The beaker was placed in a constant temperature heated magnetic stirrer and heated and stirred in a 60°C water bath for 1 h. After the zein was completely dissolved in the acetic acid, the beaker was removed and allowed to cool at room temperature to obtain electrospinning solution Z@A-1. Another beaker was charged with equal amounts of the above acetic acid and zein, a magnetic rotor was added, and the beaker was placed in a constant temperature heated magnetic stirrer and heated and stirred in an 80°C water bath for 3 h. After the zein was completely dissolved in the acetic acid, the beaker was removed and allowed to cool at room temperature to obtain electrospinning solution Z@A-3.
[0043] (2) Preparation of electrospinning parallel circuit 20:
[0044] 5 mL of Z@A-1 and Z@A-3 solution were taken respectively and added to a 10 mL syringe. The syringe was installed on a microinjection pump, and the electrostatic spray process parameters were set: propulsion rate of 1.0 mL / h, voltage of 10 kV, distance from the needle tip of the injection syringe 10 to the receiving device of 10 cm, and electrospinning time of 1.0 h.
[0045] Connect the syringe to the circuit. Connect the syringes equipped with Z@A-1 and Z@A-3 in parallel, and connect a sliding rheostat 30 in series in the Z@A-3 branch. Adjust the resistance of the sliding rheostat so that it is 2 / 5 of the resistance of the syringe.
[0046] (3) Preparation of gradient fibers: Start the electrospinning experiment to obtain gradient fibers. The scanning electron microscope image of the gradient fibers is shown in Figure 6 .Depend on Figure 6 It can be seen that there are a large number of thicker fibers and a small number of very fine fibers interspersed among them, which shows that the fiber formation during the electrospinning process is unstable.
[0047] Example 3
[0048] This embodiment provides a method for preparing gradient fibers, the method comprising the following steps:
[0049] (1) Preparation of electrospinning solution: 20 mL of 80% acetic acid was measured with a graduated cylinder and added to a 100 mL beaker. 5 g of zein powder was weighed with an electronic analytical balance and added to the beaker containing acetic acid. A magnetic rotor was added. The beaker was placed in a constant temperature heated magnetic stirrer and heated and stirred in an 80°C water bath for 2 h. After the zein was completely dissolved in the acetic acid, the beaker was removed and allowed to cool at room temperature to obtain electrospinning solution Z@A-2. Another beaker was charged with equal amounts of the above acetic acid and zein, a magnetic rotor was added, and the beaker was placed in a constant temperature heated magnetic stirrer and heated and stirred in an 80°C water bath for 3 h. After the zein was completely dissolved in the acetic acid, the beaker was removed and allowed to cool at room temperature to obtain electrospinning solution Z@A-3.
[0050] (2) Preparation of electrospinning parallel circuit:
[0051] 5 mL of each Z@A-2 and Z@A-3 solution was added to a 10 mL syringe. The syringe was then mounted on a microinjection pump. The electrostatic spraying parameters were set as follows: propulsion rate of 1.5 mL / h, voltage of 15 kV, distance from the syringe needle to the receiving device of 14 cm, and electrospinning time of 1.5 h.
[0052] Connect the syringe to the circuit. Connect the syringes equipped with Z@A-2 and Z@A-3 in parallel, and connect a sliding rheostat in series in the Z@A-3 branch. Adjust the resistance of the sliding rheostat so that its resistance is 3 / 5 of that of the syringe.
[0053] (3) Preparation of gradient fibers: Gradient fibers can be obtained by starting the electrospinning experiment.
[0054] Example 4
[0055] This embodiment provides a method for preparing gradient fibers, the method comprising the following steps:
[0056] (1) Preparation of electrospinning solution: 20 mL of 80% acetic acid was measured with a graduated cylinder and added to a 100 mL beaker. 5 g of zein powder was weighed with an electronic analytical balance and added to the beaker containing acetic acid. A magnetic rotor was added. The beaker was placed in a constant temperature heated magnetic stirrer and heated and stirred in an 80°C water bath for 1 h. After the zein was completely dissolved in the acetic acid, the beaker was removed and allowed to cool at room temperature to obtain electrospinning solution Z@A-1. Another beaker was charged with equal amounts of the above acetic acid and zein, a magnetic rotor was added, and the beaker was placed in a constant temperature heated magnetic stirrer and heated and stirred in an 80°C water bath for 4 h. After the zein was completely dissolved in the acetic acid, the beaker was removed and allowed to cool at room temperature to obtain electrospinning solution Z@A-4.
[0057] (2) Preparation of electrospinning parallel circuit:
[0058] 5 mL of each Z@A-1 and Z@A-4 solution was added to a 10 mL syringe. The syringe was then mounted on a microinjection pump. The electrostatic spraying parameters were set as follows: propulsion rate of 2.0 mL / h, voltage of 20 kV, distance from the syringe needle to the receiving device of 16 cm, and electrospinning time of 2.0 h.
[0059] Connect the syringe to the circuit. Connect the syringes equipped with Z@A-1 and Z@A-4 in parallel, and connect a sliding rheostat in series in the Z@A-4 branch. Adjust the resistance of the sliding rheostat so that its resistance is 4 / 5 of that of the syringe.
[0060] (3) Preparation of gradient fibers: Gradient fibers can be obtained by starting the electrospinning experiment.
[0061] Example 5
[0062] This embodiment provides a method for preparing gradient fibers, the method comprising the following steps:
[0063] (1) Preparation of electrospinning solution: 20 mL of 80% acetic acid was measured with a graduated cylinder and added to a 100 mL beaker. 5 g of zein powder was weighed with an electronic analytical balance and added to the beaker containing acetic acid. A magnetic rotor was added. The beaker was placed in a constant temperature heated magnetic stirrer in a 100°C water bath and heated and stirred for 1 h. After the zein was completely dissolved in the acetic acid, the beaker was removed and allowed to cool at room temperature to obtain electrospinning solution Z@A-1. Another beaker was charged with equal amounts of the above acetic acid and zein, a magnetic rotor was added, and the beaker was placed in a constant temperature heated magnetic stirrer in an 80°C water bath and heated and stirred for 5 h. After the zein was completely dissolved in the acetic acid, the beaker was removed and allowed to cool at room temperature to obtain electrospinning solution Z@A-5.
[0064] (2) Preparation of electrospinning parallel circuit:
[0065] 5 mL of each Z@A-1 and Z@A-5 solution was added to a 10 mL syringe. The syringe was then mounted on a microinjection pump. The electrostatic spraying parameters were set as follows: propulsion rate of 3.0 mL / h, voltage of 20 kV, distance from the syringe needle to the receiving device of 16 cm, and electrospinning time of 2.0 h.
[0066] Connect the syringe to the circuit. Connect the syringes equipped with Z@A-1 and Z@A-5 in parallel, and connect a sliding rheostat in series in the Z@A-5 branch. Adjust the resistance of the sliding rheostat so that its resistance is 5 / 5 of that of the syringe.
[0067] (3) Preparation of gradient fibers: Gradient fibers can be obtained by starting the electrospinning experiment.
[0068] Example 6
[0069] This embodiment provides a packaging material for preserving fruits. The packaging material is prepared from the gradient fiber obtained in Example 2 of the present invention. The preparation method of the packaging material is as follows:
[0070] First, the gradient structure fibers obtained in Example 2 were deposited onto a pre-prepared tissue substrate via electrospinning. The resulting fiber membrane was then dried in a vacuum drying oven at room temperature or an appropriate temperature for 12-24 hours to remove residual solvent. The dried fiber membrane was then cut and shaped.
[0071] The packaging material is coated on the surface of fresh fruits or covered on fruit and vegetable containers, which can effectively maintain the appearance quality of the fruits and extend the shelf life of the fruits.
[0072] Comparative Example 1
[0073] This comparative example is the same as Example 2, except that the electrospinning liquid Z@A-1 is replaced with the electrospinning liquid Z@A-PVB. The electrospinning liquid Z@A-PVB is prepared as follows: 20 mL of 80% acetic acid is accurately measured using a graduated cylinder and added to a 100 mL beaker. 5 g of zein powder is weighed using an electronic analytical balance and added to the beaker containing the acetic acid. An appropriate amount of polyvinyl butyral (PVB) powder (e.g., 1 g or 2 g) is weighed using an electronic analytical balance and slowly added to the same beaker. A magnetic rotor is added to the beaker, and the beaker is placed in a constant temperature heated magnetic stirrer and heated in an 80°C water bath with stirring for 1 hour to ensure that the zein and PVB are fully dissolved to form a homogeneous solution. After dissolution is complete, the beaker is removed and allowed to cool to room temperature to obtain the electrospinning liquid Z@A-PVB.
[0074] Comparative Example 2
[0075] This comparative example is the same as Example 2, except that both Z@A-1 and Z@A-2 are replaced with electrospinning liquid Z@A-PVB. The electrospinning liquid Z@A-PVB is prepared as follows: 20 mL of 80% acetic acid is accurately measured using a graduated cylinder and added to a 100 mL beaker. 5 g of zein powder is weighed using an electronic analytical balance and added to the beaker containing acetic acid. An appropriate amount of polyvinyl butyral (PVB) powder (e.g., 1 g or 2 g) is weighed using an electronic analytical balance and slowly added to the same beaker. A magnetic rotor is added to the beaker, and the beaker is heated and stirred in an 80°C water bath in a constant temperature magnetic stirrer for 1 h to ensure that the zein and PVB are fully dissolved to form a homogeneous solution. After dissolution is complete, the beaker is removed and allowed to cool to room temperature to obtain the electrospinning liquid Z@A-PVB.
[0076] Effect verification
[0077] Provided is the use of a packaging material prepared from the gradient fibers obtained in Example 2 and Comparative Examples 1-2 for adsorbing endogenous ethylene from fruits and extending the shelf life of fruits; wherein,
[0078] Subject: Taipo Pear
[0079] Experimental Methods: Taipo pears were purchased from Yitong Fruit Shop in Tangshan, Hebei Province, China. Pears of similar maturity were selected as test samples and placed in sealed film bags along with GIF. The bags were then stored at room temperature for 20 days, and their skin browning was observed every 10 days. The skin and flesh firmness of the Taipo pears were tested using a TA.Plus physical property analyzer, and the shelf life of the fruit was calculated.
[0080] Experimental results: see Table 1 and Table 2.
[0081] Table 1 Results of skin hardness and flesh hardness
[0082] Experimental group Peel hardness (kPa) Pulp hardness (kPa) Example 2 416.93±23.59 328.36±31.23 Comparative Example 1 274.89±34.24 152.83±6.79 Comparative Example 2 292.74±4.27 116.93±23.58
[0083] Table 2 Results of extending the shelf life of fruits
[0084] Experimental group Fruit shelf life (days) Example 2 20 Comparative Example 1 10 Comparative Example 2 10
[0085] As shown in Table 1, the peel hardness and pulp hardness of Example 2 are significantly higher than those of Comparative Examples 1 and 2, which confirms the significant advantage of the GIF material in Example 2 in terms of freshness preservation performance.
[0086] As shown in Table 2, the Taipo pears of Example 2 showed almost no visible signs of decay after 20 days, while the Taipo pears of Comparative Examples 1 and 2 showed obvious decay and browning on the surface after 10 days, indicating that the GIF material in Example 2 had the best preservation effect on the Taipo pears.
[0087] To further illustrate the beneficial effects of the present invention, the present invention verified the application of packaging materials prepared from the gradient fibers obtained in Examples 1, 3, 4, and 5, respectively, in the adsorption of endogenous and exogenous ethylene in fruits and in extending the shelf life of fruits. The results showed that the effects were similar to those in Tables 1 and 2.
[0088] The embodiments described above are some, but not all, of the embodiments of the present invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the invention as claimed, but rather represents selected embodiments of the present invention. All other embodiments obtained without creative effort and through deduction and substitution by a person of ordinary skill in the art based on the concepts of the present invention are within the scope of protection of the present invention.
Claims
1. A method for preparing a gradient fiber, characterized in that: The preparation method comprises the following steps: (1) preparing an electrospinning solution: adding zein to an 80% acetic acid aqueous solution and stirring in a constant temperature heated magnetic stirrer until the zein is completely dissolved, thereby obtaining an electrospinning solution; (2) Preparation of an electrospinning parallel circuit: connecting the injection needles to the parallel circuits respectively, then connecting the injection needles filled with electrospinning liquid in parallel, and connecting a sliding resistor in series in one of the circuits to obtain an electrospinning parallel circuit; (3) Preparation of gradient fibers: electrospinning is performed using the electrospinning solution obtained in step (1) and the electrospinning parallel circuit obtained in step (2) to obtain gradient fibers.
2. The preparation method according to claim 1, characterized in that The heating temperature of the constant temperature heating magnetic stirrer is 60-100°C.
3. The preparation method according to claim 1, characterized in that The stirring time of the constant temperature heating magnetic stirrer is 1-5h.
4. The preparation method according to claim 1, characterized in that The resistance of the sliding rheostat is adjusted to 1 / 5-5 / 5 of the injection needle.
5. The preparation method according to claim 1, characterized in that The process parameters of the electrospinning are: a propulsion rate of 0.5-3 mL / h, a voltage of 10-20 kV, a distance from the needle tip of the injection needle to the receiving device of 8-16 cm, and an electrospinning time of 0.5-2 h.
6. The preparation method according to claim 5, characterized in that The receiving device is a tissue paper flat plate.
7. A gradient fiber, characterized in that The gradient fiber is prepared by the preparation method according to any one of claims 1 to 6.
8. A packaging material for preserving fruits, characterized in that: The packaging material is prepared from the gradient fiber according to claim 7.
9. Use of the gradient fiber according to claim 7 and / or the packaging material according to claim 8 in preserving fruits.
10. Use of the gradient fiber according to claim 7 and / or the packaging material according to claim 8 for adsorbing endogenous ethylene from fruits and extending the shelf life of fruits.